城市化进展和城市水环境   总被引：2，自引：0，他引：2  

温彦  李云凤 《河南地质情报》1996,(4):28-32

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Geochemical features of heavy metals in core sediments of northwestern Taihu Lake, China     

刘恩峰沈吉  刘兴起 《中国地球化学学报》2005,24(1):73-81

Sequential core sediments from northwestern Taihu Lake in China were analyzed for grain size, organic carbon and heavy metal content. The sediments are composed of organic-poor clayey-fine silts. The chemical speciations of Cu, Fe, Mn, Ni, Pb, and Zn were also analyzed using the BCR sequential extraction procedure. Cu, Fe, Ni, and Zn are mainly associated with the residue fraction; Mn is concentrated mainly in exchangeable/carbonate fraction and residue fraction; and Pb mainly in Fe/Mn oxide fraction and organic/sulfide fraction. The exchangeable/carbonate fractions of Cu, Fe, Ni, Zn and Pb are lower. The fractions of Ni, Pb and Zn bound to the Fe/Mn oxide have significant correlations with reducible Mn; the organic/sulfide fractions of Cu, Mn, Ni, Pb, and Zn have significant correlations with TOC. The extractable fractions of Cu, Mn, Ni, Pb, and Zn are high at the top 4 cm of the core sediments as compared to those in the deeper layers, showing the anthropogenic input of heavy metals is due to rapid industrial development. The heavy metal pollution history of the sediments has been recorded since the late 1970s, determined by the result of ^137Cs dating.  相似文献   

Landscape pattern dynamics of water body in Kaifeng city in the 20th century     

CAOXinxiang DINGShengyan 《地理学报(英文版)》2005,15(1):106-114

Landscape spatial pattern mainly refers to the distribution of patches, which are different in size and shape in space owing to the interaction of various ecological activities. In landscape ecology study, landscape pattern has been one of the key study areas. Water body landscape plays an important role in the development history of a city, but at present city water body landscape in many cities has been destroyed, hence protecting water body in the city is becoming more and more important. In order to protect city water body landscape reasonably, the precondition is to probe the dynamics of water body landscape. Based on historical data and remote sensing data, six indexes including patch number, patch area, landscape dominance index, fractal dimension, patch density and connectivity index etc. were used to analyze landscape pattern dynamics of water body in Kaifeng city since the end of the Qing Dynasty (in the 20th century). The results showed: (1) Since the end of the Qing Dynasty, landscape area of water body in Kaifeng city increased first and then decreased from 1898 to 2002AD; the landscape dominant degree had the same changing tendency with the area. (2) Patch number of water body landscape in Kaifeng city had an increase from 1898 to 2002, but maximum area of patch, minimum area of patch and average area of patch decreased, which resulted in an increase in landscape fragment degree. (3) Connectivity index decreased and fractal dimension increased from 1898 to 2002. The reasons for these changes were the repeated overflows and flooding of the Yellow River and the influence of human activities.  相似文献   

谨防长江水资源遭污染     

钟立勋  殷跃平 《中国地质》1989,(7):29-30

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Distribution and behavior of heavy metals in a river polluted by acid mine drainage in the Dabaoshan mine area, China     

Xingchun DUAN Zhi DANG Jianmin ZHOU Xiaoyun YI 《中国地球化学学报》2006,25(B08):34-35

Acid mine drainage （AMD） has been recognized as a major environmental pollution problem over past decades. This pollutant effluent is complex and is characterized by elevated concentrations of iron and sulfate, low pH, and high concentrations of a wide variety of metals depending on the host rock geology. Massive inadvertent discharges from acid mines have given rise to dramatic cases of ecological damage. These events indicate an improved understanding of the mechanism controlling metal transport to the river is important, since the aquatic ecology will be affected, to some degree, dependent on the phase （dissolved or particulate） in which the metal is transported. In this study, polluted water samples were collected along the Hengshi River near the Dabaoshan mine, Guangdong, China, in April 2005. The concentrations of dissolved Cu, Zn, Cd and Pb have been determined using ICP-MS and the chemical speciation of those metals in suspended particles was examined using BCR methods and SEM/EDX mineralogical analysis. Combining these two sets of data, the intention was to develop geochemical concepts, which explain the behavior of Cu, Zn, Cd and Pb in particle-water interactions of heavy metals in AMD. The results show that the dissolved heavy metals exhibited non-conservative behavior in the Hengshi River. The dissolved and particulate Cu, Zn, Cd and Pb have the similar spatial distribution, which decreased gradually along the river except in the lower reaches because of the absorption-desorption between dissolved and particulate phases. Although the metal concentrations in both phases were elevated, dissolved metals were dominant and had the maximum concentrations in the low pH region.  相似文献   

Arsenic pollution of groundwater and its release mechanism in the central part of the Hetao Plain, Inner Mongolia, China     

Hanjin LUO Hiroki Hagiwara Kouichi Terasaki Fumio Kanai Takahisa Yoshimura Junji Akai Takeo Ta kano Tadashi Hasegawa Yoh＇ichi Sakai 《中国地球化学学报》2006,25(B08):101-102

Arsenic pollution of groundwater has become a serious health problem in several regions of the world. Wuyuan County located in the central part of the Hetao Plain, Inner Mongolia, is one of the most severely arsenic polluted areas. Peoples of the county have used groundwater of shallow （12-25 m） tube-well as drinking water. The groundwater is Na-HCO3 and Na-Cl type on the piper plots and aligns with steady Ca ： Mg ratio on cation diagram. The arsenic content in the water is more than 0.2 mg/L and the highest value reaches up to 0.52 mg/L. Drilling data show that Holocene sediments are divided into three zones on the basis of their color appearances; brown, grey and dark gray zones. The strata from 2m to 9-14m under the surface are mainly composed of clay and silt which are impermeable layers. The grey and dark grey zones composed of sand underlie the impermeable bed and the condition of their zones is reductive. At the depth of 30 m near the bottom of drilling, ORP of the groundwater is -300- -400 mV. The dark grey sand changes to yellow in color under the atmosphere. Under reducing environment, the color returns to its original dark grey. The characteristic color is due to amorphous or low-crystalline Fe sulfide coating sand grains. The sediments are of fluvial origin by the Yellow River. The arsenic content in the sediments is rich in fine-grained part and its values are more than 20 mg/kg in clay layer. The highest is 38 mg/kg. X-ray diffraction and macroscopic observation show that the clay layer is made of minerals such as chlorite and illite and contains high quantities of organic matter.  相似文献   

Groundwater pollution by arsenic concentration in sedimentary aquifers in the Indo-Gangetic Basin of Nepal     

Sunil Kumar Dwivedi Pusker Raj Joshi Sanjiv Shrestha Yaga Raj Bhandari Ram Bhadur Sah 《中国地球化学学报》2006,25(B08):139-139

Naturally occurring arsenic （As） in groundwater of sedimentary aquifers has emerged as a global problem, and the Indo-Gangetic Basin of Nepal is no exception. In the sedimentary aquifers of the Indo-Gangetic Basin, arsenic enrichment and mobilization in groundwater by natural processes is considered an issue of major environmental health concern. About 11 million people, 47% of Nepali＇s total population living in the region and approximately 90% of them are relying on groundwater as their major source of drinking water. Moreover, 205555 ha of agricultural land in the basin are irrigated by groundwater through large numbers of deep and shallow irrigation tubewells for extensive cultivation of crops which has lead to creation of other pathways for arsenic ingestion among the people living in the region. It is estimated that around 0.5 million people in the basin are living at risk of arsenic poisoning In addition, some recent research shows the prevalence of dermatosis related to arsenicosis from 1.3% to 5.2 % and the accumulation of arsenic in biological samples like hair and nails much higher than the acceptance level. In these circumstances, the source of the natural arsenic concentration in groundwater of the Indo-Gangetic Basin is quite essential to explore. Therefore, to investigate the source of arsenic and management of arseniferious groundwater used for human consumption and irrigation, along with treatment or avoidance, is clearly an issue of research concern. Present research is carried out to understand the source of natural arsenic and its mobilization in groundwater of the Indo-Gangetic Basin. For this, we have collected bedrock, aquifer sediments and water samples from the study area. Sediment samples were taken from different lithofacies viz. clay, silt, sand and sandy gravels from groundwater aquifer where arsenic concentration is high. Water samples were taken from domestic shallow and deep tubewells in grid pattern. Bedrock samples were collected from source of the aquifer sediment, northern part of the Indo-Gangetic Basin, especially from the Siwalik and Lesser Himalaya. This paper particularly focuses on geology, mineralogy, hydro-geochemistry and sedimentary analysis of the high arsenic affected districts; Rautahat, Sarlahi, Parsa, and Kailali of Nepal.  相似文献   

Non-point source pollution of Wujiang River watershed in Guizhou Province, SW China     

Congguo TANG Congqiang LIU 《中国地球化学学报》2006,25(B08):141-142

The amount of pollution from non-point sources flowing in the streams of the Wujiang River watershed in Guizhou Province, SW China, is estimated by a GIS-based method using rainfall, surface runoff and land use data. A grid of cells, 100 m in size, is laid over the landscape. For each cell, mean annual surface runoff is estimated from rainfall and percent land use, and expected pollutant concentration is estimated from land use. The product of surface runoff and concentration gives expected pollutant loading from that cell. These loadings are accumulated going downstream to give expected annual pollutant loadings in streams and rivers. By dividing these accumulated loadings by the similarly accumulated mean annual surface runoff, the expected pollutant concentration from non-point sources is determined for each location in a stream or river. Observed pollutant concentrations in the watershed are averaged at each sample point and compared to the expected concentrations at the same locations determined from the grid cell model. In general, annual non-point source nutrient loadings in the Wujiang River watershed are seen to be predominantly from the agricultural and meadow areas.  相似文献   

Sediment records of persistent organic pollutants （POPs） in relation to regional economic development： A comparison study in both Pearl River Delta and Yangtze River Delta, China     

Gan ZHANG Lingli GUO Guoqing LIU Jun LI Zhangdong JIN Shihua QI Xiangdong LI 《中国地球化学学报》2006,25(B08):188-189

Persistent organic pollutants （POPs） are semi-volatile chemicals that are toxic to wildlife and human. Typical POPs include most organochlorine pesticides （OCPs）, polycyclic aromatic hydrocarbons （PAHs）, polychlorobiphenyls （PCBs）, polybrominated biphenyl ethers （PBDEs）, etc. Most POPs are hydrophobic, capable of accumulating and existing for a long time in the sediments. Well preserved, laminated sediment layers hence can serve as archives for POP pollution history in the sediment pool. Rapid economic growth has taken place since the early 1980s in most parts of China, of which the Yangtze River Delta, the Pearl River Delta and the Pan-Bohai Bay took the lead. Along with the brilliant regional economic development, the environmental quality has been severely deteriorated. For a more sustainable economic and social development, it is of vital need to understand the relationship between regional economic development and environmental pollution.  相似文献   

Assessment of cadmium contamination in the sediments of Changjiang （Yangtze） River by reflectance spectroscopy     

Farid Moore Fatemeh Rastmanesh 《中国地球化学学报》2006,25(B08):226-226

The Takab area in NW of Iran is an important gold mineralized region with a long history of gold mining. In this study ASTER data is used to evaluate environmental effects of gold mining. The results show that mining activities have resulted in release of potentially toxic metals （PTMs） in the area. Principal component analysis （PCA） of ASTER data is used to map sources of PTMs and their secondary hosts （iron oxides） through alteration mapping. The results show that selective PCA is a robust yet time consuming technique for alteration mapping. A color composite is created for finding common hydrothermally altered rocks. The created color composite successfully mapped the known deposits and anomalous areas identified by geological survey of Iran. Because of the low spatial resolution of ASTER sensor, the iron oxide mapping is restricted to the wider portions of the streams. Spectral analyses confirm the presence of hematite and goethite in stream sediments. This is in accordance with measured pH values.  相似文献