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1.
The increasing demand for building materials has led to indiscriminate exploitation of clay-rich topsoil from wetlands including the paddy lands of Central Kerala in the southwestern coast of India. The problem is critical in areas adjoining the major developmental centers having low per capita land and natural resource availability. Loss of fertile topsoil, shrinkage of agricultural lands and consequent food security issues, erosion of naturally evolved nutrients, lowering of water table in wells adjacent to the mining sites, etc., are some of the major environmental issues arising from indiscriminate brick and tile clay mining. Although, brick and tile clay mining brings short-term economic benefits and employment opportunities to a section of people, the process in the long run creates severe damages to the environmental settings of the area. The present paper deals with a few aspects of brick and tile clay mining in the paddy lands of Central Kerala, especially around Kochi City, a fast developing urban-cum-industrial center in South India, which demands large quantities of building materials including bricks and tiles for construction of infrastructural facilities. It is estimated that 729,695 tons/year (ty?1) of brick and tile clays are extracted from the coastal lowlands of Central Kerala, spreading to the Chalakudy (135,975 ty?1), Periyar (483,820 ty?1) and Muvattupuzha (109,900 ty?1) river basins. The N, P and K loss through extraction of brick and tile clays amounts to 210 ty?1, 96 ty?1 and 9,352 ty?1, respectively. As nutrient loss is an irreversible process in human time scale, its implications on agricultural productivity is a matter of serious concern. The study warrants the need for a comprehensive policy with an aim to regulate the mining activities on an environment- friendly basis in the densely populated coasts of the world, in general, and the study area in particular.  相似文献   

2.
The main ions were measured seasonally during two years at 13 sampling stations in the Salado River and its main tributaries. The importance of each ion was assessed by standard methods used to examine ionic composition and by multivariate methods. The K-means clustering and Principal Component Analysis were applied to the percentages of the major ions. The concentration of the major cations are in the order Na+ > Mg2+ > Ca2+ > K+ and the major anions, Cl− > SO42− > HCO3− > CO32−, and the salinity was high (mean TDS 2,691 mg l−1) due to sodium chloride. Using the proportions of the ions was possible to identify seven types of water within the basin related to discharges of different river sub-catchments and from endorheic catchments (in a sand dune region) actually connected with the basin by canals. The chemical composition of the basin is consequence of surface waters receiving salts from groundwater, evaporation and weathering of Post-Pampeano materials, and of anthropogenic impact by diversion between subcatchments for flood control. These results allowed us to test the marked effects on the ionic balance of basin at the base of a diversion management from endorheic catchments characterized by high salinity waters.  相似文献   

3.
The dissolved fluoride (F−) in the Lower Ganges-Brahmaputra-Meghna (GBM) river system, Bengal basin, Bangladesh, was studied during 1991–1993 to determine its distribution and source in the basin, and its annual flux to the Bay of Bengal. The concentration of dissolved F− varied between 2 and 11 μmol l−1 with statistically significant variations both spatially and temporally in the basin. Such variations are attributable to the geology of the individual subbasins (Ganges, Brahmaputra and Meghna), dilution by rainwater during monsoon and groundwater contribution to the river systems during dry season. Correlation coefficients among F− and major cations and anions suggest diverse inorganic processes responsible for regulating the concentration of F− in these river systems. However, fluorite seems to be one of the major sources of dissolved F−. The concentration of F− in the Lower GBM river system is low compared to the rivers draining Deccan Plateau and arid regions of the subcontinent, for example, Yamuna and its tributaries. However, it is within the range of most of the other Peninsular and Himalayan rivers. The GBM system contributes about 115×103 tonnes year−1 of dissolved F− into the Bay of Bengal, and thus accounts for about 3% of the global F− flux to the oceans annually. Received: 19 May 1999 · Accepted: 11 October 1999  相似文献   

4.
Geochemical characteristics of Fe and Mn in sand, silt, and clay fractions as well as in bulk sediments of the tropical perennial Muvattupuzha river and the Central Vembanad estuary of the southwest coast of India have been studied and discussed. The results of a physical fractionation study of Fe and Mn indicated a substantial increase in the content of these metals in silt and clay fractions above that in sand. The riverine silt and clay fractions account for two to three times the enrichment of Fe and Mn than the corresponding sand fraction; the estuarine counterparts indicate four to eight times the enrichment. The observed enrichment of Fe and Mn towards the more finer size grades is mainly due to the increased surface area of the finer clastics, which in turn increase the absorptive ability. However, the mineralogical diversities of the three size fractions also influence the enrichment of Fe and Mn. The spatial distribution of Fe and Mn indicates a marked decrease in the content of the latter than the former towards the high saline zones of the river and the estuary. This variation could be due to the higher solubility of Mn towards the high saline zones of the aquatic environment where reducing condition prevails most of the year.  相似文献   

5.
Vembanad lake system (VLS) is a Ramsar wetland of premier importance along the south west coast of India. This system spread over 13098 km2 accounts for 33.7% of total geographic area of Kerala state. VLS sustains by the input of six main river systems of Kerala viz., Achankovil, Pampa, Manimala, Meenachil, Muvattupuzha and Periyar. Central focus of this study is to find out the influence of morphometric variables on hydrological processes using geo-informatics and correlation analysis and to analyse the scale dependence of basin hypsometry in steady state topography and hydrology. The study also examines the contribution of each river in making the entities of this wetland system by portraying the morphometric and hypsometric parameters of its watershed. The results of this analysis reveals that the Manimala river basin has survived with rapid denudation activities and run off mechanism, while Periyar and Pampa river basins have culminating stage of development and are tectonically active. This study immensely contributes to the knowledge on the influence of morphometric variables on hydrological process and scale dependence of basin hypsometry in steady state topography including hydrology of VLS. The results will shed some light on hydrologic makeup of inflow rivers and will be beneficial for the sustainable management of India’s one of the premier wetlands.  相似文献   

6.
It is essential to have suitable tools able to trace the fate of manure organic matter in the environment to assess whether manure disposal on the soils of catchments could affect the organic quality of rivers. Sterol compounds – mainly expressed as C29 + 28/C27 and 5β/C27 ratios – have been shown to be specific molecular tracers of pig, dairy and poultry manures in soils. The objective of this study was to measure C29 + 28/C27 and 5β/C27 ratios in five Brittany rivers (Elorn, Yar, Léguer, Min Ran and Couesnon) draining agricultural catchments receiving massive annual inputs of pig, poultry and dairy manures and compare these ratios with ratios published for enriched soils and manure samples. The particulate organic fractions from the studied rivers yielded steroid signatures typical of animal manures. More specifically, a stanol compound diagnostic of pig slurry – the 5β-stanol known as coprostanol – was found to be very widespread, with particularly high concentrations in one of the rivers (Elorn). The C29 + 28/C27 and 5β/C27 ratios of the particulate fractions of the rivers were compared with ratios measured directly in pig, dairy and poultry manure samples, as well as with the breeding activities on river catchments. These comparisons show that the steroid profiles of the five investigated rivers correlate closely with the types of manure (i.e. pig, poultry or dairy) spread on soils in their catchments. For instance, the C29 + 28/C27 and 5β/C27 ratios in the Elorn river are similar to the values typical of pig slurry (e.g. 5β/C27 > 4); compared with other catchments, the soils in this area receive by far the largest amount of pig slurry. By contrast, the Yar river drains a catchment receiving only poultry and dairy manures, and its soils exhibit C29 + 28/C27 and 5β/C27 ratios similar to those of dairy and poultry manures (e.g. 5β/C27 ∼ 1). Thus, this study indicates that the organic quality of rivers is modified in catchments where there is intense manure spreading on soils. It also provides evidence that rivers draining areas receiving different manure types may exhibit differences in the long-term evolution of their OM content. Indeed, two of the investigated river catchments receive dominantly dairy and poultry manure, and exhibit clear long-term upward trends in OM. On the other hand, one catchment receiving high proportions of pig slurry clearly shows a long-term downward trend in OM contents. A survey of the literature shows that the relative amount of OM and N received by soils in agricultural catchments could be the key parameter in determining the direction of the long-term OM trend of the river, rather than the absolute amount and/or type of manure that is applied to the soil. In any case, the present study suggests that sterol/stanol compounds may be of diagnostic value in determining whether a stream or a river is undergoing contamination by manure-derived organic matter.  相似文献   

7.
A field study was conducted to determine the effect of landscape spatial pattern and micro-topography on nutrient transfer via runoff from two catchments into Yuqiao Reservoir in north China. The surface runoff discharge was measured during rainfall events and water samples were analyzed in 2004 and 2005. The mean annual total nitrogen (TN) and total phosphorus (TP) exports per unit area from Caogezhuang catchment (C catchment) were 1.048 and 0.561 kg ha−1 year−1, respectively, while the TN and TP exports from Taohuasi catchment (T catchment) were 0.158 and 0.027 kg ha−1 year−1. In both catchments, village and vineyard shared the highest nutrient export ability due to the accumulated animal waste and heavy application of fertilizer and manure. In T catchment, the distance of village and vineyard was about 1,500 m away from the receiving water and in between were woodland and cropland. In the hydrological pathway, there were sink landscape structures of small stone dams, roadside swale, vegetated filter strip and dry ponds, which could detain water and nutrients. In C catchment, the distance between the village and the receiving water was about 200 m, and the hydrological pathway was compacted roads and ditches with no sink structures. It is suggested that the distance between the pollution source area and the receiving water and the micro-topographical features were the main factors to control the great difference in nutrient export rates.  相似文献   

8.
The study was designed to establish the distributions of trace metals, dissolved organic carbon, and inorganic nutrients as well as to assess the extent of anthropogenic inputs into the Narmada and Tapti rivers. Water and sediment qualities are variable in the rivers, and there are major pollution problems at certain locations, mainly associated with urban and industrial centers. The metal concentrations of samples of the aquatic compartments investigated were close to the maximum permissible concentration for the survival of aquatic life, except for higher values of Cu (5–763 μg l−1), Pb (24–376 μg l−1), Zn (24–730 μg l−1), and Cr (70–740 μg l−1) and for drinking water except for elevated concentrations of metals such as Pb, Fe (850–2,060 μg l−1), Cr, and Ni (20–120 μg l−1). In general, the concentrations of trace metals in the rivers vary down stream which may affect the “health” of the aquatic ecosystem and may also affect the health of the rural community that depends on the untreated river water directly for domestic use. The assessment of EF, I geo, and PLI in the sediments reveals overall moderate pollution in the river basins.  相似文献   

9.
Among several salt lakes in the Thar Desert of western India, the Sambhar is the largest lake producing about 2 × 105 tons of salt (NaCl) annually. The “lake system” (lake waters, inflowing river waters, and sub-surface brines) provides a unique setting to study the geo-chemical behavior of uranium isotopes (238U, 234U) in conjunction with the evolution of brines over the annual wetting and evaporation cycles. The concentration of 238U and the total dissolved solids (TDS) in lake water increase from ~8 μg L−1 and ~8 g L−1 in monsoon to ~1,400 μg L−1 and 370 g L−1, respectively, during summer time. The U/TDS ratio (~1 μg g−1 salt) and the 234U/238U activity ratio (1.65 ± 0.05), however, remain almost unchanged throughout the year, except when U/TDS ratio approaches to 3.8 at/or beyond halite crystallization. These observations suggest that uranium behaves conservatively in the lake waters during the annual cycle of evaporation. Also, uranium and salt content (TDS) are intimately coupled, which has been used to infer the origin and source of salt in the lake basin. Furthermore, near uniform ratios in evaporating lake waters, when compared to the ratio in seawater (~0.1 μg g−1 salt and 1.14 ± 0.02, respectively), imply that aeolian transport of marine salts is unlikely to be significant source of salt to the lake in the present-day hydrologic conditions. This inference is further consistent with the chemical composition of wet-precipitation occurring in and around the Sambhar lake. The seasonal streams feeding the lake and groundwaters (within the lake’s periphery) have distinctly different ratios of U/TDS (2–69 μg g−1 salt) and 234U/238U (1.15–2.26) compared to those in the lake. The average U/TDS ratio of ~1 μg g−1 salt in lake waters and ~19 μg g−1 salt in river waters suggest dilution of the uranium content by the recycled salt and/or removal processes presently operating in the lake during the extraction of salt for commercial use. Based on mass-balance calculations, a conservative estimate of "uranium sink" (in the form of bittern crust) accounts for ~5 tons year−1 from the lake basin, an estimate similar to its input flux from rivers, i.e., 4.4 tons year−1.  相似文献   

10.
We investigated the geochemical characteristics of major, trace and rare earth elements and Sr–Nd isotope patterns of bed sediments from the headwaters and upper reaches of the six large rivers draining the Tibetan Plateau (the Jinsha River—Yangtze, Lancang River—Mekong, Nujiang River—Salween, Huang He—Yellow, Indus, and Yarlung Tsangpo—Brahmaputra). By using Ca/Al versus Mg/Al, La/Sc versus Co/Th, and 87Sr/86Sr versus εNd (0) binary differentiation diagrams of provenance, some typical contributors to the different catchment sediments can be identified. In the Three-River (the Jinsha, Lancang, and Nujiang Rivers) tectonomagmatic belt, acidic–intermediate-acidic volcanic rocks are very important provenance of sediments. Carbonate rocks and Permian Emeishan basalts are dominant in the Jinsha River. The Yellow River sediments have similar geochemical characteristics with loess in catchments. The Indus and Yarlung Tsangpo Rivers sediments are mainly from ultra-K volcanic rocks and Cenozoic granitoids widely distributed in the Indus–Yarlung suture. The intensity of chemical weathering in these river catchments is evaluated by calculating the chemical indices of alteration (CIA) of sediments and comparing them with bedrocks. The CIA values of the six river sediments are from 46.5 to 69.6, closing to those of bedrocks in the corresponding catchment, which indicates relatively weak chemical weathering intensity. Lithology, climate, and topography affect the chemical weathering intensity in these river catchments.  相似文献   

11.
The distribution of temperature and salinity in the upper 500 m of the northwestern Bay of Bengal, adjoining the east coast of India, during the retreat of southwest monsoon (September) of 1983 is presented. This study reveals coastal upwelling (limited to the upper 40 m) induced by the local winds. Waters of higher surface salinity near the coast characterize the upwelling. The freshwater influx near the head of the Bay diluted the surface salinity to as low as 26.0 × 10−3. The surface circulation was weak and led to a net transport of 2.0 × 106m3.s−1 directed towards northeast.  相似文献   

12.
Weathering fluxes of arsenic from a small catchment in Slovak Republic   总被引：1，自引：1，他引：0  
Inputs of As to a small catchment due to chemical weathering of bedrock, mechanical weathering of bedrock, and atmospheric precipitation were 71.53, 23.98 and 0.02 g ha−1 year−1, respectively. The output fluxes of As due to mechanical erosion of soil, biological uptake, stream discharge, and groundwater flow were 6.32, 4.77, 0.37 and 0.02 g ha−1 year−1, respectively. The results indicate that arsenic accumulates in soil and regolith with a very high rate. This is attributed to the selective weathering and erosion with respect to arsenic and fixation of arsenic in the secondary solids produced by weathering. The output fluxes of As in stream and groundwater in Vydrica catchment in Slovak Republic (0.39 g ha−1 year−1) based on muscovite–biotite granites and granodiorites were much lower compared to catchments in a gold district in the Czech Republic. These results may be ascribed to the low levels of arsenic pollution measured in Vydrica catchment. The arsenic fluxes were estimated by calculation of mechanical and chemical weathering rates of the bedrocks in Vydrica catchment from mass balance data on sodium and silica. The justification of the steady state of Na and Si is that neither of the elements is appreciably accumulated in plants and in exchangeable pool of ions in soil.  相似文献   

13.
This paper examines the soil loss spatial patterns in the Keiskamma catchment using the GIS-based Sediment Assessment Tool for Effective Erosion Control (SATEEC) to assess the soil erosion risk of the catchment. SATEEC estimates soil loss and sediment yield within river catchments using the Revised Universal Soil Loss Equation (RUSLE) and a spatially distributed sediment delivery ratio. Vegetation cover in protected areas has a significant effect in curtailing soil loss. The effect of rainfall was noted as two pronged, higher rainfall amounts received in the escarpment promote vegetation growth and vigour in the Amatole mountain range which in turn positively provides a protective cover to shield the soil from soil loss. The negative aspect of high rainfall is that it increases the rainfall erosivity. The Keiskamma catchment is predisposed to excessive rates of soil loss due to high soil erodibility, steep slopes, poor conservation practices and low vegetation cover. This soil erosion risk assessment shows that 35% of the catchment is prone to high to extremely high soil losses higher than 25 ton ha−1 year−1 whilst 65% still experience very low to moderate levels of soil loss of less than 25 ton ha−1 year−1. Object based classification highlighted the occurrence of enriched valley infill which flourishes in sediment laden ephemeral stream channels. This occurrence increases gully erosion due to overgrazing within ephemeral stream channels. Measures to curb further degradation in the catchment should thrive to strengthen the role of local institutions in controlling conservation practice.  相似文献   

14.
Alaknanda and Bhagirathi (AB) river basins in the Himalayan region in India expose lithologies comprising mainly of granites, low–high-grade metamorphics, shales and carbonates which, in conjunction with the monsoon rains and glacial melt, control water chemistry and dissolved elemental flux rates. In the present study, we monitored two locations: (a) Srinagar on the Alaknanda river and (b) Maneri on the Bhagirathi river for daily variations in total suspended sediments, major ions and dissolved silica over one complete year (July 2004–June 2005). Based on long-term discharge data, discharge-weighted composition and dissolved elemental flux rates (with respect to Ca, Mg, HCO3, Si) of the river were estimated. The information thus obtained has substantially added up to the existing chemical data of these rivers and has refined the flux rates. Our high-frequency samples provide informations such as (a) water chemical compositions that show a large temporal and spatial variation and (b) carbonate lithology that controls water chemistry predominantly. The dissolution kinetics of various lithologies namely leucogranite, gneiss, quartzite, phyllite and shale of the AB river basins were studied through batch experiments at controlled temperature (25 and 5°C) and pH (8.4) condition. In laboratory, these lithologies undergo slow rates of dissolution (10−13 to 10−15 mol/m2 s), while field weathering rates based on dissolved elemental flux rates in the AB rivers are much higher (10−8 to 10−9 mol/m2 s). Extremely high physical weathering rates in AB rivers, which enhance chemical weathering significantly, mainly attribute this wide discrepancy in laboratory-derived rates of representative basin rocks and dissolved elemental fluxes in the field. However, laboratory-simulated experiments facilitate to quantify elemental release rates, understand the kinetics of the dissolution reactions, and compare their roles at individual level.  相似文献   

15.
A comprehensive set of measurements of oxygen and hydrogen isotopic ratios in groundwaters as well as waters from rivers, lakes, hot springs etc. taken from a variety of locations in India has been carried out for the first time. Isotopically the most depleted samples occur in the high altitude precipitations in the Himalayas e.g. in the lakes of Bhutan and the source water of the Ganga. The shallow groundwater data display a continental effect where the heavy isotope content decreases with distance from the coast (about 4 to 6 per mil decrease in δ18O per 1000 km). The δ D and δ18O of these fresh waters are linearly related and an analysis of this relation vis-a-vis the meteoric water line shows the unambiguous effect of enrichment due to evaporation from soils.  相似文献   

16.
Systematic hydrogeochemical survey has been carried out for understanding the sources of dissolved ions in the groundwaters of the area occupied by Sarada river basin, Visakhapatnam district, Andhra Pradesh, India. Khondalites, charnockites and granite gneisses and calc-granulites of Precambrians and alluvial deposits of Quaternaries underlie the study area. Groundwaters are both fresh and brackish; the latter waters being a dominant. Most groundwaters are characterized by Na+:HCO3− facies due to chemical weathering of the rocks. Enrichment of Na+, K+, Cl−, SO42−, NO3− and F− in some groundwater samples is caused by seawater intrusion, locally accompanied by ion-exchange, and anthropogenic activities, resulting in an increase of brackish in the groundwaters. Based on the results of this hydrogeochemical study, suitable management measures are recommended to solve the water quality problems.  相似文献   

17.
Documenting the interaction between groundwater and rivers is fundamental to understanding hydrological systems. While many studies have examined the location and magnitude of groundwater inflows to rivers, much less is known about the transit times of water in catchments and from where in the aquifer the groundwater originates. Resolving those questions is vital for protecting riverine ecosystems, assessing the impact of contamination, and understanding the potential consequences of groundwater pumping. This study uses tritium (3H) to evaluate the mean transit times of water contributing to Deep Creek (southeast Australia), which is a chain-of-ponds river system. 3H activities of river water vary between 1.47 and 2.91 TU with lower 3H activities recorded during cease-to-flow periods when the river comprises isolated groundwater-fed pools. Regional groundwater 1–2.5 km away from Deep Creek at depths of 7.5–46.5 m has 3H activities of between <0.02 and 0.84 TU. The variation in 3H activities suggest that the water that inflows into Deep Creek is dominated by near-river shallow groundwater with the deeper groundwater only providing significant inflows during drier periods. If the water in the catchment can be represented by a single store with a continuum of ages, mean transit times of the river water range between <1 and 31 years whereas those of the groundwater are at least 75 years and mainly >100 years. Alternatively the variation in 3H activities can be explained by mixing of a young near-river water component with up to 50% older groundwater. The results of this study reinforce the need to protect shallow near-river groundwater from contamination in order to safeguard riverine ecosystems and also illustrate the potential pitfalls in using regional bores to characterise the geochemistry of near-river groundwater.  相似文献   

18.
Increasing sediment loads entering the Lake Tanganyika ecosystem are hastening the need for improved understanding of the linkages between catchment characteristics and influent sediment transport and loading. Sediment loads of two catchments at the southern end of the lake were estimated for October 1998–December 1999, and catchment characteristics determined using GIS. It was found that both sediment yields and loads were higher from the catchment of the Lunzua River (19.8 t km?2 and 20,114 t, respectively) compared with that of the Kalambo (4.1 t km?2 and 12,197 t) in 1999. These differences were both attributed to the smaller size and higher road density of the Lunzua catchment, and suggest that previous recommendations regarding the positioning of underwater lake reserves fail to take into account the low sediment retention capacity of small mountainous rivers. Differences between the study rivers in the transport of suspended sediments, organic matter, and bedload sediments into the lake were also found, the latter determined by the novel application of the 'McLaren Model'.  相似文献   

19.
The purpose of this research was to assess the effects of dredging performed in a marginal wetland colonized by aquatic macrophytes on eutrophication of the adjacent shallow tropical lake (Imboassica Lake, Brazil). The river mouth of the Imboassica River that drains into Imboassica Lake had been densely colonized by aquatic vegetation dominated by Typha domingensis (Pers.) when it was dredged. Total and dissolved nitrogen and phosphorus concentrations were measured monthly over 13 years at four stations in the Imboassica river-lake system. Dredging activities reduced phosphorus and nitrogen retention at the river mouth and subsequently increased these nutrient stocks in the lake waters. Nutrient retention by non-dredged wetland was estimated to be ca. 1,200 kg year−1 (87.3 g m−2 year−1) for nitrogen and 60 kg year−1 (4.5 g m−2 year−1) for phosphorus. Our whole-lake approach suggested that dredging might intensify rather than mitigate eutrophication in shallow tropical lakes when the removal of aquatic macrophytes is coupled to the persistence of anthropogenic nutrient inputs from the watershed.  相似文献   

20.
The technique of competitive ligand-exchange/anodic stripping voltammetry (CLE-SV) was used to investigate effects of pH and Ca concentration on cadmium complexation by fulvic acid (FA), as well as Cd speciation in two different freshwaters, a hardwater Lake Greifen and a softwater River Wyre. Binding of Cd to Suwannee river FA (10 mg/l) was determined at different pH (7–8.5) and in the presence of various concentration of Ca2+ (0–2 mmol/l). The results from one-ligand discrete models were compared to simulations by the WHAM VI model. In Lake Greifen, the determined dissolved [Cd2+] ranged from 10−13 to 10−12 mol/l, and the conditional stability constant with natural ligands was log K CdL about 9.5–10.5 (pH 8.6–8.8) with ligand concentrations of 1.2–7.8 × 10−6 mol/g C. In the softwater River Wyre, dissolved [Cd2+] ranged from 4 × 10−12 to 1 × 10−11 mol/l, and the ligands were weaker (log K CdL 8.9–9.8, pH 8.0) with lower ligand concentrations (0.9–2.3 × 10−6 mol/g C). The titration curves of FA samples were close to the simulated curves by the WHAM VI model at pH 8.0–8.5, but deviated more from the model at lower pH, indicating that the results determined with CLE-SV for Cd-FA complexation are relevant to the data base in the model. Calculation of the Ca competition for Cd binding by FA showed a competition effect of similar strength as the measured one, but indicated a systematic difference between measured and modeled data at pH 7.5. Using the WHAM model for comparison with FA, the complexation of Cd by the River Wyre ligands was close to that of FA, whereas stronger complexation was observed in the Lake Greifen water. These differences may originate from different ligand composition in the lake and the river.  相似文献   

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