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Competitive and cooperative adsorption of arsenate and citrate on goethite

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Journal of Environmental Sciences 2009年第1期21卷 106-112页

作者： SHI Rong,JIA Yongfeng,WANG Chengzhi institute of applied ecology,Chinese Academy of Sciences,Shenyang 110016,China institute of applied ecology Chinese Academy of Sciences Shenyang 110016 China

The fate of arsenic in natural environments is influenced by adsorption onto metal （hydr）oxides. The extent of arsenic adsorption is strongly affected by coexisting dissolved natural organic acids. Recently, some studies reported that there existed competitive adsorption between arsenate and citrate on goethite. Humic acid is known to interact strongly with arsenate by forming complexes in aqueous solution, hence it is necessary to undertake a comprehensive study of the adsorption of arsenate/citrate onto goethite in the presence of one another. The results showed that at the arsenate concentrations used in this study （0.006-0.27 mmol/L）, citrate decreased arsenate adsorption at acidic pH but no effect was observed at alkaline pH. In comparison, citrate adsorption was inhibited at acidic pH, but enhanced at alkaline pH by arsenate. This was probably due to the formation of complex between arsenate and citrate like the case of arsenate with humic acid. These results implied that the mechanism of the adsorption of arsenate and citrate onto goethite in the presence of one another involved not only competition for binding sites, but the cooperation between the two species at the watergoethite interface as well.

关键词： adsorption arsenate citrate goethite

Ecological engineering land treatment systems──A new development in China

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Journal of Environmental Sciences 1996年第3期8卷 341-353页

作者： Gong Ping Sun Tieheng (institute of applied ecology, Chinese Academy of Sciences, Shenyang 110015, China) institute of applied ecology Chinese Academy of Sciences Shenyang 110015 China

This paper elucidated the necessity and possibility of developing the technology of land treatment on the basis of the analysis of shortage and pollution status of water resources in *** historical development of this technology in the world was briefly reviewed and the distinction between land treatment and conventional wastewater irrigation was discussed in details. The fundamental characteristics and functions as well as the integrity and compatibility of this ecological engineering were also summarized. It was finally concluded that this technology for wastewater treatment has broad prospects of application in China.

关键词： wastewater treatment ecological engineering land treatment system (EELTS) water pollution water resources sewage irrigation.

Simulating　sensitivities　of　Changbai　Mountain　forests　to　potential　climate　change

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Journal of Environmental Sciences 1996年第3期8卷 354-366页

作者： Yan Xiaodong Zhao Shidong (institute of applied ecology. Chinese Academy of Sciences,Shenyang 110015, China) institute of applied ecology Chinese Academy of Sciences Shenyang 110015 China

Changbai Mt. forest in the northeastern China is both a very important timber resource of China and one of the most typical and less disturbed temperate mixed evergreen coniferous-deciduous forest in the *** this paper, NEWCOP. a gap class model of forest growth and succession was proposed to simulate the sensitivity of the forest in Changbai Mountain to elevate CO_2. warmer temperature and precipitation change. NEWCOP was tested on long term simulation behaviors and short term fitting ability to field data. About the response of forests of Changbai Mountain to possible climate change, NEWCOP suggested that forest landscape go up within long term and forest biomass comes down within short term because of dieback of forest trees.

关键词： gap model climate change forests China.

Compound contamination and secondary ecological effects of Cd and As in soil－alfalfa ecosystems

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Journal of Environmental Sciences 1994年第3期6卷 330-336页

作者： Zhou Qixing Gao Zhengmin(institute of applied ecology, Chinese academy of Sciences),Shenyang 10015,China)

d and As both have harmful effects on the growth,development and seed germination of alfalfa, especially in such a condition as the coexistence of Cd and As in soil environment The research using the pot-culture imitative method first found that if soil was simultaneously polluted by Cd and As,function of alfalfa absorbing Cd from soil may be promoted because of the existence of As,in conversely,Cd may inhibit alfalfa plant from absorbing As It was also found that secon- dary ecological effects were most likely to be brought out due to the coexistence of Cd and As. For example,alfalfa is passive to excessively absorb Cu and Pb .The harmful effects undoubtedly intensi- fy the contamination of alfalfa, The results showed that the mechanism of the interaction among Cd,As,Pb and Cu in soil-alfalfa ecosystems is very complicated.

关键词： compound contamination,ecological effects,Cd As soil.

Effect of Cultivation on Spatial Distribution of Nematode Trophic Groups in Black Soil

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Pedosphere 2003年第2期13卷 97-102页

作者： LIANG WENJU, LI QI, JIANG YONG, CHEN WENBO and WEN DAZHONGShenyang Experimental Station of ecology, institute of applied ecology, the Chinese Academy of Sciences, Shenyang 110016 (China) Shenyang Experimental Station of ecology Institute of Applied Ecology the Chinese Academy of Sciences Shenyang 110016 China

Geostatistics combined with GIS was applied to assess the spatial distribution of nematode trophic groups following two contrasting soil uses in the black soil region of Northeast China. Two plots, one with fallow for 12 years and the other cultivated, were marked on regular square grids with 2-m spacing. Soil samples were collected from each sampling point, nematodes were extracted from these samples and classified into four trophic groups: bacterivores, fungivores, plant parasites, and omnivores/predators. The numbers of total nematodes and trophic groups analyzed had normal distributions on both fallow and cultivated plots. The absolute abundances of total nematodes and trophic groups were observed to be much more homogeneous on cultivated plot than on fallow one. Geostatistical analysis showed that the densities of total nematodes and trophic groups on both fallow and cultivated plots exhibited spatial dependence at the sampled scale and their experimental semivariograms were adjusted to a spherical or exponential model, except those of bacterivores and fungivores on cultivated plot. The spatial distribution of nematode trophic groups was found to be different for the two land uses, indicating that cultivation changed the native condition for soil nematode activities.

关键词： cultivation GIS, soil nematode spatial distribution trophic group

Techno-economic analysis of municipal wastewater land treatment systems in China

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Journal of Environmental Sciences 1993年第1期5卷 16-22页

作者： Huang Chuyuinstitute of Environmental Protection of Jilin Province, Jilin 132011, ChinaOu Ziqing institute of applied ecology, Chinese Academy of Sciences, Shenyang 110015, China Inst of Env Protection of Jilin Province Jilin 132011 China China

This paper analyses the capital costs, power consumption and operation costs of municipal wastewater land treatment systems, including rapid infiltration, slow-rate infiltration, overflow and constructed wetland, by means of series engineering design. The results show that land treatment can save 50-70% of capital costs, 80-90% of power and 75-85% of operation costs when compared with secondary treatment.

关键词： land treatment system techno-economy series design cost model.

Resourceful ecological treatment of wastewater in urban ecosystem

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Journal of Environmental Sciences 1994年第4期6卷 487-495页

作者： Song Yufang Sun Tieheng Gong Ping Chang Zhijun (institute of applied ecology, Chinese Academy of Sciences, Shenyang 110015 . China)

The treatment amount of wastewater is restricted to a small percentage in China. One of thereasons for that is the shortage of funds. Therefore , developing the technology of cost-effective , low energy-consuming and high efficiency is one of the important way to speed up the steps of wastewater *** paper elucidated the principal and charactertics of the resourceful ecological treatment of wastewater. Asuccessful example of resourceful ecological land treatment of wastewater was given. The key points and therelative policies concerning the further development of resourceful ecological treatment of wastewater as asets of technologies have been suggested.

关键词： ecological treatment water resources wastewater pollution.

Compound pollution of Cd,Pb,Cu,Zn,As in plant-soil system and its prevention

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Journal of Environmental Sciences 1996年第4期8卷 474-482页

作者： Wu Yanyu Wang Xin Li Ying(institute of applied ecology,Chinese Academy of Sciences,Shenyang 110015, China) institute of applied ecology Chinese Academy of Sciences Shenyang 110015 China

By means of both pot and field tests,this paper studied the contents of Cd,Pb,Cu,Zn and As and their ecological effects on plant-soil *** tissues of crops and soil *** was found that there exist synergistic effect among these five elements,especially for Cd in *** reclaniation of soil polluted by these elements in combination is rather difficult to be carried *** distinctive ecological and chemical behaviors between Cd and As make various reclamation measures less applicable,and thus,further research measures are necessary.

关键词： compound pollution plant-soil system heavy metals.

Changes　of　landscape　pattern　and　its　influence　on　environment　in　Dongling　District，Shenyang　City，China

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Journal of Environmental Sciences 1996年第4期8卷 466-473页

作者： Zhao Yi Liu Zhenguo Xu Lan (institute of applied ecology,Chinese Academy of Sciences,Shenyang 110015,China) institute of applied ecology Chinese Academy of Sciences Shenyang 110015 China

Dongling District of Shenyang City is an ecotone between city and countryside. Human disturbance causes serious changes of the landscape pattern studed by using indices of landscape pattern: proportion in land cover types,average area and number of patches,fractal dimension of patches,indices of diversity, dominance and contagion and index of human *** are many changes of the landscape pattern of Dongling District for the last 30 *** landscape pattern is breaking, the diversity is increasing and the dominance is *** are different fractal dimension and contagion in distinct geomorphological *** changes of landscape pattern bring some beneficial results but causes deterioration of ecological environment.

关键词： landscape pattern ecotone ecological environment.