Contents of some heavy metals in plants from Saginaw Bay (Lake Huron) and some small lakes in wilderness areas of Michigan's Upper Peninsula as analyzed by neutron activation analysis

Our results indicate that the highest concentrations of heavy metals occurred in those plants collected near the mouth of the Saginaw River. The alga, Cladophora sp., and the flowering plant, Typha augustifolia (cat-tail), are notable for the high concentration of heavy metals that they accumulated. In addition, several other species that were sampled from small lakes in Michigan's Upper Peninsula contained higher concentrations of certain metals (Ba, Cr, Rb) than from any samples obtained from Saginaw Bay. Different organs of the same species, or of the same plant, such as cat-tail, vary widely in concentrations of the same elements. A computer-derived analysis of our data is presented, and the implications of our results as they relate to pollution by heavy metals in fresh-water lakes is discussed. This work was supported by a private subsidy from Edna Newnan, Bloomfield Hills, Michigan to whom we express our thanks for hernerous support. We also wish to thank the Division of Biological Sciences, The University of Michigan, for making funds available for the computer analyses performed in this study.     

Fatty-acid composition of the lipids of coregonids of the Ob basin

The fatty acid compositions of the lipids of the muscles of the back and of the abdomen of a pelyad from the lakes of the Ob basin have been studied by gas-liquid chromatography; 29 acids have been detected of which 27 have been identified. It has been established that the lipids of the muscles of the back of the pelyad contain 37.2% of polyunsaturated and 37.3% of monoenoic acids the main components of which are oleic, palmitic, palmitoleic, octadecatetraenoic, and eicosapentaenoic acids, amounting in total to 65%. The lipids of the muscles of the pelyad are unique among lipids of fresh-water fish in their content of tri- and tetraenoic acids. As compared with the usual composition, the neutral lipids are characterized by higher amounts of monoenoic and lower amounts of polyenoic acids.     

A simple and sensitive method for the determination of hydroxylamine in fresh-water samples using hypochlorite followed by gas chromatography.

A new and simple method for the determination of hydroxylamine in environmental water, such as fresh rivers and lakes using hypochlorite, followed by its gas choromatographic detection, has been developed. A glass vial filled with sample water was sealed by a butyl-rubber stopper and aluminum cap without head-space, and then sodium hypochlorite solution was injected into the vial through a syringe to convert hydroxylamine to nitrous oxide. The head-space in the glass vial was prepared with 99.9% grade N2 using a gas-tight syringe. After the glass vial was shaken for a few minutes, nitrous oxide in the gas-phase was measured by a gas chromatograph with an electron-capture detector. The dissolved nitrous oxide in the liquid-phase was calculated according to the solubility formula. The proposed method was applied to the analysis of fresh-water samples taken from Iu river and Hii river, flowing into brackish Lakes Nakaumi and Shinji, respectively.     

Fatty-acid composition of the lipids of coregonids of the Ob basin

The fatty acid compositions of the lipids of the muscles of the back and of the abdomen of a pelyad from the lakes of the Ob basin have been studied by gas-liquid chromatography; 29 acids have been detected of which 27 have been identified. It has been established that the lipids of the muscles of the back of the pelyad contain 37.2% of polyunsaturated and 37.3% of monoenoic acids the main components of which are oleic, palmitic, palmitoleic, octadecatetraenoic, and eicosapentaenoic acids, amounting in total to 65%. The lipids of the muscles of the pelyad are unique among lipids of fresh-water fish in their content of tri- and tetraenoic acids. As compared with the usual composition, the neutral lipids are characterized by higher amounts of monoenoic and lower amounts of polyenoic acids.Tyumen' State Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 555–558, September–October, 1981.     

Properties of the forpolymer of N-vinylpyrrolidone with itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid as a fluid-loss reducer for drilling fluid at high temperatures

The forpolymer of N-vinylpyrrolidone (NVP), itaconic acid (IA), acrylamide (AM) and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) was synthesized through free-radical polymerization and was characterized using Fourier transform IR spectroscopy. The colloidal properties of the drilling fluid were investigated in the form of fresh-water or salt-water mud. It was found that the NVP–IA–AM–AMPS forpolymer had strong effects on the properties of the mud. The filtrate volume decreased with the increase of the forpolymer concentration before or after the aging test at 220 °C, and the filtrate volume after the aging test was larger than that before the aging test, but was still very small compared with the corresponding base mud. In addition, the rheological properties of both fresh-water mud and salt-water mud were modified by the forpolymer. The particle size data demonstrated that the average size of the clay particle after the aging test was larger than that before the aging test and that the particle size of the fresh-water mud was narrower compared with that of the salt-water mud before and after the aging test, respectively. The drilling fluid containing the forpolymer had an excellent tolerance to salt and high temperature. Received: 13 September 2000/Accepted: 9 January 2001     

Factors affecting antibiotic production in bioreactors with immobilized algal cells

Applied Biochemistry and Biotechnology - A fresh-water, nitrogen-fixing blue-green alga (cyanobacterium),Scytonema sp. No. 11 (TISTR 8208), was isolated from a paddy field in northern Thailand....     

Recycling of process streams in ethanol production from softwoods based on enzymatic hydrolysis

In ethanol production from lignocellulose by enzymatic hydrolysis and fermentation, it is desirable to minimize addition of fresh-water and waste-water streams, which leads to an accumulation of substances in the process. This study shows that the amount of fresh water used and the amount of waste water thereby produced in the production of fuel ethanol from softwood, can be reduced to a large extent by recycling of either the stillage stream or part of the liquid stream from the fermenter. A reduction in fresh-water demand of more than 50%, from 3 kg/kg dry raw material to 1.5 kg/kg dry raw material was obtained without any negative effects on either hydrolysis or fermentation. A further decrease in the amount of fresh water, to one-fourth of what was used without recycling of process streams, resulted in a considerable decrease in the ethanol productivity and a slight decrease in the ethanol yield     

PRELIMINARY RESEARCH ON CLAY MINERALS IN SALT LAKE SEDIMENTS OF CHINA AND ITS SIGNIFICANCE

Most of the clay minerals in salt lakes of China are characterized by illite-chlorite as-semblage, with a minor amount of montmorillonite and kaolinite and so on. There are ob-vious differences between mineral assemblages, relative contents and chemical compositionof clay minerals in salt lakes of different areas and in different sedimentary stages. Clayminerals in these salt lakes are basically allogenic, but transitional origin may also exist.The characteristics of clay minerals in salt lakes are controlled by the arid climatic zone ofChina and the different material supplies of salt lakes. With the data taken from clay miner-al study, the author discusses the relation of sedimentary environment of salt lakes, theregularities of immigration and enrichment of mineralization elements.     

Fast neutron activation analysis of Nga-Khu (Clarias Magur) fresh-water fish

14 MeV neutrons from a KAMAN A-710 neutron generator were used for the activation analysis of Nga-Khu (Clarias Magur) fresh-water fish. Na, P, K, Ca, Cl, Fe and Mg were determined in whole and in edible portions of fish.     

Phosphorus fractions and phosphate sorption characteristics in relation to the sediment compositions of shallow lakes in the middle and lower reaches of Yangtze River region, China

Phosphorus is recognized as the most critical nutrient limiting lake productivity. The trophic status and development of lake systems are also influenced by the phosphorus content and fractions and phosphate sorption characteristics of the lake sediments. The phosphorus fractions and phosphate sorption characteristics of sediments in shallow lakes from the middle and lower reaches of Yangtze River region in China were investigated. The results show that the phosphorus contents in the sediments ranged from 217.8 to 1640 mg kg(-1); inorganic phosphorus (IP) was the major fraction of total phosphorus (TP); phosphorus bound to Al, Fe, Mn oxides, and hydroxides (Fe/Al-P), and calcium bound phosphorus (Ca-P) were the main fractions of IP. Phosphate sorption on the sediments mainly occurred within 2 h and then reached equilibrium in 10 h. The phosphate sorption rate was closely related to the concentration of fine particles. The phosphate sorption capacity ranged from 128.21 to 833.33 mg kg(-1), showing a significant correlation with the contents of Fe, Fe+Al, total organic carbon (TOC), cationic exchange capacity, total nitrogen, TP, Ca, IP, and the ratio of P/(Al+Fe), and it was higher in the sediments of eutrophic lakes than in mesotrophic lakes. Phosphate was mainly sorbed onto Fe and Al particles. The phosphate sorption efficiency ranged from 26.74 to 312.50 L kg(-1), and had a strong positive correlation with Fe content. For the eutrophic lake sediments, there were no significant relationships between the phosphate sorption efficiency and the selected physical and chemical parameters. But for the mesotrophic lake sediments, the phosphate sorption efficiency was found to be positively related to the contents of Al and Fe+Al.     

Water quality of two glacial alpine Italian lakes

The purpose of this study was to characterize, in a period of one year, two glacial lakes, Alice and Meugliano, located in an alpine reservoir on the basis of physical and chemical features. The two lakes show two periods of mixing: one in the spring and one in the autumn, so can be classified as dimictic lakes. They are characterized by pH, alkalinity, low conductivity and and quite dilute ionic concentrations. With regard to nutrients, most nitrogen occurred in the nitric form in the superficial layers. During the period of thermal stratification, in the anoxic layer NO3- decreases and NH4+ increases, confirming the activity of the anaerobic denitrificant bacteria. Total and soluble phosphorus levels show homogeneity during the cold period at different depths, while with stratification concentrations increase in the hypolimnium and metalimnium. In both lakes there is an inverse correlation between transparency and chlorophyll a. To evaluate the trophic state the conventional criteria of Nurnberg 2 and four lake trophic indices (TSIs) are used. Both evaluations suggest that the two lakes are eutrophic, with worse conditions in Alice. Deviations of the trophic states, based on the relation between TSIs, indicate that factors other than phosphorous limit the algal biomass, and that non-algal particles influence light attenuation     

Accumulation of uranium by filamentous green algae under natural environmental conditions

The capacity of algae to concentrate uranium under natural environmental conditions is measured by a-spectrometry. Spirogyra, a filamentous green fresh-water alga, has concentrated uranium from a surface concrete ponds with elevated uranium levels (140-1140 ppb). The concentration factors (CFs) ranged from 8.9-67 with an average value of 22.Cladophora spp, a filamentous green marine alga has concentrated uranium from the marine water with a concentration factor ranged from 220–280. The average concentration factor was 250. The factors affecting the sorption process are discussed in detail. This revised version was published online in July 2006 with corrections to the Cover Date.     

Heavy metals in lake water: a review on occurrence and analytical determination

Many lakes especially in Asia are source of livelihood for the surrounding communities. With increased urbanisation and industrialisation, however, these lakes are threatened with emerging environmental contaminants, including heavy metals. Some heavy metals are harmful to human health and the environment. This review aims to describe the different sampling, sample preparation and pretreatment, and instrumental methods of analysis for heavy metals in lake water. Filtration and acid digestion are common sample treatment methods used prior to analytical determination. Atomic absorption spectroscopy and inductively-coupled plasma – mass spectrometry (ICP-MS) are typical analytical techniques but nowadays ICP-MS is frequently used. This review also describes the sources and extent of heavy metals contamination in different lakes. Although some lakes still have natural levels of heavy metals in the water, many have elevated concentrations due to anthropogenic sources, such as vehicular, household, agricultural, industrial and mining activities.     

盐湖资源开发利用进展

本世纪头十年里,国际上再度掀起盐湖资源开发热潮。这很大程度上是由于锂的开发热带动的,同时也是和钾肥的广泛施用、价格一路走高有关。南美安第斯高原地区盐湖蕴藏世界70%以上的锂资源,且卤水锂、钾、硼浓度高。该地区极度干旱,少雨多风,非常适合采用卤水盐田蒸发的节能浓缩工艺技术。老的盐湖开发企业则在钾肥需求的带动下,稳步发展。在我国,新疆罗布泊和青海柴达木盆地盐湖则钾锂镁硼产品多元化,经营多元化取得长足进步。本文对近十年来,国内外盐湖开发的新动向做了概括介绍,特别着重于南美"锂三角"地区这一新的生长点。     

气相色谱全分析海水和淡水养殖南美白对虾组织中脂肪酸组成与含量

采用超声提取-毛细管气相色谱法分析测定了海水养殖和淡水养殖的南美白对虾的肌肉和肝胰腺(中肠腺)中脂肪酸的组成与含量,以用于对虾繁殖与营养的研究。采用Folch 液超声提取对虾组织中的脂质,脂质经氢氧化钾-三氟化硼法甲酯化后上机分析。采用BPX70(60 m×0.25 mm i.d.)石英毛细管柱分离,火焰离子化检测器检测。以线性程序升温等当碳长度(ECLT)值结合标准品对照的方法对17种脂肪酸定性,用面积归一化法定量。结果表明,两种对虾的脂肪酸组成均以不饱和脂肪酸为主,而且不饱和多烯酸的含量明显高于不饱和单烯酸。两种对虾的肌肉脂肪酸中高度不饱和脂肪酸,如二十碳五烯酸(EPA)与二十二碳六烯酸(DHA)的总含量均较高,达20%以上;肝胰腺中EPA和DHA的总含量较低,为11%～17%。淡水虾中n-6族不饱和脂肪酸含量比海水虾高,海水虾中n-3族与n-6族脂肪酸含量之比值比淡水虾高。     

Determination of copper,nickel, and cadmium in sea water by apdc chelate coprecipitation and flameless atomic absorption spectrometry

Copper, nickel, and cadmium can be determined in 100 ml of sea water by coprecipitation with cobalt pyrrolidinedithiocarbamate and graphite atomizer atomic absorption spectrometry. Concentration ranges likely to be encountered and estimated (1 σ ) analytical precisions are 1–6 nmol kg^-1 (±0.1) for copper, 3–12 nmol kg^-1 (±0.3) for nickel and 0.0–1.1 nmol kg^-1 (±0.1) for cadmium. The technique may be applied to fresh-water samples with slight modification.     

Environmental isotope-based integrated hydrogeological study of some Ethiopian rift lakes

Environmental isotope (²H and ¹⁸O) techniques supported by hydrochemical surveying, water balance and conventional hydrogeological mapping were used to study the hydrogeological system of four major lakes located in a closed central Ethiopian rift basin. The focus of attention is the groundwater and surface water interaction and the subsurface hydraulic connection of the lakes. The result shows that despite their geographic proximity, the lakes have highly variable isotopic and hydrochemical signature owing to geological and geomorphological factors. Two of the lakes are alkaline and found to be terminal from both surface water and groundwater point of view. They are in the state of high evaporation with respect to present day precipitation. The groundwater flow converges from all sides of the basin and plays very important role in the water balance of all the lakes. Major flow system in the rift and the hydraulic connection of the lakes is strongly controlled by the direction and extent of the extensional normal faults.     

The role of solar UV radiation in the ecology of alpine lakes.

Solar ultraviolet radiation (UVR, 290-400 nm) is a crucial environmental factor in alpine lakes because of the natural increase of the UVR flux with elevation and the high water transparency of these ecosystems. The ecological importance of UVR, however, has only recently been recognized. This review, examines the general features of alpine lakes regarding UVR, summarizes what is known about the role of solar UVR in the ecology of alpine lakes, and identifies future research directions. Unlike the pattern observed in most lowland lakes, variability of UV attenuation in alpine lakes is poorly explained by differences in dissolved organic carbon (DOC) concentrations, and depends mainly on optical characteristics (absorption) of the chromophoric dissolved organic matter (CDOM). Within the water column of lakes with low DOC concentrations (0.2-0.4 mg l(-1)), UV attenuation is influenced by phytoplankton whose development at depth (i.e. the deep chlorophyll maximum) causes important changes in UV attenuation. Alpine aquatic organisms have developed a number of strategies to minimize UV damage. The widespread synthesis or bioaccumulation of different compounds that directly or indirectly absorb UV energy is one such strategy. Although most benthic and planktonic primary producers and crustacean zooplankton are well adapted to high intensities of solar radiation, heterotrophic protists, bacteria, and viruses seem to be particularly sensitive to UVR. Understanding the overall impact of UVR on alpine lakes would need to consider synergistic and antagonistic processes resulting from the pronounced climatic warming, which have the potential to modify the UV underwater climate and consequently the stress on aquatic organisms.     

Some peculiarities of metal migration in the aerobic and anaerobic conditions in the surface water bodies

The results of research on metal migration (Mn, Cu, Zn, Pb, Cr) in the surface water bodies of the different type (the Kiev and the Kanev reservoirs of the Dnieper cascade, and Verbnoye and Telbin lakes of the Kiev city) in dependence on their oxygenous regime are considered. It was shown that the metal migration in the aerobic conditions is mainly directed from water thickness to bottom sediments. In contrast, the migration of metal compounds from bottom sediments in the anaerobic conditions is increased. Manganese is mostly in a form of free ions Mn²⁺ in the pore solutions, therefore, it migrates from bottom sediments in the greatest extent. The migration of other studied metals occurs in a much smaller extent and depends on the migration mobility of organic substances which they are bound to complexes. Migration mobility of copper, lead and chromium decreases essentially when the hydrogen sulphide is in the water of bottom layer. The data on a degree of metal binding to complexes and their chemical nature in water of reservoirs and lakes are given. The greater part of metals is found to be in complex compounds with humic substances in water of the Dnieper reservoirs, whereas in the lakes a share of neutral (mainly with carbohydrates) and cationic (mainly with protein-like substances) complexes essentially increases. The distribution of metals is explained by distinction in a component composition of dissolved organic matters in the reservoirs and in the lakes.     

Uptake and Elimination of 14C-Aldrin and 14C-Dieldrin by the Ostracod Chlamydotheca Arcuata (Sars)

Laboratory-reared, insecticide-free fresh-water ostracods, Chlamydotheca arcuata (Sars), were exposed to various concentrations of ¹⁴C-aldrin and ¹⁴C-dieldrin. Aldrin and dieldrin were accumulated in or by ostracod tissue both with and against concentration gradients from water. The initial rate of aldrin accumulation was approximately twice that of dieldrin, and accumulation of either insecticide was dependent upon the insecticide concentration in water, the duration of exposure, and the activity of the animals. Aldrin was readily metabolized to dieldrin in living ostracods, and small amounts of dieldrin were eliminated. The rate of elimination was in part dependent upon ostracod activity, although some elimination occurred with dead animal tissues. Dieldrin was eliminated more rapidly by dieldrin-exposed ostracods than by aldrin-exposed ostracods.