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Letteratura scientifica selezionata sul tema "TREATED SOIL"

Autore: Grafiati

Pubblicato: 11 settembre 2023

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Articoli di riviste sul tema "TREATED SOIL"

Hamad, Asal Mahmud, e Mahmood Gazey Jassam. "A Comparative Study for the Effect of Some Petroleum Products on the Engineering Properties of Gypseous Soils". Tikrit Journal of Engineering Sciences 29, n. 3 (15 ottobre 2022): 69. http://dx.doi.org/10.25130/tjes.29.3.7.

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Gypseous soils are considered problematic soils because the soil cavities happen during receiving the water or this type of soil and solving gypsum materials and contract in a soil volume. In this study, three types of gypseous soils are used; soil1, soil2, and soil3 with gypsum content (28.71%, 43.6%, and 54.88%) respectively, petroleum products (engine oil, fuel oil, and kerosene) are added to the soils with percentages (3%, 6%, 9%, and 12%) for each product. The result showed that specific gravity, liquid limit, optimum moisture content (O.M.C), and maximum dry density decreased with an increased percentage of product for all types of products. The direct shear (dry and soaked case) results show that increasing the (angle of internal friction and the soil cohesion) for soil1, soil2, and soil3 by adding engine oil and fuel oil. Still, when the soils were treated with kerosene, the angle of internal friction increased while cohesion decreased. The collapse potential for the treated soils increases with increasing gypsum content for all petroleum products. The collapse potential (CP) for (soil1) decreased by 47% when using 6% of the engine oil, 48.8% when using 9% of the fuel oil, and 55% when using 9% of the kerosene. The same percentage of the petroleum products (engine oil, fuel oil, and kerosene) decrease the collapse potential for (soil2), (47%, 46%, and 50%) respectively and decrease the collapse potential for (soil 3), (51%, 47.7%, and 52%) respectively. In the unconfined compressive test applied on (soil1) using maximum density, the results show that the soil strength increased (26% and 10%) when using 6% and engine oil and fuel oil, respectively, while the soil strength decreased by 29% when treated with 9% of kerosene.

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Sinegani, A. A. S., e A. Mahohi. "Soil water potential effects on the cellulase activities of soil treated with sewage sludge". Plant, Soil and Environment 56, No. 7 (14 luglio 2010): 333–39. http://dx.doi.org/10.17221/256/2009-pse.

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To better understand how water stress and availability affect the enzyme activity and microbial communities in soil, we measured the changes of organic carbon (OC), bacteria and fungi populations, and endoglucanase and exoglucanase activities in a semiarid soil treated with air-dried primary sewage sludge at a rate of 20 g/kg. The water potentials established for soil incubation were: saturation (SA, 0 bar), field capacity (FC, –0.3 bar), and permanent wilting point (PWP, –15 bar). An irrigation treatment was a drying-rewetting cycle (DWC) between –0.3 to –15 bars. After 0, 20, 60 and 90 days of incubation soils were sampled for analysis. The addition of sewage sludge increased soil OC, endoglucanase and exoglucanase activities significantly. The effects of soil moisture, incubation time and their interactions on OC, and endoglucanase and exoglucanase activities in soil were significant. During 20 days of incubation, OC, endoglucanase and exoglucanase activities decreased significantly. Soils incubated in DWC and FC compared to soils incubated in SA and PWP had lower OC contents due to organic matter mineralization. Organic C, exoglucanase and endoglucanase activities significantly increased with increasing soil water potential. The activities of exoglucanase and endoglucanase in soils incubated in SA were significantly higher than those in soils incubated in PWP.

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Akrivos, J., D. Mamais, K. Katsara e A. Andreadakis. "Agricultural utilisation of lime treated sewage sludge". Water Science and Technology 42, n. 9 (1 novembre 2000): 203–10. http://dx.doi.org/10.2166/wst.2000.0207.

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Over one growing season, lime treated dewatered sludge was applied to pot and field cotton cultivation at rates of 0, 10, 20 and 30 t/ha to determine the effects of sludge agricultural reuse on physical and chemical soil properties, on soil and plant heavy metal content and on plant production. In most cases total N and total and soluble P content of the soil increased with addition of sludge. Maximum pH increase caused by addition of lime treated sludge to alkaline soils did not exceed 0.2. Heavy metal content in all plant tissues and soil samples did not increase significantly as a result of sludge amendment. Plant yields increased significantly with sludge addition for the three alkaline soils used in this study. A low plant productivity observed with one of the soil types studied, was attributed to the high concentration of Ni in the soil and the low nutrient content of the soil.

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Makino, M., T. Takeyama e M. Kitazume. "The influence of soil disturbance on material properties and micro-structure of cement-treated soil". Lowland Technology International 17, n. 3 (2015): 139–46. http://dx.doi.org/10.14247/lti.17.3_139.

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Watabe, Yoichi, Takashi Kaneko e Yu Watanabe. "Cement mix proportion for treated soils recycled from a cement treated soil". Japanese Geotechnical Society Special Publication 4, n. 7 (2016): 168–72. http://dx.doi.org/10.3208/jgssp.v04.j16.

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Aldaood, Abdulrahman, Amina Khalil, Ibrahim Alkiki e Madyan Alsaffar. "Volume Change and Cracks Behavior of Lime Treated Expansive Soils". Academic Journal of Nawroz University 7, n. 4 (21 dicembre 2018): 81. http://dx.doi.org/10.25007/ajnu.v7n4a274.

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This research work study the influence of cyclic wetting and drying on free swell potential of untreated and lime treated expansive clayey soils. Such a study is required to understand the behavior of these soils during wet-dry cycles. Two expansive soils (a polwhite bentonite and a kaolinite) with different plasticity indexes were used in this study. The soil samples were treated with different lime content in the order of (3, 5 and 7% by the dry weight of soil). The lime treated soil samples were cured at 20ºC for 28 and 180 days. The untreated and lime treated soil samples were subjected to four wet-dry cycles. Free swell potential and cracks propagation were studied during lime addition and wet-dry cycles. Results showed that, the free swell potential of untreated soil samples; in general; decreased with increasing wet-dry cycles, and all of the soil samples reached equilibrium after the second cycle. While the cracks propagation increased with these cycles, especially of bentonite soil samples. Larger cracks propagation has been observed in the bentonite soil samples. Lime addition enhanced the free swell potential values of the two expansive soils and there was a drastic decrease in free swelling potential and cracks propagation of these soils. The beneficial effect of lime treatment to control the swelling values was partly lost by the first wet–dry cycles, and the free swell potential increased at the subsequent cycles.

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Ou, Ou, Xin Gui Zhang e Nian Ping Yi. "The Experimental Study on Strength of Subgrade Soil Treated with Liquid Stabilizer". Advanced Materials Research 194-196 (febbraio 2011): 985–88. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.985.

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The liquid soil stabilizer technology is a chemically modified method that can stabilize or reinforce those soils with weak engineering properties. In this paper, two typical high liquid limit soils ，which can not be directly used as subgrade materials，were treated with a new soil stabilizer and it were processed that serials of comparison test on the main engineer properties of soil that pre-and post-treated with soil stabilizer. Then the results show that the soil liquid stabilizer is effective to improve strength and moisture susceptibility for two selected soils. The liquid soil stabilizer technology opened up a new approach for soil improvement and ground treatment.

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Ali, Nizakat, Aneel Kumar e Manoj Kumar. "Compaction and consolidation characteristics of chemically treated expansive soil of Jamshoro". Mehran University Research Journal of Engineering and Technology 41, n. 2 (1 aprile 2022): 2–11. http://dx.doi.org/10.22581/muet1982.2202.01.

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Abstract (sommario):

The Jamshoro soil is a weak and expansive soil. The construction of infrastructure on such soils has resulted severe damages and huge maintenance costs. Thus, it needs treatment to enhance its geotechnical properties. This research work investigates the effects of chemical stabilizers such as lime, fly ash, and silica fume on the compaction and consolidation characteristics of expansive soil of Jamshoro. The stabilizers were added individually in different proportions (5%, 10%, 15%, and 20%) in the soil. The results show that maximum dry density decreased, while optimum moisture content increased with the increase of the stabilizers’ content in the soil. The compression index and swelling index of lime treated soil significantly decreased than that of soils treated with silica fume and fly ash. On the other side, the coefficient of consolidation and permeability of fly ash treated soil considerably increased than that of soils treated with silica fume and lime.

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Kurt Albayrak, Zeynep Nese, e Banu Altun. "Strength properties of biopolymer treated clay/marble powder mixtures". Challenge Journal of Concrete Research Letters 12, n. 4 (16 dicembre 2021): 131. http://dx.doi.org/10.20528/cjcrl.2021.04.003.

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Depending on their unique layer structures and chemical structures, soil problems such as swelling, settlement and loss of strength can be seen especially on clay soils when exposed to water. Settlement occurring on clay soils on which the structure is built, causes various damages in the building. Additionally, in the clay soil interacting with water, strength loss occurs due to the effect of the building load. Today, when soil improvement techniques are developed and diversified, clay soils can be stabilized by using different additives. A clay soil that has been improved by adding waste marble powder within the scope of this study in certain percentages (5%, 15%, 25%), biopolymer added clay / marble powder samples were obtained by interacting with locust bean gum in certain percentages (0.5%, 1%, 1.5%). There are many studies in the literature on improving clay soils using only marble powder or only biopolymer. In this study, marble powder and biopolymer were used together and thus, the feasibility of a more effective soil improvement has been investigated. The results showed that the unconfined compressive strength of the biopolymer added clay-marble powder mixtures are higher when compared with natural clay. Similarly, shear box test results showed that the unconsolidated-undrained cohesions and internal friction angles of the doped clay samples increased. It was observed that the strength values of marble powder-added clay increased after improving with biopolymer.

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Sivapullaiah, P. V., A. Sridharan e H. N. Ramesh. "Strength behaviour of lime-treated soils in the presence of sulphate". Canadian Geotechnical Journal 37, n. 6 (1 dicembre 2000): 1358–67. http://dx.doi.org/10.1139/t00-052.

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Lime has been used extensively to improve the shear strength of fine-grained soils. It has been recently reported that the presence of sulphate causes abnormal volume changes in lime-stabilized soil. The paper presents the strength behaviour of lime-treated montmorillonitic natural black cotton soil in the presence of varying sulphate contents after curing for periods of up to 365 days. Alteration of soillime reactions in the presence of sulphate affects the strength development by cementation. Consequently, the stressstrain behaviour effective stress paths of soil cured with sulphate are similar to those of normally consolidated soil rather than cemented soils. The reduction in shear strength due to a reduction in effective cohesion intercept occurs for lime-treated soil cured with sulphate for long periods.Key words: clays, cohesion, fabric, friction, shear strength.

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Più fonti

Tesi sul tema "TREATED SOIL"

BELCHIOR, INGRID MILENA REYES MARTINEZ. "BEHAVIOR OF A LIME-TREATED EXPANSIVE SOIL". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=29430@1.

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Abstract (sommario):

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE EXCELENCIA ACADEMICA
Os principais objetivos desta pesquisa são investigar o efeito da cal hidratada (HL) no comportamento de um solo expansivo, Eagle Ford do Texas (USA), e medir a eficiência do tratamento com cal sobre a redução da expansão através de variações das condições de preparação das amostras. Este estudo envolveu ensaios edométricos e ensaios de centrífuga, que é uma nova técnica desenvolvida pela Universidade do Texas em Austin (EUA). Até o presente trabalho, nenhum estudo tem sido desenvolvido usando esta centrífuga para analisar a redução da expansão em solos expansivos estabilizados. Além disso, nenhum estudo tem medido o melhoramento da eficiência do tratamento com cal devido às variáveis controladas durante a preparação das misturas solo-cal (ou seja, umidade, densidade, período entre a mistura e a compactação e tempo de cura), como também da tensão aplicada. Este trabalho também incluiu investigações sobre modificações das propriedades geotécnicas, composição mineralógica e constituição microestrutural, devido à adição de cal. A partir da análise das curvas de expansão vs. tempo, três valores foram definidos para examinar o comportamento expansivo: o potencial expansivo (Sp) e as inclinações de expansão primária (PSS) e secundária (SSS). A avaliação da eficiência do tratamento com cal, quantificada através do parâmetro Razão da Redução do Potencial Expansivo (SPR), indica: (i) eliminação de 97 por cento de Sp com 4 por cento de HL; (ii) melhoramento do SPR pelo aumento do tempo de cura; (iii) efeito adverso na SPR de períodos longos entre mistura e a compactação; (iv) possibilidade de diminuir a dosagem de cal necessária para reduzir a expansão através do aumento da umidade de compactação e/ou redução da densidade seca de compactação; e (v) dependência da dosagem da cal para prevenir a expansão no nível-g.
The main objectives of this research are to investigate the effect of hydrated lime (HL) treatment on the swelling behavior of a natural expansive soil, Eagle Ford clay from Texas (USA), and to measure the efficiency of lime treatment on swelling reduction due to variations in the condition of specimen preparation. This study involved conventional free swell tests and centrifuge tests, which are a new technique developed by the University of Texas at Austin (USA). So far, no studies have been performed using this centrifuge to analyze the swelling reduction in expansive soils by stabilization treatments. Also, no studies have measured the improving of lime treatment efficiency due to variables controlled during preparation of lime-soil mixtures (i.e. compaction moisture content, compaction dry density, mellowing and curing time), as well as the applied effective stress. This work also involved investigations about modifications of geotechnical properties, mineralogical composition and microstructural constitution due to the addition of lime. From the analysis of the swelling vs. time curves, three values were defined to examine the swelling behavior: the swelling potential (Sp), the primary swelling slope (PSS) and the secondary swelling slope (SSS). Assessment of the lime treatment efficiency, as quantified by the Swelling Potential Reduction Ratio (SPR) indicates: (i) the elimination of 97 per cent of Sp with 4 per cent HL; (ii) SPR enhancement with increasing curing time; (iii) adverse effect of mellowing periods on the SPR; (iv) the possibility to decrease the necessary lime dosage by increasing the compaction moisture and/or reducing the compaction dry density; and (v) dependency of the hydrated lime dosage to prevent swelling on the applied g-level (i.e. applied stress).

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Warren, Jason George. "Management of Alum-Treated Poultry Litter". Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/30232.

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Previous research has shown that treatment of poultry litter with alum is an effective management strategy to reduce phosphorus (P) solubility in litter thereby reducing potential P losses to surface runoff after surface applications. However, limited data are available evaluating alum-treated poultry litter (ATPL) environmental impact in cultivated systems and how its application will affect crop production. In addition little is known as to how its application affects various P fractions or exchangeable Aluminum (Al) content in treated soils. Two, 3-yr field trials with corn (Zea mays L.) were used to show that, when applied at rates based on current litter management strategies, ATPL resulted in yields similar to those achieved through applications of non-treated poultry litter (NPL). These trials also showed that ATPL applications resulted in lower soil P status and decreased P losses in surface water runoff compared to application of NPL. A 4-yr field trial with fescue (Festuca arudinacea) also showed no significant differences in productivity when comparing ATPL and NPL. This trial was utilized to evaluate the distribution of P in soils receiving ATPL. Soil analysis data showed that ATPL applications result in decreased water-extractable P (H2O-P) and that this decrease was associated with an elevation in NaOH extractable organic soil P. A laboratory incubation was utilized to evaluate the short and long-term impact of ATPL application on soil pH, exchangeable soil Al and H2O-P. Data from this incubation confirmed that the relationship between soil pH and exchangeable Al is not adversely affected by ATPL applications. Also, variations in the H2O-P content of soils treated with two different ATPL sources could not be associated with differences in Al:P ratio or soluble P content of the two litters, providing evidence that additional characteristics also control P availability after incorporation in soil.
Ph. D.

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Sariosseiri, Farid. "Critical state framework for interpretation of geotechnical properties of cement treated soils". Online access for everyone, 2008. http://www.dissertations.wsu.edu/Dissertations/Summer2008/f_sariosseiri_070208.pdf.

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Flynn, Colleen P. "The fate of nitrate in soil treated with hog manure". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq23304.pdf.

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Bennett, Michael Dever. "Effect of Concentration of Sphagnum Peat Moss on Strength of Binder-Treated Soil". Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/93210.

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Organic soils are formed as deceased plant and animal wildlife is deposited and decomposed in wet environs. These soils have loose structures, low undrained strengths, and high natural water contents, and require improvement before they can be used as foundation materials. Previous researchers have found that the deep mixing method effectively improves organic soils. This study presents a quantitative and reliable method for predicting the strength of one organic soil treated with deep mixing. For this thesis, organic soils were manufactured from commercially available components. Soil-binder mixture specimens with different values of organic matter content, OM, binder content, water-to-binder ratio, and curing time were tested for unconfined compressive strength (UCS). Least-squares regression was used to fit a predictive equation, modified from the findings of previous researchers, to this data. The equation estimates the UCS of a deep-mixed organic soil specimen using its total water-to-binder ratio and mixture dry unit weight. Soil OM is incorporated into the equation as a threshold binder content, aT, required to improve a soil with a given OM; the aT term is used to calculate an effective total water-to-binder ratio. This thesis reached several important conclusions. The modified equation was successfully fitted to the data, meaning that the UCS of some organic soil-binder mixtures may be predicted in the same manner as that of inorganic soil-binder mixtures. The fitting coefficients from the predictive equations indicated that for the soils and binder tested, specimens of organic soil-binder mixtures have a greater relative gain of UCS immediately after mixing compared to specimens of inorganic soil-binder mixtures. However, the inorganic mixtures generally have a greater relative gain of UCS during the curing period. The influence of curing temperature was found to be similar for organic and inorganic mixtures. For the organic soils and binder tested in this research, aT may be expressed as a linear or power function of OM. For both functions, the value of aT was negligible at values of OM below 45%, which reflects the chemistry of the organic matter in the peat moss. For projects involving deep mixing of organic soils, the predictive equation will be used most effectively by fitting it to the results of bench-scale testing and then checking it against the results of field-scale testing.
Master of Science
Organic soils are formed continuously as matter from deceased organisms – mainly plants – is deposited in wet environs and decomposes. Organic soils are most commonly found in swamps, marshes, and coastal areas. These soils make poor foundation materials due to their low strengths. Deep mixing, or soil mixing, involves introducing a binder like Portland cement or lime into soil and blending the soil and binder together to form columns or blocks. Upon mixing, cementitious reactions occur, and the soil-binder mixture gains strength as it cures. Deep mixing may be performed using either a dry binder, known as dry mixing, or a binder-water slurry, referred to as wet mixing. Deep mixing may be used to treat either inorganic or organic soils to depths of 30 meters or greater. Contractor experience has shown that deep mixing is one of the most effective methods of improving the strength of organic soils. Lab-scale studies (by previous researchers) of wet mixing of inorganic soils have found that the strength of soil-binder mixtures can be expressed as a function of mixture curing time and curing temperature, as well as the quantity of binder used, or binder factor, and the consistency of the binder slurry. No corresponding expression has been generated for wet mixing of organic soils, although many studies on the subject have been performed by previous researchers. The goal of this research was to generate such an expression for one organic soil. The soil used was made of sphagnum peat moss, an organic material commonly found in nature, and an inorganic clay used by previous researchers in studies of deep mixing in inorganic soils. The binder used in this research was a Portland cement. For this research, 43 unique soil-binder mixtures were manufactured. Each mixture involved a unique combination of soil organic matter content, binder factor, and binder slurry consistency. After a soil-binder mixture was made, it was divided, placed into cylindrical molds, and allowed to cure. The temperature of the curing environment of the mixture was monitored. Mixture compressive strength was assessed after 7, 14, and 28 days of curing using two cylindrically molded specimens of the mixture. Data on mixture strength was then evaluated to assess whether it could be expressed as a function of the variables tested. iv This research determined that the strength of at least some organic soils improved with wet mixing can be expressed as a function of soil organic matter content, binder factor, binder slurry consistency, and mixture curing time and curing temperature. The function will likely prove useful to deep mixing contractors, who routinely perform lab-scale deep mixing trials on samples of the soils to be improved in the field. Assuming wet mixing is used, the results of the trials are used to select values of binder factor and binder slurry consistency for the project. The function generated from this research will allow deep mixing contractors to select these values more reliably during the lab-scale phase of their work.

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Faraj, Mustafa Ali. "The effect on soil and sugar beet plants of irrigating polyacrylamide treated soil with saline water". Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329578.

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Herring, Ian James. "The effect of soil inhabiting micro-organisms on preservative treated wood". Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298364.

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Garnett, Kathryn. "Interactions of metals and nitrilotriacetic acid in sewage sludge-treated soil". Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38325.

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Spencer, Laura Marie. "Evaluation of sand treated with colloidal silica gel". Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37131.

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Liquefiable soils are common at ports due to the use of hydraulic fills for construction of waterfront facilities. Liquefaction-induced ground failure can result in permanent ground deformations that can cause loss of foundation support and structural damage. This can lead to substantial repair and/or replacement costs and business interruption losses that can have an adverse effect on the port and the surrounding community. Although numerous soil improvement methods exist for remediating a liquefaction-prone site, many of these methods are poorly suited for developed sites because they could damage existing infrastructure and disrupt port operations. An alternative is to use a passive remediation technique. Treating liquefiable soils with colloidal silica gel via permeation grouting has been shown to resist cyclic deformations and is a candidate to be used as a soil stabilizer in passive mitigation. The small-strain dynamic properties are essential to determine the response to seismic loading. The small-to-intermediate strain shear modulus and damping ratio of loose sand treated with colloidal silica gel was investigated and the influence of colloidal silica concentration was determined. The effect of introducing colloidal silica gel into the pore space in the initial phase of treatment results in a 10% to 12% increase in the small-strain shear modulus, depending on colloidal silica concentration. The modulus reduction curve indicates that treatment does not affect the linear threshold shear strain, however the treated samples reduce at a greater rate than the untreated samples in the intermediate-strain range above 0.01% cyclic shear strain. It was observed that the treated sand has slightly higher damping ratio in the small-strain range; however, at cyclic shear strains around 0.003% the trend reverses and the untreated sand begins to have higher damping ratio. Due to the nature of the colloidal silica gelation process, chemical bonds continue to form with time, thus the effect of aging on the dynamic properties is important. A parametric study was performed to investigate the influence of gel time on the increase in small-strain shear modulus. The effect of aging increases the small-strain shear modulus after gelling by 200 to 300% for the 40-minute-gel time samples with a distance from gelation (time after gelation normalized by gel time) of 1000 to 2000; 700% for the 2-hour-gel time sample with a distance from gelation of 1000; and 200 to 400% for the 20-hour-gel time samples with a distance from gelation of 40 to 100. The treatment of all potentially liquefiable soil at port facilities with colloidal silica would be cost prohibitive. Identifying treatment zones that would reduce the lateral pressure and resulting pile bending moments and displacements caused by liquefaction-induced lateral spreading to prevent foundation damage is an economic alternative. Colloidal silica gel treatment zones of varying size and location were evaluated by subjecting a 3-by-3 pile group in gently sloping liquefiable ground to 1-g shaking table tests. The results are compared to an untreated sample. The use of a colloidal silica treatment zone upslope of the pile group results in reduced maximum bending moments and pile displacements in the downslope row of piles when compared to an untreated sample; the presence of the treatment zone had minimal effect on the other rows of piles within the group.

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Cid, João Filipe Xavier. "Response of grapevine to irrigation with treated wastewater". Master's thesis, ISA, 2019. http://hdl.handle.net/10400.5/19445.

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Mestrado em Viticultura e Enologia - Instituto Superior de Agronomia / Faculdade de Ciências. Universidade do Porto
Climate change, population growth, industry expansion and increasing water demand in agriculture are pressuring water resources in dry, warm-climate regions, such as Mediterranean Europe. The aim of this study was to evaluate the possibility of using treated wastewater (TWW) for vineyard irrigation, as a strategy to maintain grapevine's water status within acceptable levels, while contributing to decrease the pressure on natural water resources. To achieve this goal, the effects of TWW and conventional water (CW) on grapevine and soil were compared after two years of irrigation. TWW appears to have had a significant impact on soil salinity, with TWW irrigated soil having a 10% higher salinity (VIC) than the CW irrigated one. Concerning grapevine growth rate and ecophysiology, shoot length of TWW irrigated vines was significantly lower (15%), though there were generally no differences in phenology and reflectance indexes (PRI and NDVI) between treatments. In one measurement during summer peak, though, NDVI values were significantly lower for TWW irrigated vines. Also during summer peak, berries of TWW irrigated vines were significantly darker and greener, and had higher total acidity than CW irrigated vines. Canopy traits such as exposed leaf area, total leaf area and leaf layer number did not differ between treatments, and the same occurred for grape and wood yield, suggesting that TWW had no impact on vine balance and yield. It is crucial to continue exploring the use of TWW for irrigation as an answer to drought and water scarcity, while studying its effects on crops and soil within wider time periods, to scout for long-term impacts of this practice
N/A

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Più fonti

Libri sul tema "TREATED SOIL"

Kaddous, Farid G. A. Recycling of secondary treated effluent through vegetable and a loamy sand soil. [Melbourne: Victoria] Dept. of Agriculture and Rural Affairs, 1986.

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Lay, Russell D. Frost heave of a Montana silt treated with reduced cement contents. Provo, Utah: Brigham Young University, 2005.

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Levy, Guy J., Pinchas Fine e A. Bar-Tal. Treated wastewater in agriculture: Use and impacts on the soil environment and crops. Chichester, West Sussex, U.K: Wiley-Blackwell, 2011.

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E, Horn M., Owens J. B, Holcombe L. J, Electric Power Research Institute, Radian Corporation e Environmental Management Services (Firm), a cura di. Creosote-treated wood poles and crossarms: Toxicity characteristic leaching procedure (TCLP) results. Palo Alto, Calif: Electric Power Research Institute, 1992.

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Stocking, Michael A. Soil erosion in developing countries: Where geomorphology fears to tread!. Norwich: University of EastAnglia, School of Development Studies, 1993.

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Ltd, Intera Kenting, Canada Centre for Inland Waters., National Groundwater and Soil Remediation Program. e National Groundwater and Soil Remediation Program. Excavate and Treat Technical Sub-Committee., a cura di. Final report on current and innovative excavate and treat technologies for the remediation of contaminated soils. Burlington, ON: Burlington Environmental Technology Office, Canada Centre for Inland Waters, 1991.

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United States. Environmental Protection Agency. Office of Research and Development, a cura di. Land Remediation and Pollution Control Division: Science and technology to treat contaminated soils, sludges, and sediments. Washington, DC: U.S. Environmental Protection Agency, Office of Research and Development, 1998.

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Robert, Rogers. A concise account of North America: Containing a description of the several British colonies on that continent, including the islands of Newfoundland, Cape Breton, &c. as to their situation, extent, climate, soil, produce, rise, government, religion, present boundaries, and the number of inhabitants supposed to be in each : also of the interior, or westerly parts of the country, upon the rivers St. Laurence, the Mississipi, Christino, and the Great Lakes ... containing many useful and entertaining facts, never before treated of. Dublin: Printed for J. Milliken, ..., 1985.

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US GOVERNMENT. International narcotics control and United States foreign policy: A compilation of laws, treaties, executive documents, and related materials : report. Washington: U.S. G.P.O., 1994.

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Imlay, Gilbert. A topographical description of the western territory of North America: Containing a succinct account of its soil, climate, natural history, population, agriculture, manners, customs ... to which are added, the discovery, settlement, and present state of Kentucky, and an essay towards the topography and natural history of that important country by John Filson, to which is added, I. The adventures of Col. Daniel Boon ... II. The minutes of the Piankashaw council ... III. An account of the Indian nations inhabiting within the limits of the thirteen United States ... London: Printed for J. Debrett ..., 1986.

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Più fonti

Capitoli di libri sul tema "TREATED SOIL"

Velde, R. T., C. Guchte, M. R. B. Dillen e L. R. M. Poorter. "Bioassays to Assess Treated (Remediated) Sediments". In Soil & Environment, 393–402. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-2018-0_56.

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Gombert, Dirk. "Cesium Contaminated Soils: Can They Be Effectively Treated?" In Contaminated Soil ’95, 1217–18. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0421-0_82.

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Goetz, D., e A. N. H. Claussen. "Analysis Concerning Thermically, Physically-Chemically and Biologically Treated Contaminated Sites". In Contaminated Soil ’88, 535–37. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-2807-7_86.

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Holz, Constanze, Gunnar Meyenburg e Dietmar Goetz. "Prevention of Colliery Waste Material Acidification by Addition of Thermally Treated Soil Material". In Soil & Environment, 387–88. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0415-9_95.

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Hashmi, Muhammad Zaffar, Aatika Kanwal, Rabbia Murtaza, Sunbal Siddique, Xiaomei Su, Xianjin Tang e Muhammad Afzaal. "Arsenic in Untreated and Treated Manure: Sources, Biotransformation, and Environmental Risk in Application on Soils: A Review". In Soil Biology, 179–95. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-93671-0_12.

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Pham Ngoc, Thang, Behzad Fatahi e Hadi Khabbaz. "Impact of Liquid Whey Waste on Strength and Stiffness of Cement Treated Clay". In New Developments in Soil Characterization and Soil Stability, 1–10. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95756-2_1.

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Minz, Dror, Rachel Karyo e Zev Gerstl. "Effects of Treated Municipal Wastewater Irrigation on Soil Microbiology". In Treated Wastewater in Agriculture, 351–81. Oxford, UK: Wiley-Blackwell, 2010. http://dx.doi.org/10.1002/9781444328561.ch11.

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Rohweder, U. "The Hamburg Utilization Concept for Excavated or Treated Soil, Residual Materials and Recycled Building Materials". In Soil & Environment, 977–78. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-2018-0_185.

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Meyenburg, G., C. Holz e D. Goetz. "Suitability of thermally treated soil material for the treatment of waters contaminated with heavy metals". In Contaminated Soil ’95, 1303–4. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0421-0_124.

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Anandha Kumar, S., e Evangelin Ramani Sujatha. "Compaction and Permeability Characteristics of Biopolymer-Treated Soil". In Lecture Notes in Civil Engineering, 107–17. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5101-7_11.

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Atti di convegni sul tema "TREATED SOIL"

Lapointe, Emilie, Jonathan Fannin e Brian W. Wilson. "Cement-Treated Soil: Variation of UCS with Soil Type". In Proceedings of the Fourth International Conference on Grouting and Deep Mixing. Reston, VA: American Society of Civil Engineers, 2012. http://dx.doi.org/10.1061/9780784412350.0037.

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Almajed, Abdullah, Hamed Khodadadi e Edward Kavazanjian. "Sisal Fiber Reinforcement of EICP-Treated Soil". In IFCEE 2018. Reston, VA: American Society of Civil Engineers, 2018. http://dx.doi.org/10.1061/9780784481592.004.

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Vydehi, K. Venkata, Arif Ali Baig Moghal e Romana Mariyam Rasheed. "Shrinkage Characteristics of Biopolymer Treated Expansive Soil". In Geo-Congress 2022. Reston, VA: American Society of Civil Engineers, 2022. http://dx.doi.org/10.1061/9780784484012.009.

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Emery, Tenli W., Robert J. Stevens, Jashod Roy, Estefania Flores e W. Spencer Guthrie. "Soil-Water Characteristic Curves for Clayey Soil Treated with Cement or Lime". In 2020 Intermountain Engineering, Technology and Computing (IETC). IEEE, 2020. http://dx.doi.org/10.1109/ietc47856.2020.9249212.

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Osinubi, K. J., e A. A. Amadi. "Variations in Soil Water Characteristic Curves of Lateritic Soil Treated with Bentonite". In GeoShanghai International Conference 2010. Reston, VA: American Society of Civil Engineers, 2010. http://dx.doi.org/10.1061/41103(376)12.

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Hoyos, L. R., H. R. Thudi e A. J. Puppala. "Soil-Water Retention Properties of Cement Treated Clay". In Geo-Denver 2007. Reston, VA: American Society of Civil Engineers, 2007. http://dx.doi.org/10.1061/40906(225)4.

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Bhatia, Sudha, Reshmi S. Nair e Ved Prakash Mishra. "Nutrient Analysis of Soil Samples Treated with Agrochemicals". In 2021 International Conference on Computational Intelligence and Knowledge Economy (ICCIKE). IEEE, 2021. http://dx.doi.org/10.1109/iccike51210.2021.9410729.

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Wagner Walker de Albuquerque Alves, Carlos Alberto Vieira de Azevedo, José Dantas Neto e José Tavares de Souza. "Fertirrigation with Treated Wastewater: Effect on Soil Fertility". In 2007 Minneapolis, Minnesota, June 17-20, 2007. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2007. http://dx.doi.org/10.13031/2013.24068.

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Liu, Shihui, e Lin Li. "Performance of MICP-Treated Soil against Environmental Deterioration". In Geo-Congress 2023. Reston, VA: American Society of Civil Engineers, 2023. http://dx.doi.org/10.1061/9780784484661.016.

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Shankar, A. U. Ravi, Shivashankar R e N. Sachith Pai. "Load Deformation Behavior of Coir Mat Treated Soil". In International Conference on Ground Improvement & Ground Control. Singapore: Research Publishing Services, 2012. http://dx.doi.org/10.3850/978-981-07-3560-9_09-0908.

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Rapporti di organizzazioni sul tema "TREATED SOIL"

Shivakumar, Pranavkumar, Kanika Gupta, Antonio Bobet, Boonam Shin e Peter J. Becker. Estimating Strength from Stiffness for Chemically Treated Soils. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317383.

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The central theme of this study is to identify strength-stiffness correlations for chemically treated subgrade soils in Indiana. This was done by conducting Unconfined Compression (UC) Tests and Resilient Modulus Tests for soils collected at three different sites—US-31, SR-37, and I-65. At each site, soil samples were obtained from 11 locations at 30 ft spacing. The soils were treated in the laboratory with cement, using the same proportions used for construction, and cured for 7 and 28 days before testing. Results from the UC tests were compared with the resilient modulus results that were available. No direct correlation was found between resilient modulus and UCS parameters for the soils investigated in this study. A brief statistical analysis of the results was conducted, and a simple linear regression model involving the soil characteristics (plasticity index, optimum moisture content and maximum dry density) along with UCS and resilient modulus parameters was proposed.

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Minz, Dror, Stefan J. Green, Noa Sela, Yitzhak Hadar, Janet Jansson e Steven Lindow. Soil and rhizosphere microbiome response to treated waste water irrigation. United States Department of Agriculture, gennaio 2013. http://dx.doi.org/10.32747/2013.7598153.bard.

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Research objectives : Identify genetic potential and community structure of soil and rhizosphere microbial community structure as affected by treated wastewater (TWW) irrigation. This objective was achieved through the examination soil and rhizosphere microbial communities of plants irrigated with fresh water (FW) and TWW. Genomic DNA extracted from soil and rhizosphere samples (Minz laboratory) was processed for DNA-based shotgun metagenome sequencing (Green laboratory). High-throughput bioinformatics was performed to compare both taxonomic and functional gene (and pathway) differences between sample types (treatment and location). Identify metabolic pathways induced or repressed by TWW irrigation. To accomplish this objective, shotgun metatranscriptome (RNA-based) sequencing was performed. Expressed genes and pathways were compared to identify significantly differentially expressed features between rhizosphere communities of plants irrigated with FW and TWW. Identify microbial gene functions and pathways affected by TWW irrigation*. To accomplish this objective, we will perform a metaproteome comparison between rhizosphere communities of plants irrigated with FW and TWW and selected soil microbial activities. Integration and evaluation of microbial community function in relation to its structure and genetic potential, and to infer the in situ physiology and function of microbial communities in soil and rhizospere under FW and TWW irrigation regimes. This objective is ongoing due to the need for extensive bioinformatics analysis. As a result of the capabilities of the new PI, we have also been characterizing the transcriptome of the plant roots as affected by the TWW irrigation and comparing the function of the plants to that of the microbiome. *This original objective was not achieved in the course of this study due to technical issues, especially the need to replace the American PIs during the project. However, the fact we were able to analyze more than one plant system as a result of the abilities of the new American PI strengthened the power of the conclusions derived from studies for the 1ˢᵗ and 2ⁿᵈ objectives. Background: As the world population grows, more urban waste is discharged to the environment, and fresh water sources are being polluted. Developing and industrial countries are increasing the use of wastewater and treated wastewater (TWW) for agriculture practice, thus turning the waste product into a valuable resource. Wastewater supplies a year- round reliable source of nutrient-rich water. Despite continuing enhancements in TWW quality, TWW irrigation can still result in unexplained and undesirable effects on crops. In part, these undesirable effects may be attributed to, among other factors, to the effects of TWW on the plant microbiome. Previous studies, including our own, have presented the TWW effect on soil microbial activity and community composition. To the best of our knowledge, however, no comprehensive study yet has been conducted on the microbial population associated BARD Report - Project 4662 Page 2 of 16 BARD Report - Project 4662 Page 3 of 16 with plant roots irrigated with TWW – a critical information gap. In this work, we characterize the effect of TWW irrigation on root-associated microbial community structure and function by using the most innovative tools available in analyzing bacterial community- a combination of microbial marker gene amplicon sequencing, microbial shotunmetagenomics (DNA-based total community and gene content characterization), microbial metatranscriptomics (RNA-based total community and gene content characterization), and plant host transcriptome response. At the core of this research, a mesocosm experiment was conducted to study and characterize the effect of TWW irrigation on tomato and lettuce plants. A focus of this study was on the plant roots, their associated microbial communities, and on the functional activities of plant root-associated microbial communities. We have found that TWW irrigation changes both the soil and root microbial community composition, and that the shift in the plant root microbiome associated with different irrigation was as significant as the changes caused by the plant host or soil type. The change in microbial community structure was accompanied by changes in the microbial community-wide functional potential (i.e., gene content of the entire microbial community, as determined through shotgun metagenome sequencing). The relative abundance of many genes was significantly different in TWW irrigated root microbiome relative to FW-irrigated root microbial communities. For example, the relative abundance of genes encoding for transporters increased in TWW-irrigated roots increased relative to FW-irrigated roots. Similarly, the relative abundance of genes linked to potassium efflux, respiratory systems and nitrogen metabolism were elevated in TWW irrigated roots when compared to FW-irrigated roots. The increased relative abundance of denitrifying genes in TWW systems relative FW systems, suggests that TWW-irrigated roots are more anaerobic compare to FW irrigated root. These gene functional data are consistent with geochemical measurements made from these systems. Specifically, the TWW irrigated soils had higher pH, total organic compound (TOC), sodium, potassium and electric conductivity values in comparison to FW soils. Thus, the root microbiome genetic functional potential can be correlated with pH, TOC and EC values and these factors must take part in the shaping the root microbiome. The expressed functions, as found by the metatranscriptome analysis, revealed many genes that increase in TWW-irrigated plant root microbial population relative to those in the FW-irrigated plants. The most substantial (and significant) were sodium-proton antiporters and Na(+)-translocatingNADH-quinoneoxidoreductase (NQR). The latter protein uses the cell respiratory machinery to harness redox force and convert the energy for efflux of sodium. As the roots and their microbiomes are exposed to the same environmental conditions, it was previously hypothesized that understanding the soil and rhizospheremicrobiome response will shed light on natural processes in these niches. This study demonstrate how newly available tools can better define complex processes and their downstream consequences, such as irrigation with water from different qualities, and to identify primary cues sensed by the plant host irrigated with TWW. From an agricultural perspective, many common practices are complicated processes with many ‘moving parts’, and are hard to characterize and predict. Multiple edaphic and microbial factors are involved, and these can react to many environmental cues. These complex systems are in turn affected by plant growth and exudation, and associated features such as irrigation, fertilization and use of pesticides. However, the combination of shotgun metagenomics, microbial shotgun metatranscriptomics, plant transcriptomics, and physical measurement of soil characteristics provides a mechanism for integrating data from highly complex agricultural systems to eventually provide for plant physiological response prediction and monitoring. BARD Report

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Shenker, Moshe, Paul R. Bloom, Abraham Shaviv, Adina Paytan, Barbara J. Cade-Menun, Yona Chen e Jorge Tarchitzky. Fate of Phosphorus Originated from Treated Wastewater and Biosolids in Soils: Speciation, Transport, and Accumulation. United States Department of Agriculture, giugno 2011. http://dx.doi.org/10.32747/2011.7697103.bard.

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Beneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levelsBeneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levels that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction.

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Chefetz, Benny, e Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7592117.bard.

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Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.

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Terry Brown, Jeffrey Morris, Patrick Richards e Joel Mason. Effects of Irrigating with Treated Oil and Gas Product Water on Crop Biomass and Soil Permeability. Office of Scientific and Technical Information (OSTI), settembre 2010. http://dx.doi.org/10.2172/1007996.

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Graber, Ellen R., Linda S. Lee e M. Borisover. An Inquiry into the Phenomenon of Enhanced Transport of Pesticides Caused by Effluents. United States Department of Agriculture, luglio 1995. http://dx.doi.org/10.32747/1995.7570559.bard.

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The objective of this collaborative research project was to determine the factors that may cause enhanced pesticide transport under effluent irrigation. For s-triazines, the potential for enhanced transport through association with effluent dissolved organic matter (OM) was shown to be small in batch and column studies and in numerical simulations. High alkalinity and pH of treated effluents increased soil-solution pH for selected soil-effluent combinations, promoting the dissolution of soil OM and mobilizing otherwise OM-retained pesticides. Evapotranspiration in column studies resulted in increased pore-water concentrations of dissolved OM and some pesticide transport enhancement with the greatest effect observed with OM-poor soils. For ionogenic pesticides, effluent-induced increases in soil-solution pH increased the mobility of pesticides with acid dissociation constants within 2 pH units of the initial soil-solution pH. Effluents high in suspended solids and/or monovalent cations resulted in blockage of soil pores reducing water-flow velocity and/or changing flow paths. Reduced flow resulted in an increase in desorption time of soil sorbed pesticides, increasing the amount available for further transport with the net effect being soil texture dependent. In terms of pesticide degradation in soils, effluents appeared to have only a minor effect for the few pesticides investigated.

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Avnimelech, Yoram, Richard C. Stehouwer e Jon Chorover. Use of Composted Waste Materials for Enhanced Ca Migration and Exchange in Sodic Soils and Acidic Minespoils. United States Department of Agriculture, giugno 2001. http://dx.doi.org/10.32747/2001.7575291.bard.

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Restoration of degraded lands and the development of beneficial uses for waste products are important challenges facing our society. In addition there is a need to find useful and environmentally friendly applications for the organic fractions of municipal and other solid waste. Recent studies have shown that composted wastes combined with gypsum or gypsum-containing flue gas desulfurization by-products enhance restoration of sodic soils and acidic minespoils. The mechanism by which this synergistic effect occurs in systems at opposite pH extremes appears to involve enhanced Ca migration and exchange. Our original research objectives were to (1) identify and quantify the active compost components involved in Ca transport, (2) determine the relative affinity of the compost components for Ca and competing metals in the two soil/spoil systems, (3) determine the efficacy of the compost components in Ca transport to subjacent soil and subsequent exchange with native soil cations, and (4) assess the impacts of compost enhanced Ca transport on soil properties and plant growth. Acidic mine spoils: During the course of the project the focus for objective (1) and (2) shifted more towards developing and evaluating methods to appropriately quantify Ca2+ and Al3+ binding to compost derived dissolved organic matter (DOM). It could be shown that calcium complexation by sewage sludge compost derived DOM did not significantly change during the composting process. A method for studying Al3+ binding to DOM was successfully developed and should allow future insight into DOM-Al3+ interactions in general. Laboratory column experiments as well as greenhouse experiments showed that in very acidic mine spoil material mineral dissolution controls solution Al3+ concentration as opposed to exchange with Ca2+. Therefore compost appeared to have no effect on Al3+ and Ca2+ mobility and did not affect subsoil acidity. Sodic alkaline soils: Batch experiments with Na+ saturated cation exchange resins as a model for sodic soils showed that compost home cations exchanged readily with Na+. Unlike filtered compost extracts, unfiltered compost suspensions also significantly increased Ca2+ release from CaCO3. Soil lysimeter experiments demonstrated a clear impact of compost on structural improvement in sodic alkaline soils. Young compost had faster, clearer and longer lasting effects on soil physical and chemical properties than mature compost. Even after 2 growing seasons differences could still be observed. Compost increased Ca2+ concentration in soil solution and solubility of pedogenic CaCO3 that is highly insoluble under alkaline conditions. The solubilized Ca2+ efficiently exchanged Na+ in the compost treated soils and thus greatly improved the soil structure.

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Gillor, Osnat, Stefan Wuertz, Karen Shapiro, Nirit Bernstein, Woutrina Miller, Patricia Conrad e Moshe Herzberg. Science-Based Monitoring for Produce Safety: Comparing Indicators and Pathogens in Water, Soil, and Crops. United States Department of Agriculture, maggio 2013. http://dx.doi.org/10.32747/2013.7613884.bard.

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Using treated wastewater (TWW) for crop irrigation represents an important opportunity for ensuring adequate food production in light of growing freshwater scarcity worldwide. However, the environmentally sustainable approach of using TWW for irrigation can lead to contamination of produce with fecal pathogens that may remain in treated water. The overall goal of this research was to evaluate the correlation between the presence of fecal indicator bacteria (FIB) and that of a suite of human pathogens in TWW, the irrigated soil, and crops. Field experiments were conducted to compare secondary and tertiary TWW with dechlorinated tap water for irrigation of tomatoes, a typical commercial crop, in Israel, a semi-arid country. Human pathogens including bacteria (Salmonella), protozoa (Cryptosporidiumand Giardia), and viruses (Adenovirus [AV Types A, B, C & 40/41] and Enterovirus [EV71 subtypes]) were monitored in two field trials using a combination of microscopic, cultivation-based, and molecular (qPCR) techniques. Results from the field trials indicate that microbial contamination on the surface of tomatoes did not appear to be associated with the source of irrigated waters; FIB contamination was not statistically different on tomatoes irrigated with TWW as compared to tomatoes irrigated with potable water. In fact, Indicator bacteria testing did not predict the presence of pathogens in any of the matrices tested. High concentrations of FIB were detected in water and on tomato surfaces from all irrigation treatment schemes, while pathogen contamination on tomato surfaces (Cryptosporidiumand Salmonella) was only detected on crops irrigated with TWW. These results suggest that regular monitoring for pathogens should take place to accurately detect presence of harmful microorganisms that could threaten consumer safety. A notable result from our study is that the large numbers of FIB in the water did not appear to lead to FIB accumulation in the soil. With the exception of two samples, E. coli that was present at 10³ to 10⁴ cells/100 mL in the water, was not detected in the soil. Other bacterial targets associated with the enteric environment (e. g., Proteusspp.) as well as protozoal pathogens were detected in the TWW, but not in the soil. These findings suggest that significant microbial transfer to the soil from TWW did not occur in this study. The pattern of FIB contamination on the surfaces of tomatoes was the same for all treatment types, and showed a temporal effect with more contamination detected as the duration of the field trial increased. An important observation revealed that water quality dramatically deteriorated between the time of its release from the wastewater treatment plant and the time it was utilized for irrigation, highlighting the importance of performing water quality testing throughout the growing season at the cultivation site.

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Shillito, Rose, Markus Berli e Teamrat Ghezzehei. Quantifying the effect of subcritical water repellency on sorptivity : a physically based model. Engineer Research and Development Center (U.S.), luglio 2021. http://dx.doi.org/10.21079/11681/41054.

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Abstract (sommario):

Soil water wettability or water repellency is a phenomenon that can affect infiltration and, ultimately, runoff. Thus, there is a need to develop a model that can quantitatively capture the influence of water repellency on infiltration in a physically meaningful way and within the framework of existing infiltration theory. The analytical model developed in this study relates soil sorptivity (an infiltration parameter) with contact angle (a direct measure of water repellency) for variably saturated media. The model was validated with laboratory experiments using a silica sand of known properties treated to produce controlled degrees of water repellency. The measured contact angle and sorptivity values closely matched the model‐predicted values. Further, the relationship between the frequently used water drop penetration time test (used to assess water repellency) and sorptivity was illustrated. Finally, the direct impact of water repellency on saturated hydraulic conductivity was investigated due to its role in infiltration equations and to shed light on inconsistent field observations. It was found that water repellency had minimal effect on the saturated hydraulic conductivity of structureless sand. A quantitative model for infiltration incorporating the effect of water repellency is particularly important for post‐fire hydrologic modeling of burned areas exhibiting water repellent soils.

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