Journal of Environmental Sciences - Volume 12, issue 4

Authors: Li, Jie | Wu, Yan | Wang, Ning-hui | Yang, Li-ming

Article Type: Research Article

Abstract: NH_3-activated electrode is placed in front of the electrode system of pulse corona discharge plasma. There are nozzles on the electrode. Positive DC high-voltage is applied on the nozzle-plate gap. NH_3 is injected into the reactor through nozzles, at the same time, activated and treated. These nozzles were proposed in order to make the additional gas pass through corona discharge regions near the tip of nozzles and increase the mount of radicals. The aim is to …improve the De-SO_2 efficiency by pulse discharge plasma in flue gas. The following topics are investigated and discussed in the paper: De-SO_2 effect of single NH_3-activated electrode, De-SO_2 effect of activated NH_3, the relationship between stoichiometric ratio of NH_3 to SO_2 and De-SO_2 effect of activated NH_3, mechanism of activated NH_3 De-SO_2 effect. The experimental result indicates that the De-SO_2 efficiency can be increased 5 %-10 % by activated NH_3 on the original base of De-SO_2 efficiency. Show more

Keywords: activated NH_3, De-SO_2, pulse discharge

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 448-451, 2000

Authors: Lin, Min

Article Type: Research Article

Abstract: In this work, a thorough examinations on the extractability of zinc and lead present in the steelmaking dusts using alkaline leaching process and the effectiveness of the zinc and lead separation in the resultant leaching solutions using sulfide precipitation method were made. It was found that only about 53% of zinc and over 70% of the lead could be leached out of the dusts, while the other 47% of zinc and 306 of lead were left in the leaching …residues. The zinc and lead in the resultant leaching solution can be effectively and selectively separated. When the weight ratio of sodium sulfide (M. W. = 222-240) to Pb was kept at 1.8, the lead in the solution could be precipitated out quantitatively while all the zinc was remained in the solution. The zinc left in the solution can be further recovered by the addition of extra sodium sulfide with a weight ratio of sodium sulfide to the zinc over 2.6. The resultant filtrate can be recycled to the leaching of dust in the next leaching process. Show more

Keywords: alkaline leach , leaching solutions, zinc, lead

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 452-457, 2000

Authors: Yu, Guo-ying | Wang, Guo-ping | He, Chi-quan

Article Type: Research Article

Abstract: Physiological responses on the bases of activities of antioxidant enzymes: peroxidase, catalase, superoxide dismutase and glutathione reductase as well as estimation of total protein, lipid peroxidation and thiols in the form of iprotein, non-protein, glutathione and phytochelatin measured in growing seedlings of paddy, Oryza sativa L. , from day 2 to 8 were compared following treatment of seeds for 5h with oxidative agents, paraquat 5 x 10^-5, 10^-4, 10^-3 mol/L, H_2O_2 10^-3, 5 x 10^-3, 10^-2 …mol/L, and CdCl_2 10^-5, 10^-4, 5 x 10^-3 mol/L. A significant induction of all antioxidant enzymes along with an increase in the levels of protein, lipid peroxidation and glutathione was noted in response to oxidative stress, CdCl_2 induced significant peroxidase and catalase activities but not superoxide dismutase. In a marked contrast from oxidative stress, CdCl_2 decreased glutathione reductase activity as well as glutathione levels but increased phytochelatin level. The different physiological responses thus underlined the crucial involvement of glutathione and phytochelatin in the oxidative and heavy metal-induced adaptive responses respectively. Show more

Keywords: adaptive response, oxidative stress, heavy metal, antioxidant enzymes, glutathione, phytochelatin

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 458-462, 2000

Authors: Dong, Yun-she | Scharffe, Dieter | Domroes, Manfred | Qi, Yu-chun | Zhang, Shen

Article Type: Research Article

Abstract: An enclosed chamber technique was used to measure N_2O emissions from intensively agricultural soils of the North China Plain during the periods of 1995-1996 and 1997-1998, to reflect distinct components of winter wheat and summer maize growing seasons. The results showed that the continuous application of fertilizer in agricultural soils increased N_2O emissions by a factor of 24. 1-28.1, the calculated annual chemical N fertilizer-transformed N_2O-N emissions was 0.67%. Our results indicated that the application of …organic manure also had a significant influence on soil N_2O emissions, which combined with the use of chemical N increased about 20% in a year. It was calculated that there were about 0.11% N of organic manure transformed as N_2O-N. Annual mean N_2O emission from our study area of fertilized soils was estimated to be 57.1 µgN_2O/(m² · h). A weak correlation was also found between. N_2O emissions and soil available nitrogen content NH^+_4 . Show more

Keywords: N_2O, emissions, the North China Plain, agricultural soils, chemical nitrogen, organic manure

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 463-468, 2000

Authors: Zeng, Guang-ming | Jiang, Yi-min | Guo, Huai-cheng | Huang, Gordon Guo-He

Article Type: Research Article

Abstract: In this paper, a two-dimensional numerical calculation algorithm for the water quality modeling in the Hengyang City section of the Xiangjiang River is researched considering the effect of the Dayuandu navigational key project. The research fiver is winding and has two branches resulted from an isle. The numerical calculation algorithm for the water quality modeling is set up on the basis of applying topographic map of the river course and the finite element method. The calculation …result for the water quality modeling includes the concentration fields for various pollutants. The numerical calculation algorithm for the water quality modeling set up in this paper can be applied to shallow fiver with similar topographically complicated river course. Show more

Keywords: two-dimensional river, water quality, numerical calculation algorithm

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 469-473, 2000

Authors: Wang, Yan | Wang, Hong-rui | Ning, Da-tong

Article Type: Research Article

Abstract: With the swift development of economy, the water quality of Beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater structure in the industrial sectors are analysed and discussed in terms of the indicators, such as direct wastewater-discharge coefficient, complete wastewater-discharge coefficient, direct discharge coefficient of COD and complete discharge coefficient of COD, by taking a year of 1990s as the base year. …Some countermeasures are studied and the corresponding recommendations are put forward in order to improve the water environment in Beijing. This provides a scientific ground for coordinating the relationship between the aquatic environment and economic growth in this city. Show more

Keywords: direct wastewater-discharge coefficient (DWDC), complete wastewater-discharge coefficient (CWDC), direct discharge efficient of COD (DDC of COD), complete discharge coefficient of COD (CDC of COD)

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 474-477, 2000

Authors: Wu, Kai-fen | Qiu, Ping | Wang, Zheng-jun | Wang, Jing-rong

Article Type: Research Article

Abstract: The effects of the components of solution for membrane casting and preparation conditions on the membrane perrormances are studied in this paper. Polyacrylonitrile(PAN) was used as polymer and DMAC as solvent. The ultrafiltration (UF) membranes whose cut-off of molecular weight is 150000 and flux of pure water reaches 150-200 ml/(cm² · h) were prepared by selecting proper components of solution for membrane casting and membrane preparation conditions.

Keywords: PAN, ultrafiltration membrane, large pore size

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 478-481, 2000

Authors: Xiong, De-qi | Reed, Mark | Ekrol, Narve

Article Type: Research Article

Abstract: The oil spill impact analysis (OSIA) software system has been developed to supply a tool for comprehensive, quantitative environmental impact assessments resulting from oil spills. In the system, a biological component evaluates potential effects on exposed organisms based on results from a physico-chemieal fates component, including the extent and characteristics of the surface slick, and dissolved and total concentrations of hydrocarbons in the water column. The component includes a particle-based exposure model for …migratory adult fish populations, a particle-based exposure model for spawning planktonic organisms (eggs and larvae), and an exposure model for wildlife species (sea birds or marine mammals). The exposure model for migratory adult fish populations simulates the migration behaviors of fish populations migrating to or staying in their feeding areas, over-wintering areas or spawning areas, and determines the acute effects (mortality) and chronic accumulation (body burdens) from the dissolved contaminant. The exposure model for spawning planktonic organisms simulates the release of eggs and larvae, also as particles, from specific spawning areas during the spawning period, and determines their potential exposure to contaminants in the water or sediment. The exposure model for wild species calculates the exposure to surrace oil of wildlife (bird and marine mammal ) categories inhabiting the contaminated area. Compared with the earlier models in which all kinds of organisms are assumed evenly and randomly distributed, the updated biological exposure models can more realistically estimate potential effects on marine ecological system from oil spill pollution events. Show more

Keywords: oil spill, biological exposure, acute effects, chronic accumulation, migration of fish, spawning of eggs and larvae, habitat

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 482-485, 2000

Authors: Miao, Ze-wei | Bai, Zhong-ke | Gao, Lin

Article Type: Research Article

Abstract: It is well known that the mining industry produces a large amount of derelict land, and muses pollution of water loss and soil erosion as well as other environmental damage in China. As land is under pressure in China, it is now policy to restore or reclaim land despoiled by mining, the aim being to develop sustainable and healthy arable land ecosystems. This paper outlines the principles and approaches of ecological restoration, which have been adopted in …Shanxi Province with reference to three typical surface mines. In the research, the principles of ecological engineering and ecological succession are considered as the critical theories of ecological restoration in mine degraded land. Meanwhile, the paper made a comparative research on main links of ecological rebuilding in three surface mines in Shanxi Province, which include new land construction, treatment of toxic substances, control of soil erosion, fertility management, irrigation, ecological planning and the establishment of legislation systems. As the research demonstrated, for successful restoration, new land construction is the fundamental framework, but it must be integrated with ecological engineering including ecological planning, the control of soil erosion and vegetation establishment and ecosystem creation in order to optimiee land productivity and soil fertility. In addition, the establishment of the legislation systems and organization of administration are also indispensable aspects of ecological rebuilding in mined land. Show more

Keywords: ecological restoration, land reclamation, open-pit mine

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 486-497, 2000

Authors: Duo, Li-an | Zhao, Shu-lan

Article Type: Research Article

Abstract: Abundant material with low cost was utilized to raise medium function of producing carpet turf by life rubbish. The results showed that the material used could strikingly raise water retentiveness and ventilating of medium. Through the determination of the effect of each growth index of several turfgrass, emergence density, plant height, root growth and individual plant's net primary production were all positively related to the materials amount mixed, showing that the mixture of material could promote …turfgrass growth, further proving that the material used raised medium function of producing carpet turf by life rubbish and made most use of life rubbish resources. It provided a scientific base is for application of environmental engineering by using life rubbish to produce carpet turf. So the study had both important theoretic meaning and applied value. Show more

Keywords: life rubbish, carpet turf, medium function, environmental engineering

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 498-505, 2000

Authors: Cairns, John

Article Type: Book Review

Citation: Journal of Environmental Sciences, vol. 12, no. 4, pp. 506-509, 2000