Journal of Environmental Sciences - Volume 16, issue 5

Authors: YE, Ya-ping | WANG, Ru-song | REN, Jing-ming | HU, Dan | YUAN, Shao-jun | WANG, Min

Article Type: Research Article

Abstract: Freshwater ecosystems provide a host of services to humanity. These services are now rapidly being lost, not least because of the inability of making the impacts measurable. To overcome this obstacle, assessment frameworks for freshwater ecosystem services are needed. A simple water equivalent framework to assess the ecological services provided by freshwater ecosystems was developed in this study. It translated the occupation of freshwater ecosystem services into biologically freshwater volumes and then compares this …consumption to the freshwater throughput, that is, the ecological capacity available in this region. In this way, we use the example of Yangzhou Prefecture, to account the main categories of human occupation of water ecosystem services. The result showed that there is a huge gap between the consumption and the supply of freshwater ecosystem services. This must encourage local government to make land-use and water management decisions both economically rational and environmentally sound. Show more

Keywords: freshwater ecosystems, services, human impacts, assessment, water equivalent, Yangzhou Prefecture

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 755-761, 2004

Authors: TANG, Jun | SHEN, Yong-ming | ZOU, Zhi-li | QIU, Da-hong | ZHENG, Yong-hong

Article Type: Research Article

Abstract: The experiments on pollutant movement in surf zone were conducted on the two gentle beaches (with slope of 1:100 and 1:40, respectively), for diverse wave cases. The movement contours and direction of pollutants, under the action of regular and random waves with diverse wave amplitudes, were provided and studied in this paper. It was shown that, due to complicated hydrodynamics in surf zone, the pollutant movement state is quite complicated and different from that in pure …current zone. Show more

Keywords: surf zone, random wave, regular wave, pollutants

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 762-764, 2004

Authors: OUYANG, Zhi-yun | ZHAO, Tong-qian | WANG, Ru-song | SÖDERLUND, Leif | ZHANG, Qiao-xian

Article Type: Research Article

Abstract: Limited water resources, increasing demand, low use efficiency, and serious pollution result in severe water resource difficult in China. The evaluation of addressing water problems and the search for effective countermeasures that ensure sustainable water use are key to China's sustainable development. The "compound water security" consists of food security, life security, environmental security, and economic security. By establishing a conceptual model, the water security of China has been simulated in terms …of four scenarios called BAU (the business-as-usual scenario), TEC (the technology and economics scenario), IVL (the institution, values, and lifestyles scenario) and TSD (toward sustainable development) in this paper. The results indicated that water crises, especially water shortages, are being experienced now and will continue to do so for a relatively long time in China and that it is possible to reach a basic balance between supply and demand of water and grain under the TSD developing pattern by a series of approaches including technological innovation, policy adjustments, and behaviour inducement. Show more

Keywords: water resource, water security, scenarios, simulation, China

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 765-769, 2004

Authors: SHENG, Xiu-mei | XIONG, Li | WU, Zhen-bin | TANG, Hong-feng | LIU, Tao | WANG, Yuan

Article Type: Research Article

Abstract: The acute toxic effect of the pesticide cypermethrin to Daphnia magna HB was examined. D. magna HB was exposed to cypermethrin at concentrations of 0, 1, 3, 5, 7, and 9 mg/L for 24 h. Data showed that the 24 h-LC_{50} of cypermthrin on D. magna HB was 4.81 mg/L. In contrast, the 24 h-LC_{50} of K_2 Cr_2 O_7 (the national standard toxicant) to Daphnia magna was 0.38 …mg/L in the current study. Results indicated that the Daphnia magna was very sensitive to pesticides. In addition, the effects of the culture condition (such as hardness, temperature and DO etc.) on Daphnia magna HB was also studied. Show more

Keywords: cypermethrin, Daphnia magna HB, toxicity

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 770-771, 2004

Authors: WANG, Rong-chang | WEN, Xiang-hua | QIAN, Yi

Article Type: Research Article

Abstract: The changes of structural and functional parameters of aquatic microbial communities in continuous water on campus of Tsinghua University, China are investigated by polyurethane foam unit (PFU) method. The measured compositions of the communities include alga, protozoa, and some metazoa (such as rotifers). The measured indicators of water quality include water temperature, pH value, dissolved oxygen (DO), potassium permanganate index(COD_{Mn} ), total nitrogen (TN), total phosphorus (TP) and chlorophyll-a (Chla). The …trophic level, expressed by the trophic level indices (TLIc), is assessed with analytic hierarchy process and principal component analysis (AHP-PCA) method. The changing trends of the structural and functional parameters of aquatic microbial communities, such as Margalef index of diversity (D), Shannon-weaver index of diversity (H), Heterotropy index (HI), number of species when the colonization gets equilibrium (S_{eq} ), colonizing speed constant (G) and time spent when 90 percent of S_{eq} colonized in PFU (T_{90%} ), are also analyzed. The experimental results showed the succession of aquatic microbial communities along the water flow is consistent with the water quality changes, so the parameters of microbial community can reflect the changes of water quality from the ecological view. Show more

Keywords: succession, aquatic microbial community, polyurethane foam unit (PFU) method, water quality, biodiversity, biomonitoring

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 772-778, 2004

Authors: LI, Can | XU, Li | SHAO, Min | ZHANG, Ren-jian

Article Type: Research Article

Abstract: A 2-dimensional atmospheric transport model is deployed in a simplified CO_2 inverse study. Calculated carbon flux distribution for the interval from 1981 to 1997 confirms the existence of a terrestrial carbon sink in mid-high latitude area of North Hemisphere. Strong interannual variability exists in carbon flux patterns, implying a possible link with ENSO and other natural episodes such as Pinatubo volcano eruption in 1991. Mechanism of this possible link was investigated with statistic method. …Correlation analysis indicated that in North Hemisphere, climatic factors such as temperature and precipitation, to some extend, could influence the carbon cycle process of land and ocean, thus cause considerable change in carbon flux distribution. In addition, correlation study also demonstrated the possible important role of Asian terrestrial ecosystems in carbon cycle. Show more

Keywords: 2-D transport model, inverse study, carbon cycle, ENSO, interannual variability

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 779-783, 2004

Authors: MA, Tao-wu | WANG, Zi-jian | LIU, Jian-kang

Article Type: Research Article

Abstract: The potential endocrine disrupting effects and other toxicity effects on aquatic biota resulted from food uptake was simulated by feeding the laboratory cultured rare minnow (Gobiocypris rarus) with field collected Limnodrilus sp. The results indicated that the food chain processes affected significantly the growth, slightly reduced gonadosomatic indices, and elevated hepatosomatic indices. There was an obvious vitellogenin (VTG) induction, which generally only occurred in mature female, in the serum of juvenile rare minnow …and mature male when fed with Limnodrilus sp. In addition, the rare minnow feeding on Limnodrilus sp. had significantly high renal indices, it meant obvious renal hyperplasia. The present work suggested that Limnodrilus sp. from field water may contain toxic pollutants and could lead to endocrine disruption effects to the predators. It was concluded that endocrine disruptors may not only be assimilated through water, but also be bioconcentrated through food web. The results also suggested the importance of food selection in conducting the study of endocrine disruption effects using sensitive species. Show more

Keywords: rare minnow (Grobiocypris rarus), Limnodrilus sp., endocrine disruption, food chain, vitellogenin

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 784-787, 2004

Authors: CHEN, Ying-xu | HUA, Yu-mei | ZHANG, Shao-hui

Article Type: Research Article

Abstract: The effect of elemental sulfur concentration on bioleaching of Cu, Zn and Pb and loss of fertilizer value from sewage sludge was investigated in flasks by batch experiments. The results showed that the ultimate pH of sludges with 3–5 g/L of sulfur added was about 1.3 and the production of SO_4^{2-} had good correlation with the elemental sulfur concentration. The sensitivity of removal efficiency of metals to sulfur concentration was: Pb>Cu>Zn. The sulfur concentration …except for 3–5 g/L had significant effect on the solubilization of Cu, Pb and Zn. The highest solubilization efficiency for sludge with 3 g/L of sulfur was 87.86% for Cu, 32.72% for Pb and 92.14% for Zn, which could make the treated sludge easily meet the metal limitations for land application. The sulfur concentration of 3 g/L was enough for the solubilization of all three heavy metals. The influence of sulfur concentration on solubilization of total nitrogen and potassium from sludge was negligible, but that on solublization of total phosphorus was of great importance. The loss of nitrogen, phosphorus and potassium of sludge with 3 g/L of sulfur by bioleaching was 38.2%, 52.1% and 42.8% respectively, and the sludge still remained satisfactory fertilizer value after bioleaching. Show more

Keywords: sewage sludge, heavy metals, bioleaching, substrate, fertilizer value

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 788-792, 2004

Authors: ZHANG, Run-duo | HE, Hong | SHI, Xiao-yan | ZHANG, Chang-bin | HE, Bang-quan | WANG, Jian-xin

Article Type: Research Article

Abstract: The preparation of ethanol-diesel fuel blends and their emission characteristics were investigated. Results showed the absolute ethanol can dissolve in diesel fuel at an arbitrary ratio and a small quantity of water (0.2%) addition can lead to the phase separation of blends. An organic additive was synthesized and it can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The emission characteristics of 10%, 20%, and 30% …ethanol-diesel fuel blends, with or without additives, were compared with those of diesel fuel in a direct injection (DI) diesel engine. The experimental results indicated that the blend of ethanol with diesel fuel significantly reduced the concentrations of smoke, hydrocarbon (HC), and carbon monoxide (CO) in exhaust gas. Using 20% ethanol-diesel fuel blend with the additive of 2% of the total volume, the optimum mixing ratio was achieved, at which the bench diesel engine testing showed a significant decrease in exhaust gas. Bosch smoke number was reduced by 55%, HC emission by 70%, and CO emission by 45%, at 13 kW/1540 r/min. However, ethanol-diesel fuel blends produced a few ppm acetaldehydes and more ethanol in exhaust gas. Show more

Keywords: ethanol-diesel fuel blends, preparation, emission, acetaldehyde, ethanol

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 793-796, 2004

Authors: LIU, Yun-guo | XU, Wei-hua | ZENG, Guang-ming | TANG, Chun-fang | LI, Cheng-feng

Article Type: Research Article

Abstract: Investigation on Cr(VI) reduction was conducted using Pseudomonas aeruginosa. The study demonstrated that the Cr(VI) can be effectively reduced to Cr(III) by Pseudomonas aeruginosa. The effects of the factors affecting Cr(VI) reduction rate including carbon source type, pH, initial Cr(VI) concentration and amount of cells inoculum were thoroughly studied. Malate was found to yield maximum biotransformation, followed by succinate and glucose, with the reduction rate of 60.86%, 43.76% and 28.86% respectively. The optimum …pH for Cr(VI) reduction was 7.0, with reduction efficiency of 61.71% being achieved. With the increase of initial Cr(VI) concentration, the rate of Cr(VI) reduction decreased. The reduction was inhibited strongly when the initial Cr(VI) concentration increased to 157 mg/L. As the amount of cells inoculum increased, the rate of Cr(VI) reduction also increased. The mechanism of Cr(VI) reduction and final products were also analysed. The results suggested that the soluble enzymes appear to be responsible for Cr(VI) reduction by Pseudomonas aeruginosa, and the reduced Cr(III) was not precipitated in the form of Cr(OH)_3 . Show more

Keywords: Pseudomonas aeruginosa, Cr(VI) reduction, reduction rate, Cr(VI) remediation

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 797-801, 2004

Authors: GUO, Hui-dong | HE, Pin-jing | SHAO, Li-ming | LI, Guo-jian

Article Type: Research Article

Abstract: The landfill of municipal solid waste (MSW) could be regarded as denitrification reactor and used in ammonia nitrogen biological removal process. In this research, the process was applied to municipal solid waste (MSW) collected in Shanghai, China, which was characterized with high food waste content. The NH_4^+ removal efficiency in the system of SBR nitrifying reactor followed by fresh and matured landfilled waste layer in series was studied. In the nitrifying reactor, above 90% …of NH_4^+ in leachate was oxidized to NO_2^- and NO_3^- . Then high concentrated NO_2^- and NO_3^- was removed in the way of denitrification process in fresh landfilled waste layer. At the same time, degradation of fresh landfilled waste was accelerated. Up to the day 120, 136.5 gC/(kg dry waste) and 17.9 gN/(kg dry waste) were produced from waste layer. It accounted for 50.15% and 86.89% of the total carbon and nitrogen content of preliminary fresh waste, which was 4.42 times and 5.17 times higher than that of reference column respectively. After filtering through matured landfilled waste, BOD5 concentration in leachate dropped to below 100 mg/L, which would not affect following nitrification adversely. Because the matured landfilled waste acted as a well methanogenic reactor, 23% of carbon produced accumulatively from fresh landfilled waste degradation was converted into CH_4 . Show more

Keywords: landfill leachate recirculation, ammonia biological removal, fresh landfilled waste, matured landfilled waste

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 802-807, 2004

Authors: ZHANG, Ruo-bing | WU, Yan | LI, Guo-feng | WANG, Ning-hui | LI, Jie

Article Type: Research Article

Abstract: Degradation of the Indigo Carmine (IC) by the bipolar pulsed DBD in water-air mixture was studied. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetitive rate and ect., on color removal efficiency of dying wastewater were investigated. Concentrations of gas phase O_3 and aqueous phase H_2 O_2 under various conditions were measured. Experimental results showed that air bubbling facilitates the breakdown of water …and promotes generation of chemically active species. Color removal efficiency of IC solution can be greatly improved by the air aeration under various solution conductivities. Decolorization efficiency increases with the increase of the gas flow rate, and decreases with the increase of the initial solution conductivity. A higher pulse repetitive rate and a larger pulse capacitor C_p are favorable for the decolorization process. Ozone and hydrogen peroxide formed decreases with the increase of initial solution conductivity. In addition, preliminary analysis of the decolorization mechanisms is given. Show more

Keywords: water treatment, water-air mixture, DBD, Indigo Carmine

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 808-812, 2004

Authors: YU, Xue-chun | HE, Ke-bin | MA, Yong-liang | YANG, Fu-mo | DUAN, Feng-kui | ZHENG, Ai-hua | ZHAO, Cheng-yi

Article Type: Research Article

Abstract: A simple, sensitive and convenient ion chromatography (IC) method was established for the simultaneous determination of twelve water-soluble inorganic ions (F^- , Cl^- , NO_2^- , NO_3^- , SO_3^{2-} , SO_4^{2-} , PO_4^{3-} , Na^+ , NH_4^+ , K^+ , Mg^{2+} ) and sixteen water-soluble organic ions (formate, acetate, MSA, oxalate, malonate, succinate, phthalates, etc.) in atmospheric …aerosols. The linear concentrations ranged from 0.005 μg/m^3 to 500 μ/m^3 (r = 0.999–0.9999). The relative standard deviation (RSD) were 0.43%–2.00% and the detection limits were from 2.7 ng/m^3 to 88 ng/m^3 . The proposed method was successfully applied to the simultaneous determination of those inorganic ions and organic ions in PM_{2.5} of Beijing. Show more

Keywords: ion chromatography, water-soluble ions, aerosols, Beijing

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 813-815, 2004

Authors: LI, Pei-jun | JING, De-bing | ZHOU, Qi-xing | ZHANG, Chun-gui

Article Type: Research Article

Abstract: To exploit peashrub resources in Ordos as fodders, it is very crucial to realize industrial production of cheap cellulase of high activity by optimizing culture technology, especially culture substrate. In this study, a new prescription experiment based on uniform design ideal was invented and successfully applied in the solid fermentation of Trichoderma koningii F244, which being performed with two different temperature degrees. The activities of FPA, cotton lyase, CMCase and β-glucosidase were assayed and then …mathematical models of enzymatic activities, which were figured out by Unconstraint Mathematical Programming, were developed by Multivariate Regression Program of SPSS10.0. Enzymatic activities of optimized substrate prescriptions corresponding to mathematical models were forecasted to determine an ideal substrate prescription. It is revealed that in solid fermentation, Tween80 has negative effect on cellulase production. Furthermore, the ideal prescription for cellulase complex production by Trichoderma koningii F244 was straw powder 16.9%,wheat bran 26.5%, (NH_4 )_2 SO_4 9.5% and water 47.1%, whose corresponding cellulase activity was expected to be at the same high level with that of Trichoderma reesei Q9414 on its own recommended substrate. Especially, goats mainly fed on peashrub tissues mixed with cellulase complex of this prescription and culture technology, got an incremental ratio of 0.3 kg/d, which brought a very promising feeding prospect for local peashrub resource. By populization of this cellulase complex, it can integrate living standard, economic construction of local residents into vegetational restoration tightly and thus this paper will be very meaningful to be use for reference for western China like Ordos to realize its sustainable development of economy, society and environment. Show more

Keywords: Trichoderma koningii, substrate prescription, FPA, CMCase, cotton lyase, β-glucosidase

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 816-820, 2004

Authors: LU, Qing-gang | LI, Zhi-wei | NA, Yong-jie | BAO, Shao-lin | SUN, Yun-kai | HE, Jun

Article Type: Research Article

Abstract: Influence of co-firing rate on SO2 emission from co-firing municipal solid waste (MSW) and bituminous containing high amount of sulfur (1.79%) was studied in a 0.15 MWt circulating fluidized bed (CFB). The temperature selected is 1123 K, typical for MSW incineration using CFB. The particle concentration in the dilution zone of the furnace, the alkali metal concentration and sulfate concentration in the recirculating ash and fly ash, and flue gas composition were determined. The results showed …that the addition of MSW leads to a significant decrease in SO_2 emission. Concentration of SO_2 in flue gas decreased to 0 with the co-firing rate greater than 51%. This reduction in SO_2 emission is attributed both to the high particle concentration in the dilution zone of the furnace, the high content of alkali metals in the bed material, and to the comparatively high concentration of HCl in flue gas during co-firing of MSW and bituminous. Show more

Keywords: co-firing, municipal solid waste, bituminous, CFB, SO_2

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 821-824, 2004

Authors: JIN, Xing-long | HUANG, Guo-lan | JIANG, Gui-bin | ZHOU, Qun-fang | LIU, Jing-fu

Article Type: Research Article

Abstract: The wide occurrence of estrogenic compounds 4-tert-octylphenol, 4-nonylphenol, bisphenol A in surface water of Guanting Reservoir was successfully determined. The target compounds in water samples were preconcentrated by liquid-liquid extraction with dichloromethane, derivatized by trifluoroacetic anhydride, and quantified by gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring (SIM). In the selected seven sampling sites (S1–S7), the concentrations of NP in sample S7 were significantly higher than the other in reservoir. The pollution …status in S3 and S7 were much more serious. The concentrations of OP, NP and BPA were in the range of 44.5–48.8, 221.6–349.6 and 30.2–82.7 ng/L, respectively. The pollution were mainly inputted from the upper river and released from sediments in Guanting Reservoir. Show more

Keywords: 4-tert-octylphenol, 4-nonylphenol, bisphenol A, Guanting Reservoir, GC-MS-SIM

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 825-828, 2004

Authors: LIU, Wen-li | TANG, Bo

Article Type: Research Article

Abstract: Based on the significant enhancement of fluorescence intensity of carbaryl in inclusion complex, a spetrofluorimetric method with high sensitivity was developed for the determination of carbaryl in aqueous solution. Under the optimum conditions, the complex had excitation and emission maxima at 278 nm and 332 nm, respectively. The linear range of the method was 7.0 ng/ml–1500 ng/ml with a detection limit of 1.2 ng/ml. The proposed method was successfully used to determine quantitatively of carbaryl in …cottonseeds. Show more

Keywords: carbaryl, β-cycclodextrin, spectrofluorimetry, supramolecular interaction, determination

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 829-831, 2004

Authors: XIA, Xiang-ao | CHEN, Hong-bin | WANG, Pu-cai

Article Type: Research Article

Abstract: MODIS aerosol retrievals onboard Terra/Aqua and ground truth data obtained from AERONET (Aerosol Robtic Network) solar direct radiance measurements are collocated to evaluate the quality of the former in East Asia. AERONET stations in East Asia are separated into two groups according to their locations and the preliminary validation results for each station. The validation results showed that the accuracy of MODIS aerosol retrievals in East Asia is a little worse than that obtained in other …regions such as Eastern U.S., Western Europe, Brazil and so on. The primary reason is due to the improper aerosol model used in MODIS aerosol retrieval algorithm, so it is of significance to characterize aerosol properties properly according to long term ground-based remote sensing or other relevant in situ observations in order to improve MODIS retrievals in East Asia. Cloud contamination is proved to be one of large errors, which is demonstrated by the significant relation between MODIS aerosol retrievals versus cloud fraction, as well as notable improvement of linear relation between satellite and ground aerosol data after potential cloud contamination screened. Hence, it is suggested that more stringent clear sky condition be set in use of MODIS aerosol data. It should be pointed out that the improvement might be offset by other error sources in some cases because of complex relation between different errors. Large seasonal variation of surface reflection and uncertainties associated with it result in large intercepts and random error in MODIS aerosol retrievals in northern inland of East Asia. It remains to be a big problem to retrieve aerosols accurately in inland characterized by relatively larger surface reflection than the requirement in MODIS aerosol retrieval algorithm. Show more

Keywords: MODIS, aerosol retrieval, validation, AERONET

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 832-837, 2004

Authors: ZHANG, Dan | ZHANG, De-min | LIU, Yao-ping | CAO, Wen-wei | CHEN, Guan-xiong

Article Type: Research Article

Abstract: OLAND (oxygen limited autotrophic nitrification and denitrification) nitrogen removal system was constructed by coupling with oxygen limited nitritation stage and anaerobic ammonium oxidation stage. Ammonia oxidizer, as a kind of key bacteria in N cycle, plays an important role at the oxygen limited nitritation stage of OLAND nitrogen removal system. In this study, specific amplification of 16S rDNA fragment of ammonia oxidizer by nested PCR, separation of mixed PCR samples by denaturing gradient gel electrophoresis …(DGGE), and the quantification of ammonia oxidizer by Fluorescence in situ hybridization (FISH) were combined to investigate the shifts of community composition and quantity of ammonia oxidizer of the oxygen limited nitritation stage in OLAND system. It showed that the community composition of ammonia oxidizer changed drastically when dissolved oxygen was decreased gradually, and the dominant ammonia oxidizer of the steady nitrite accumulation stage were completely different from that of the early stage of oxygen limited nitritation identified by DGGE. It was concluded that the Nitrosomonas may be the dominant genus of ammonia oxidizer at the oxygen limited nitritation stage of OLAND system characterized by nested PCR-DGGE and FISH, and the percentage of Nitrosomonas was 72.5% ± 0.8% of ammonia oxidizer at the steady nitrite accumulation stage detected by FISH. Show more

Keywords: OLAND, nitritation, ammonia oxidizer, DGGE, FISH

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 838-842, 2004

Authors: YE, Wei-hong | WEN, Yue-zhong | LIU, Wei-ping | WANG, Zhong-qiang

Article Type: Research Article

Abstract: The acute and chronic toxic effects of bifenthrin on Daphnia magna were studied. The results showed that 24 h-EC_{50} , 48 h-LC_{50} and 96 h-LC_{50} of bifenthrin on D. magna were 3.24, 12.40 and 1.40 μg/L respectively. And the LOEC and NOEC of bifenthrin were 0.02 and 0.004 μg/L respectively. The recovery test of bifenthrin on Daphnia magna was presented. Daphnia magna (F_0 generation) were exposed during 21 d …to different bifenthrin concentrations. Offspring (animals from the first and third brood: F_1 (1st) and F_1 (3rd), respectively) were transferred to a free pesticide medium during a 21-day recovery period. In this recovery study, survival, growth, reproduction (mean total young per female, onset of reproduction and number broods per female) and the intrinsic rate of natural increase (r) were assessed as parameters. Reproduction such as number of young per female as well as length was still reduced in F_1 (1st) generation daphnids from parentals (F_0 ) exposed to the bifenthrin. However F_1 (3rd) individuals from parentals exposed to pesticide concentrations were able to restore reproduction when a recovery period of 21 d was allowed, but the length of F_1 (3rd) from parentals exposed to the 0.5 and 0.75 μg/L bifenthrin concentration was still significantly effected (P<0.05). Show more

Keywords: bifenthrin, Daphnia magna, parental generation (F_0), F_1(1st) and F_1(3rd), recovery test, toxic test

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 843-846, 2004

Authors: LUO, Yi | ZHANG, Ting-zhou | ZHOU, Qi-xing | MAO, Da-qing | WAN, Dong-mei

Article Type: Research Article

Abstract: The fate of the litter of dominant vegetation (willows and reeds) is one of the aspects studied in the frame of the project "Onderzoek Milieu Effecten Sigmaplan". One of the questions to be considered is how long the litter stays within the estuary. In this paper, the time the leaf litter (Salix triandra and Phragmites australis) stayed in the Schelde estuary was studied by using plant pigment as biomarkers with HPLC application. After analyzing the original …data from the incubation experiment described by Dubuison and Geers (1999), the decomposition dynamics patterns of pigments were analyzed and described, and these decomposition dynamics patterns were used as calibration patterns. By using Spearman Rank Order Correlation, the calibration patterns of the pigments which were significant (p<0.05) were grouped. In this way, several groups of the calibration patterns of pigment decomposition were achieved. The presence or absence of these groups of pigments (whether they can be detected or not from HPLC) was shown to be useful in determining the time the litter has stayed in the water. Combining data of DW and POC, more precise timing can be obtained. Show more

Keywords: decomposition dynamics pattern, Salix triandra, Phragmites australis, Spearman Rank Order Correlation, Schelde estuary, HPLC

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 847-850, 2004

Authors: Bejankiwar, Rajesh S. | Basu, Abir | Cementi, Max

Article Type: Research Article

Abstract: Electrochemical oxidation of polyethylene glycol (PEG) in an acidic (pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified (PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon (TOC) concentrations during the course of the reaction were …monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model. Show more

Keywords: polyethylene glycol(PEG), paraffin composite copper hexacyanoferrate modified (PCCHM) electrode, electroplating solution, two stage first-order kinetic model, generalized kinetic model

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 851-855, 2004

Authors: CHENG, Yang-xue | JIANG, An-xi | LIU, Bo | ZHAO, Yang-guo | LI, Zheng | BAI, Yu

Article Type: Research Article

Abstract: Strain Jll screened out from different odor origins can efficiently degrade methyl mercaptan and ethanethiol whereas has no ability to remove dimethyl sulfide. The results indicated that the strain Jll breaks only the C-SH bond. The optimum temperature and pH of Jll are 20–30°C and 6.0–8.3 respectively. A systematic identification method–16S rDNA gene sequence comparison, for deodorizing bacteria was carried out. The 16S rDNA gene sequence analysis of strain Jll showed the highest level of 97% …homology to Rape rhizosphere. Show more

Keywords: 16S rDNA gene, methyl mercaptan, Ethanethiol, Rape rhizosphere

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 856-859, 2004

Authors: WANG, Jing-li | ZHANG, Yuan-hang | SHAO, Min | Liu, Xu-lin | ZENG, Li-min | CHENG, Cong-lan | XU, Xiao-feng

Article Type: Research Article

Abstract: The recent year's monitor results of Beijing indicated that the pollution level of fine particles PM_{2.5} showed an increasing trend. To understand pollution characteristics of PM_{2.5} and its relationship with the meteorological conditions in Beijing, a one-year monitoring of PM_{2.5} mass concentration and correspondent meteorological parameters was performed in Beijing in 2001. The PM_{2.5} levels in Beijing were very high, the annual average PM_{2.5} …concentration in 2001 was 7 times of the National Ambient Air Quality Standards proposed by US EPA. The major chemical compositions were organics, sulfate, crustals and nitrate. It was found that the mass concentrations of PM_{2.5} were influenced by meteorological conditions. The correlation between the mass concentrations of PM_{2.5} and the relative humidity was found. And the correlation became closer at higher relative humidity. And the mass concentrations of PM_{2.5} were negtive-correlated to wind speeds, but the correlation between the mass concentration of PM_{2.5} and wind speed was not good at stronger wind. Show more

Keywords: meteorological conditions, quantitative relation, fine particles (PM_{2.5}), Beijing

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 860-864, 2004

Authors: Tsou, Ming-Shu | ZHAN, Xiao-yong

Article Type: Research Article

Abstract: Sediment has been identified as a significant threat to water quality and channel clogging that in turn may lead to river flooding. With the increasing awareness of the impairment from sediment to water bodies in a watershed, identifying the locations of the major sediment sources and reducing the sediment through management practices will be important for an effective watershed management. The annualized agricultural non-point source pollution (AnnAGNPS) model and newly developed GIS interface for it were …applied in a small agricultural watershed, Redrock Creek watershed, Kansas, in this pilot study for exploring the effectiveness of using this model as a management tool. The calibrated model appropriately simulated monthly runoff and sediment yield through the practices in this study and potentially suggested the ways of sediment reduction through evaluating the changes of land use and field operation in the model for the purpose of watershed management. Show more

Keywords: annualized agricultural non-point source pollution (AnnAGNPS), GIS, sediment yield, runoff

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 865-867, 2004

Authors: WEI, Shu-He | ZHOU, Qi-Xing | WANG, Xin | CAO, Wei | REN, Li-ping | SONG, Yu-fang

Article Type: Research Article

Abstract: To screen out a series of ideal plants that can effectively remedy contaminated soils by heavy metals is the main groundwork of phytoremediation engineering and the first step of its commercial application on a large scale. In this study, accumulation and endurance of 45 weed species in 16 families from an agricultural site were in situ examined by using the pot-culture field experiment, and remediation potential of some weed species with high accumulation of heavy metals …was assayed. The results showed that Solanum nigrum and Conyza canadensis can not only accumulate high concentration of Cd, but also strongly endure to single Cd and Cd-Pb-Cu-Zn combined pollution. Thus the 2 weed species can be regarded as good hyperaccumulators for the remediation of Cd-contaminated soils. Although there were high Cd-accumulation in Artemigia selengensis, Znula britannica, Artemigia selengensis and Cephalanoplos setosum, their biomass was adversely affected due to action of heavy metals in the soils. If the problem of low endurance to heavy metals can be solved by a reinforcer, the 4 weed species can be perhaps applied commercially. Show more

Keywords: weed species, heavy metal, contaminated soil, phytoremediation, hyperaccumulation, endurance

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 868-873, 2004

Authors: LUO, Feng | CHEN, Wan-zhi | SONG, Fu-zhong | LI, Xiao-peng | ZHANG, Guo-qing

Article Type: Research Article

Abstract: Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The results of laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste (MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and …temperature can used to decompose MSW. The results of waste biodegradation were compared with that of the simulators of the leachate-recirculated landfill and conservative sanitary landfill. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown, and heavy metals concentration was observed. An obvious enhancement of effective disposal from simulator of conservative sanitary landfill (CSL), to that of leachate-recirculated landfill (LRL) and to that of conditioned bioreactor landfill (CBL) would be noted, through displaying the compared results of solid waste settlement, heavy metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio. Show more

Keywords: landfill bioreactor, methanogenesis, methane production, municipal solid waste, leachate recirculation, biodegradation of solid waste, specific methanogenic activity (SMA)

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 874-880, 2004