Distribution of uranium and thorium in Irtysh River and the upriver wastewater from a rare metal mine impact on it     

Shehong LI Baoshan ZHENG Jianming ZHU Xiaoying YU 《中国地球化学学报》2006,25(B08):43-44

Uranium and Th are important radioactive elements. Most studies were focused on their environmental impact from uranium deposits and mining sites. But other sorts of mines such as rare metals mines are associated highly with uranium and thorium, too. In China, the Irtysh River is the only river that runs into the Arctic Ocean. The famous Koktokay rare metal pegmatite deposit is located in the headwater region of this river and has been exploited for several decades. The waste ore piled along the riverside as long as several kilometers. The wastewater flom the concentrating plant is discharged into the river directly. In addition, uranium and thorium can be leached from the waste ore into the river in the weathering process. So it is necessary to study the uranium and thorium distribution in the branch and trunk streams of the Irtysh River and the wastewater from the mining site impact on it. In this study, the contents of uranium and thorium in water samples from the Irtysh River and rare metal mine wastewater have been detected directly with ICP-MS. Uranium and thorium distribution and geochemical behaviors in the Irtysh River basin have been studied. The environmental uranium and thorium pollution status in the Irtysh River and wastewater from a rare metal mine impact on it have also been evaluated. The study shows that uranium and thorium contents in wastewater from a rare metal mine are as high as 78.311 μg/L and 0.627 μg/L, respectively, so we should also pay attention to the radioactive pollution from the rare metal mine. The average contents of U and Th in the branch streams of the Irtysh River are 0.572 μg/L and 0.015 μg/L, respectively. At the mean time, in the trunk of the Irtysh River, average thorium content is 0.019 μg/L while U is up to 2.234 μg/L, much higher than the average content （0.0309 μg/L） of the world rivers. From upstream to downstream in the trunk of the Irtysh River, thorium content declines gradually due to dilution by other branches and deposition itself.  相似文献   

Major ion geochemistry of Godavari River at Rajahmundry, India     

K. Balakrishna S.S. Suvarna G. Srinikethan G. Mugeraya P.K. Krishnakumar 《中国地球化学学报》2006,25(B08):268-269

Detailed time-series studies on the major ion geochemistry of tropical peninsular Indian rivers are lacking. In this backdrop, a small stretch of the Godavari River, globally ranking 32nd in terms of total discharge, is chosen for sampling at its mouth. The objectives are： （1） to understand the natural and anthropogenic sources controlling the major ion chemistry of the Godavari River at Rajahmundry, （2） processes controlling the temporal variations in major ions over a period of two years, （3） comparison of total dissolved solid （TDS） fluxes and weathering rates at Godavari River with other major tropical rivers. A total of 47 surface samples were collected, bimonthly, at five stations in the Godavari at Rajahmundry spaced over a distance of 6 km for a period of two years. Water samples were collected in pre-cleaned PP bottles. Parameters like temperature, pH, conductivity, dissolved oxygen, alkalinity were measured on-site. Samples collected for analysis of major ions were processed within a few hours of collection by filtering through 0.45 mm pore size millipore filters. Filtered water samples for major ions were transported to the laboratory in cleaned 250 mL PP bottles. Sodium and K were measured on a Flame Photometer, Ca and Mg on a Flame Atomic Absorption Spectrophotometer, Cl, NO3, SO4 by Ion Chromatography and SiO2 on a spectrophotometer. Chemical weathering of rocks controls the major ion chemistry of the Godavari River at its mouth as indicated by the alkaline nature of the river and dominant presence of Ca, Mg and HCO3 ions. Ca/Mg and Na/Mg ratios point its source to a mixture of lithological assemblages of basalt, granite-granodiorite,  相似文献   

Rare-earth element geochemistry as a tracer for clarifying the provenance of the stream sediments in Namhan River, Korea     

Seunggu LEE Jinkwan KIM Dongyoon YANG Juyong KIM 《中国地球化学学报》2006,25(B08):270-270

In the last forty years, the rare-earth elements （REEs） have been used as a powerful tool for solving various geological and geochemical problems due to their unique and chemically coherent behavior. The river sediments are produced by weathering, transportation and deposition. Nesbitt suggested that the rare-earth elements had been mobilized and fractionated during supracrustal alteration of the Torrongo granite, southeastern Australia. Nevertheless, recently, our replicate estimation for REE patterns in sediments revealed that there is nearly no variation in REE patterns. This suggests that invariability of REE patterns in weathering and solidification can be used as a tracer for constraining the provenance of stream sediments. In order to trace the pathway of the river sediments geochemically, based on the REE geochemistry from the river sediments and rocks, we have monitored the REE abundance of stream sediments at branch rivers of the Namhan River in South Korea for three years. The branches studied are Bokhacheon, Shinduncheon and Yanghwacheon. The sediments were divided into coarse （〉300 μm） and fine fractions （〈300 μm）. As a result, we could observe that major element compositions were similar to each other regardless of particle size and sampling date. This suggests that it is difficult to deduce a geochemical difference between river sediments based on major element composition and particle size. The geochemical characteristics of surrounding soils were similar to those of fine river sediments. And the chondrite-normalized REE patterns of most of the fine and coarse sediments in combination with grain sizes and drainage area showed very close relationship with the surrounding rocks. However, some sites showed that there were large variations in REE patterns including total REE abundance and Eu anomaly due to feldspars. This variation trend of REE patterns suggests that changes might have happened in sediment supply for the drainage system in the study area due to floods or large-scale construction.  相似文献   

Water geochemistry and boron isotope in the Xijiang River, SW China     

《中国地球化学学报》2006,25(B08):271-271

  相似文献   

Strontium isotope composition of the Arno River Valley waters （Tuscany, Italy） as a natural tracer of water-rock interaction and mixing processes     

Barbara Nisi Orlando Vaselli Antonella Buccianti Giulia Perini Angelo Minissale Giordano Montegrossi Franco Tassi 《中国地球化学学报》2006,25(B08):273-273

Sr isotope studies of surficial waters have highlighted that differences in the ^87Sr/^86Sr ratio and Sr concentration are primarily caused by mixing of waters of various origins with specific isotopic and chemical characteristics, resulting from water-rock interaction processes. In this paper we reported the first Sr isotopic ratios, coupled with water chemistry, the measurement was carried out on samples related to （1） the Amo River （Tuscany, central-northern Italy）, between the source and the mouth, （2） the most important tributaries and to （3） the thermal water discharges seeping out in the southern part of the basin. The main goals are： a） to use the ^87Sr/^86Sr ratio as a discriminative parameter of source areas, b） to define its variation along both the main course and principal tributaries, and c） to estimate the effects of the mixing process of the different end-embers. The outcropping rocks in the Amo River Basin are predominantly sedimentary, mainly made up of Mesozoic limestones, Oligocene sandstones and Plio-Pleistocene marine-lacustrine formations. Triassic and Mesosinian evaporites crop out in the Elsa and Era reaches, whereas Paleozoic quartzitic formations occur in the Mrs. Pisani area. Strontium isotopic composition is generally controlled by lithology and does not seem to be affected by anthropic input and flow rate. The ^87Sr/^86Sr ratios in the Arno Basin vary between 0.707963 and 0.712743, the highest ratios being related to waters circulating in the Palezoic rocks and Oligocene sandstone formations. Less radiogenic values pertain to the Elsa and Era tributaries where contributions related to the dissolution of evaporitic sequences, and mixing processes with the thermal discharges have been distinguished. The tributaries show that water samples in the pristine area have higher ^87Sr/^86Sr ratios than the respective tributaries from which water samples were collected near the confluence. Eventually, water samples collected along the Arno River, close to the mouth, tend to have Sr isotopic ratios similar to those of the present seawater.  相似文献   

Characteristics of trace elements in contaminated rivers and their environmental significance     

Xuyin YUAN Zhiyong SHEN Xu DENG Yun GAO 《中国地球化学学报》2006,25(B08):140-141

Several rivers researched around Taihu Lake in Chinese eastern plain are distributed to the west of the lake. Pollutants of different types from tributaries and inlets flow directly into the main rivers and finally into the lake. They change trace elements of rivers fi＇om which we can analyze. Researches about trace elements are helpful for understanding the pollutant characteristics, industrial structure and agricultural cultivation in the area of network rivers in the plain of China. Samples of water column, suspended matter and sediment were collected fi＇om the west rivers of Taihu Lake, which represent three typical rivers. Observation in the field and the primary composition analysis showed the Caoqiao River was mainly contaminated by industrial wastewater, the Liangxi River was discharged by domestic sewage and the Dapu River was principally input by farmland runoff. REE concentrations and their normalized curves showed obvious characters for rivers discharged by different sewages. The contents of total REE in water column followed the order of the Caoqiao River, the Dapu River and the Liangxi River fi＇om high to low. TREEs in suspended matter and sediments follow the order of the Dapu River 〉 the Caoqiao River 〉 the Liangxi River. REE normalized curves （for Australia shale） suggested that significant diversities were presented in water column, suspended matter and sediments, i.e., heavy REE enrichment in water, middle REE enrichment in suspended matter, and smooth curves for sediments. But the heavy pollution resulted in several anomalous curves in the same rivers. Some element ratios were selected as indices for polluted rivers based on their geochemical properties and diversities between rivers. The results displayed the discriminative indices for water column, suspended matter and sediment. The effective indices were Pb/Fe, Cr/Fe, Ni/Fe, Pb/Ni, Zn/Ni for water column, Cu/Al, Cu/Fe, Zn/Fe, K/Ca, K/Na, Pb/Co, Zn/Co for suspend matter and Pb/Fe, K/Ca, Ca/Mg, Zn/Ni for sediment, respectively. In general, rivers mainly discharged by industrial sewage have high ratios of Pb/Ni, K/Ca, are enriched in the middle REE and have positive Gd anomaly. The domestic sewage flowing into rivers reveals high ratios of Zn/Ni, Pb/Fe, and is enriched in the heavy REE, and has the positive Eu anomaly. If runoff of farmland enters into the rivers, it will have high ratios of Ca/Mg, K/Na, high lanthanum, and show the smooth normalized curves of REE.  相似文献   

Mercury levels in surface waters of six reservoirs in the Wujiang River     

《中国地球化学学报》2006,25(B08):151-151

  相似文献   

Mercury concentrations in a contaminated river system in Kazakhstan and biomonitoring of the local population     

Susanne M. Ullrich Huiwen HSIAO 《中国地球化学学报》2006,25(B08):238-239

The River Nura in central Kazakhstan has been heavily contaminated by mercury （Hg） from an acetaldehyde plant located in the industrial city of Temirtau. The plant released Hg-containing wastewater into the river from the 1950s until the mid 1990s and strongly contaminated the bed sediments up to 25 km downstream. In addition, a local power station released an estimated 6 million tonnes of fly-ash into the water which has adsorbed much of the Hg and has become mixed with the natural sediments. River water,fish and agricultural land in the floodplain are also contaminated by Hg. Humans are exposed to Hg primarily via the consumption of contaminated fish from the river. A survey was undertaken in June/July 2005 to investigate Hg concentrations in river water, drinking water, sediments and fish. To estimate the risk posed to the local population, approximately 300 hair samples were collected from people living in villages near the most contaminated section of the river, at a distance of between 5 and 30 km downstream of the acetaldehyde plant, and their dietary habits were recorded. Mercury concentrations in river water ranged from 2-3 ng/L upstream of the source of the pollution to 348 ng/L downstream of the factory outfall pipe. Some drinking water wells close to the river were contaminated, but deeper wells had Hg concentrations below the detection limit.  相似文献   

Groundwater Systems and Eco-hydrological Features in the Main Karst Regions of China     

LU Yaoru  ZHANG Feng''e  LIU Changli  TONG Guobang  ZHANG Yun Chinese Academy of Geological Sciences  Beijing Institute of Hydrogeology  Environmental Geology  Chinese Academy of Geological Sciences  Shijiazhuang  Hebei 《《地质学报》英文版》2006,80(5):743-753

1 Introduction Karst topography is widespread in China (Lu et al., 1973; Lu, 1986a), but its basic features are quite different in the main karstified areas in southern and northern China (Lu, 1999, 2003). The karst development appears to differ not only in the karst geomorphological types but also in the forms of the different karst water systems. The eco-hydrological features have obviously been influenced by human activities. The eco-hydrogeology is thus of great importance to study. Th…  相似文献   

疏勒河流域中下游三大盆地 地下水潜力评价          下载免费PDF全文

闫成云 《甘肃地质》2006,15(2):81-84

地下水潜力评价是资源评价的重要内容之一。本文浅析了全国地下水资源及环境问题调查评价技术要求的地下水潜力的概念和方法,以水文地质盆地为地下水系统单元,对疏勒河流域中下游三大盆地———玉门踏实、安西敦煌和花海盆地地下水潜力进行了评价,分别分析了3个盆地地下水开采潜力、利用潜力的方向,并计算各潜力大小、潜力系数级别、潜力模数大小,为疏勒河流域盆地地下水资源的开发利用、管理和调配提供了科学依据。  相似文献