Journal of Environmental Sciences - Volume 16, issue 5

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