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Two strains of green microalgae C. reinhardti and C. pyrenoidosa were examined for their biosorption of Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ from aqueous multi-metal solutions. A wide range of biosorption capacities can be observed due to different strains of microalgae and different species of trace metals. This characteristic was ascribed to the distinct components and structures of algal cell walls and the different physicochemical properties of trace metals, such as atomic weight and ion density. C. pyrenoidosa showed higher uptake capacities than C. reinhardti and both of them had a preference for the uptake of cadmium over others in the trace metal solution, suggesting they can be a good biomaterial for biosorption of cadmium. Live microalgal cells displayed a more complex sorption process than dead microalgal cells because of cell assimilation.

Vicia villosa is an annual legume plant, and is mainly used for green manure by farmers in southwest China. Field growth experiments were performed on six plots. The concentrations of mineral nutrients and soluble sugar, and the changes of carbon and nitrogen isotopic composition within and among organs of Vicia were determined. Significant differences in legume growth were found in response to soil type and its moisture conditions. The Vicia villosa was relatively well adapted to growth in limestone soils than sandstone soils. The distribution of sugar concentrations and δ13C-differences between roots and leaves indicate that the translocation of sugars from leaves to roots may be restricted by soil drought. Therefore, there was an inhibition of Pi distribution from roots to leaves, resulting in over optimum threshold of N/P ratio. Those may originate from the feedback regulation in the legume, where soluble sugar could not be distributed from leaves to roots. The results of δ15N values in tissues suggest that there should be different preferential use of nitrogen resource by legume during the formation of nodules: before nodule formation the legume preferentially utilizes inorganic nitrogen from soils, but afterwards the nitrogen should be mainly from N2-fixation. Our results indicate that the lack of nodulation development, except for S2, should be ascribed to the factor controlling bi-direction nutrient transfer, which should be efficiency of establishment symbiosis with arbuscular mycorrhiza before nodulation formation. It is predicted that the species of Vicia villosa should be a legume associated with dual symbiosis with rhizobia and mycorrhiza.

We have investigated the diurnal variations of the pCO2 and related environmental factors in the cascade reservoirs with different trophic levels along Wujiang River. In surface water the pCO2 was 357±11 μatm in Hongjiadu Reservoir, 338±48 μatm in Dongfeng Reservoir, 682±303 μatm in Wujiangdu Reservoir, and 1677±429 μatm in Liuguang, respectively. The results indicated that these cascade reservoirs had much lower pCO2 values in surface water than river did, and hypereutrophic reservoir showed larger diurnal variations of pCO2 than meso-eutrophic reservoir. In water column, pCO2 tended to increase with the depth. Phytoplankton and the environmental factors such as temperature and pH had different influences on pCO2 diurnal variations due to different trophic levels, and the effect of phytoplankton on pCO2 variation increased with the increase of trophic level in these reservoirs.

The Aha Lake is a seasonal anoxic water system in the southwest of Guiyang City, Guizhou Province, China. Seasonal variations in SO42− concentrations and their isotopic compositions in lake water as well as in the tributaries were investigated in this study. The results showed that sulfate concentrations in river water range from 0.94 to 6.52 mmol/L and their δ34S values range from t14.9‰ and 0.9‰, while lake water has sulfate concentrations ranging from 1.91 to 2.79 mmol/L, and δ34S values from −9.8‰ to −5.9‰. It is suggested that coal mining drainage is the major source of SO42− in the Aha Lake. Rainfall, sewage discharge, sulfide oxidation and gypsum dissolution have made only limited contributions. Different depth-dependent distributions of dissolved SO42− and δ34S were developed for both DB and LJK in summer and winter. Due to water overturn, δ34S values display homogenous vertical distributions in winter and spring. While in summer and autumn, significant positive shifts of δ34S were clearly observed in epilimnion and bottom strata as a result of water stratification. High δ34S values in epilimnion may result from the retention of rainwater during water stratification. Dissimilatory sulfate reduction by bacteria was thought to be responsible for the increase of δ34S value in hypolimnion.

Geochemical studies on REE, trace elements and oxygen isotopes from metamorphic veins and their host metasedimentary rocks in the Zhoutan Group at two localities, Xiangshan and Yihuang, in central Jiangxi Province have been conducted in this paper. The results show that the metamorphic quartz veins inherited the REE and oxygen isotope geochemical characteristics from their host rocks, suggesting that the vein-forming fluids were derived from the host rocks. Additionally, fractionation degrees of the trace element pairs Zr-Hf, Nb-Ta, Y-Ho and U-Th in the veins are different from those of their host rocks. It is also indicated that the veins are the products of the fluids. The metamorphic veins within the Zhoutan Group metasedimentary rocks were formed principally as a result of lateral diffusion of the metamorphic fluids.

Vicia villosa is an annual legume plant. Field-growing experiments were performed on six plots under different soil conditions. Variations in the concentrations of Zn and Cd in tissues were investigated. Differences in distribution patterns between Zn and Cd appeared during growing: the concentrations of Zn in roots in sandstone-derived soils were relatively higher than those in limestone-derived soils, and the uptake patterns of Zn by roots should be similar to those of iron (Fe). However, the concentrations of Cd in roots in limestone-derived soils were higher than those in sandstone-derived soils, and the uptake patterns of Cd by roots should be similar to those of manganese (Mn). On the contrast, the distribution patterns of Zn were similar to those of Mn, while the distribution patterns of Cd were similar to those of Fe in tissues, indicating that the uptake patterns of Zn and Cd were different from distribution patterns.

This paper focuses on the flocculability of simulated wastewater containing heavy metal ions (Fe3+, Cd2+) or phosphorus by zeolite, microbial flocculants (MBF) produced by Aspergillus niger and the composite flocculant composed of zeolite and MBF. The main results are presented as follows: zeolite was a good flocculant when the contamination of the three simulated wastewaters was low, but the treated water is of turbidness and the particles in it are hard to precipitate. The MBF have a good flocculability toward Fe3+ wastewater, as well as particulate matter. Significant changes in flocculability occurred after adding the composite flocculant in different simulated wastewaters, the best or least effect respective for Fe3+ and Cd2+ wastewater. The research we have done shows that the method by which the composite flocculant is used to treat the wastewater containing heavy metal ions or phosphorus provides important reference value for practical application.

Detailed REE and trace elements geochemical studies of the Zhoutan Group metasedimentary rocks in central Jiangxi Province, China, and rock-forming minerals such as garnet were conducted and the results showed that the REEs are partly present in the rock-forming minerals and are dominantly contained in the lattice of accessory minerals. In the process of metamorphism the REEs between garnet porphyroblast and rock and the partitioning of REEs between garnet and the host rock is obviously controlled by the chemical composition of the system. The REEs compositions of metamorphic veins and their minerals display remarked lanthanide tetrad effects and the element pairs Zr-Hf, Y-Ho, Pb-Nd and U-Th have also experienced a certain degree of fractionation with respect to the metasedimentary rocks and they can be used as discriminating indicators to some extent for the occurrence of fluid processes in the process of metamorphism of the Zhoutan Group.

Sixty-two soil samples collected from different functional zones of Guiyang were analyzed for total concentrations and sequential extraction of Cr, Cu, Pb, Zn and Cd by ICP spectrometry. The average total concentrations of Cr, Cu, Pb, Zn and Cd in the soils of Guiyang were 92.9, 51.6, 44.1, 139.3 and 0.28 mg/kg, respectively. The soils have been polluted by Cr, Cu, Pb, Zn and Cd to some extent in comparison with the background values of Guiyang. Significant differences were recognized in the concentrations of Cr, Cu, Pb, Zn and Cd in different functional zones. As for the sequential extraction, Cr, Cu and Zn were present mainly in the residual fraction, and Pb was present mainly in the oxidizable fraction. The reducible fraction of Cd accounts for 47.5%, and the residual fraction is lowest. The mobility and bioavailability of heavy metals follow the order of Cd>Pb>Cu>Cr>Zn.

This study dealt with the distribution characteristics of soil organic carbon (SOC) and the variation of stable carbon isotopic composition (δ13C values) with depth in six soil profiles, including two soil types and three vegetation forms in the karst areas of Southwest China. The δ13C values of plant-dominant species, leaf litter and soils were measured using the sealed-tube high-temperature combustion method. Soil organic carbon contents of the limestone soil profiles are all above 11.4 g/kg, with the highest value of 71.1 g/kg in the surface soil. However, the contents vary between 2.9 g/kg and 46.0 g/kg in three yellow soil profiles. The difference between the maximum and minimum δ13C values of soil organic matter (SOM) changes from 2.2‰ to 2.9‰ for the three yellow soil profiles. But it changes from 0.8‰ to 1.6‰ for the limestone soil profiles. The contrast research indicated that there existed significant difference in vertical patterns of organic carbon and δ13C values of SOM between yellow soil and limestone soil. This difference may reflect site-specific factors, such as soil type, vegetation form, soil pH value, and clay content, etc., which control the contents of different organic components comprising SOM and soil carbon turnover rates in the profiles. The vertical variation patterns of stable carbon isotope in SOM have a distinct regional character in the karst areas.

The authors investigated the effect of Bacillus mucilaginosus on weathering of phosphorite. Analysis of different proteins was of significance in exploring the molecular biological mechanism in the bacterial weathering process. The concrete methods are described as follows: Mineral powder was put into liquid culture medium and B. mucilaginosus was incubated in the medium. The control (group) had no mineral powder in the medium. The treatments and controls were cultured simultaneously under the same condition. In a few days, the supernatant was filtrated, the main cations (Ca2+, Mg2+, Na+, Mn2+, Al3+, Fe3+, K+) were measured by ICP-OES, and the contents of water soluble phosphorus (Pws) and silicon (Siws) were determined by colorimetry. The residual solid was weighed on the filter paper, followed by digestion with concentrated HNO3. The concentrations of the main cations and Pws, Siws in the digest liquid were measured by using the method mentioned above. After the supernatant was centrifuged, the precipitation was used to analyze the protein differences between the treatment groups and the control groups by 2-dimentional gel electrophoresis (2-DE). The experimental results showed that apatite and quartz were partially weathered, but kaolinite was dissolved completely. The population of bacteria increased when mineral powder was added in the liquid medium. Software analysis and comparison of the 2-DE pictures of bacterial proteins revealed 1134 visible protein spots in the treatment group, and 729 visible protein spots in the control group. To compare the bacterial protein expression contents of the treatment group with those of the control group, there were 496 different protein spots, including 214 protein spots which indicated that the protein contents increased, 75 protein spots were indicative of a decrease, and 207 proteins were newly synthesized. It is proposed that the increased bacterial contents may be related to some protein expression and activation after the input of mineral powder. Newly synthesized proteins, the increase of expression contents and the reduction of proteins may be connected with bacterial metabolic regulations, cell activation and signal transmission.

Strong interaction between natural dissolved organic matter (DOM) and Hg(II) may influence the transport, conversion, toxicity and bio-validity of mercury in the environment. In this paper ultraviolet (UV) absorbance titration was employed for the first time for the determination of the conditional stability constants of Hg(II) and (DOM). With increasing Hg(II) concentrations, the UV absorbance of fulvic acid, humic acid, and DOM in river increases progressively. By linear and non-linear model fitting, the conditional stability constants (lgK) of Hg(II) and DOM were worked out to be 3.54–4.93 and 3.64–4.85, respectively. The results are consistent with those acquired by the typical fluorescence quenching titration method, with the maximum relative error of lgK being 2.6% and the average relative error being 0.2%. The UV absorbance titration method has the advantages of rapid determination, simple performance, and it will probably become a new approach to studying interactions between DOM and trace metallic ions.

Surface runoff in the Wujiang River watershed was simulated by a GIS-based method using precipitation, hydrology data, and land-use data. The volume of surface runoff is chiefly controlled by climates, topographical characteristics and types of land use at the watershed. Five subwatersheds that can represent the whole watershed were chosen and their average annual precipitation, average annual surface runoff and current land use were calculated respectively in the grid model of the Wujiang River watershed based on the climate and hydrology data from 1965 to 2000 and the land-use data acquired in the year of 2000. Surface runoff is assumed to be a function of precipitation and land use and the multiple regression tool is used to determine the relationship between surface runoff, precipitation and present land use. Thus, the rainfall-runoff model for each land-use type has been established. When calibrating these models, the results show that the percent errors are all below 7%, which indicates that the accuracy of this simulation is high.

The distribution of nutrients (N, P, Si, C) in the Wujiang River surface water was studied during the high-flow and low-flow periods in 2002. The results showed that nitrate nitrogen (NO3-N) is the main form of dissolved inorganic nitrogen (DIN) in the Wujiang River Basin. It accounts for about 90% of DIN. The average NO3-N concentrations in the mainstream are 147.5 µM in the high-flow period and 158.0 µM in the low-flow period, respectively. The average concentrations of total phosphorus (TP) are 6.43 µM in the high-flow period and 4.18 µM in the low-flow period, respectively. Of the various forms of phosphorus, particulate phosphorus (PP) has the highest percentage (62.9%) of TP in the high-flow period. In the low-flow period, however, phosphate is the main form of phosphorus, which accounts for 49% of TP. With the Wujiangdu Reservoir as the boundary, the concentrations of DIN and phosphorus in the upper reaches are different from those in the lower reaches of the Wujiang River. As a whole, the concentrations of DIN and phosphorus are both higher in the low-flow period than in the high-flow period. The spatial and temporal variations of DIN and phosphorus concentrations suggested that DIN and phosphorus come from agricultural and domestic wastewaters and groundwaters and that the Wujiangdu Reservoir has an important impact on the concentrations and distribution of DIN and phosphorus in the Wujiang River. The distribution patterns of dissolved silica (DSi) and dissolved organic carbon (DOC) are similar. Both of them maintain no change in the whole course of the river and their concentrations (with the exception of the reservoir itself) are higher in the high-flow period than in the low-flow period. The average DSi and DOC concentrations in the mainstream are 85.4, 84.6 µM in the high-flow period and 60.8, 53.9 µM in the low-flow period, respectively. The concentrations of nutrients in most of the major tributaries are lower than in the mainstream. This suggested that the contributions of most tributaries are relatively small but importance should be attached to the influence of some individual tributaries such as the Qingshuijiang River and the Weng’ an River on the mainstream.

Background: Radiographic signs of Pneumoconiosis found in farming Ladakhi despite absences of mines and industries were believed to be due to exposure to frequent dust storms and domestic fire pollutions. Seasonal Koilonychia (spoon nail) occurring predominantly in farming women in absences of iron deficiency anaemia was thought to arise from exposure to water made alkaline by weathering of hornblende minerals. The relation of these health conditions to environmental geohydrochemistry is postulated as the source of irrigation water in the affected population originates from glaciers in trans-Himalaya range of sedimentary geology and steep landscape favouring flushing of silica/silicate containing silts. Methods and results: Survey in two central Ladakh villages revealed radiographic evidence of silicosis in all middle aged women and half in middle aged men. In a large-scale study of 3105 subjects aged over 30 years from three villages; 101 (22.5%) of the 449 radiographed showed signs of pneumoconiosis (ILO 1980 criteria) including eggshell calcification of hilar gland and progressive massive fibrosis. Indoor dust analyzed using Philips 400T electron microscope with energy dispersive analysis system attached showed SiO2 levels upto 53.27% with particle size of 0.5 to 5.0 microns and the concentration during cooking period in the worst affected area was 7.495 mg/m 3. Microscopy and histopathology from the subject was characteristic of pneumoconiosis. Analysis of the inorganic dust in the lung showed 40.2% muscovite, 37.3% quartz with the extracted dust wt 147.9 mg/gm of dry tissue. Prevalence of chronic cough with chronic phlegm and percentage of villagers with FEV1/FVC ratio of less than 65% rose with age. Of 70 subjects studied 19 women and 2 men had Koilonychia with incidence being highest in summer. Absence of seasonal Koilonychia in villages fed by water derived from northern mountain range glaciers with mainly igneous geology supports our hypothesis. Conclusions: Clinical, epidemiological, radiological, environmental and histopathological studies and analysis of dust samples in the lungs proved beyond doubt that high prevalence of pneumoconiosis in central Ladakh is due to inhalation of respirable particles of SiO2 and soot. Seasonal Koilonychia in the study area with high pH and siliceous content of the soil in absence of iron deficiency anaemia support our hypothesis.

Chongshan L I A N G 1'2, Weilin H U A N G 2, Zhi D A N G 3, Congqiang LIU 1 1 State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2 Department of Environmental Sciences, Rutgers University, New Brunswicks, USA 3 College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510641, China

In southwestern China, karst rocky desertification, a process of land degradation, takes place widely due to human impacts on the fragile karstic ecological systems, which includes soil erosion, extensive exposure of basement rocks, and drastic decrease in soil productivity. A study on biogeochemical cycling of nutrients in the karstic catchments has been carried out to understand the relationships between degradation of ecological system and nutrient cycling. Our studies on chemical and isotopic compositions ( 6 13C, 6 34S, 5 15N, 87Sr/S6Sr) of river, lake, rain, and ground water in the karstic catchments of southwestern China provided important information on the sources of major ions to them, chemical weathering rates of river basins, fluxes of dissolved materials from the drainage basins, and on their linkages to changes of ecological systems and environments. The weathering rates of carbonate rocks and the fluxes of nutrients from the river basins are high as compared with karstic terrains in the world. Comparative studies on the carbon isotopic composition of dissolved inorganic carbon in surface water of karstic and none-karstic catchments indicate that more dissolved inorganic carbon in the karstic rivers originated from respiration of soil organic carbon. The interrelationships between isotopic composition and chemical composition of the surface water suggest that the high weathering rates of carbonate rocks and large fluxes of carbon, sulfur, and nitrogen from the karstic river basins may be ascribed to the roles of sulfur and nitrogen cycling in the catchments. Weathering of carbonate rocks by sulfuric and nitric acids can give rise to a net source of CO2 to atmosphere through precipitation of carbonate minerals, which will change our view that weathering of carbonate rocks can neither subtract nor produce greenhouse gas in atmosphere from a long-term point of view. The sulfur and nitrogen isotopic compositions respectively of sulfate and nitrate ions in rain and ground and surface waters indicate important anthropogenic sources of these ions, in addition to natural origin. It is concluded that human activities can disturb the natural cycling of nutrients, and result in changes in ecological environments.

In the bed of the Rudnaja River( Primorye, Russia) the influents of the polymetallic mine tailings and processing factories affected the river water chemistry, especially heavy metal concentrations. Decreasing of production in the last 10-15 years was reflected in decreasing of the river pollution. Nevertheless, waters from closed mines are still input to the Rudnaya River. Borum processing factory of Dalnegorsk City developed new quarry of the borum material, including carbonates, B and others elements in the river. The most detail data obtained in the dry period of 2005 showed that in the upper flow after discharge of mine water and mine tailings conductivity of river water grows up to 3-5 times and stay high up to the lower flow of the river. This about one order of magnitude exceeds the conductivity of other rivers of the area. Moreover, destroyed mines and damps in the upper river catchment introduce high concentrations of the Mg, Sr, Li, Fe, Mn, Cd, Zn; after Dalnegorsk City the highest concentrations of Na, K, Ca, As, Li, Cu were found. The investigation shows that the Rudnaya River is still the most polluted river of Primorye and it discharges to the Sea of Japan a lot of anthropogenic trace elements.

Boron has two stable isotopes (l~ and liB) with relative abundances of about 20% and 80%, respectively. Boron isotopic ratios in natural materials show a huge range of variations, from -7096o to +60%0, when expressed with the classical 8laB notation. Most of these isotopic variations occur at the surface of the Earth. Hence, boron isotopic composition can be used as a sensitive tracer in geochemical study, for instance, to identify the different sources of contamination and factors controlling the salinity of groundwater. During the last decade, boron isotopes have been used to discriminate between the influences of seawater intrusion and anthropogenic discharge. But few of those researches can precisely identify the different sources of contamination. We measured the boron concentrations and boron isotopic ratios of groundwater samples collected in Guiyang City, as well as the major ions. The results indicate that the major ion composition of the groundwater in the investigated area is mainly controlled by the interactions between water and the dominant rock i.e. carbonates. All the water compositions are characterized by high concentrations of Ca 2+, Mg 2+, HCO3, SO42, and NOr, which are the dominant contaminants. Both dissolved boron concentrations and isotopic ratios show large variations among the ground waters, from 2 lag/L to 90 lag/L and from -6%o to +26%0, respectively. The boron concentrations and isotopic ratios indicate that the river across the studied city has been seriously contaminated by urban discharge. Boron concentrations of river water samples varied from 20 lag/L to 140 lag/L, with an average 811B value of +2.0%0. Using boron isotopic compositions and different geochemical indices allowed us to clearly identify and distinguish the two major sources of contamination, agricultural activity and urban wastewater. Both of the two sources are characterized by high boron concentrations but their boron isotopic compositions significantly differ. The 8nB values of urban effluents range from -6.0%0 to +5.0%o, clearly lower than the mean 8nB values of a typical fertilizer, about +15%o. For the studied city, some groundwater sites of the suburban area were contaminated by agricultural activities and most sites of the urban area were contaminated by sewerage waters. The two types of contamination present distinct evolution during a hydrologic cycle.

A groundwater system in a karstic terrain is easily subject to pollution and its remediation is difficult once contaminated by human activities. The groundwater samples collected in both winter and summer seasons at Gulyang, SW China, show a wide range of variations in chemical composition and dominance of Ca 2., Mg 2+, SO42-, and HCO3 ions. The anthropogenic inputs include CI, NO3, SO42-, Na +, and K +, as judged from the relationships between different elemental ratios and sewage samples. C1- concentrations of all water samples in the study area vary from 0 to 3.9 mmol/L in winter and are higher than in summer. In most of the samples, SO4 zconcentrations are high, ranging from 0.1 to 11 mmol/L. The studies show that the cycling of sulfur plays an important role in controlling water chemistry and fate of contaminants in groundwater. In order to understand the source of SO42- and the geochemical cycling of some elements in the karstic groundwater environment, we have carried out a study on the variations of S and C1 isotope compositions, in addition to other isotopic tracers such as 87Sr/86Sr and ~13C studied previously. The ~37C1 values of the groundwater samples present a seasonal variation, ranging from 0.00%0 to +2.03%0 in winter and from -1.46%o to +0.29%0 in summer. The surface water samples show a similar range of variations as observed for groundwater. Two rainwater samples collected at Gulyang have a distinct isotopic signature (mean value is --3%0) compared to the ~37C1 values reported in literature. These results indicate that ground water is mainly derived from precipitation and suggest a fast recharge of the karst system by surface water. The G34S values of SO42 in the groundwater range from -20%0 to +22%0, with most of the values between -15 9/00 and +10 9/00 and no seasonality is observed for the G 34S values. Correlations between G34S and C1/HCO3, Ca/SO4, G13C and 87Sr]86Sr are in favor of mixing between at least 3 sulfur sources into the karst system: dissolution of sulfate evaporites, oxydation of sulfide minerals present in coal-containing strata and anthropogenic inputs including atmospheric inputs and domestic discharge. The covariations between G34S, G13C, and 87Sr]86Sr indicate that sulfuric acid produced via oxidation of sulfide minerals and organic sulfur probably takes a significant part in the dissolution of carbonate rocks in this karstic region.