Journal articles: 'Acidic waters'

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Baldisserotto, Bernardo, Carlos Eduardo Copatti, Levy Carvalho Gomes, Edsandra Campos Chagas, Richard Philip Brinn, and Rodrigo Roubach. "Calcium fluxes in Hoplosternum littorale (tamoatá) exposed to different types of Amazonian waters." Neotropical Ichthyology 7, no. 3 (September 4, 2009): 465–70. http://dx.doi.org/10.1590/s1679-62252009005000002.

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Fishes that live in the Amazonian environment may be exposed to several kinds of waters: "black waters", containing high dissolved organic carbon and acidic pH, "white waters", with ten fold higher Ca2+ concentrations than black waters and neutral pH, and "clear waters", with two fold higher Ca2+ concentrations than black waters and also neutral pH. Therefore, the aim of the present study was to analyze Ca2+ fluxes in the facultative air-breather Hoplosternum littorale (tamoatá) exposed to different Amazonian waters. Fishes were acclimated in well water (similar to clear water) and later placed in individual chambers for Ca2+ fluxes measurements. After 4 h, water from the chambers was replaced by a different type of water. Transfer of tamoatás to ion-poor black or acidic black water resulted in net Ca2+ loss only in the first 2 h of experiment. However, transfer from black or acidic black water to white water led to only net Ca2+ influxes. The results obtained allowed us to conclude that transfer of tamoatás to ion-poor waters (black and acidic black water) led to transient net Ca2+ loss, while the amount of Ca2+ in the ion-rich white water seems adequate to prevent Ca2+ loss after transfer. Therefore, transfer of tamoatás between these Amazonian waters does not seem to result in serious Ca2+ disturbance.

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Nordstrom, D. K. "Mine Waters: Acidic to Circmneutral." Elements 7, no. 6 (December 1, 2011): 393–98. http://dx.doi.org/10.2113/gselements.7.6.393.

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Simonin, Howard A. "ES Views: Neutralization of acidic waters." Environmental Science & Technology 22, no. 10 (October 1988): 1143–45. http://dx.doi.org/10.1021/es00175a600.

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Johnson, D. Barrie, and Kevin B. Hallberg. "The microbiology of acidic mine waters." Research in Microbiology 154, no. 7 (September 2003): 466–73. http://dx.doi.org/10.1016/s0923-2508(03)00114-1.

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Zamana, L. V. "Mineral waters and sediments of the ferruginous spring Ulan-Bulak Urulyunguevsky (South-Eastern Transbaikalia, Russia)." IOP Conference Series: Earth and Environmental Science 962, no. 1 (January 1, 2022): 012063. http://dx.doi.org/10.1088/1755-1315/962/1/012063.

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Abstract The data on the chemical composition and content of balneological components (Fe, H2SiO3, CO2, S2-) for three water samples from the Ulan-Bulak acidic ferruginous spring are presented. For the first time, carbonic water was released in the composition of the spring waters, the origin of which is explained by the ingress of hydrocarbonate water into an acidic medium, followed by dissociation according to the HCO3 - + H+ → H2CO3 → H2O + CO2 scheme. An acidic environment is formed as a result of oxidation of sulfide mineralization, presumably gold-bearing. From secondary minerals at the spring, modern sulfate minerals (gypsum, jarosite), hydromica (illite) were found, ocher sediments are widely developed. Given the uncertain nature of the formation of the spring waters, it is considered worthy of special studies, including an inspection of the presence of sulfide mineralization.

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Brauner, C. J., C. L. Ballantyne, D. J. Randall, and A. L. Val. "Air breathing in the armoured catfish (Hoplosternum littorale) as an adaptation to hypoxic, acidic, and hydrogen sulphide rich waters." Canadian Journal of Zoology 73, no. 4 (April 1, 1995): 739–44. http://dx.doi.org/10.1139/z95-086.

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The armoured catfish (Hoplosternum littorale) from the Amazon River system is a facultative air breather that is tolerant to both acidic and hydrogen sulphide rich waters. Facultative air breathing in fishes is known to be an important strategy for surviving hypoxia, but its importance for surviving in acidic and hydrogen sulphide rich waters has not previously been investigated. Air-breathing frequency in H. littorale increased from 2 to 28 breaths/h as the partial pressure of oxygen [Formula: see text] in the water was reduced from 137 to 105 mmHg (1 mmHg = 133.322 Pa). Further reduction in [Formula: see text] to 55 mmHg resulted in a reduction in air-breathing frequency and depression of the metabolic rate. During exposure to acidic water (pH 2.8, [Formula: see text] = 155 mmHg), air-breathing frequency was 28 breaths/h, and during exposure to hydrogen sulphide in water buffered to pH 5.6 (700 μM, [Formula: see text] = 155 mmHg), air-breathing frequency was 40 breaths/h. In fish denied access to air, 200 μM hydrogen sulphide is lethal. Thus, in the armoured catfish, air breathing may be more important for surviving in hydrogen sulphide rich and acidic waters than for surviving in mild hypoxia.

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Simonescu, Claudia Maria, Daniela Cristina Culita, Virgil Marinescu, Christu Tardei, and Dorinel Talpeanu. "Hydroxyapatite Nanoparticles for Acidic Mine Waters Remediation." Revista de Chimie 70, no. 9 (October 15, 2019): 3167–75. http://dx.doi.org/10.37358/rc.19.9.7509.

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Mining activities have a high negative impact on the environment and on human health. Environmental impacts can result in contamination of surface water, groundwater, soil and air. Large volumes of wastewater produced by mining activities have to be remediated before being discharged into the environment. Due to the complex composition of wastewater coming from the mining industry and because their negative impacts, numerous remediation techniques have been applied. Adsorption is one of the most extensively used ways to remediate mining wastewater as a consequence of its low cost, easiness to be performed, and also due to the wide variety of materials (natural and synthetic) that can be use as adsorbents. Hydroxyapatite (HAP, Ca10(PO4)6(OH)2), a naturally occurring form of calcium phosphate has a good capacity to remove heavy metal ions from aqueous solutions due to its excellent properties. By preparing hydroxyapatite using different synthesis methods, its properties can be manipulated in order to increase the adsorption properties and reactivity. Herein, we reported synthesis of hydroxyapatite (HAP) samples using different synthesis conditions to establish the effect of synthesis conditions onto HAP properties. The HAP samples prepared have been characterized by the use of X-ray diffraction, FT-IR spectroscopy, specific surface measurements, Scanning Electron Microscopy (SEM). The stoichiometric compounds with high degree of crystallinity, low average particle diameter values, and low specific surface have been prepared by the solid state reaction and high calcination temepratures. The addition of surfactant (dispersant) has resulted in an increase in the specific surface area, which will result in an increase in the retention capacity of heavy metal ions in wastewater. The adsorbents prepared were used to remediate mine water. Results showed that non-calcinated HAP samples have a higher heavy metals adsorption capacity compared to HAP samples calcinated at 600 �C and 900 �C. The HAP samples prepared in presence of surfactant exhibit a higher heavy metals adsorption capacity than samples prepared in absence of surfactant. The values of the retention capacity differ depending on the nature of the metal ion: QMn(II) ] QFe(III) ] QZn(II) ] QPb(II) ] QNi(II). A change in the pH of mine water from 2.6 to 5.5 has occur that means that the metal ion retention mechanism goes through chemical reactions. The metal ions retention capacity suggests application of hydroxyapatite for remediation of mining wastewater.

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Nixdorf, B., A. Fyson, and H. Krumbeck. "Review: plant life in extremely acidic waters." Environmental and Experimental Botany 46, no. 3 (December 2001): 203–11. http://dx.doi.org/10.1016/s0098-8472(01)00104-6.

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9

Davies, T. D., M. Tranter, P. J. Wigington, and K. N. Eshleman. "‘Acidic episodes’ in surface waters in Europe." Journal of Hydrology 132, no. 1-4 (March 1992): 25–69. http://dx.doi.org/10.1016/0022-1694(92)90172-r.

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10

Leiva, Eduardo, Camila Tapia, and Carolina Rodríguez. "Highly Efficient Removal of Cu(II) Ions from Acidic Aqueous Solution Using ZnO Nanoparticles as Nano-Adsorbents." Water 13, no. 21 (October 20, 2021): 2960. http://dx.doi.org/10.3390/w13212960.

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Water pollution by heavy metals has significant effects on aquatic ecosystems. Copper is one of the heavy metals that can cause environmental pollution and toxic effects in natural waters. This encourages the development of better technological alternatives for the removal of this pollutant. This work explores the application of ZnO nanoparticles (ZnO-NPs) for the removal of Cu(II) ions from acidic waters. ZnO NPs were characterized and adsorption experiments were performed under different acidic pHs to evaluate the removal of Cu(II) ions with ZnO NPs. The ZnO NPs were chemically stable under acidic conditions. The adsorption capacity of ZnO NPs for Cu(II) was up to 47.5 and 40.2 mg·g−1 at pH 4.8 and pH 4.0, respectively. The results revealed that qmax (47.5 mg·g−1) and maximum removal efficiency of Cu(II) (98.4%) are achieved at pH = 4.8. In addition, the surface roughness of ZnO NPs decreases approximately 70% after adsorption of Cu(II) at pH 4. The Cu(II) adsorption behavior was more adequately explained by Temkin isotherm model. Additionally, adsorption kinetics were efficiently explained with the pseudo-second-order kinetic model. These results show that ZnO NPs can be an efficient alternative for the removal of Cu(II) from acidic waters and the adsorption process was more efficient under pH = 4.8. This study provides new information about the potential application of ZnO NPs as an effective adsorbent for the remediation and treatment of acidic waters contaminated with Cu(II).

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Holland, Aleicia, Leo J. Duivenvoorden, and Susan H. W. Kinnear. "Effect of key water quality variables on macroinvertebrate and fish communities within naturally acidic wallum streams." Marine and Freshwater Research 66, no. 1 (2015): 50. http://dx.doi.org/10.1071/mf13285.

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Adverse impacts of acidification on aquatic biota have been observed worldwide; however, most reports are based on fresh waters acidified by anthropogenic means. By contrast, naturally low pH values may not affect biota within naturally acidic fresh waters. This field study provides information on the water quality, macroinvertebrate and fish communities in little-studied, naturally acidic wallum streams in Central Queensland, Australia. Mid-range pH sites (pH 5–6) were compared with low pH sites (pH 5–3.8) to investigate the effect of pH and other key water quality variables on these communities. Field data indicated that pH had less of an effect in these systems in terms of biotic changes compared with other water quality variables, with dissolved oxygen (% saturation) identified as the key driver for changes in macroinvertebrate composition. Fish were present at all sites, including those with pH <4. Several possible explanations for this lack of pH effect are discussed. These results provide support for the reduced importance of acidity, relative to other water quality parameters, in naturally acidic waters. The work also provides baseline data on the biota of little-studied wallum streams.

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12

Servos, Mark R., Martha Smith, Rodney McInnis, B. Kent Burnison, Bill-H. Lee, Peter Seto, and Sean Backus. "The Presence of Selected Pharmaceuticals and the Antimicrobial Triclosan in Drinking Water in Ontario, Canada." Water Quality Research Journal 42, no. 2 (May 1, 2007): 130–37. http://dx.doi.org/10.2166/wqrj.2007.016.

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Abstract The presence of pharmaceuticals and personal care products in the environment is a rapidly emerging international issue. A variety of drugs have been found in sewage effluents and surface waters in Europe, the United States, and Canada. This study examines the presence of selected pharmaceuticals (8 acidic drugs) and the antimicrobial substance, triclosan, in raw water and finished water of drinking water plants across southern Ontario. Twenty drinking water treatment plants that represented a variety of water sources and treatment process parameters were sampled. None of the raw or finished water samples taken from wells showed detectable levels of any of the acidic drugs or triclosan. River water samples downstream of sewage effluent outfalls showed the highest levels of contamination of the source water. Levels of naproxen and ibuprofen were elevated to levels as high as 176 and 150 ng/L, respectively, in raw water entering the treatment plants from a river source. Low levels of gemfibrozil (19.2 ng/L), diclofenac (15 ng/L), indomethacin (6 ng/L), and the antimicrobial triclosan (34 ng/L) could be also detected in raw water from river sources. Raw water taken from large lakes also had very low but detectable levels of several acidic drugs, suggesting that these chemicals are widespread in the environment. Although treatment systems are not designed to remove these specific types of substances, most of the acidic drugs were not detectable in finished waters. Naproxen and triclosan were detectable in finished water but were significantly reduced in concentration relative to the raw water. The concentration of ibuprofen was detectable in the finished water of almost all treatment plants that used surface water as a source. This work demonstrates the potential of Ontario source waters, particularly river water sources, to contain trace levels of selected pharmaceuticals and personal care products. There is a need to complete a more comprehensive assessment of these compounds in source waters and of the factors influencing their treatment and removal from finished drinking water.

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13

Wright, Richard F., and Michael Hauhs. "Reversibility of acidification: soils and surface waters." Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 97 (1990): 169–91. http://dx.doi.org/10.1017/s0269727000005340.

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SynopsisAs empirical relationships between acidic deposition and its effects on soils and surface waters have become increasingly understood, the focus of attention has shifted to the reversal of acidification in response to decreased amounts of acidic deposition.Recent decreases in acidic deposition, in both North America and parts of Europe, have initiated the reversal of acidification and the recovery of impacted ecosystems. Reversal has also been investigated in large-scale experiments with whole ecosystems. Predictive models can account for much of this empirical and experimental data, at least at the catchment scale, over periods of years.Discrepancies between observed and predicted effects are attributable in part to the increasingly important role of nitrogen in soil and water acidification. ‘Nitrogen saturation’ threatens to offset the incipient recovery following decreases in SO2 emissions. Future climate change might further exacerbate the problem by increasing the rate of mineralisation of soil organic matter and releasing stored nitrogen.

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14

Nafliu, Ion Marius, Alexandra Raluca Grosu (Miron), Hussam Nadum Abdalraheem Al-Ani, Paul Constantin Albu, Gavril Gheorghievici, and Mihaela Emanuela Craciun. "Neutralization with Simultaneously Separation of Aluminum Ions from Condensate Water through Cellulose Derivatives-Capillary Polypropylene Composite Membranes." Materiale Plastice 56, no. 2 (June 30, 2019): 301–5. http://dx.doi.org/10.37358/mp.19.2.5175.

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Environmental problems that arise from acidic water containing aluminum generated from condensing thermal power plants can be suitably solved using membrane processes. In this paper, simultaneous neutralization with aluminum ion separation, from acidic waters containing aluminum traces, through permeation with polypropylene with inclusions of cellulose derivatives (PP / CellD)capillary composite membranes is approached. Cellulose derivatives considered are: acetylcellulose, carboxymethylcellulose, 2-hydroxyethyl cellulose, methyl 2 hydroxyethyl cellulose. The optimum working parameters for the best performance of composite membrane based on carboxymethylcellulose were determined: operating time and pH of the receiving phase. Simultaneously with the quantitative removal of the aluminum ions, it is obtained an almost neutral pH purified water, compatible with the natural waters in which it can be dispersed.

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Plankey, Brian J., Howard H. Patterson, and Christopher S. Cronan. "Kinetics of aluminum fluoride complexation in acidic waters." Environmental Science & Technology 20, no. 2 (February 1986): 160–65. http://dx.doi.org/10.1021/es00144a008.

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16

Schreiber, R. Kent. "Amelioration of Surface Waters Affected By Acidic Deposition." Restoration Ecology 4, no. 3 (September 1996): 203–5. http://dx.doi.org/10.1111/j.1526-100x.1996.tb00173.x.

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17

Ye, Tao, and Gerald H. Pollack. "Do aqueous solutions contain net charge?" PLOS ONE 17, no. 10 (October 27, 2022): e0275953. http://dx.doi.org/10.1371/journal.pone.0275953.

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Solutions with high pH values are sometimes thought to contain net negative charge because of an excess of OH- groups, while solutions with low pH values are thought opposite. To follow up on these speculations, we used a simple electrochemical cell to study three types of solution: electrolyzed waters with differing pH values; acids and bases with different pH values; and various salt solutions. When electrolyzed waters of various pH values were tested against water of pH 7, we found that acidic waters were indeed positively charged, while basic waters were negatively charged. We found much the same when standard acids and bases were compared to reference solutions: acidic solutions were positively charged while basic solutions were negatively charged. Various salts, including NaCl, KCl, Na2SO4, and K2SO4, were also tested against DI water (containing trace amounts of NaCl to lend conductivity). Surprisingly, all salts were found to be negatively charged, more so as their concentrations increased. This collection of results supports the hypothesis that at least some aqueous solutions may contain net charge.

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Abril, G., S. Bouillon, F. Darchambeau, C. R. Teodoru, T. R. Marwick, F. Tamooh, F. Ochieng Omengo, et al. "Technical Note: Large overestimation of pCO2 calculated from pH and alkalinity in acidic, organic-rich freshwaters." Biogeosciences 12, no. 1 (January 6, 2015): 67–78. http://dx.doi.org/10.5194/bg-12-67-2015.

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Abstract. Inland waters have been recognized as a significant source of carbon dioxide (CO2) to the atmosphere at the global scale. Fluxes of CO2 between aquatic systems and the atmosphere are calculated from the gas transfer velocity and the water–air gradient of the partial pressure of CO2 (pCO2). Currently, direct measurements of water pCO2 remain scarce in freshwaters, and most published pCO2 data are calculated from temperature, pH and total alkalinity (TA). Here, we compare calculated (pH and TA) and measured (equilibrator and headspace) water pCO2 in a large array of temperate and tropical freshwaters. The 761 data points cover a wide range of values for TA (0 to 14 200 μmol L−1), pH (3.94 to 9.17), measured pCO2 (36 to 23 000 ppmv), and dissolved organic carbon (DOC) (29 to 3970 μmol L−1). Calculated pCO2 were >10% higher than measured pCO2 in 60% of the samples (with a median overestimation of calculated pCO2 compared to measured pCO2 of 2560 ppmv) and were >100% higher in the 25% most organic-rich and acidic samples (with a median overestimation of 9080 ppmv). We suggest these large overestimations of calculated pCO2 with respect to measured pCO2 are due to the combination of two cumulative effects: (1) a more significant contribution of organic acids anions to TA in waters with low carbonate alkalinity and high DOC concentrations; (2) a lower buffering capacity of the carbonate system at low pH, which increases the sensitivity of calculated pCO2 to TA in acidic and organic-rich waters. No empirical relationship could be derived from our data set in order to correct calculated pCO2 for this bias. Owing to the widespread distribution of acidic, organic-rich freshwaters, we conclude that regional and global estimates of CO2 outgassing from freshwaters based on pH and TA data only are most likely overestimated, although the magnitude of the overestimation needs further quantitative analysis. Direct measurements of pCO2 are recommended in inland waters in general, and in particular in acidic, poorly buffered freshwaters.

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Isgró, Melisa A., M. Dolores Basallote, Isabel Caballero, and Luis Barbero. "Comparison of UAS and Sentinel-2 Multispectral Imagery for Water Quality Monitoring: A Case Study for Acid Mine Drainage Affected Areas (SW Spain)." Remote Sensing 14, no. 16 (August 19, 2022): 4053. http://dx.doi.org/10.3390/rs14164053.

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Uncrewed Aerial Systems (UAS) and satellites are used for monitoring and assessing the quality of surface waters. Combining both sensors in a joint tool may scale local water quality retrieval models to regional and global scales by translating UAS-based models to satellite imagery. The main objective of this study is to examine whether Sentinel-2 (S2) data can complement UAS data, specifically from the MicaSense RedEdge MX-Dual sensor, for inland water quality monitoring in mining environments affected by acid mine drainage (AMD). For this purpose, a comparison between UAS reflectance maps and atmospherically corrected S2 imagery was performed. S2 data were processed with Case 2 Regional Coast Colour (C2RCC) and Case 2 Regional Coast Colour for Complex waters (C2X) atmospheric correction (AC) processors. The correlation between the UAS data and the atmospherically corrected S2 data was evaluated on a band-by-band and a pixel-by-pixel basis, and the compatibility of the spectral data was analyzed through statistical methods. The results showed C2RCC and C2X performed better for acidic greenish-blue and non-acidic greenish-brown water bodies concerning the UAS data than for acidic dark reddish-brown waters. However, significant differences in reflectance between the UAS sensor and both S2 AC processors have been detected. The poor agreement between sensors should be considered when combining data from both instruments since these could have further consequences in developing multi-scale models.

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20

Driscoll, C. T. "Aluminum in acidic surface waters: chemistry, transport, and effects." Environmental Health Perspectives 63 (November 1985): 93–104. http://dx.doi.org/10.1289/ehp.856393.

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Hallberg, Kevin B., and D. Barrie Johnson. "Novel acidophiles isolated from moderately acidic mine drainage waters." Hydrometallurgy 71, no. 1-2 (October 2003): 139–48. http://dx.doi.org/10.1016/s0304-386x(03)00150-6.

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Plankey, Brian J., and Howard H. Patterson. "Kinetics of aluminum-fulvic acid complexation in acidic waters." Environmental Science & Technology 21, no. 6 (June 1987): 595–601. http://dx.doi.org/10.1021/es00160a011.

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23

Dutkowsky, Donald, and Fredrick C. Menz. "A cost function for neutralizing acidic Adirondack surface waters." Journal of Environmental Economics and Management 12, no. 3 (September 1985): 277–85. http://dx.doi.org/10.1016/0095-0696(85)90035-x.

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24

Triantafyllidis, S., and N. Skarpelis. "GEOCHEMICAL INVESTIGATION AND MODELLING OF AN ACID PIT LAKE FROM A HIGH SULFIDATION ORE DEPOSIT: KIRKI, NE GREECE." Bulletin of the Geological Society of Greece 43, no. 5 (July 31, 2017): 2417. http://dx.doi.org/10.12681/bgsg.11642.

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Open pit mining of a high sulfidation epithermal type deposit at Kirki (Thrace, NE Greece) resulted in the formation of an acid pit lake by infilling of the open cast by rain and drainage waters after mine closure. The acidic and oxidative pit lake waters show high concentrations of trace metals largely due to the high toxic metals content of the ore, the limited buffering capacity of host rocks and the direct exposure of the ore zone to weathering. The floor of the pit lake is covered by a finegrained mineral precipitate that comprises mainly detrital minerals, originating from erosion of the rocks exposed on the walls of the open pit. Secondary anglesite, several species of the jarosite-group, rozenite, melanterite, gypsum, bukovskyite, beaverite, scorodite and minor goethite are also detected. The mineral precipitate presents significant heavy metal content indicating effective removal of metals from the acidic waters. The speciation/mass transfer computer code PHREEQC-2 and the MINTEQ database were employed for geochemical modelling of the equilibrium between the acidic pit lake waters and the secondary phases of the mineral precipitate.

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Stout, Ben M. "Practical Guide to Managing Acidic Waters and Their Fisheries. Robert W. Brocksen , Michael D. Marcus , Harvey OlemLiming Acidic Surface Waters. Harvey Olem." Journal of the North American Benthological Society 12, no. 1 (March 1993): 107. http://dx.doi.org/10.2307/1467697.

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Abril, G., S. Bouillon, F. Darchambeau, C. R. Teodoru, T. R. Marwick, F. Tamooh, F. O. Omengo, et al. "Technical Note: Large overestimation of pCO2 calculated from pH and alkalinity in acidic, organic-rich freshwaters." Biogeosciences Discussions 11, no. 7 (July 31, 2014): 11701–25. http://dx.doi.org/10.5194/bgd-11-11701-2014.

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Abstract. Inland waters have been recognized as a~significant source of carbon dioxide (CO2) to the atmosphere at the global scale. Fluxes of CO2 between aquatic systems and the atmosphere are calculated from the gas transfer velocity and the water-air gradient of the partial pressure of CO2 (pCO2). Nowadays, direct measurements of water pCO2 remain scarce in freshwaters and most published pCO2 data are calculated from temperature, pH and total alkalinity (TA). Here, we compare calculated (pH and TA) and measured (Equilibrator and headspace) water pCO2 in a large array of temperate and tropical freshwaters. The 761 data points cover a wide range of values for TA (0 to 14.2 mmol L−1), pH (3.94 to 9.17), measured pCO2 (36 to 23 000 ppmv), and dissolved organic carbon (DOC) (29 to 3970 μmol L−1). Calculated pCO2 were > 10% higher than measured pCO2 in 60% of the samples (with a median overestimation of calculated pCO2 compared to measured pCO2 of 2560 ppmv) and were > 100% higher in the 25% most organic-rich and acidic samples (with a median overestimation of 9080 ppmv). We suggest these large overestimations of calculated pCO2 with respect to measured pCO2 are due to the combination of two cumulative effects: (1) a more significant contribution of organic acids anions to TA in waters with low carbonate alkalinity and high DOC concentrations; (2) a lower buffering capacity of the carbonate system at low pH, that increases the sensitivity of calculated pCO2 to TA in acidic and organic-rich waters. We recommend that regional studies on pCO2 should not be based on pH and TA data only, and that direct measurements of pCO2 should become the primary method in inland waters in general, and in particular in acidic, poorly buffered, freshwaters.

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Rosborg, Ingegerd, Lars Gerhardsson, and Bengt Nihlgård. "Mineral Element Concentrations in Vegetables Cultivated in Acidic Compared to Alkaline Areas of South Sweden." Air, Soil and Water Research 2 (January 2009): ASWR.S1004. http://dx.doi.org/10.4137/aswr.s1004.

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A study in 1997, on mineral levels in acidic compared to alkaline well waters, and in women's hair, revealed higher concentrations of a number of mineral elements like Ca, Mo and Se in alkaline waters and hair. Thus, median Ca levels were six times higher in well water and five times higher in hair from the alkaline area compared to the acidic area. This finding raised the probability of similar differences in vegetables from these areas. Thus, in the year 2006, 60 women who had participated in the study in 1997 were asked to cultivate parsley, lettuce, carrot and chive. During the spring of 2006, the women from the water and hair study of 1997, 30 of them from the acidic area and 30 women from the alkaline district cultivated vegetables: carrot (Daucus carota L), parsley (Petroselinum crispum), chive (Allium schoenoprasum) and lettuce (Eruca sativa). The vegetables were harvested, and rinsed in tap water from the kitchens of the participating women in August. The concentrations of about 35 elements and ions were determined by ICP OES and ICP-MS predominantly. In addition, soil samples from the different cultivators were also analyzed for a number of elements. Lettuce and parsley showed the highest concentrations of mineral elements per gram dry weight. Only Mo concentrations were significantly higher in all the different vegetables from the alkaline district compared to vegetables from the acidic areas. On the other hand, the concentrations of Ba, Br, Mn, Rb and Zn were higher in all the different vegetables from the acidic area. In the soil, only pH and exchangeable Ca from the alkaline area were higher than from the acidic area, while exchangeable Fe, Mn and Na concentrations were higher in soils from the acidic area. Soil elements like Al, Fe, Li, Ni, Pb, Si, Ti, V, Zn and Zr were found in higher concentrations in lettuce and parsley, which were attributed to soil particles being splashed on the plants by the rain and absorbed by the leaves. Strong correlations appeared between Ca and Sr in all the vegetables, except for carrot. No strong correlations were found between soil elements and vegetable elements, except for soil Mn and carrot/lettuce Mn. The differences in mineral levels in both, vegetables and soils were however small, compared to differences in well waters and hair. It was also suggested that the garden soils on limestone bedrock had been drained of minerals and thereby, the soil had an acidic pH. The contribution of mineral elements to daily intake in humans was considered minor from the analysed vegetables, except for some samples of lettuce that should give significant contributions of Ca, Zn, Mn and Mo. The main conclusion is that, differences in water and hair mineral levels between the two areas in the earlier study (1997) were not mirrored in vegetables cultivated in 2006. Principally, this suggests that, for humans the mineral intake of some elements from water may be more important than from vegetables.

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Bradford, David F., Scott D. Cooper, Thomas M. Jenkins, Jr., Kim Kratz, Orlando Sarnelle, and Aaron D. Brown. "Influences of natural acidity and introduced fish on faunal assemblages in California alpine lakes." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 11 (November 1, 1998): 2478–91. http://dx.doi.org/10.1139/f98-128.

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In an alpine area of the Sierra Nevada of California, naturally acidic waters and introduced fishes both strongly affect the distributions of native amphibians, zooplankton, and macroinvertebrates. The study area in Kings Canyon National Park contains 104 lakes with pH values between 5.0 and 9.3, including 10 lakes with pH < 6.0 (defined here as acidic lakes) and 18 lakes with introduced trout. We surveyed 33 of these lakes (8 acidic, 7 non-acidic with trout, 18 non-acidic without trout) for water chemistry and faunal assemblages. Yellow-legged frog tadpoles (Rana muscosa), common microcrustaceans (Daphnia, Hesperodiaptomus, Diaptomus), and larvae of a caddisfly (Hesperophylax) were rare or absent in acidic lakes but common in non-acidic lakes, and microcrustacean and macroinvertebrate species richness decreased with decreasing pH. Large and (or) mobile, conspicuous taxa, including tadpoles, large-bodied microcrustaceans (Hesperodiaptomus, Daphnia middendorffiana), and many epibenthic or limnetic macroinvertebrates (baetid and siphlonurid mayfly nymphs, notonectids, corixids, limnephilid caddis larvae, and dytiscid beetles), were rare or absent in trout lakes but were relatively common in lakes lacking trout, and the taxon richness of macroinvertebrates was reduced by trout.

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Abramova, V. A. "Rare Alkali Metals in the Waters of Lithium-containing Deposits in Eastern Transbaikalia." IOP Conference Series: Earth and Environmental Science 962, no. 1 (January 1, 2022): 012001. http://dx.doi.org/10.1088/1755-1315/962/1/012001.

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Abstract The results of hydrogeochemical studies on the content of rare alkaline elements in man-made waters of mining facilities at Zavitinskoye, Orlovskoye, and Etykinskoye rare metal deposits of Eastern Transbaikalia are presented. Concentrations of these elements are determined both by the content in the ores and rocks of deposits and by their water-migration properties. It was found that the acidic sub-basement waters of the Orlovskoye and the quarry waters of the Zavitinskoye deposits contain abnormally high concentrations of lithium, up to 3.74 and 3.88 mg / L, respectively. The high content of lithium (Li) in the waters of these deposits was determined relative to the average values for the waters of the hypergenesis zone, as well as the standards of maximum permissible concentrations (MPC) of chemicals for water bodies used for fisheries, drinking water, and other activities.

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Di Corcia, Antonio, Manuela Nazzari, Ramesh Rao, Roberto Samperi, and Eligio Sebastiani. "Simultaneous determination of acidic and non-acidic pesticides in natural waters by liquid chromatography–mass spectrometry." Journal of Chromatography A 878, no. 1 (May 2000): 87–98. http://dx.doi.org/10.1016/s0021-9673(00)00263-6.

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Nagafuchi, O., H. Kakimoto, S. Ebise, T. Inoue, and M. Koga. "Runoff of acidic substances that originated from atmospheric deposition on Yakushima Island, a world natural heritage site." Water Science and Technology 44, no. 7 (October 1, 2001): 57–62. http://dx.doi.org/10.2166/wst.2001.0389.

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In this paper we present monitoring data of stream waters that may reflect acidic impacts on the island as well as the rainwater qualities. The pH ranges of the river water in the Kawara streams in the western part of the island and the Yodogo stream in the central part of the island were 5.71-6.35 and 5.85-6.12 during 1992-1999, respectively. The concentrations of SO42− and NO3− in the river water were lower than those in the rainwater. Many differences were observed among the sampling sites. Higher concentrations of acid substances are found in the stream waters of the western area compared to the other areas. On the other hand, sulfuric acid is the major acid in the rainwater, snow and rime ice. No differences were observed in the ion constituents of the rainwater collected in the areas. These results suggested that the densely growing canopy may play a role in holding air pollutants, and acidic substances deposited on the canopy would be discharged as a through-fall and a stem flow. Furthermore, the water mass containing high ionic substances in the western area has been held in the groundwater layer, continuously supplying the stream waters during dry weather days. On the other hand, part of the basic runoff will be diluted with a surface runoff during the rainy days. As a result, the concentrations of the ionic substances in the stream waters during rainy days decreased.

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FABRIZIO, K. A., and C. N. CUTTER. "Stability of Electrolyzed Oxidizing Water and Its Efficacy against Cell Suspensions of Salmonella Typhimurium and Listeria monocytogenes." Journal of Food Protection 66, no. 8 (August 1, 2003): 1379–84. http://dx.doi.org/10.4315/0362-028x-66.8.1379.

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Electrolyzed oxidizing (EO) water has proved to be effective against foodborne pathogens attached to cutting boards and poultry surfaces and against spoilage organisms on vegetables; however, its levels of effectiveness against Listeria monocytogenes and Salmonella Typhimurium in cell suspensions have not been compared with those of other treatments. In this study, the oxidation reduction potentials (ORPs), chlorine concentrations, and pHs of acidic and basic EO water were monitored for 3 days at 4 and 25°C after generation. There were no differences between the pHs or ORPs of acidic and basic EO waters stored at 4 or 25°C. However, the free chlorine concentration in acidic EO water stored at 4°C increased after 24 h. In contrast, the free chlorine concentration in acidic EO water stored at 25°C decreased after one day. Cell suspensions of Salmonella Typhimurium and L. monocytogenes were treated with distilled water, chlorinated water (20 ppm), acidified chlorinated water (20 ppm, 4.5 pH), acidic EO water (EOA), basic EO water (EOB), or acidic EO water that was “aged” at 4°C for 24 h (AEOA) for up to 15 min at either 4 or 25°C. The largest reductions observed were those following treatments carried out at 25°C. EOA and AEOA treatments at both temperatures significantly reduced Salmonella Typhimurium populations by >8 log10 CFU/ml. EOA and AEOA treatments effectively reduced L. monocytogenes populations by >8 log10 CFU/ml at 25°C. These results demonstrate the stability of EO water under different conditions and that EO water effectively reduced Salmonella Typhimurium and L. monocytogenes populations in cell suspensions.

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NELSON, JAY A. "Critical Swimming Speeds of Yellow Perch Perca Flavescens: Comparison of Populations from a Naturally Acidic Lake and a Circumneutral Lake in Acid and Neutral Water." Journal of Experimental Biology 145, no. 1 (September 1, 1989): 239–54. http://dx.doi.org/10.1242/jeb.145.1.239.

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The objectives of this study were to determine if environmental acidity reduces swimming performance in the acid-tolerant yellow perch (Perca flavescens) and to use swimming performance as an indicator of fitness in testing whether fish from naturally acidic environments perform better in acidic water. Perch from a naturally acidic lake (pH4.4) or a nearby circumneutral lake were swum after either 5–7 months of laboratory acclimation to simulated soft, natural waters or after more than 2 years of acclimation to hard, circumneutral water. The performance test was a critical swimming speed (Ucrit) determination, with 5 cms−1 velocity increments at 30min intervals. Low environmental pH (4.0) produced significant decreases in average swimming performance in each of three experimental series. Acid decreased performance in most but not all fish. The two perch populations had similar mean Ucrit values when swimming in acid water. Pre-acclimation to hard water significantly increased swimming performance. Gravid females acclimated to acid water had very low critical swimming speeds in acid water, whereas Ucrit, changed little in acid water when oogenesis occurred in neutral water.

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Franzmann, P. D., J. J. Plumb, J. T. Wylie, W. J. Robertson, G. B. Douglas, T. P. Bastow, A. H. Kaksonen, and J. A. Puhakka. "Treatment of saline, acidic, metal-contaminated groundwater from the Western Australian Wheatbelt." Water Science and Technology 58, no. 12 (December 1, 2008): 2353–64. http://dx.doi.org/10.2166/wst.2008.582.

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Managing acidic, metal-containing saline ground and drainage waters in the Wheatbelt of Western Australia is an environmental and economic challenge. Sulfate-reducing fluidised bed bioreactors are shown to be technically capable of treating high salt, low pH, metal containing waters from the town of Narembeen in the Wheatbelt so as to reduce acidity and to remove most of the undesirable metal contaminants. The hydraulic residence time (HRT) limit for a stable process with groundwater from the region of Narembeen was >16 hours. The maximal rate of sulfate reduction in the laboratory system treating Narembeen groundwater was similar to rates observed in comparable applications of the process at other sites, ca. 3 g sulfate (L-reactor)−1 day−1. Salts that are relatively free of metal contaminants can be produced from water that has been treated by the sulfate-reducing fluidised bed bioreactor. It is unlikely that metal precipitates, captured from Wheatbelt waters by the process, would be of economic value. If sulfate-reducing fluidised bed reactors were considered technologically appropriate at larger scale, the decision to use them would be based on the necessity to take action, the comparative effectiveness of competing technologies, and the relative costs of competing technologies.

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Kvartenko, Oleksandr, Larysa Sabliy, Nataliya Kovalchuk, and Andriy Lysytsya. "The use of the biological method for treating iron containing underground waters." Journal of Water and Land Development 39, no. 1 (December 1, 2018): 77–82. http://dx.doi.org/10.2478/jwld-2018-0061.

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AbstractThe use of the biological method is promising for treating underground waters from iron compounds. Iron bacteria used in the process are widely spread in weak acidic and neutral underground waters containing iron ions (II), dissolved carbon dioxide and minimum concentrations of oxygen. The relevant direction of present-day biotechnology is the use of iron bacteria for treating underground waters. The goal of this research is to compare the efficiency of using the biological method for treating underground iron containing weak acidic and neutral waters under different conditions. As the test-objects, Gallionella and Lepthotrix iron bacteria were used. The sedimentation of bio-minerals was obtained from the washout waters of the biological deironing station. Calcium soda was used as an additional source of inorganic carbon for bacteria. As a result of the studies it is established that the use of the non-reagent method gives the possibility to achieve only 80% efficiency in removing iron compounds while the use of sodium carbonate results in increasing efficiency up to 93%. To determine the contribution of biological purification of ground water from iron compounds, the bacteria were inhibited with the preparation of polyhexamethylene guanidine (PHMG) chloride. It was found that inhibition of Gallionella and Lepthotrix led to the reduction of 50% of the iron removal effect. The mechanism was developed of inhibiting the process of iron bacteria metabolism by PHMG (polyhexamethylene guanidine). The new technology of arranging a block-module station for treating underground waters is proposed.

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Muraviev, D. "Conversion of pollutants to fertilisers: ion exchange synthesis of potassium sulphate from acidic mine waters." Water Science and Technology 48, no. 1 (July 1, 2003): 199–206. http://dx.doi.org/10.2166/wst.2003.0054.

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The paper reports the results obtained by the development of ion exchange synthesis of K2SO4 from the natural acidic mine waters (AMW) of Rio Tinto area (Huelva, Spain). The process flowsheet includes several sequential stages permitting production of potassium sulphate and desalinated water along with the recovery of four metals.

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Zharkov, R. V. "Thermal fields of the Ebeko volcano (Paramushir Island, Kuril Islands) and their recreational and tourist potential." Geosystems of Transition Zones 4, no. 4 (2020): 514–25. http://dx.doi.org/10.30730/gtrz.2020.4.4.514-525.

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The paper provides with the research results of physicochemical and balneological properties of thermal waters and hydrothermal mud of the Ebeko volcano (Paramushir Island, Kuril Islands). To assess recreational and tourist potential, we sample the most intensive thermal waters outputs. Ultra-acidic spring no. 1 of the Verkhne-Yuryeva group has a temperature of 88 °C, its mineralized (M – 13 g/l) chloride-sulfate waters contain biologically active elements in elevated concentrations (Si, B, Br, Fe2 +). Thermal waters of the Verkhne-Yuryeva springs can be roughly attributed to the Gaisky type of the acid water group and recommended for external use in the treatment and prevention of a wide range of diseases. Given the complexity of the route to the springs, the real development of this territory is considered not as a balneotherapy complex, but as an object of recreational and tourist activities. A similar situation is with an ultra-acidic sulfate thermal spring in the North-Eastern solfataric field. In addition to hydrotherms, it contains thin deposits of hydrothermal mud , which is almost impossible to use as a therapeutic due to its insufficiently good physical indicators and relatively small volume. The most promising deep hydrotherms for recreation and balneotherapy are opened by a well P-2 in the area of Severo-Kurilsk. In 2014, the hydrotherms temperature was 82 °C, mineralized water (M – 8.6 g/l) chloride-hydrocarbonate sodium, slightly alkaline (pH 7.6), with an elevated content of biologically active components (Si, B, Br). According to the physical and chemical properties, the thermal waters of well P-2 can be tentatively attributed to the Lazarevsky hydrochemical type of therapeutic drinking water of chloride-hydrocarbonate sodium group, and as an external (balneological) use, they are tentatively close to the Kuldur type of siliceous thermal waters of various ion composition.

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Wu, F. C., R. B. Mills, Y. R. Cai, R. D. Evans, and P. J. Dillon. "Photodegradation-induced changes in dissolved organic matter in acidic waters." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 5 (May 1, 2005): 1019–27. http://dx.doi.org/10.1139/f05-009.

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Photodegradation of dissolved organic matter (DOM) from stream waters was investigated using dissolved organic carbon (DOC) analysis, ultraviolet-visible absorbance, three-dimensional excitational emission matrix fluorescence, and high-performance size exclusion chromatography. The effects of altering pH and various iron concentrations on DOM characteristics during irradiation were examined. DOC concentration, absorbance, and fluorescence all decreased with increasing irradiation. These decreases were accompanied by a decrease in absorbance spectral slope and average molecular size and a blue-shift in fluorescence maximum; decreasing pH enhanced these changes. The photooxidation rate constants were wavelength dependent. For the ratio of the photooxidation rate constant at pH 4 to that at pH 8 under ultraviolet irradiation, there were two maxima at wavelengths of approximately 280 and 320 nm, respectively, indicating that aromatic fractions were most pH photosensitive. The isolated humic acid (HA) and fulvic acid (FA) fractions had different photodegradation characteristics in terms of the photooxidation rate constant and the effects of pH and iron. The results suggest that iron played a more significant role in the photodegradation of the HA fraction than that of the FA fraction and that the HA fraction was mainly responsible for the observed DOM photodegradation. The results indicate that DOM photodegradation in stream waters is strongly influenced by iron and acidity.

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Haywood, Lorren K. "Xenopus laevisembryos and tadpoles as biological indicators of acidic waters." African Journal of Herpetology 50, no. 2 (December 2001): 97–104. http://dx.doi.org/10.1080/21564574.2001.9635454.

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Goenaga, Xabier, Robert Bryant, and David J. A. Williams. "Influence of sorption processes on aluminum determinations in acidic waters." Analytical Chemistry 59, no. 22 (November 15, 1987): 2673–78. http://dx.doi.org/10.1021/ac00149a010.

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Kay, Catherine M., Anu Haanela, and D. Barrie Johnson. "Microorganisms in subterranean acidic waters within Europe's deepest metal mine." Research in Microbiology 165, no. 9 (November 2014): 705–12. http://dx.doi.org/10.1016/j.resmic.2014.07.007.

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Nancucheo, Ivan, José A. P. Bitencourt, Prafulla K. Sahoo, Joner Oliveira Alves, José O. Siqueira, and Guilherme Oliveira. "Recent Developments for Remediating Acidic Mine Waters Using Sulfidogenic Bacteria." BioMed Research International 2017 (2017): 1–17. http://dx.doi.org/10.1155/2017/7256582.

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Acidic mine drainage (AMD) is regarded as a pollutant and considered as potential source of valuable metals. With diminishing metal resources and ever-increasing demand on industry, recovering AMD metals is a sustainable initiative, despite facing major challenges. AMD refers to effluents draining from abandoned mines and mine wastes usually highly acidic that contain a variety of dissolved metals (Fe, Mn, Cu, Ni, and Zn) in much greater concentration than what is found in natural water bodies. There are numerous remediation treatments including chemical (lime treatment) or biological methods (aerobic wetlands and compost bioreactors) used for metal precipitation and removal from AMD. However, controlled biomineralization and selective recovering of metals using sulfidogenic bacteria are advantageous, reducing costs and environmental risks of sludge disposal. The increased understanding of the microbiology of acid-tolerant sulfidogenic bacteria will lead to the development of novel approaches to AMD treatment. We present and discuss several important recent approaches using low sulfidogenic bioreactors to both remediate and selectively recover metal sulfides from AMD. This work also highlights the efficiency and drawbacks of these types of treatments for metal recovery and points to future research for enhancing the use of novel acidophilic and acid-tolerant sulfidogenic microorganisms in AMD treatment.

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Rufo, Lourdes, Nuria Rodríguez, and Vicenta de la Fuente. "Plant communities of extreme acidic waters: The Rio Tinto case." Aquatic Botany 95, no. 2 (August 2011): 129–39. http://dx.doi.org/10.1016/j.aquabot.2011.05.001.

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Dixit, Sushil S., Aruna S. Dixit, and R. Douglas Evans. "Scaled Chrysophytes (Chrysophyceae) as Indicators of pH in Sudbury, Ontario, Lakes." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 8 (August 1, 1988): 1411–21. http://dx.doi.org/10.1139/f88-165.

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Surface sediment chrysophytes (Chrysophyceae) of 30 Sudbury, Ontario, lakes were analyzed to investigate the relationship of these algal microfossils with the limnological characteristics of the study lakes. The distribution of the majority of common chrysophyte taxa is correlated closely with lake water pH, pH-related factors, or both. Chrysodidymus synuroideus, Synura echinulata, Mallomonas hamata, M. acaroides var. muskokana, and Chrysosphaerella longispina appear to be indicators of strongly to moderately acidic waters whereas M. pseudocoronata and M. caudata are indicators of circumneutral to alkaline waters. Using multiple regression of pH indicator chrysophyte assemblages against the measured lake pH, a calibration equation was developed to compute chrysophyte-inferred pH. Chrysophyte-inferred pH values were closely related with measured lake water pH (r2 = 0.74). The study indicates that in the absence of historical pH data, stratigraphic analysis of scaled chrysophytes would provide useful information about the history of lake acidification in the Sudbury area. There is some indication that high metal concentrations, in addition to pH, may influence chrysophycean species distribution in acidic lakes.

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45

Mount, D. R., C. G. Ingersoll, D. D. Gulley, J. D. Fernandez, T. W. LaPoint, and H. L. Bergman. "Effect of Long-Term Exposure to Acid, Aluminum, and Low Calcium on Adult Brook Trout (Salvelinus fontinalis). 1. Survival, Growth, Fecundity, and Progeny Survival." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 9 (September 1, 1988): 1623–32. http://dx.doi.org/10.1139/f88-192.

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Adult brook trout (Salvelinus fontinalis) were exposed to concentrations of acid, Al, and Ca representative of acidic and acid-sensitive surface waters. At low pH (4.42–5.03), survival and growth were reduced by elevated Al concentrations (486 μg/L) and low Ca concentrations (0.5 mg/L). Fecundity (number of eggs per female) was reduced by exposure to some treatment combinations, but this effect was mediated through reduced growth; number of eggs per unit body weight was not related to treatment. Viability of eggs from ail parental exposures was high when incubated in neutral water. In spite of this high viability, eggs from parents exposed to low Ca concentrations showed greater mortality when incubated in the parental exposure conditions than did eggs from unexposed parents. Although the potential for such "carryover effects" cannot be discounted, we conclude that impairment of egg production is not a likely mechanism for loss of brook trout populations from acidic surface waters.

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Davydov, Vadim. "Study of the technogenesis of the Degtyarsky mine by audio-magnetotelluric express sounding." Journal of Mining Institute 243 (June 10, 2020): 378. http://dx.doi.org/10.31897/pmi.2020.3.378.

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The audio-magnetotelluric express sounding was performed at four sections crossing the mine field of the currently not functioning Degtyarsky mine. Field measurements were carried out by a universal broadband receiver “OMAR-2m” with active electromagnetic field sensors developed at the Institute of Geophysics UB RAS. Based on the obtained data, deep sections of the electrophysical parameters of the medium – apparent resistivity and effective longitudinal conductivity – are drawn. The nature of the geoelectric structure of the section allows mapping of the major lithochemical contamination plume and identifying the tectonic disturbance zones that drain aggressive mine waters. The mine waters of the Degtyarsky mine are a source of dangerous technogenic pollution. Despite the neutralization of surface runoff, underground routes of acidic water migration occur along tectonic cracks, primarily in the zone of the regional Serovsko-Mauksky fault. Tectonic zones in the mine area contain contaminated fissure-vein water, which is transited at a depth of 70 to over 200 m. Discharging ascending springs of such waters can be located at a great distance from controlled hydrological objects and pollute sources of drinking and household water supply. Urban development in the western and eastern parts of Degtyarsk does not fall within the distribution zone of polluted water. The southern part of the city is located beyond the watershed of the mine water flow area, but a danger of local contamination by tectonic disturbance zones remains possible. The worst environmental situation is observed in the northern outskirts of Degtyarsk, which falls into the area of heavy pollution of underground and surface waters. Besides, acidic fumes from the flooded Kolchedanny quarry can affect the health of city residents when emitted to the atmosphere.

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Vela, María Lorena, Gisela Masachessi, María Alejandra Giaveno, Maria Eugenia Roca Jalil, Gonzalo Castro, Ariana Mariela Cachi, María de los Ángeles Marinzalda, Ana Zugarramurdi, and Miria Baschini. "A Preliminary Study of SARS-CoV-2’s Permanence and Potential Infective Capacity in Mineromedicinal Waters of Copahue, Neuquén, Argentina." International Journal of Environmental Research and Public Health 19, no. 10 (May 13, 2022): 5923. http://dx.doi.org/10.3390/ijerph19105923.

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Copahue Thermal Center is characterized by the presence of mineromedicinal acidic waters with high temperatures, therapeutic peloids, and relevant consortia of extremophiles species, distributed in small natural pools which cannot be disinfected. The objective of this research was to investigate the survival of SARS-CoV-2 in Copahue’s waters and its remaining infective capacity. In a first assay, a decrease of more than 50% of the initially viral load compared to the initially inoculated positive sample was detected for all the water samples analyzed. After that, two of the Copahue springs, which are used as an immersion bath in closed environments without going through any disinfection treatment, was selected to determine the viral viability. VERO cell infections were performed, with no cytopathic effect detected, but a strikingly high resistance of the virus, detecting its genome by real time PCR, during the seven days of study under laboratory conditions. SARS-CoV-2 survival in acid media was reaffirmed, which is a peculiarity for a covered virus. A decrease in the detectable viral load of the positive sample was found as the infection time passed, becoming completely negative in the subsequent blind passages. More research is needed to further study the feasibility of SARS-CoV-2 in mineromedicinal waters, especially natural acidic waters that cannot disinfected, in order to expand information about the risk to populations that are exposed to them.

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Lush, Lynn, Isabel Costa, Kimberly Marshall, Juan Carlos Pérez-Casanova, Rénald Belley, and Dounia Hamoutene. "Effects of acidic pH on wild, farmed, and F1 hybrid Atlantic salmon (Salmo salar) parr." Canadian Journal of Fisheries and Aquatic Sciences 75, no. 1 (January 2018): 116–20. http://dx.doi.org/10.1139/cjfas-2017-0006.

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Farmed escapees have the potential to introduce novel genes to wild salmon and alter locally adapted populations. We tested whether the acidic conditions found in rivers on Newfoundland’s south coast might differentially impact offspring of farmed Atlantic salmon (Salmo salar) in comparison to wild populations. We performed crosses with wild and farmed parents to obtain wild (W♂ × W♀), farmed (F♂ × F♀), and F1 hybrid (W♂ × F♀, F♂ × W♀) parr and conducted a common garden experiment at neutral or acidic pH. No differences were observed between pure wild crosses and F1 hybrids, suggesting that acidic waters do not differentially affect survival, growth, condition factor, and Na+/K+-ATPase activity of F1 hybrids. Trends in mortality show that pure farmed parr had lower survival than pure wild and F1 hybrids in low pH. Considering that production of F1 hybrids rather than pure farmed offspring is the most likely outcome in the wild, pure farmed parr survival may have little bearing on the prediction of genetic risks of farmed–wild interactions. There is no evidence to indicate that the survival of the F1 generation in acidic waters acts as a potential barrier against introgression.

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Bennike, Ole, Pernille Pantmann, and Esben Aarsleff. "Holocene development of the Arresø area, north-east Sjælland, Denmark." Bulletin of the Geological Society of Denmark 65 (April 5, 2017): 25–35. http://dx.doi.org/10.37570/bgsd-2017-65-02.

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The Arresø area in north-east Sjælland, Denmark, was deglaciated about 18,000 to 16,000 years ago. In the Holocene it was probably a land area until it was transgressed by the sea c. 8500 years BP. During a first marine phase the area housed a species-rich marine fauna that included the oyster Ostrea edulis, the salinity and water temperatures were higher than at present, and there was a wide connection to the Kattegat sea. At about 6500 years BP there was a short-lived lake or brackish-water phase, but marine conditions were soon re-established with a fauna less diverse than before, and both salinity and water temperatures decreased. The present lake Arresø became isolated from the sea about 2500 years BP. The transition from brackish water to fresh water was rapid; the lake developed from shallow alkaline waters to deeper more acidic waters and finally to eutrophic waters.

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Pavlikova, Petra, Magdalena Balintova, and Marian Holub. "Study of sulphate ions removal from acidic waters using ion exchange resin." Selected Scientific Papers - Journal of Civil Engineering 13, no. 1 (December 1, 2018): 51–58. http://dx.doi.org/10.1515/sspjce-2018-0019.

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Abstract Acid Mine Drainage (AMD) is the most common pollution related to mining. It consists of an aqueous solution containing high metals and sulphate concentration, which impact surface and groundwater and lead to serious environmental problems. Low pH and high concentrations of heavy metals and sulphates are limiting for many various treatment technologies in these acidic waters. Ion - exchange is a very powerful technology where one or more undesirable contaminants are removed from water by exchange with another non-objectionable or less objectionable substance. Many of materials for the ion - exchange treatment is available in a variety forms and have widely differing chemical and physical properties. The paper deals with study of ion - exchange process under static and dynamic conditions for sulphate removal from acidic waters using ion - exchange resin with the aim to apply the results for treatment of acid mine drainage. Two types of experiments were performed under static and dynamic conditions. The efficiency of AMBERLITE MB20 resin for SO4 2- removal from model solution H2SO4 under static conditions decreases from 86.6 % for concentration 100 mg/L to efficiency 66.9 % for concertation 1000 mg/L. The efficiency for sulphate removal from AMD was only 41%. The study also presents three experiments under dynamic conditions, one with new ion - exchange resin a two experiments with its regenerated form. It was find that ion-exchange capacity decreases numbers of regeneration steps.

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Journal articles on the topic 'Acidic waters'

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