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Kim, Hyesu, Jaehyung Yu, Lei Wang, Yongsik Jeong, and Jieun Kim. "Variations in Spectral Signals of Heavy Metal Contamination in Mine Soils Controlled by Mineral Assemblages." Remote Sensing 12, no. 20 (October 9, 2020): 3273. http://dx.doi.org/10.3390/rs12203273.
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This paper illustrates a spectroscopic analysis of heavy metal concentration in mine soils with the consideration of mineral assemblages originated by weathering and mineralization processes. The mine soils were classified into two groups based on the mineral composition: silicate clay mineral group (Group A) and silicate–carbonate–skarn–clay mineral group (Group B). Both soil groups are contaminated with Cu, Zn, As, and Pb, while the contamination level was higher for Group A. The two groups exhibit different geochemical behaviors with different heavy metal contamination. The spectral variation associated with heavy metal was highly correlated with absorption features of clay and iron oxide minerals for Group A, and the absorption features of skarn minerals, iron oxides, and clay minerals for Group B. It indicates that the geochemical adsorption of heavy metal elements mainly occurs with clay minerals and iron oxides from weathering, and of skarn minerals, iron oxides, and clay minerals from mineralization. Therefore, soils from different secondary mineral production processes should be analyzed with different spectral models. We constructed spectral models for predicting Cu, Zn, As, and Pb in soil group A and Zn and Pb in soil group B using corresponding absorptions. Both models were statistically significant with sufficient accuracy.
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Chandler, Neil, John Palson, and Todd Burns. "Capillary rise experiment to assess effectiveness of an enzyme soil stabilizer." Canadian Geotechnical Journal 54, no. 10 (October 2017): 1509–17. http://dx.doi.org/10.1139/cgj-2016-0511.
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An experimental program to assess of the attributes of an enzyme soil stabilizer is described. The focus of the program was two 1 year capillary rise experiments designed to test the influence of the soil additive on the soil’s adsorption of water. The enzyme additive is typically applied to marginal clay-based soils to improve the performance of road subgrades. The study investigated the potential increase in shear strength and the reduction in swelling. The two long-term soil column tests were conducted to measure water absorption due to capillary rise for soil specimens with, and without, enzyme treatment. The test results demonstrated that the addition of the enzyme soil additive had the effect of reducing water retained in the pore spaces of a partially saturated soil. The soil treated with the enzyme additive absorbed a lower quantity of water in the capillary rise test, and at a slower rate of absorption. The results from a concurrent suite of tests suggested that partially saturated clay having lower moisture content was linked to an increase in shear strength.
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Mahdy, Ahmed M., Elsayed Elkhatib, Tiequan Zhang, Nieven O. Fathi, and Zhi-Qing Lin. "Nano-Scale Drinking Water Treatment Residuals Affect Arsenic Fractionation and Speciation in Biosolids-Amended Agricultural Soil." Applied Sciences 10, no. 16 (August 14, 2020): 5633. http://dx.doi.org/10.3390/app10165633.
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An incubation experiment was conducted to determine the effects of nanoscale drinking water treatment residuals (nWTRs) on arsenic (As) fractionation and speciation in agricultural soil amended with biosolids. The soils were treated with biosolids of 3% (w/w), along with nWTR application rates of 0, 0.25, 0.50, or 1.00% (w/w). The results revealed that the As adsorption rate increased with increasing the As treatment level from 50 to 800 mg/L. The maximum efficiency of As adsorption was 95%–98% in the soil treated with nWTRs of 1%, while the least As adsorption was 53%–91% in the soil treated with nWTRs of 0.25%. The overall As bioavailability in the biosolids-amended soil followed a descending order of nWTRs treatment: (0%) > 0.25% nWTRs, >0.50% nWTRs, and >1% nWTRs. The addition of nWTRs significantly changed As speciation in biosolids-amended soil. The X-ray absorption near-edge structure spectroscopy (XANES) and MINEQL+4.6 analyses showed that most of As was in a oxidized form of As5+ that likely incorporated in As pentoxide, and thus, with low mobility, bioavailability, and toxicity. This study demonstrated that nWTRs were effective in adsorbing and immobilizing As in biosolids-amended agricultural soils by forming stable As-nWTR surface complexes.
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Sun, Lei, Han Qiao Liu, Guo Xia Wei, Zhen Hua Wu, and Wei Yang. "Removal of Heavy Metals from Contaminated Soils by Washing with Citric Acid and Subsequent Treatment of Soil-Washing Solutions." Advanced Materials Research 937 (May 2014): 646–51. http://dx.doi.org/10.4028/www.scientific.net/amr.937.646.
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Soil washing experiments were carried out with citric acid as washing reagent for the remediation of soils highly contaminated with heavy metals, then activated carbon was used in absorption processing for leaching solution. In this study, the effects of the main operating variables for removal of metals from soils were first discussed. The results showed that 36.% Pb, 47.74% Cu and 61.88% Cd were removed from the contaminated soils by optimizing the washing parameters at citric acid concentration 0.2 mol/l, mixing time 2 h, liquid-soil ratio 20 and solution pH=4, respectively. In the adsorption experiments of leachates, the optimum conditions were found as follows: solution pH=7, mixing time of 2 h, standing time of 60 min and activated carbon dosage of 1g/100ml.
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Prilutskaya, Natal'ya S., Tat'yana A. Korel'skaya, and Lyudmila F. Popova. "STUDY OF STRUCTURAL AND FUNCTIONAL COMPOSITION OF SOIL HUMUS ACIDS OF EURO-ARCTIC REGION BY MOLECULAR ABSORPTION SPECTROSCOPY (UV / VISIBLE)." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 61, no. 2 (January 29, 2018): 97. http://dx.doi.org/10.6060/tcct.20186102.5610.
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Results of the structural and functional composition of soil humus acids in the Euro-Arctic Region are presented. The molecular absorption spectroscopy (UV / visible) was used to evaluate eco-protective role of soils in relation to heavy metals, which is especially important for the sensitive soils of the Arctic, formed under the influence of cryogenic processes. Different types of soils of the Euro-Arctic region: gleyish easy loamy pelosi on loamy moraine (Kanin Peninsula, Cape Kanin Nos); humus peat oligotrophic soil (Kolguev Island, Bugrino village); typical non-calcic loamy gley soil (Vaigach Island); gray humous iron sandy lithozem (Archipelago Franz Josef Land, Heys Island) were analyzed. An alkaline solution of sodium pyrophosphate was used to extract humus acids for investigate of the structural and functional composition. Humic, fulvic and gimatomelanic acids were extracted from a humus by conforming solvents with additional fulvic acids extraction by adsorption chromatography using activated carbon as a sorbent. UV mini-1240 spectrophotometer (Shimadzu) was used to record the UV / visible spectra using 0.005% alkaline solutions (0.1 N NaOH) of humus acids. It was demonstrated that humic and gimatomelanoic acids of humus peat oligotrophic soil have more developed peripheral aliphatic component. These acids have more ability to bind heavy metals and show their eco-protective role. The humus acids of other types of soils region have a more developed aromatic component in the Euro-Arctic. Such parameters as: calculated by the Pieravuori formula aromaticity, extinction coefficient Е0.005%1cm,465, adsorption ratio D400 /D600, characterizing the degree of humification and the adsorption ratio D465 / D650, characterizing the degree of aromatic nucleus condensation and conjugate fragments were used in the quantitative assessment of the nature of humus acids. Quantitative analysis of UV/visible spectra confirmed that the maximum barrier mechanism with respect to heavy metals will be the humic and gimatomelanoic acids of humus-peat oligotrophic soil, due to the high content of phenolic and carboxyl groups in these molecules, oxidation and a more developed chain of conjugated bonds in them in comparison with other acids. However, it was found that in all types of soils studied the process of humus formation proceeds mainly by a degradation type, that is, in the direction of formation of fulvic acids. Forcitation:Prilutskaya N.S., Korel'skaya T.A., Popova L.F. Study of structural and functional composition of soil humus acids of euro-arctic region by molecular absorption spectroscopy (UV / visible). Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 2. P. 97-103
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Bairwa, Rajendra, Mamta ., Nintu Mandal, Nilanjan Chattopadhyaya, and Neeraj Bagoria. "Adsorption and Desorption of zinc in soil and its implication." International Journal of Agricultural Invention 3, no. 02 (November 27, 2018): 191–202. http://dx.doi.org/10.46492/ijai/2018.3.2.17.
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Zn availability mostly regulated through adsorption-desorption on soil (or adsorbent). Fly ash (FA) application influence on zinc adsorption-desorption in recommended chemical fertilizer (RDF) and farmyard manure (FYM) treatments of acidic Inceptisols of Assam. Zinc adsorption was better explained by Freundlich over the Langmuir adsorption equation. Adsorption was greatest in the treatment receiving FA only at 15 t ha−1 and least in the treatment receiving RDF 50 percent + FYM 5 t ha−1 + FA 5 t ha−1. Ni and Zn co-sorption to aluminium oxides (γ-Al2O3) in binary-sorbate systems were compared to their sorptionin single-sorbate systems as a function of pH using both macroscopic batch experiments and synchrotron-based X-ray absorption fine structure spectroscopy At pH 6.0, Ni and Zn were sorbed as inner-sphere surface complexes and competed for the limited number of reactive sites on γ-Al2O3.In binary-sorbate systems, Ni had no effect on Zn sorption, owning to its lower affinity for the metal oxide surface. In contrast, Zn had a higher affinity for the metal oxide surface and reduced Ni sorption. The influence of P on the Zn adsorption capacity of eight surface horizons in soils on granite and amphibolites materials. The presence of P, especially at high concentrations, was found to boost Zn adsorption. The effect was more marked in the soils on amphibolite, which contained increased concentrations of Fe and Al oxides relative to those on granite. The increased adsorption of zinc by effect of the presence of phosphate is ascribed primarily to the formation of a P–Zn complex in colloid surfaces.Studies should be undertaken while considering adsorption and desorption capacities of Zn for soils as well as ionic interactions for better Zn management in soils.
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Lu, Haijun, Qian Zhang, Yiqie Dong, Jixiang Li, and Xiong Zhang. "The Adsorption Capacity, Pore Structure, and Thermal Behavior of the Modified Clay Containing SSA." Advances in Materials Science and Engineering 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/9894657.
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Sewage sludge ash (SSA) was created by burning municipal sludge. The potential of clay containing 1 or 3 or 5% SSA was assessed for use as a landfill liner-soil material. Batch adsorption, low temperature N2adsorption, and TG-DTA tests were performed to evaluate the adsorption capacity, micropore structure, thermostability, and components of soils under Cr(VI) and Pb(II) chemical solutions. With the increasing amount of SSA in modified clay, the adsorption capacity of Cr(VI) and Pb(II) to the modified clay increases gradually. After absorption, the pore size of modified clay ranges from 2 nm to 8 nm. With the increasing amount of absorption, the pore volume decreases and the specific surface area increases. With the increasing of adsorption concentration of Cr(VI) and Pb(II), the mass loss percentage of modified clay increases to 23.4% and 12.6%, respectively. The modified clay containing SSA may be used as a good barrier material to attenuate contamination of Cr(VI) and Pb(II) in landfills.
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Fan, Yuan, Wuyan Shen, and Fangqin Cheng. "Reclamation of two saline-sodic soils by the combined use of vinegar residue and silicon-potash fertiliser." Soil Research 56, no. 8 (2018): 801. http://dx.doi.org/10.1071/sr18074.
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Amelioration of saline-sodic soil is essential to increase crop production and preserve the ecological environment in arid and semiarid regions. In this study, a pot experiment was conducted to investigate the effect of combined use of vinegar residue and silicon-potash (Si-K) fertiliser on the physical and chemical properties of two calcareous saline-sodic soils (saline soil (H-soil) and saline-sodic soil (S-soil)) and the growth of oat plants. The results showed that soil electrical conductivity was significantly decreased when vinegar residue was applied in two soils, which could be attributed to that vinegar residue could release H+, and react with HCO3−. When the combination of vinegar residue and Si-K fertiliser were used, equilibrium condition between monovalent cations and divalent cations could be altered. The divalent cations (e.g. Ca2+, Mg2+) were adsorbed at the cost of monovalent cations (Na+), resulting in the reduction of sodium adsorption ratio in the two soils. The decrease in soil pH was mainly due to the decrease in the activity of CO32− and HCO3−, which would react with H+ while vinegar residue was applied. As a saline-sodic soil, S-soil exhibited larger decrease in the pH compared with H-soil, a saline soil. The increase in the relative weight of wet stable macro-aggregate could be attributed to the release of Ca2+ and H+ and the flocculation of the dispersed clay by the application of Si-K fertiliser and vinegar residue. The application of Si-K fertiliser and vinegar residue contributed to a significant increase in survival rate and plant height of oat plants. It also led to increased relative water content and reduced electrolyte leakage for oat plants. This could be ascribed to the improvement of soil aggregate structure and nutrient supply, which promoted selective absorption and transportation of K+ over Na+ and decreased leaf damage. Therefore, the combined use of vinegar residue and Si-K fertiliser was considered to be a wise method for ameliorating two calcareous saline-sodic soils in Shanxi Province, Northern China.
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Мank, V., O. Тоnkha, V. Galimova, S. Surovtsev, O. Menshov, O. Bukova, and I. Rogovskiy. "ELECTROCHEMICAL INVESTIGATION OF COBALT ABSORBTION PROCESSES BY SOILS OF UKRAINE." Visnyk of Taras Shevchenko National University of Kyiv. Geology, no. 3 (86) (2019): 34–39. http://dx.doi.org/10.17721/1728-2713.86.05.
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In this paper, the processes of cobalt absorption by soils of Ukraine are investigated by using the electrochemical method of pulsed inversion chronopotentiometry. It has been established that the absorption capacity of cobalt by soil varieties from complexing media is 64–98 %. In solutions of KNO3, NH4OH and CSN2H4 mobile compounds of cobalt are part of [Co(H2O)n]2+, [Co(NH3)n]2+,[Co(CSN2H4)n]2+, and in solutions of Na4P2O7, Na5P3O10 and ЕДТА4– anionic complexes [Co(P2O7)n]2–4n, [Co(P3O10)n]2–5n ³ [CoЕДТА]2– are formed. The cobalt cationic complexes [Co(H2O)n]2+, [Co(NH3)n]2+, [Co(CSN2H4)n]2+ are almost completely absorbed by the soils. Anionic complexes – [Co(P2O7) n] 2–4n, [Co(P3O10) n]2–5n ³ [CoЕДТА]2– largely remain mobile in the soil profile. The sorption effect depends on the charge of the complex ions, their strength and on the steriîìåtric parameters of the complex ions. A close positive relationship was established between the cobalt absorption by soils and the cation exchange capacity of soils, the correlation coefficient was 0,7976, and between the cobalt absorption by soils and the humus content (0,7034). In the study of biohumus, it was found that cobalt goes into the solution of 0,02M ЕДТАNa2 + 0,09M NH4Cl by the mechanism of competitive complexation, its transition to the HCl solution occurs due to the protonization of the functional groups of biohumus with which the metal is bound. Biohumus has rather high sorption properties of cobalt and may be promising for its use as an effective carrier matrix in various combinations with basic fertilizers. Isotherms of sorption or exchange of cobalt for exchange ions of biohumus in various solutions correspond to isotherms of Langmuir single layer adsorption. The method of IIHP analysis is important to use to control the content of trace elements at the level of their trace concentrations necessary for plant development.
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Sulakhudin, Abdul Syukur, and Bambang Hendro Sunarminto. "Zeolite and Hucalcia as Coating Material for Improving Quality of NPK Fertilizer in Costal Sandy Soil." Journal of Tropical Soils 16, no. 2 (July 3, 2013): 99–106. http://dx.doi.org/10.5400/jts.2011.v16i2.99-106.
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The growth and yield of plants are mainly a function of the quantity of fertilizer and water. In coastal sandy soil, nutrient losses and dry soils are seriously problems. The objective of the research was to study effect of zeolite and hucalci concentrations as NPK coating materials on NPK qualities i.e. water adsorption and release of N, P and K. The research used a coastal sandy soil as media. It was conducted in a laboratory of Soil Science Department, Gadjah Mada University from July to August 2009. Experimental design used was a factorial in a completely randomized design. The first factor was hucalci concentration, consisted of 10% (H1), 20% (H2), and 30% (H3). The second factor was zeolite concentration, consisted of 25% (Z1), 50% (Z2), 75% (Z3), and 100% (Z4). NPK fertilizer (without coating) used as a control. The results showed that hucalci and zeolite had a capability to increase water adsorption and to retard the release of N, P, K. The coated NPK with hucalci 30% and zeolite 100% had the highest quality in water absorption, water retention and release of nutrients.Keywords: Coastal sandy soil, humic-calcium, NPK fertilizer, zeolite
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Lima, Regina Lúcia Félix de Aguiar. "Micorrizas arbusculares e absorção de fósforo em função da capacidade de fixação de fósforo do solo e da competição com a microbiota." Revista Brasileira de Geografia Física 13, no. 3 (June 1, 2020): 1062. http://dx.doi.org/10.26848/rbgf.v13.3.p1062-1079.
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Fungos micorrízicos arbusculares (FMA) se associam às raízes das plantas e incrementam a absorção de fósforo (P), macronutriente com baixa mobilidade no solo. A capacidade de fixação de P do solo e a competição com a biota heterotrófica afetam sua disponibilidade para plantas. Visando avaliar a contribuição dos FMA na absorção de P em solos com capacidade crescente de fixação ou em situação de competição com a biota foram realizados experimentos em vasos compartimentalizados cultivados com braquiária associada a FMA, contendo substrato marcado com 32P. Foram quantificadas a massa seca das plantas, o conteúdo e a atividade específica do P. No experimento 1 avaliou-se a absorção de P por raízes e hifas de FMA ou somente por hifas em solos com alta, média e baixa capacidade fixação de P. No experimento 2 avaliou-se a absorção de P por raízes e hifas de FMA ou somente por hifas em solos com alta e baixa capacidade fixação de P em situação de competição com a biota do solo ativada por fontes de carbono. O aumento da capacidade de fixação de P pelo solo resultou em diminuição de massa seca, conteúdo de P e atividade específica nas plantas. No solo com alta fixação de P, plantas com absorção exclusiva por hifas de FMA tiveram aumento da massa seca e conteúdo de P. Em situação de competição, houve diminuição na massa seca e no conteúdo de P nas plantas. Plantas com absorção por raízes e hifas de FMA tiveram maior atividade específica de P. Arbuscular mycorrhizae and phosphorus uptake in soils as a function of adsorption capacity and competition with microbiota A B S T R A C TArbuscular mycorrhizal fungi (AMF) are associated with plant roots and increase the absorption of phosphorus (P), macronutrient with low soil mobility. Soil P fixation capacity and competition with heterotrophic biota affect its availability. To evaluate the contribution of AMF to P uptake in soils with increasing fixation capacity or in competition with biota, experiments were carried out in compartmentalized pots cultivated with AMF-associated Brachiaria decumbens containing 32P-labeled substrate. Plant dry mass, content and specific activity of P. were quantified. In experiment 1, the absorption of P by roots and hyphae of AMF or only by hyphae in soils with high, medium and low P. fixation capacity was evaluated. In experiment 2, the absorption of P by roots and hyphae of AMF or only by hyphae in soils with high and low P fixation capacity in competition with carbon-activated soil biota was evaluated. Increasing P fixation capacity by soil resulted in decreased dry matter, P content and specific activity in plants. In soil with high P fixation, plants with exclusive absorption by FMA hyphae had increased dry matter and P content. In a competition situation, there was a decrease in dry matter and P content in plants. Plants absorbed by roots and hyphae of AMF had higher P-specific activity.Keywords: 32P, P-soil fixing, AMF, extraradical mycelium, hyphal absorption
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Olshansky, Yaniv, Robert A. Root, and Jon Chorover. "Wet–dry cycles impact DOM retention in subsurface soils." Biogeosciences 15, no. 3 (February 9, 2018): 821–32. http://dx.doi.org/10.5194/bg-15-821-2018.
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Abstract. Transport and reactivity of carbon in the critical zone are highly controlled by reactions of dissolved organic matter (DOM) with subsurface soils, including adsorption, transformation and exchange. These reactions are dependent on frequent wet–dry cycles common to the unsaturated zone, particularly in semi-arid regions. To test for an effect of wet–dry cycles on DOM interaction and stabilization in subsoils, samples were collected from subsurface (Bw) horizons of an Entisol and an Alfisol from the Catalina-Jemez Critical Zone Observatory and sequentially reacted (four batch steps) with DOM extracted from the corresponding soil litter layers. Between each reaction step, soils either were allowed to air dry (wet–dry treatment) before introduction of the following DOM solution or were maintained under constant wetness (continually wet treatment). Microbial degradation was the dominant mechanism of DOM loss from solution for the Entisol subsoil, which had higher initial organic C content, whereas sorptive retention predominated in the lower C Alfisol subsoil. For a given soil, bulk dissolved organic C losses from solution were similar across treatments. However, a combination of Fourier transform infrared (FTIR) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopic analyses revealed that wet–dry treatments enhanced the interactions between carboxyl functional groups and soil particle surfaces. Scanning transmission X-ray microscopy (STXM) data suggested that cation bridging by Ca2+ was the primary mechanism for carboxyl association with soil surfaces. STXM data also showed that spatial fractionation of adsorbed OM on soil organo-mineral surfaces was diminished relative to what might be inferred from previously published observations pertaining to DOM fractionation on reaction with specimen mineral phases. This study provides direct evidence of the role of wet–dry cycles in affecting sorption reactions of DOM to a complex soil matrix. In the soil environment, where wet–dry cycles occur at different frequencies from site to site and along the soil profile, different interactions between DOM and soil surfaces are expected and need to be considered for the overall assessment of carbon dynamics.
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Han, Mengxuan, Huan Yang, Na Ding, Shaohong You, and Guo Yu. "The role of plant-associated bacteria in the phytoremediation of heavy metal contaminated soils." E3S Web of Conferences 261 (2021): 04006. http://dx.doi.org/10.1051/e3sconf/202126104006.
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Soil heavy metal pollution is an important environmental problem threatening people’s health and sustainable economic development. Phytoremediation has become an important technology for the treatment of heavy metal contaminated soil with the characteristics of economy and environmental protection. This paper mainly analyzed the role of microbial community in heavy metal contaminated soil remediation process. Bacterias mainly strengthen the remediation effect of plants on heavy metal contaminated soil in two ways: first, bacterias have adsorption effect on heavy metals and reduce the toxicity of heavy metals to plants in soil; Two is to secrete organic acids and nutrients needed for plant growth to promote the absorption of heavy metals by hyperaccumulators.
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Arocha, Marco A., Ben J. McCoy, and Alan P. Jackman. "VOC immobilization in soil by adsorption, absorption and encapsulation." Journal of Hazardous Materials 51, no. 1-3 (November 1996): 131–49. http://dx.doi.org/10.1016/s0304-3894(96)01824-9.
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Liu, Pei Ya, Huan Liu, Yu Jiao Li, and Chang Xun Dong. "Remediation of Arsenic Contaminated Soils and Treatment of Washing Effluent Using Calcined Mn-Fe Layered Double Hydroxide." Advanced Materials Research 955-959 (June 2014): 2014–21. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.2014.
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Arsenic contaminated soil is a serious worldwide problem nowadays, and soil washing technique is one of hottest topics in the area of remediating arsenic contaminated soils, while treatment of the washing effluent is still an urgent problem. In this study, in order to select the best washing extractants for arsenic contaminated soil of the Xiangxi Autonomous Prefecture, nine kinds of extractants (citric acid, oxalic acid, malic acid, tartaric acid, H3PO4, KH2PO4, KOH, NH4Ac and ultra-pure water) were studied. Innovatively, a new material (calcined Mn-Fe Layered double hydroxide) was firstly introduced and fully applied to the adsorption of arsenic washing effluents. Results showed citric acid, oxalic acid and KH2PO4 were the optimal extractants for arsenic contaminated soil, considering the extraction rate and environmental perspective. When the concentrations were 200, 300, 300 mmol/ L , solution soil ratios were 10, 10, 20 mL/g , extraction times were 12,12,12 h, the citric acid, oxalic acid and KH2PO4, respectively, achieved the maximum extraction rate of 39%, 65% and 29%. Calcined Mn-Fe LDH used in this work was characterized by SEM and FT-IR, indicating the unique structure and high phase purity of the synthetic samples. For the 28mg/L arsenic effluent washing by citric acid, calcined Mn-Fe LDH showed the most effective capacity as adsorbent under neutral or weak base condition as well as 2 h absorption time.
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Kellman, Martin. "Nutrient retention by tropical ecosystems: soil adsorption and plant absorption as synergistic processes." Journal of Tropical Ecology 18, no. 6 (September 25, 2002): 877–95. http://dx.doi.org/10.1017/s0266467402002572.
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Laboratory and growth-chamber experiments were used to evaluate whether there was evidence for nutrient retention by tropical terrestrial ecosystems being a two-stage process involving first soil adsorption and then plant absorption. Quartz sand with and without Fe and Al oxide coatings were treated with nutrient solution, then subjected to a leaching regime that simulated early wet-season conditions at a tropical location. Nutrient cations applied were rapidly lost in the initial leaches from quartz sand without oxide coatings, but showed a more gradual loss from oxide-coated sand, indicating temporary adsorption by the latter. In a second experiment, oxide-coated sand with and without seedlings of Grevillea robusta (a non-mycorrhizal tree species) were subjected to a similar treatment and leaching losses were compared. The presence of seedlings significantly reduced the losses of all nutrient cations, with the effect being minimal for Na and greatest for K, confirming that plants can gain access to temporarily adsorbed nutrients. More typical tropical soil-vegetation systems are likely to possess properties that magnify both the adsorptive and absorptive processes that have been documented in these experiments, justifying extrapolation of the experimental results to these natural systems. The existence of a two-stage process of nutrient retention provides a plausible explanation for the resistance of most tropical ecosystems to rapid loss of nutrients following events such as fires, which provide acute nutrient loading to the system.
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Nie, Zhaojun, Jinfeng Li, Haiyang Liu, Shiliang Liu, Daichang Wang, Peng Zhao, and Hongen Liu. "Adsorption kinetic characteristics of molybdenum in yellow-brown soil in response to pH and phosphate." Open Chemistry 18, no. 1 (June 18, 2020): 663–68. http://dx.doi.org/10.1515/chem-2020-0501.
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AbstractMolybdenum (Mo) adsorption by acidic yellow-brown soil was investigated as a function of a pH (1–13) and the equilibrium of P solution (0, 3.1, and 31 mg L−1) concentration. Mo adsorption by acidic yellow-brown soil increased within the pH range from 1 to 4. Above pH 4, Mo adsorption decreases with an increase in pH. The maximum adsorption was found between pH 2 and 4. Competitive adsorption experiments showed that the equilibrium sorption data fitted into Langmuir and Freundlich isotherms. The sorption data of Mo on the acidic yellow-brown soil fitted well with the Langmuir isotherm model due to the higher R2 value. A reduction in Mo adsorption by the acidic yellow-brown soil was noticed at higher addition levels of P (3.1 and 31 mg L−1). Therefore, P increasing the bioavailability of Mo and enhancing Mo uptake by plants might be related to the inhibition of Mo absorption by the acidic yellow-brown soil.
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Mei, Ying, Hang Zhou, Xiao-Han Zhu, Peng Zhang, Xiao-Fei Li, Yi-Ming Zuo, Xiu-Mei Wang, and Jun-Jiang Bao. "Isothermal adsorption characteristics of bioretention media for fecal Escherichia coli." Thermal Science 24, no. 4 (2020): 2427–36. http://dx.doi.org/10.2298/tsci2004427m.
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Rainfall runoff contains a huge number of pathogenic bacteria that seriously deteriorate water quality. Bioretention is an effective approach to removal of pathogenic bacteria from rainwater. This study uses sandy soil, fly ash, slag, sandy soil+5% fly ash, and sandy soil+5% slag as media to evaluate the adsorption of fecal Escherichia coli. The mechanisms of the five media conform to the Langmuir?s isotherm adsorption equation, and a pseudo-first-order kinetic model is adopted to reveal the absorption kinetics.
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Lu, S., and M. H. Miller. "Determination of the most efficient phosphorus placement for field-grown maize (Zea mays L.) in early growth stages." Canadian Journal of Soil Science 73, no. 3 (August 1, 1993): 349–58. http://dx.doi.org/10.4141/cjss93-037.
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Field experiments were conducted in 1988 and 1989 to determine the most efficient phosphorus (P) placement for P absorption by maize (Zea mays L.) in early growth stages. The treatments consisted of four rates of applied P (0, 25, 50 and 100 kg P ha−1) mixed with 3, 6, 12 and 25% of the soil volume in the row. Shoots and roots were sampled at 3- to 4-leaf, 6-leaf, and 8- to 9-leaf stages. The roots inside and outside the zone of P fertilization were sampled separately. There was no evidence of root proliferation in the fertilized zones, even with the 100 kg P ha−1 rate mixed with 3% of the soil volume. There was a significant response of shoot dry matter, shoot P concentration, shoot P uptake, and root growth to applied P. Shoot P concentration and shoot P content increased as the volume of soil with which fertilizer P was mixed decreased. Mixing 100 kg P ha−1 with 3–6% of the soil volume resulted in the highest shoot P content in the early growth stages. There was no evidence that fertilizing a greater proportion of soil than the conventional band method will result in higher P uptake of maize in early growth in the soil studied. Because the soil in the study had a relatively low P adsorptive capacity, this conclusion is likely valid for a broad range of soils, which have a greater P adsorptive capacity. Key words: Phosphorus placement, maize, root growth, phosphorus absorption
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Wang, Ning, Huihui Du, Qiaoyun Huang, Peng Cai, Xingmin Rong, Xionghan Feng, and Wenli Chen. "Surface complexation modeling of Cd(II) sorption to montmorillonite, bacteria, and their composite." Biogeosciences 13, no. 19 (October 6, 2016): 5557–66. http://dx.doi.org/10.5194/bg-13-5557-2016.
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Abstract. Surface complexation modeling (SCM) has emerged as a powerful tool for simulating heavy metal adsorption processes on the surface of soil solid components under different geochemical conditions. The component additivity (CA) approach is one of the strategies that have been widely used in multicomponent systems. In this study, potentiometric titration, isothermal adsorption, zeta potential measurement, and extended X-ray absorption fine-structure (EXAFS) spectra analysis were conducted to investigate Cd adsorption on 2 : 1 clay mineral montmorillonite, on Gram-positive bacteria Bacillus subtilis, and their mineral–organic composite. We developed constant capacitance models of Cd adsorption on montmorillonite, bacterial cells, and mineral–organic composite. The adsorption behavior of Cd on the surface of the composite was well explained by CA-SCM. Some deviations were observed from the model simulations at pH < 5, where the values predicted by the model were lower than the experimental results. The Cd complexes of X2Cd, SOCd+, R-COOCd+, and R-POCd+ were the predominant species on the composite surface over the pH range of 3 to 8. The distribution ratio of the adsorbed Cd between montmorillonite and bacterial fractions in the composite as predicted by CA-SCM closely coincided with the estimated value of EXAFS at pH 6. The model could be useful for the prediction of heavy metal distribution at the interface of multicomponents and their risk evaluation in soils and associated environments.
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Pérez-Esteban, Javier, Consuelo Escolástico, Inés Sanchis, Alberto Masaguer, and Ana Moliner. "Effects of pH Conditions and Application Rates of Commercial Humic Substances on Cu and Zn Mobility in Anthropogenic Mine Soils." Sustainability 11, no. 18 (September 5, 2019): 4844. http://dx.doi.org/10.3390/su11184844.
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We studied the effects of commercial humic substances derived from leonardite at different rates (0, 0.25, 2, 10 g kg−1) and pH (4.5, 6.0, 8.0) on Cu and Zn mobility, to evaluate their use for remediation of metal contaminated mine soils and to optimize their application conditions. We conducted a single-step extraction experiment and analyzed extracts for metal concentrations, soluble organic carbon and their E4/E6 ratio (ratio of absorption at 465 to 665 nm). Metal speciation in a soil solution was simulated by the non-ideal competitive adsorption-Donnan (NICA-Donnan) model. Increasing the amount of humic substances and the pH caused higher release rates of soluble organic carbon with a lower humic/fulvic acids ratio. This led to a higher mobility of metals (up to 110 times Cu concentration in control and 12 times for Zn) due to the formation of soluble metal-humic complexes. Speciation modeling predicted that increasing rates of humic substances would result in a higher proportion of Cu and Zn associated with fulvic acids, more mobile than the humic acids fraction. Application of commercial leonardite humic substances at 2–10 g kg−1 and with pH levels similar to or below natural soil could be useful for assisted-phytoextraction of contaminated anthropogenic soils. High rates of humic substances in more alkaline conditions could entail a considerable risk of metal leaching to groundwater, toxicity and transfer to the trophic chain.
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Chavez, Luis Fernando, Telmo Jorge Carneiro Amado, Cimélio Bayer, Newton Junior La Scala, Luisa Fernanda Escobar, Jackson Ernani Fiorin, and Ben-Hur Costa de Campos. "Carbon dioxide efflux in a rhodic hapludox as affected by tillage systems in southern Brazil." Revista Brasileira de Ciência do Solo 33, no. 2 (April 2009): 325–34. http://dx.doi.org/10.1590/s0100-06832009000200010.
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Agricultural soils can act as a source or sink of atmospheric C, according to the soil management. This long-term experiment (22 years) was evaluated during 30 days in autumn, to quantify the effect of tillage systems (conventional tillage-CT and no-till-NT) on the soil CO2-C flux in a Rhodic Hapludox in Rio Grande do Sul State, Southern Brazil. A closed-dynamic system (Flux Chamber 6400-09, Licor) and a static system (alkali absorption) were used to measure soil CO2-C flux immediately after soybean harvest. Soil temperature and soil moisture were measured simultaneously with CO2-C flux, by Licor-6400 soil temperature probe and manual TDR, respectively. During the entire month, a CO2-C emission of less than 30 % of the C input through soybean crop residues was estimated. In the mean of a 30 day period, the CO2-C flux in NT soil was similar to CT, independent of the chamber type used for measurements. Differences in tillage systems with dynamic chamber were verified only in short term (daily evaluation), where NT had higher CO2-C flux than CT at the beginning of the evaluation period and lower flux at the end. The dynamic chamber was more efficient than the static chamber in capturing variations in CO2-C flux as a function of abiotic factors. In this chamber, the soil temperature and the water-filled pore space (WFPS), in the NT soil, explained 83 and 62 % of CO2-C flux, respectively. The Q10 factor, which evaluates CO2-C flux dependence on soil temperature, was estimated as 3.93, suggesting a high sensitivity of the biological activity to changes in soil temperature during fall season. The CO2-C flux measured in a closed dynamic chamber was correlated with the static alkali adsorption chamber only in the NT system, although the values were underestimated in comparison to the other, particularly in the case of high flux values. At low soil temperature and WFPS conditions, soil tillage caused a limited increase in soil CO2-C flux.
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Miroshnychenko, N. N., and O. A. Kutz. "Selective absorption of heavy metals by soil and humic acids at different pH levels." Fundamental and Applied Soil Science 17, no. 1-2 (May 26, 2016): 74–82. http://dx.doi.org/10.15421/041607.
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Studying processes of sorption-desorption of heavy metals from soil and its individual components allow to predict long-term effects under conditions of multielement contamination. Cations of heavy metals are showing competitive relationship due to their specific adsorption by components of the soil absorption complex, in particular humic acids. Interaction of chernozem podzolized heavy loam, isolated preparation of humic acids and soil residue after its removal with the solution which contain sulphates of Zn, Cd, Ni, Co and Cu in equal ratio were simulated at different pH levels. The task of research was to compare selective absorption of some heavy metals in soil and humic acids at pH values from 3 to 9. The experiment was performed by mixing 10 g of soil material or 0.1 g of humic acid with 100 ml of buffer solution, adding 10 ml 0.01 n equal mixture of Cd, Zn, Ni, Co, Cu and 2-hour exposure. Humic acids were extracted from this soil by 0.1 n NaOH after decalcification using 0.05 n H2SO4. Crystalline Copper sulphate, Zinc, Nickel, Cobalt, Cadmium were used to prepare the solution level of heavy metals. Ammonium acetate-buffer solutions with different pH (3.0, 5.0, 7.0, 9.0) were obtained by varying the ratio CH3СOOH and NH4OH. The experiment showed that competitive relationship between heavy metal in soil and humic acids. Copper has the highest specificity adsorption, Cobalt – the smallest. Under acidic and strongly acidic reaction content of Zn, Cd, Ni in equilibrium solution is close enough. The absorption of copper was increased by 50 % from strongly acidic to neutral reaction. Under alkaline conditions Cobalt and Copper were practically absent in the solution. Has been found that the absorption of heavy metals by soil decreases in sequence: Cu, Zn > Cd, Ni > Co. The selectivity of the absorption of heavy metals by humic acids was less marked, but the ability to sorption has the similar sequence: Cu > Zn > Ni > Cd > Co. The residue of soil after removal of humic acids has a high affinity for copper ions, which was absorbed twice from each other metals. Has been proved experimentally that selective adsorption of heavy metals in soil significantly depends on the pH, decreasing under acidic and strongly acidic conditions where hydrogen is successfully competing with them for exchange places in soil absorption complex. Deviation from the equivalent absorption (20 %) of each heavy metal in soil accounted for 15.0–26.0 % in acidic pH and 1.6–45.4 % in alkaline pH. After the interaction of heavy metals with humic acids in the most acidic medium fluctuations content elements in the equilibrium solution was 15.7–25.3 %, while the highest pH 11.0–26.7 %. Overall, the decrease of sorption capacity for humic acids elements can be placed in the following order: Cu > Zn > Ni > Cd > Co. This sequence is saved by a narrow ratio solution: adsorbent. Thus, under condition of polyelement contamination migration of Cobalt in soil may be more intensive than Zink, Cadmium, Nickel and a lot more than Copper, especially in alkaline pH.
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Webster, Eva M. "Models of the equilibrium distribution of organic chemicals between water and solid phases of environmental media." Environmental Reviews 22, no. 4 (December 2014): 430–44. http://dx.doi.org/10.1139/er-2013-0079.
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Water–solid phase equilibrium distributions are foundational to multimedia environmental fate models of anthropogenic organic chemicals. This contextual review of equilibrium models of ionizing organics in aqueous–solids systems highlights the broad range of modeling assumptions and paradigms that have been employed. The complexity of soils and sediment, especially the organic phase, is provided as background along with a description of equilibrium models for nonpolar, nonionizing organics. The ways in which these single-species models have been modified and adapted for application to ionizing organics is detailed. The individual species proposed as contributing to observed distributions include the neutral parent, ions, and ion pairs. The debate over the role of the organic phase in soil and sediment solids is presented. Both absorption and surface adsorption models are described. Organic carbon (OC)-dependent models range from the simple Karickhoff equation to complex molecular connectivity indices models and polyparameter linear free energy relationship (pp-LFER) models. Adsorption models are derived from inorganic interaction chemistry. They include the early Langmuir model and Freundlich equation and continue to the modern Model VI and the NICA-Donnan model. Adsorption models focus on the mineral phase, but the role of the organic phase is not entirely dismissed. Dual mode models seek to combine absorption to OC with adsorption interactions. Conclusions drawn from studies of acid behavior do not predict the sorption of bases; bases are described separately. No single explanation and accompanying model of the distribution behavior of ionizing organics has emerged as the clear choice for regulatory use. The complexity of chemical–environment interactions is such that models are either challenging to parameterize and understand or they fail to capture key aspect(s) of the system critical to understanding of one or more classes of chemical or environmental medium. Future research directions are suggested including the possible benefit of removing sorbate–sorbent or chemical–environment distinctions.
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Pham, Tien Duc, Hoang Hiep Nguyen, Ngoc Viet Nguyen, Thanh Tu Vu, Thi Ngoc Mai Pham, Thi Hai Yen Doan, Manh Ha Nguyen, and Thi Mai Viet Ngo. "Adsorptive Removal of Copper by Using Surfactant Modified Laterite Soil." Journal of Chemistry 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/1986071.
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Removal of copper ion (Cu2+) by using surfactant modified laterite (SML) was investigated in the present study. Characterizations of laterite were examined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma mass spectrometry (ICP-MS), and total carbon analysis. The optimum conditions for removal of Cu2+ by adsorption using SML were systematically studied and found as pH 6, contact time 90 min, adsorbent dosage 5 mg/mL, and ionic strength 10 mM NaCl. The equilibrium concentration of copper ions was measured by flame atomic absorption spectrometry (F-AAS). Surface modification of laterite by anionic surfactant sodium dodecyl sulfate (SDS) induced a significant increase of the removal efficiency of Cu2+. The surface modifications of laterite by preadsorption of SDS and sequential adsorption of Cu2+ were also evaluated by XRD and FT-IR. The adsorption of Cu2+ onto SML increases with increasing NaCl concentration from 1 to 10 mM, but at high salt concentration this trend is reversed because desorption of SDS from laterite surface was enhanced by increasing salt concentration. Experimental results of Cu2+/SML adsorption isotherms at different ionic strengths can be represented well by a two-step adsorption model. Based on adsorption isotherms, surface charge effects, and surface modification, we suggest that the adsorption mechanism of Cu2+ onto SML was induced by electrostatic attraction between Cu2+ and the negatively charged SML surface and nonelectrostatic interactions between Cu2+ and organic substances in the laterite.
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Cesar, Ricardo Gonçalves, Silvia Gonçalves Egler, Renata De Carvalho Jimenez Alamino, Helena Polivanov, Raphael Corrêa da Silva, Zuleica Carmen Castilhos, and Patricia Correa Araujo. "Avaliação do potencial tóxico de latossolos e chernossolos acrescidos de lodo de esgoto utilizando bioensaios com oligoquetas da espécie Eisenia andrei." Anuário do Instituto de Geociências 31, no. 2 (December 1, 2008): 53–60. http://dx.doi.org/10.11137/2008_2_53-60.
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Sewage Sludge (SEL) has been used in agricultural activities to improve physical and chemical properties of soils. However, this compound also contains very high levels of heavy metals and pathogenic microorganisms, which can cause serious negative effects on biota and human health. This paper aims to assess potential toxicity of latosols and chernosols amended with SEL, using Eisenia andrei earthworms. Acute toxicity and behavioral tests were performed according to ASMT (2004) and ISO (2002) procedures, respectively. Heavy metals determination was made by Atomic Absorption, and mineralogical characterization by Ray-X Difratometry. Biomass loss was evaluated considering average individual weight. Mercury, lead, zinc and cooper determination in SEL in natura and soils amended with SEL revealed values higher than that recommended by Brazilian legislation. SEL addition to the soils caused no mortality to the organisms, while SEL in natura provoked lethal effects on 100% of the earthworms. Latosol in natura demonstrated higher mortality in comparison to chernosol in natura Behavioral tests indicated that 98,3% and 96,43% of the organisms avoided SEL in natura and latosol with SEL, respectively. However, only 31% of the organisms avoided chernosol with SEL, suggesting a lower level of toxicity in comparison to latosol. Possibly the natural properties of the studied soils (fertility, organic matter content, clay mineralogy, etc.) played an important role in the avoidance behavior of the organisms. Probably expansive clays presence in chernosol stimulates ions adsorption and their concentrations decreasing in soil solution; consequently contaminants bioavailability also tends to decrease. Biomass loss results revealed that the SEL addition decreased the weight loss of the tested organisms, and biomass losses were higher for latosol than for chernosol. In conclusion, it is expected that these results can be used in human health and ecological risk assessment, as well as in sustainable reconditioning of tillable soils, facilitating decision actions in environmental control and public health programs
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Rogova, O., and Yu Vodyanitsky. "ZINC AND COPPER SORPTION IN THE AFFECTED SOILS OF THE CHEREPOVETS METALLURGICAL COMPLEX." Dokuchaev Soil Bulletin, no. 65 (June 30, 2010): 65–74. http://dx.doi.org/10.19047/0136-1694-2010-65-65-74.
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The laws of zinc and copper absorption by agrarian and carbonate soils in the area of Cherepovets Steel Mill are described. Sorption isotherms demonstrate high affinity of PPK of the studied soils to zinc and copper. Approximation of experimentally obtained isotherms by three methods: Freindlich, Lengmyur, Dabinin-Radushkevich. It is shown that Langmur's model cannot to be applied to most isotherms. The Dibininin model -Raduskevich well approximates the obtained data and enables thermodynamic characteristics of the adsorption process. According to the obtained indicators, the most significant contribution to sorption processes is made by minerals of iron oxides and hydroxides. Coefficients of approximation of isotherms of adsorption by different equations are analyzed. It is recommended to use the Dibininin-Radushkevich equation when the equation Langemura is inapplicable.
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Sárközi, Edit, Levente Kardos, Panna Sepsi, Zsolt Varga, György Bisztray, and János Kátai. "Examination of lead absorption ability on chernozem soil and the observation of the accumulation effect of Lactusa sativa L. in pot experimentation." Acta Agraria Debreceniensis, no. 56 (March 11, 2014): 101–4. http://dx.doi.org/10.34101/actaagrar/56/1942.
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In our research a chernozem soil sample formed on loess was collected from an area under cultivation. Our aim was to determine the lead adsorption capacity using a soil column experiment. The study showed saturation of lead content of the soil. The lead accumulation capacity of Lactuca sativa L. was measured in the sections of roots and leaves applying pot experiments. It could be observed that the lettuce accumulated lead easily from the chernozem soil. The lead content was increased in the analyzed sections of the plants against an increasing lead content.
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Rahmayanti, Maya, Guliston Abdillah, Sri Juari Santosa, and Sutarno Sutarno. "Application of Humic Acid Isolated From Kalimatan Peat Soil Modifying Magnetite for Recovery of Gold." Jurnal Bahan Alam Terbarukan 8, no. 2 (January 6, 2020): 77–83. http://dx.doi.org/10.15294/jbat.v8i2.20392.
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Humic acid modifying magnetite particles (Mag-HA) were developed for recovery of gold from chloride solution (HAuCl4). The Mag-HA particles were prepared by co-precipitation procedure with Fe(III) and Fe(II) chloride salts, sodium hydroxide, and humic acid. FTIR characterization for Mag-HA after modification indicated the presence of the specific absorption for functional groups of humic acid and Fe-O bonds, though with lower intensity. The Mag-HA particles exhibited a typical superparamagnetic characteristic with a saturation magnetization of 66.99 emu/g. The Mag-HA particles were applied for AuCl4- adsorption and results showed that the optimum adsorption of [AuCl4]- onto Mag-HA was found at pH 3. The adsorption kinetics can be described by a pseudo-second order equation and the adsorption isotherm of the Mag-HA particles agreed well with Langmuir adsorption equation. The maximum adsorbed amount of [AuCl4]- was 0.62 mmol/g and the XRD analysis confirms that the adsorption of Au(III) by Mag-HA was accompanied by the formation of elemental gold.
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Santamarina, J. C., K. A. Klein, Y. H. Wang, and E. Prencke. "Specific surface: determination and relevance." Canadian Geotechnical Journal 39, no. 1 (February 1, 2002): 233–41. http://dx.doi.org/10.1139/t01-077.
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Specific surface captures the combined effects of particle size and slenderness in a measurement that is independent and complementary to grain-size distribution. There are various methods to measure specific surface, including gas adsorption in dry conditions and selective molecular absorption in aqueous suspensions. The measurement procedure can have an important effect on measured values, yet such sensitivity is informative in itself. The amount of surface in a soil mass determines the balance between surface-related forces and gravimetricskeletal forces acting on a soil particle, affects fabric formation, supports rich energy coupling mechanisms, governs conduction, and controls sorption and retardation during chemical diffusion.Key words: specific surface, surface area, methylene blue, gas adsorption, fabric, Atterberg limits, grain-size distribution.
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Gray-Wannell, Nia, Peter J. Holliman, H. Christopher Greenwell, Evelyne Delbos, and Stephen Hillier. "Adsorption of phosphate by halloysite (7 Å) nanotubes (HNTs)." Clay Minerals 55, no. 2 (June 2020): 184–93. http://dx.doi.org/10.1180/clm.2020.24.
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AbstractThe adsorption and retention of phosphates in soil systems is of wide environmental importance, and understanding the surface chemistry of halloysite (a common soil clay mineral) is also of prime importance in many emerging technological applications of halloysite nanotubes (HNTs). The adsorption of phosphate anions on tubular halloysite (7 Å) has been studied to gain a greater understanding of the mechanism and kinetics of adsorption on the surface of HNTs. Two well-characterized tubular halloysites with differing morphologies have been studied: one polygonal prismatic and one cylindrical, where the cylindrical form has a greater surface area and shorter tube length. Greater phosphate adsorption of up to 42 μmol g–1 is observed on the cylindrical halloysite when compared to the polygonal prismatic sample, where adsorption reached a maximum of just 15 μmol g–1 compared to a value for platy kaolinite (KGa-2) of 8 μmol g–1. Phosphate adsorption shows strong pH dependence, and the differences in phosphate sorption between the prismatic and cylindrical morphologies suggest that phosphate absorption does not occur at the same pH-dependent alumina edge sites and that the lumen may have a greater influence on uptake for the cylindrical form.
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Trots, N., and Aleksei Pakhomov. "ACCUMULATION OF HEAVY METALS BY PULSE CROPS UNDER THE APPLICATION OF BIOLOGICALLY ACTIVE SUBSTANCES IN THE VOLGA REGION FOREST-STEPPE." Bulletin Samara State Agricultural Academy 5, no. 2 (May 8, 2020): 3–7. http://dx.doi.org/10.12737/37331.
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The aim of study is reduction of accumulation of heavy metals in agrocenosis of pulse crops due to the action of biologically active substances in the conditions of the middle Volga forest. An experiment study in order to reveal the effect of pre-sowing seed treatment with biologically active substances on the accumulation of heavy metals by soils and plants in agrocenoses of peas and soybeans was conducted in 2013-2015. The results of pre – sowing treatment of soybean seeds of the Samer 3 breed and peas of the Flagman 12 with the Rizotorfin and Rizotorfin in combination with analogues – Agrica and Humariz biologically active substance are presented. The analysis of heavy metals content in soil and plant samples was performed in the laboratory of the «Samara agrochemical ser-vice» Station by method of atomic adsorption spectroscopy. It is established that the introduction of biologically ac-tive substances into the soil containing heavy metals can reduce the concentration of their mobile forms and restrict access to grain. The content of mobile forms of elements in the soil under soybean growing areas, in comparison with the control, decreases: lead by 1.14 times when treated with Rhizotorphin+Humariz, cadmium – 1.18 times when treated with Rhizotorphin, copper – 1.2 times and cobalt – 2.0 times under the influence of the combination of Rhizotorphin and Agrica. According to the coefficients of biological absorption of pea and soy grains, the studied heavy metals are referred to the elements of biological capture of CАB<1. An effective inactivating effect on heavy metals is provided by pre-sowing treatment of pea and soy seeds with biologically active substances combined with Rhizotorphin+Agrica and Rhizotorphin+Humariz.
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Smiles, D. E., and C. J. Smith. "Absorption of gypsum solution by a potassic soil: a data set." Soil Research 46, no. 1 (2008): 67. http://dx.doi.org/10.1071/sr07103.
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Reliable experimental data required to test hydrodynamic dispersion/chemical reaction models are scarce. This paper provides such a dataset based on absorption of gypsum solution by horizontal columns of relatively dry soil with an initially high exchangeable potassium ratio. Initial and boundary conditions are well defined. Water and cation concentration profiles measured after 200 and 400 min lay on single curves when graphed in terms of distance divided by the square root of time. Cation exchange occurred close to the intake surface and calcium derived from the gypsum was confined to a narrow band well behind the notional piston front that separates the absorbed solution from that originally present. Anion exchange was negligible and the solution concentration up to the piston front approximated the anion concentration of the invading solution. The interval between the region of cation exchange and the piston front maintained the original cation adsorption ratios but at a total cation solution concentration approximating that of saturated gypsum (~25 mmolc/L). Some implications of this phenomenon are discussed. Comparison of cation exchange isotherms observed when the virgin soil absorbs effluent-like solutions and when effluent-irrigated soil absorbs saturated gypsum suggest that, operationally, these isotherms may be considered to be unaffected by hysteresis in the exchange reactions.
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Beal, C. D., E. A. Gardner, and N. W. Menzies. "Process, performance, and pollution potential: A review of septic tank - soil absorption systems." Soil Research 43, no. 7 (2005): 781. http://dx.doi.org/10.1071/sr05018.
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On-site wastewater treatment and dispersal systems (OWTS) are used in non-sewered populated areas in Australia to treat and dispose of household wastewater. The most common OWTS in Australia is the septic tank–soil absorption system (SAS)—which relies on the soil to treat and disperse effluent. The mechanisms governing purification and hydraulic performance of a SAS are complex and have been shown to be highly influenced by the biological zone (biomat) which develops on the soil surface within the trench or bed. Studies suggest that removal mechanisms in the biomat zone, primarily adsorption and filtering, are important processes in the overall purification abilities of a SAS. There is growing concern that poorly functioning OWTS are impacting upon the environment, although to date, only a few investigations have been able to demonstrate pollution of waterways by on-site systems. In this paper we review some key hydrological and biogeochemical mechanisms in SAS, and the processes leading to hydraulic failure. The nutrient and pathogen removal efficiencies in soil absorption systems are also reviewed, and a critical discussion of the evidence of failure and environmental and public health impacts arising from SAS operation is presented. Future research areas identified from the review include the interactions between hydraulic and treatment mechanisms, and the biomat and sub-biomat zone gas composition and its role in effluent treatment.
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Khairuddin, Wiranto Wengkau, Dwi Juli Puspitasari, Husain Sosidi, and Nov Irmawati Inda. "Adsorpsi Logam Merkuri (Hg) dari Limbah Tanah Tercemar Menggunakan Tanaman Sawi (Brassica juncea L) pada Berbagai Waktu Tanam." KOVALEN: Jurnal Riset Kimia 7, no. 1 (April 30, 2021): 65–71. http://dx.doi.org/10.22487/kovalen.2021.v7.i1.13666.
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Mercury (Hg) as a gold extractor can cause environmental pollution, therefore, hyperaccumulator plants are needed, such as mustard greens (Brassica juncea L). Research on the effect of planting time of mustard greens on the adsorption of mercury (Hg) metal ion on contaminated soil waste has been carried out. The purpose of this research was to determine the concentration and adsorption mechanism of Hg metal ion from contaminated soil at roots and canopy of mustard plants at various planting times. Amount of Hg metal ion adsorbed on the roots and canopy of mustard greens at 2, 4, and 6 weeks of planting times were analyzed using Atomic Absorption Spectrophotometry (AAS). The results showed that the average levels of Hg metal ion adsorption at various planting time of 2, 4, and 6 weeks at roots were 156.611 μg/g, 810.256 μg/g, and 888.711 μg/g, respectively, and at the canopy were 69.486 μg/g, 134.580 μg/g, and 60.416 μg/g, respectively. The planting time of 6 weeks resulted in the highest adsorption ability of Hg at the roots. The results of the bioconcentration factor (BCF) test showed that the adsorption of Hg in the roots and canopy of the mustard plant took place using a phytoextraction mechanism (BCF < 1).
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Laufs, Sebastian, Mathieu Cazaunau, Patrick Stella, Ralf Kurtenbach, Pierre Cellier, Abdelwahid Mellouki, Benjamin Loubet, and Jörg Kleffmann. "Diurnal fluxes of HONO above a crop rotation." Atmospheric Chemistry and Physics 17, no. 11 (June 13, 2017): 6907–23. http://dx.doi.org/10.5194/acp-17-6907-2017.
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Abstract. Nitrous acid (HONO) fluxes were measured above an agricultural field site near Paris during different seasons. Above bare soil, different crops were measured using the aerodynamic gradient (AG) method. Two LOPAPs (LOng Path Absorption Photometer) were used to determine the HONO gradients between two heights. During daytime mainly positive HONO fluxes were observed, which showed strong correlation with the product of the NO2 concentration and the long wavelength UV light intensity, expressed by the photolysis frequency J(NO2). These results are consistent with HONO formation by photosensitized heterogeneous conversion of NO2 on soil surfaces as observed in recent laboratory studies. An additional influence of the soil temperature on the HONO flux can be explained by the temperature-dependent HONO adsorption on the soil surface. A parameterization of the HONO flux at this location with NO2 concentration, J(NO2), soil temperature and humidity fits reasonably well all flux observations at this location.
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Pranoto, Pranoto, Tri Martini, and Winda Maharditya. "Uji Efektivitas dan Karakterisasi Komposit Tanah Andisol/Arang Tempurung Kelapa Untuk Adsorpsi Logam Berat Besi (Fe)." ALCHEMY Jurnal Penelitian Kimia 16, no. 1 (February 21, 2020): 50. http://dx.doi.org/10.20961/alchemy.16.1.33286.50-65.
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<p>Penelitian ini untuk mengetahui kapasitas adsorpsi komposit tanah andisol/arang tempurung kelapa sebagai adsorben logam berat besi (Fe) berdasarkan pada kondisi komposisi, pH dan waktu kontak yang optimum. Tanah andisol diaktivasi dengan larutan NaOH 3 M dan arang tempurung kelapa diaktivasi menggunakan larutan HCl 4 M. Komposit tanah andisol/arang tempurung kelapa dibuat dengan mencampurkan tanah andisol dan arang tempurung kelapa pada variasi komposisi 100:0, 75:25, 50:50, 25:75 dan 0:100 (b/b) Uji adsorpsi terhadap logam besi (Fe) dilakukan pada variasi pH larutan 1, 2, 3, 4, 5 dan 6 serta waktu kontak 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, dan 60 menit dengan sistem <em>batch</em>. Pengukuran konsentrasi akhir pada saat kesetimbangan dilakukan dengan menggunakan <em>Atomic Absorption Spectroscopy</em> (AAS). Hasil karakterisasi adanya proses aktivasi dan pengompositan ditunjukkan pada spektra <em>Fourier Transform Infra Red</em> (FTIR) yang mengalami pergeseran bilangan gelombang. Karakterisasi pola difraksi <em>X-Ray Diffraction</em> (XRD) yang menunjukkan adanya puncak baru. Hasil analisis <em>Scanning Electron Microscope </em>(SEM) komposit menunjukkan bahwa permukaan adsorben telah ditutupi logam besi (Fe). Pembentukan komposit juga menunjukkan adanya peningkatan luas permukaan dan nilai keasaman komposit. Berdasarkan penelitian ini diperoleh bahwa proses adsorpsi terjadi pada kondisi optimum komposisi komposit tanah andisol/arang tempurung kelapa 75:25 (b/b), pH larutan besi (Fe) 5 dan waktu kontak selama 30 menit dengan kapasitas adsorpsi sebesar 0,54 mg/g dan presentase adsorpsi 91,57%. Isoterm adsorpsi mengikuti isoterm Freundlich dengan nilai R<sup>2</sup> sebesar 0,9456.</p><p><strong>Effectiveness Test and Characterization of Andisol Soil/Coconut Shell Charcoal for Adsorption of Iron (Fe).</strong> This research aims to determine the adsorption capacity composite of andisol soil and coconut shell charcoal as the adsorbent of iron (Fe) metal based on the composition condition, pH, and optimum contact time. Andisol soil was activated with NaOH 3 M solution, and coconut shell charcoal was activated with HCl 4 M solution. The composites were made under various composition of andisol soil/coconut shell charcoal of 100:0, 75:25, 50:50, 25:75 and 0:100 (w/w). The adsorption test was done on the pH variation of 1, 2, 3, 4, 5, 6 and used the contact time variation of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 and 60 minutes in a batch method. The concentration analysis of iron (Fe) metal was done by atomic absorption spectroscopy (AAS). The characterization result of the activation process can be shown on the Fourier transform infrared (FTIR) spectra with the shifting peak. Characterization of X-ray diffraction (XRD) diffractogram showed the emergence of a new peak in andisol soil and coconut shell charcoal. The result of scanning electron microscope (SEM) characterization analysis showed that the surface of the adsorbent was covered in iron. The composite formation also showed an increase in surface area and composite acidity value. Based on the result of the research, it can be concluded that the adsorption process happens in the optimum condition in andisol soil/coconut shell charcoal composition of 75:25 (w/w), pH solution iron (Fe) metal of 5 and contact time of 30 minutes. The adsorption capacity was 0.54 mg/g and 91.57% for adsorption percentage. The isotherm adsorption followed Freundlich isotherm with R<sup>2</sup> values 0.9456.</p>
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Pranoto, Pranoto, Tri Martini, and Winda Maharditya. "Uji Efektivitas dan Karakterisasi Komposit Tanah Andisol/Arang Tempurung Kelapa Untuk Adsorpsi Logam Berat Besi (Fe)." ALCHEMY Jurnal Penelitian Kimia 16, no. 1 (February 21, 2020): 50. http://dx.doi.org/10.20961/alchemy.16.1.33286.50-66.
Full textAbstract:
<p>Penelitian ini untuk mengetahui kapasitas adsorpsi komposit tanah andisol/arang tempurung kelapa sebagai adsorben logam berat besi (Fe) berdasarkan pada kondisi komposisi, pH dan waktu kontak yang optimum. Tanah andisol diaktivasi dengan larutan NaOH 3 M dan arang tempurung kelapa diaktivasi menggunakan larutan HCl 4 M. Komposit tanah andisol/arang tempurung kelapa dibuat dengan mencampurkan tanah andisol dan arang tempurung kelapa pada variasi komposisi 100:0, 75:25, 50:50, 25:75 dan 0:100 (b/b) Uji adsorpsi terhadap logam besi (Fe) dilakukan pada variasi pH larutan 1, 2, 3, 4, 5 dan 6 serta waktu kontak 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, dan 60 menit dengan sistem <em>batch</em>. Pengukuran konsentrasi akhir pada saat kesetimbangan dilakukan dengan menggunakan <em>Atomic Absorption Spectroscopy</em> (AAS). Hasil karakterisasi adanya proses aktivasi dan pengompositan ditunjukkan pada spektra <em>Fourier Transform Infra Red</em> (FTIR) yang mengalami pergeseran bilangan gelombang. Karakterisasi pola difraksi <em>X-Ray Diffraction</em> (XRD) yang menunjukkan adanya puncak baru. Hasil analisis <em>Scanning Electron Microscope </em>(SEM) komposit menunjukkan bahwa permukaan adsorben telah ditutupi logam besi (Fe). Pembentukan komposit juga menunjukkan adanya peningkatan luas permukaan dan nilai keasaman komposit. Berdasarkan penelitian ini diperoleh bahwa proses adsorpsi terjadi pada kondisi optimum komposisi komposit tanah andisol/arang tempurung kelapa 75:25 (b/b), pH larutan besi (Fe) 5 dan waktu kontak selama 30 menit dengan kapasitas adsorpsi sebesar 0,54 mg/g dan presentase adsorpsi 91,57%. Isoterm adsorpsi mengikuti isoterm Freundlich dengan nilai R<sup>2</sup> sebesar 0,9456.</p><p><strong>Effectiveness Test and Characterization of Andisol Soil/Coconut Shell Charcoal for Adsorption of Iron (Fe).</strong> This research aims to determine the adsorption capacity composite of andisol soil and coconut shell charcoal as the adsorbent of iron (Fe) metal based on the composition condition, pH, and optimum contact time. Andisol soil was activated with NaOH 3 M solution, and coconut shell charcoal was activated with HCl 4 M solution. The composites were made under various composition of andisol soil/coconut shell charcoal of 100:0, 75:25, 50:50, 25:75 and 0:100 (w/w). The adsorption test was done on the pH variation of 1, 2, 3, 4, 5, 6 and used the contact time variation of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 and 60 minutes in a batch method. The concentration analysis of iron (Fe) metal was done by atomic absorption spectroscopy (AAS). The characterization result of the activation process can be shown on the Fourier transform infrared (FTIR) spectra with the shifting peak. Characterization of X-ray diffraction (XRD) diffractogram showed the emergence of a new peak in andisol soil and coconut shell charcoal. The result of scanning electron microscope (SEM) characterization analysis showed that the surface of the adsorbent was covered in iron. The composite formation also showed an increase in surface area and composite acidity value. Based on the result of the research, it can be concluded that the adsorption process happens in the optimum condition in andisol soil/coconut shell charcoal composition of 75:25 (w/w), pH solution iron (Fe) metal of 5 and contact time of 30 minutes. The adsorption capacity was 0.54 mg/g and 91.57% for adsorption percentage. The isotherm adsorption followed Freundlich isotherm with R<sup>2</sup> values 0.9456.</p>
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Selvarajh, Gunavathy, and Huck Ywih Ch’ng. "Enhancing Soil Nitrogen Availability and Rice Growth by Using Urea Fertilizer Amended with Rice Straw Biochar." Agronomy 11, no. 7 (July 1, 2021): 1352. http://dx.doi.org/10.3390/agronomy11071352.
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Urea fertilizer as a nitrogen source is used widely and globally. However, N loss through ammonia volatilization from applied urea has become a major drawback to agriculture. A pot experiment was conducted to determine the effect of rice straw biochar on (1) total N, soil exchangeable NH4+, and available NO3− (2) uptake of N, P, and K in rice plants. The treatments evaluated were: (S: Soil only, U: soil + 175 kg ha−1 urea, B1: soil + 175 kg ha−1 urea + 5 t ha−1 rice straw biochar, B2: soil + 175 kg ha−1 urea + 10 t ha−1 rice straw biochar, CB1: 50% soil + 50% commercial biochar potting media and CB2: 100% commercial biochar potting media). The addition of rice straw biochar at 5–10 t ha−1 in the pot experiment significantly increased the soil total N availability by 33.33–46.67%. Treatments B1 and B2 also had significantly increased exchangeable NH4+, NO3−, P, and K in the soil over U. The soil availability nutrients increment in soil was attributed to the higher adsorption capacity of the rice straw biochar. Increment in soil nutrient availability such as N, P, and K increased the plant height, tiller number, greenness, and panicle number because of effective rice plant absorption. This resulted in dry matter production increment in line with plant nutrient uptake and use efficiency. Rice straw biochar at 5–10 t ha−1 can improve the productivity of rice plants by increasing N retention in soil.
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McCoy, Benjamin J., and Dennis E. Rolston. "Convective transport of gases in moist porous media: effect of absorption, adsorption, and diffusion in soil aggregates." Environmental Science & Technology 26, no. 12 (December 1992): 2468–76. http://dx.doi.org/10.1021/es00036a020.
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Rahmayanti, Maya, Indah Nurhikmah, and Feni Larasati. "Isolation, Characterization and Application of Humin From Sumatran Peat Soils as Adsorbent for Naphtol Blue Black and Indigosol Blue Dyes." Molekul 16, no. 1 (March 28, 2021): 67. http://dx.doi.org/10.20884/1.jm.2021.16.1.700.
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Isolation, characterization and application of humin as adsorbent for naphtol blue black (NBB) and indigosol blue (IB) dyes has been carried out. Humin application in this study aims to obtain the optimum pH conditions and kinetics model for adsorption NBB and IB dyes onto humin. Humin was isolated from peat soils originating from Riau, Sumatra. The isolation method used was the alkaline extraction method and the characterization of humin using FTIR spectrophotometer. The total acidity, carboxylic groups and –OH phenolic groups of humin were determined quantitatively using the acid-base titration method. FTIR characterization indicated the presence of an –OH group which was indicated by the appearance of absorption at a wavelength of 3425.3 cm-1 and a stretching vibration of C=O from the –COOH group at a wavelength of 1705 cm-1. The quantitative calculation of the total acidity value, the content of the carboxylic group and the -OH group phenolics of humin were 508.47 cmol kg-1, 289.42 cmol kg-1 and 219.05 cmol kg-1, respectively. The optimum pH conditions for adsorption NBB and IB onto humin occurred at pH 5 and pH 2, respectively. The adsorption kinetics model of NBB and IB on humin followed the Ho kinetics model.
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Choi, Sung-Won, Dong-Hoon Bai, Ju-Hyun Yu, and Chul Soo Shin. "Characteristics of the squalene synthase inhibitors produced by a Streptomyces species isolated from soils." Canadian Journal of Microbiology 49, no. 11 (November 1, 2003): 663–68. http://dx.doi.org/10.1139/w03-084.
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Microorganisms producing squalene synthase inhibitors were screened from soils. A high producer was selected and identified as a Streptomyces species. Two active inhibitors were obtained from culture broths via a series of purification processes involving solvent extraction, WK-10 cation-exchange column chromatography, HP-20 adsorption column chromatography, silica-gel column chromatography, preparative HPLC, and crystallization. The inhibitors were confirmed as macrolactins A and F with molecular weights of 402 by UV-absorption spectrometry, fast atom bombardment mass spectometry, and 13C- and 1H-NMR analyses. Kinetic results for macrolactins A and F showed that they appear to be noncompetitive inhibitors of rat liver squalene synthase with IC50 values of 1.66 and 1.53 µmol/L, respectively. Since mammalian squalene synthase was used, these inhibitors have significant potential as therapeutic agents for hyperlipemia and suppression of cholesterol biosynthesis.Key words: squalene synthase inhibitor, Streptomyces species, macrolactins A and F.
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Riapanitra, Anung, and Roy Andreas. "PEMANFAATAN ARANG BATOK KELAPA DAN TANAH HUMUS BATURRADEN UNTUK MENURUNKAN KADAR LOGAM KROM (Cr)." Molekul 5, no. 2 (November 1, 2010): 66. http://dx.doi.org/10.20884/1.jm.2010.5.2.78.
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Waste containing hazardous and toxic chemical compounds into the environment leads to water pollution, soil and air. These chemical compounds will endanger human life and environment. One type of compound that may pollute the environment is chromium. The metal is commonly found in industrial waste such as from exhaust and industrial wastewater from etal plating company.The purpose of this research is to utilize coconut shell charcoal and soil humus as a low-cost and ready-made alternative material to reduce the concentration chromium (Cr) on wastewater. Humus was taken from Baturraden region and was isolated using NaOH extraction and was furthermore purified using mixtures of HF(aq): HCl(aq). Coconut shell charcoal was produced and was mixed with the humus. Adsorption process was carried out by batch method on variations of charcoal: humus composition, pH, and contact time. Humus soil was identified using infrared spectrophotometry (IR). Determination of chromium concentration was performed using atomic absorption spectroscopy (AAS).The purified humus yielded was 25.92% (w/w), with 34.18% moisture, and ash content of 18.09%. The results showed that the variation of composition ratio of 2:1 charcoal and humus produced the greatest percent reduction of 18.20%, and the optimum pH for the adsorption is 9. For the variation of contacts time, the optimum reaction time is at 180minutes with decreasing concentration of Pb up to 56.07%.
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Stietiya, M. Hashem, Jim J. Wang, and Amitava Roy. "Macroscopic and Extended X-ray Absorption Fine Structure Spectroscopic Investigation of Ligand Effect on Zinc Adsorption to Kaolinite as a Function of pH." Soil Science 176, no. 9 (September 2011): 464–71. http://dx.doi.org/10.1097/ss.0b013e3182285b46.
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Li, Zhichao, Wanchun Lu, and Jilin Huang. "Monitoring, Diffusion and Source Speculation Model of Urban Soil Pollution." Processes 8, no. 11 (October 23, 2020): 1339. http://dx.doi.org/10.3390/pr8111339.
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The rapid industrialization of cities has brought many challenges to the environment and resources. Industrial wastes, automobile exhaust, coal combustion soot and other pollutants accumulate in urban soil, and the characteristics of urban soil are changed, causing many pollutants to accumulate in the urban soil environment. Heavy metals are toxic and harmful pollutants existing in soil that cannot be biodegraded or thermally degraded; thus, heavy metals pose a threat to environmental quality and humans. To solve the environmental pollution of soil heavy metals, we utilize kriging interpolation to determine the geological distribution of the environmental pollution of metal elements and analyze the main causes of soil heavy metal pollution. Next, the propagation characteristics and diffusion process of heavy metal pollutants are thoroughly analyzed; in addition, an improved one-dimensional convective dispersion model and an improved air subsidence model are established, and real urban soil data are taken as an example for the fitting test. The results show that the improved models that consider more factors, such as adsorption or decomposition factors during the process of convective dispersion, absorption and expulsion factors of the crop root and topographic factors and height changes during the process of air subsidence, are effective. This paper is helpful for distinguishing the primary pollution sources and migration routes of soil metal element pollution and provides a certain reference value for protecting the environment and reducing heavy metal pollution.
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Arai, Hirotsugu, Keizo Ishii, Shigeo Matsuyama, Fumito Fujishiro, Azusa Ishizaki, Naoyuki Osada, Hiroyuki Sugai, et al. "Evaluating radiocesium retention ability of root-mat horizon using micro-PIXE analysis." International Journal of PIXE 24, no. 01n02 (January 2014): 29–34. http://dx.doi.org/10.1142/s012908351450003x.
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A lot of radiocesium had been deposited onto pastures and grasslands following Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. More radiocesium was accumulated in root-mat horizon than in both above ground plant bodies and mineral soils. In this study, factors causing higher radiocesium concentrations in root-mat horizon were evaluated by the addition of stable cesium solution and particle-induced X-ray emission (PIXE) analysis. Results suggest that adsorption onto root surfaces played a significant role in Cs accumulation in root-mat horizon. Furthermore, absorption of Cs was key to its long-term preservation. The adsorption of Cs by clay minerals also contributed to its retention. A slow water infiltration rate may also affect the enrichment of radiocesium in root-mat horizon. Based on these results, it is concluded that both biotic and abiotic factors contributed to the effective retention of radiocesium in root-mat horizons following the FDNPP accident.
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Baghaie, Amir Hossein, and Mehran Keshavarzi. "The Effect of Montmorillonite Nano-Clay on the Changes in Petroleum Hydrocarbon Degradation and Cd Concentration in Plants Grown in Cd-Polluted Soil." Avicenna Journal of Environmental Health Engineering 5, no. 2 (December 29, 2018): 100–105. http://dx.doi.org/10.15171/ajehe.2018.13.
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Contamination with heavy metals and petroleum hydrocarbons is considered as an environmental problem. Thus, this research was done to evaluate the effect of montmorillonite nano-clay on the changes in petroleum hydrocarbon degradation and cadmium (Cd) concentration in plant grown in a Cd-polluted soil. Treatments consisted of two levels of montmorillonite nano-clay (0 and 1% W/W) in a Cd-polluted soil (0, 5, 10 mg Cd/kg soil) and crude oil-polluted soil (0, 1 and 2% W/W). The plant used in this study was Tall Fescue (Festuca arundinacea L.). After 20 weeks, the concentration of Cd in plants was measured by atomic absorption spectroscopy and the total petroleum hydrocarbon (TPHs) in the soil was determined using the GC-mass spectrometry. Soil respiration was determined according to the method used by Qiao et al. ANOVA was used for statistical analysis of data. The least significant difference (LSD) test was used to determine the differences between the means. The application of 1% (w/w) montmorillonite nano-clay in Cd-polluted soil (10 mg Cd) without crude oil decreased Cd concentration in plant and increased microbial respiration by 18% and 34%, respectively. In addition, the application of 1% montmorillonite nano-clay in soil polluted with 1% crude oil and 10 mg Cd enhanced TPHs degradation by 27%. The use of montmorillonite nano-clay increased Cd adsorption in soil which resulted in an increase in microbial respiration and, hence the degradability of petroleum hydrocarbon in the soil.
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Arocha, M., A. Jackman, and B. McCoy. "Erratum to “VOC immobilization in soil by adsorption, absorption, and encapsulation”, [J. Haz. Mats. 51 (1996) 131–149]." Journal of Hazardous Materials 56, no. 1-2 (September 1997): 225–26. http://dx.doi.org/10.1016/s0304-3894(97)00067-8.
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Rana, MM, MT Islam, S. Datta, MM Rahman, and AKM Adham. "Suitability of powerplant disposed water for irrigation of Ashuganj agro-irrigation project in Bangladesh." Progressive Agriculture 30, no. 1 (July 17, 2019): 113–24. http://dx.doi.org/10.3329/pa.v30i1.42218.
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A study was conducted to analyze the quality of power plant disposed water for irrigation and its impact on the soil of Ashuganj agro-irrigation project in Bangladesh. Water samples were collected during the irrigation period and chemically analyzed for the assessment of their quality based on pH, electrical conductivity (EC), sodium adsorption ratio (SAR), soluble sodium percentage (SSP), residual sodium bicarbonate (RSBC), Kelley‘s ratio (KR), total hardness (TH), magnesium absorption ratio (MAR) and permeability index (PI). Most of the water samples were basically excellent in case of EC and SAR, satisfactory in respect of RSBC and good based on SSP and PI for irrigation use. The relationships between the pairs of KR-SAR, KR-SSP, and SSP-SAR of the water samples were very strong with correlation coefficient around 1. Moreover, the values of pH, EC, Na, K, Ca, Mg and organic carbon of the soil samples were in the suitable range before and after crop cultivation. Therefore, it can be inferred that the power plant disposed water of the agro-irrigation project is suitable for irrigation as well as crop cultivation without any hazard of soil health.
Progressive Agriculture 30 (1): 113-124, 2019
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Baltrėnaitė, Edita, and Donatas Butkus. "MODELLING OF CU, NI, ZN, MN AND PB TRANSPORT FROM SOIL TO SEEDLINGS OF CONIFEROUS AND LEAFY TREES." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 15, no. 4 (December 31, 2007): 200–207. http://dx.doi.org/10.3846/16486897.2007.9636931.
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Transport of trace metals (TMs) from the soil to a plant involves chemical, physical and biological processes (such as diffusion, adsorption, absorption, growth of a plant, transpiration rate, etc.) in the soil, the soil rhizosphere and in the plant itself. Because of the complexity of these processes and external factors (e.g. weather conditions, biotic factors, type of substrate, etc.) the processes are difficult to describe by mathematical formulas. Modelling of TMs transport to plants is even more complex than that of organic contaminants because, contrary to organic contaminants, TMs are essential for plant growth, metabolism, enzyme activity, etc. The octanol‐water partitioning coefficient for TMs in plants gives only limited information about their accumulation, therefore, other coefficients, such as bioconcentration and translocation coefficients, must be incorporated. The aim of this work was to simulate transport of TMs (Zn, Pb, Cu, Ni and Mn) from the soil to tree seedlings by adapting a generalized model of contaminant uptake by plants. The model applied for transport of TMs from the soil to trees was created by Hung and Muckay. When employing this model for modelling transport of TMs from the soil, amended with industrial sewage sludge, to seedlings of coniferous and leafy trees, some adjustments were made by evaluating the equilibrium partitioning coefficient of TMs between octanol and water (Kow); by introducing the equilibrium partitioning coefficient of TMs in the soil and water (K d ), which depends on the soil pH and the amount of organic matter; by introducing the coefficient (KT) of TMs solubility in water as well as by introducing corrective coefficients. When using the Hung and Muckay's model of the transport of trace metals from the soil to tree seedlings, the results of modelling differed approximately by 6 % in leaves, 5 % in the stem and 8 % in roots as compared with those of measurements.