Experimental Acidification of Lake 223, Experimental Lakes Area: Background Data and the First Three Years of Acidification

1980 ◽  
Vol 37 (3) ◽  
pp. 342-354 ◽  
Author(s):  
D. W. Schindler ◽  
R. Wagemann ◽  
R. B. Cook ◽  
T. Ruszczynski ◽  
J. Prokopowich
Keyword(s):  
Sulfuric Acid ◽  
Sulfate Reduction ◽  
Dissolved Inorganic Carbon ◽  
Theoretical Calculations ◽  
Experimental Lakes Area ◽  
Manganese Zinc ◽  
Low Efficiency ◽  
Experimental Acidification ◽  
Acidification Of Lake ◽  
Iron Manganese

Sulfuric acid was used to add 1.60 eq∙m−2 of hydrogen ion ([H+]) to Lake 223 over a 3-yr period from 1976 to 1978, to simulate the effects of acid precipitation on chemical and biological characteristics of the lake. The pH of epilimnion water was lowered from 6.7 to 7.0 in 1976, to 6.0–6.2 in 1977, and to 5.7–5.9 in 1978. The effectiveness of acid addition at depleting alkalinity from the water column in the first 2 yr was 31–38%. As a result, the pH of the lake did not decrease as much as predicted from theoretical calculations. The low efficiency of acidification appeared to be due to generation of dissolved inorganic carbon (DIC) by sulfate reduction in anoxic regions of the hypolimnion. Sulfate reduction increased as addition of sulfuric acid caused the concentration of sulfate in the lake to increase. Mobilization of iron from hypolimnion sediments during anoxic periods caused DIC respired by decomposers to be accumulated as HCO3− to balance the Fe+2 charge, buffering against acidification of the lake. Most of the reduced sulfur was precipitated from the lake as FeS. As a result, H2S in the hypolimnion was usually undetectable. Concentrations of ammonia, iron, manganese, zinc, and aluminum were higher in 1977 than in 1976. The transparency of the lake increased, although there was no apparent change in chlorophyll, dissolved color, dissolved organic carbon, or primary production.Key words: lake acidification, acid rain, mass balance, water chemistry, sulfur cycling

scholarly journals Volumetric Quantification and Quality of Water Stored in a Mining Lake: A Case Study at Reocín Mine (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 212
Author(s):  
Noemí Barral ◽  
Raúl Husillos ◽  
Elena Castillo ◽  
Manuel Cánovas ◽  
Elizabeth J. Lam ◽  
...  
Keyword(s):  
Human Consumption ◽  
Business Opportunity ◽  
Manganese Zinc ◽  
Quality Of Water ◽  
New Business ◽  
Volumetric Quantification ◽  
Zinc Mine ◽  
Iron Manganese

This study deals with the potential use of water stored in a lake formed by Reocín’s old zinc mine, which has become the second most important reservoir in Cantabria, with a flow of 1300 L s−1. The methodology used is based on the hydrogeological and hydrochemical characterization of the area studied. A total of 16 piezometers were installed to monitor the amount and quality of water. Results obtained show a pH close to 8 and iron, manganese, zinc, and sulphate concentrations lower than 0.05 mg L−1, 0.05 mg L−1, 1.063 mg L−1, and 1305.5 mg L−1, respectively. The volume of the water stored in the lake amounts to 34 hm3. Measurements show that Fe, Mn, and Zn concentrations are below the limits acceptable for human consumption, according to the Spanish 0.2, 0.05, and 5.0 mg L−1 standards, respectively, while sulphate greatly exceeds the 250 mg L−1 limit accepted by the norm. Therefore, the water could be apt for human consumption after a treatment appropriate for decreasing the sulphate level by, for example, reverse osmosis, distillation, or ion exchange. Although industrial and energy uses are possible, the lake water could be utilized as a geothermal energy source. The management of the hydric resources generated when a mine is closed could improve the economic and environmental conditions of the zone, with all the benefits it brings about, thus allowing for compensating of the pumping cost that environmental protection entails, creating, at the same time, a new business opportunity for the company that owns the mine.

Copper, Iron, Manganese, Zinc, Cobalt, Arsenic, Cadmium, Chrome, and Lead Concentrations in Liver and Muscle in Iranian Camel (Camelus dromedarius)

2019 ◽  
Vol 194 (2) ◽  
pp. 390-400
Author(s):  
Mehdi Asli ◽  
Mohammad Azizzadeh ◽  
Amir Moghaddamjafari ◽  
Mohammad Mohsenzadeh
Keyword(s):  
Camelus Dromedarius ◽  
Manganese Zinc ◽  
Iron Manganese

Integrated technology for conditioning low-mineralized cold ground water

2021 ◽  
pp. 4-9
Author(s):  
А.В. Селюков
Keyword(s):  
Drinking Water ◽  
Hydrogen Sulfide ◽  
Oil And Gas ◽  
Residual Concentration ◽  
Stabilization Treatment ◽  
Integrated Technology ◽  
Main Work ◽  
Treatment Facilities ◽  
Low Efficiency ◽  
Iron Manganese

Сообщается о новой комплексной технологии кондиционирования холодных маломинерализованных подземных вод. Технология разрабатывалась для целей хозяйственно-питьевого водоснабжения нефтегазоносных районов Тюменского Севера. При благополучном соотношении ресурсов пресной воды и фактического объема водопотребления в этом регионе России вопрос питьевого водоснабжения из подземных горизонтов остается острым из-за проблемного качества воды и низкой эффективности очистных сооружений. Технология предназначена для очистки от железа, марганца, сероводорода и обеспечивает стабилизационную обработку воды. Основные работы, включавшие лабораторные исследования и пилотные испытания, выполнены в период 2001–2020 годов. На основе разработанных технологических решений построены и успешно эксплуатируются водопроводные очистные сооружения в городах Ноябрьске (75 тыс. м3/сут, 2006 г.) и Новом Уренгое (65 тыс. м3/сут, 2007 г.). Дополнительные испытания технологии, проведенные в Ханты-Мансийске и Комсомольске-на-Амуре, подтвердили ее эффективность. Технология предусматривает применение в качестве основных реагентов пероксида водорода и перманганата калия для окисления примесей воды, а также щелочного реагента для корректировки рН и стабилизационной обработки. Для обеспечения требований стандарта ВОЗ по содержанию железа и марганца дополнительно может использоваться флокулянт. Обобщены данные по составу подземных вод, использованных для испытаний, и на их основе определена рекомендуемая область применения разработанной технологии. Приведена принципиальная технологическая схема кондиционирования холодных маломинерализованных подземных вод, учитывающая 15-летний опыт эксплуатации построенных станций, а также современные решения по дозированию и смешению реагентов. Указано, что данная технология обеспечивает также частичное снижение содержания кремния в очищенной воде (до 30%). Разработанная технология позволяет получать стабильную питьевую воду при нормативном остаточном содержании железа, марганца и сероводорода. An advanced integrated technology for conditioning low-mineralized cold groundwater is presented. The technology was developed for the purpose of supplying drinking water to the oil and gas-bearing regions of the Tyumen North. With a favorable ratio of fresh water resources and the actual volume of water consumption in this region of Russia, the issue of drinking water supply from underground aquifers remains acute due to the problematic water quality and low efficiency of the treatment facilities. The technology is intended for removing iron, manganese, hydrogen sulfide and providing for the stabilization treatment of water. The main work including laboratory studies and pilot tests was carried out in the period 2001–2020. On the basis of the developed process solutions, water treatment facilities have been built and successfully operated in the cities of Noyabrsk (75 thousand m3/day, 2006) and Novy Urengoy (65 thousand m3/day, 2007). Additional tests of the technology carried out in Khanty-Mansiisk and Komsomolsk-on-Amur confirmed its effectiveness. The technology involves using hydrogen peroxide and potassium permanganate as the basic chemicals for the oxidation of water pollutants, as well as using an alkaline chemical for pH adjustment and stabilization treatment. To meet the requirements of the WHO standard for the concentrations of iron and manganese, an additional flocculant can be used. The data on the composition of groundwater used for testing are summarized, and on their basis the recommended area of ​​application of the developed technology is determined. The basic process flow scheme of conditioning low-mineralized cold groundwater in view of 15 years of experience in operating the existing facilities, and of advanced solutions for dosing and mixing of chemicals, is presented. It is indicated that the technology also provides for a partial reduction in the silicon concentration in purified water (up to 30%). The developed technology ensures stable drinking water with a standard residual concentration of iron, manganese and hydrogen sulfide.

Wallach rearrangement of azoxypyridines and azoxypyridine N-oxides — Charge distributions and dramatic reactivity differences

2008 ◽  
Vol 86 (4) ◽  
pp. 298-304 ◽  
Author(s):  
Erwin Buncel ◽  
Sam-Rok Keum ◽  
Srinivasan Rajagopal ◽  
Eric Kiepek ◽  
Robin A Cox
Keyword(s):  
Sulfuric Acid ◽  
Positive Charge ◽  
Theoretical Calculations ◽  
Medium Effect ◽  
Mulliken Charge ◽  
Reaction Intermediates ◽  
Charge Distributions ◽  
First Time ◽  
Acid Region

Extension of our studies of the generic Wallach rearrangement (of azoxybenzene to 4-hydroxyazobenzene) to the heteroaromatic series (azoxypyridines and axoxypyridine N-oxides) has revealed some dramatic reactivity differences, particularly for the α and β compounds. We have studied the 3-isomers and the 4-isomers in each series, each with α and β forms, eight compounds in all, in the 100 wt% sulfuric acid region of acidity. In those cases in which a product could be observed, the α and β isomers both give the same one, the corresponding 4′-hydroxyazo compounds. All the compounds react much more slowly than does azoxybenzene itself, presumably because of the extra positive charge present in the substrates, but the β isomers have half-lives of seconds and the α isomers half-lives of hundreds of hours in the 100 wt% H2SO4 acidity region. The α compounds have measurable pKBH+ values, but the β compounds do not, exhibiting only a medium effect in the acidity region in which the α compounds protonate. This means that for the β compounds, the protonated intermediates must be much less stable and the postulated reaction intermediates must be much more stable than for the α compounds. To clarify this, we have obtained Mulliken charge distributions for the various species concerned, calculating the charge carried by each half of the molecule, larger charge separations being taken to indicate lesser stability. As far as we can establish, this is the first time that this technique has been used to indicate the stabilities of carbocationic species.Key words: azoxypyridines, azoxypyridine N-oxides, Wallach rearrangement, excess acidity, basicities, theoretical calculations, charge distributions, reactivities.

scholarly journals CHEMICAL COMPOSITION OF WHOLE GRAINS IN COMMON BEANS LANDRACES AND BREEDING GENOTYPES

2015 ◽  
Vol 2 ◽  
pp. 81 ◽  
Author(s):  
Gilberto Antonio Peripolli Bevilaqua ◽  
Iraja Ferreira Antunes
Keyword(s):  
Nutritional Composition ◽  
Whole Grain ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Manganese Zinc ◽  
Nutritional Characteristics ◽  
Calcium Magnesium ◽  
The Common ◽  
Iron Manganese ◽  
Insoluble Fiber

The common bean has been object of breeding programs aiming the development of new cultivars adapted to varied production system and shown differentiated nutritional characteristics. Due a genetic diversity existent the landraces can be used directly for cropping, for present characteristics desirable. Little information exists about mineral content and other quality traits for those bean landraces. The aim of this paper was to verify the variability for grain nutricional caracters in breeding cultivars and landraces of bean from Rio Grande do Sul state, Brazil. The experiment was conducted in 2009/2010 in Experimental Station Cascata, of Embrapa Temperate Agriculture. In whole grain of 54 bean genotypes with black and no black coat were determined macroelements (nitrogen, phosphorus, potash, calcium, magnesium and sulfur), oligoelements (iron, manganese, zinc and cuprum), protein and ash content, insoluble fiber, digestive nutrient and antioxidant astragalina. The results shown that the landraces varieties presents nutritional composition of macro and oligoelements, fibers, protein and ash contents in whole grain similar than that of breeding lines and cultivars. The black coat grain from breeding programs showed better nutritional quality for macro and oligoelements content than coloured grain, highlighting TB 02-04 e TB 01-01. The landraces with coloured grains TB 02-26, TB 02-24 and TB 03-13 showed the high levels of astragaline.

Decline of Mysis relicta During the Acidification of Lake 223

1983 ◽  
Vol 40 (11) ◽  
pp. 1905-1911 ◽  
Author(s):  
R. W. Nero ◽  
D. W. Schindler
Keyword(s):  
Confidence Limits ◽  
Experimental Lakes Area ◽  
Mysis Relicta ◽  
Ph Values ◽  
Northwestern Ontario ◽  
Population Comparisons ◽  
Acidification Of Lake ◽  
Ph Range ◽  
Shield Lakes ◽  
Direct Toxicity

The population size of Mysis relicta in Lake 223 of the Experimental Lakes Area, northwestern Ontario, decreased from 6 700 000 ± 1 330 000 (± 95% confidence limits) during August of 1978, to 270 000 ± 75 000 during August of 1979, a 96% decrease. Because Mysis, a cold stenotherm, is restricted to the metalimnion and hypolimnion of lakes during summer, the pH range encountered by the population was 5.51 to 6.32 in 1978 and 5.23 to 6.10 in 1979, even though mean pH values in epilimnion waters for the 2 yr were 5.84 and 5.60. A decrease in pH of its habitat from 6.2 to 5.6 during fall overturn in 1979 caused the elimination of the remaining 4% of the population. Comparisons with four control lakes suggested that the decline and disappearance were not normal occurrences in unstressed lakes. Concentrations of Zn, Al, Mn, Fe, Cd, Cu, Ni, and Hg in Lake 223 water were low, and concentrations in Mysis were less than or equal to those in animals from five control lakes, suggesting that the decline in this species was not due to the toxic effects of metals. All size classes were affected, so that direct toxicity of hydrogen ion may be responsible for this abrupt population collapse. These results suggest that Mysis may be a useful early indicator of acidification damage to Precambrian Shield lakes.

Accumulation of Iron, Manganese, Zinc and Cadmium by the Australian Freshwater Mussel Velesunio ambiguus (Phillipi) and Its Potential as a Biological Monitor

1979 ◽  
Vol 30 (6) ◽  
pp. 741 ◽  
Author(s):  
WG Jones ◽  
KF Walker
Keyword(s):  
Body Weight ◽  
South Australia ◽  
Freshwater Mussel ◽  
Short Term ◽  
Manganese Zinc ◽  
Systematic Relationships ◽  
Iron Manganese ◽  
Australian Freshwater ◽  
Iron Concentrations

The accumulation of iron, manganese, zinc and cadmium by freshwater mussels in the River Murray, South Australia, and their response to changes in environmental iron concentrations are considered. Metal loads varied markedly between individuals from the same population. The variability is accounted for partly by systematic relationships between metal loads and body weight and age, but not sex. The distribution of metals between the major organs is discussed, but the analysis of separate organs showed no advantage for biological monitoring. Comparisons between iron concentrations in river water and in mussels showed no clear correspondence. The study suggests that V. ambiguus may not be a good short-term monitor of iron, but still may have potential as a long-term and site-comparison monitor of metals. once inherent variability is taken into account.

The Determination of Iodine in Biologic Material

1964 ◽  
Vol 10 (9) ◽  
pp. 799-823 ◽  
Author(s):  
H Hoch ◽  
S L Sinnett ◽  
T H McGavack
Keyword(s):  
Sulfuric Acid ◽  
Sulfate Reduction ◽  
Perchloric Acid ◽  
Healthy Subjects ◽  
Test Sample ◽  
Chloric Acid ◽  
Total Serum ◽  
Acid Digestion ◽  
Reduction Test

Abstract The chloric acid digestion of serum, followed by the ceric sulfate reduction test for iodine has been shown to give results reproducible to within ± 0.00035 µg. iodine per test sample (1) if the entire digestion tubes are kept hot during the combustion step so that products of incomplete oxidation are vaporized, (2) if the perchloric acid and sulfuric acid concentrations in the final digest are adjusted to 1.64 normal (16.5%) and 0.37 normal, respectively, (3) if attention is paid to the order of addition of the reagents, and (4) if the arsenite reagent is added within a fraction of a second. The method gave values for total serum iodine in 20 healthy subjects between 5 and 10.5 µg./100 ml.

scholarly journals Host Tree Identity Influences Leaf Nutrient Relations of the Epiphyte Dendrobium guamense Ames.

Horticulturae ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 43 ◽  
Author(s):  
Thomas Marler
Keyword(s):  
Leaf Litter ◽  
Nutrient Deficiency ◽  
Host Tree ◽  
Nutrient Concentrations ◽  
Epiphytic Orchid ◽  
Green Leaves ◽  
Manganese Zinc ◽  
Host Identity ◽  
Calcium Iron ◽  
Iron Manganese

Epiphytic orchid species grow in stressful conditions that include nutrient deficiency. A greater understanding of the factors that influence epiphytic orchid nutrition may benefit conservationists and horticulturists. Green and senesced leaf nutrient concentrations of the epiphytic Dendrobium guamense were quantified among six host tree species to more fully understand the role of contrasting host identity. Green leaves for D. guamense plants on species with vertical stems contained greater nitrogen, calcium, iron, manganese, zinc, and boron concentrations. Green leaves for D. guamense plants on species with horizontal stems contained greater phosphorus, magnesium, and copper concentrations. Senesced D. guamense leaves followed similar patterns among the host species for all elements except calcium, manganese, and boron. The stoichiometry among green leaf macronutrients indicated nitrogen was most limiting, and the limitation was more severe for plants on horizontal stems. Carbon:nitrogen of senesced leaves indicated D. guamense plants on vertical stems produced higher quality leaf litter, predicting slower decomposition of orchid leaf litter from plants growing on hosts with horizontal stems. The results may improve horticultural decisions to support conservation efforts and show that host identity is a variable that should be more fully studied to understand epiphyte biology.

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