Journal of Environmental Sciences - Volume 17, issue 3

Authors: WANG, Zhi-hui | BAI, Yu-hua | ZHANG, Shu-yu

Article Type: Research Article

Abstract: The first detailed inventory for volatile organic compounds (VOC) emissions from vegetation over Yunnan Province, China was presented. The spatially and temporally resolved inventory was developed based on a geographic information system (GIS), remote sensing (RS) data and field measurement data, such as digitized land-use data, normalized difference vegetation index (NDVl) and temperature data from direct real-time measurement. The inventory has a spatial resolution of 5 km × 5 km and a time resolution of 1 …h. Urban, agriculture, and natural land-use distributions in Yunnan Province were combined with biomass factors for each land-use category to produce a spatially resolved biomass inventory. A biogenic emission inventory was developed by combining the biomass inventory with hourly emission rates for tree, shrub and ground cover species of the study area. Correcting for environmental factors, including light intensity and temperature, a value of 1.1 × 10^{12} gC for total annual biogenic VOC emissions from Yunnan Province, including 6.1 × 10^{11} gCfor isoprene, 2.1 × 10^{11} gC for monoterpenes, and 2.6 × 10^{11} gC for OVOC was obtained. The highest VOC emissions occurred in the northwestern, southwestern and north region of Yunnan Province. Some uncertainties were also discussed in this study. Show more

Keywords: biogenic VOC, isoprene, monoterpene, emissions inventory, Yunnan Province

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 353-359, 2005

Authors: ZHU, You-feng | LIU, Hui | XI, Zhi-qun | CHENG, Hang-xin | XU, Xiao-bai

Article Type: Research Article

Abstract: Thirty-nine deep subsurface soils (150–180 Gm depth) near the outskirts of Beijing were investagated. The concentrations including n-alkanes from C_{13} to C_{36} , pristane and phytane were in the range of 0.60 to 170.10 μg/g, with a median value of 4.26. Carbon preference index values for n-alkanes ranged from 1.08 to 2.98, with a median value of 1.48. The percentage contribution of "wax" n-alkanes was in the range of 6.03%–46.22%. A predominance of …odd/even carbon n-alkanes and unresolved complex mixtures with different shapes and ranges were frequently observed. Factor analysis reduced the data set into three principal components and confirming contributions from Iow (19.58%), medium (20.49%) molecular weight species and long-chain n-alkanes (43.41%), respectively. Molecular biomarkers such as pristane, phytane, hopanes and steranes were detected. Based on the principal component analysis, the concentration profiles and molecular markers, it was found that the aliphatic hydrocarbons were from both biogenic and anthropogenic sources. Show more

Keywords: deep subsurface soil, n-alkanes, spatial distribution, molecular markers, diagnostic indices

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 360-364, 2005

Authors: ZHU, Li-zhong | WANG, Jing

Article Type: Research Article

Abstract: PAHs pollution in air of arterial roads was investigated from October 1998 to October 2001 in Hangzhou, China. The results showed that Σ10 PAHs was 13–36 μg/m3 , among which, BaP, a strong carcinogenic kind ranged from 0.034 μg/m^3 to 0.12 μg/m^3 . PAHs pollutions in four seasons were winter > autumn > spring-summer. The annual averages of ΣPAHs concentration were 25 μg/m^3 for 1999, 28 μg/m^3 …for 2000, and 29 μg/m^3 for 2001, respectively. Leaded gasoline was banned in December 1998 in Hangzhou, thus comparative measurements with PAHs in leaded and lead-free gasoline powered motor exhausts made it certain that the use of lead-free gasoline leaded to a heavier PAHs pollution in roadside air from December, 1998, in China, and ΣPAHs in air samples after the lead-banning were more than twice of that in samples before the action. For the large contribution of vehicle discharge to air pollution in roadside, further research was performed to suggest the factors influencing PAHs distribution in vehicle exhaust in order to control air pollution effectively. Compared to gasoline engines, emissions from diesel engines were less toxic, although they might produce more PAHs. Of the same vehicular and oil type, automobiles of longer mileages produced more toxic PAHs. PAHs distributions in the vehicular exhausts were related to the oil type. Large difference was found in the abundance of 3-, 5- and 6-ring PAHs between exhausts from gasoline and diesel oil engines. Diesel oil engines produced relative lighter PAHs such as NAPH, ACEN, FLUOR, while gasoline engines emitted heavier kinds such as BkF, IN and BP. The automobile produced more PAHs with the increase of mileage especially FLUR, PY, BaP, BP. Some significant ratios for traffic source in Hangzhou such as PHEN/AN, FLUR/PY, IN/BP were 0.50–4.3, 0.58–7.4, 0.51–1.5, respectively. A source fingerprint for vehicle exhausts of a mixture of vehicle and oil types in the city district for light-duty vehicle was the abundance of BaA, followed by NAPH, BP, IN. 4-ring PAHs such as FLUR, PY, BaA and CHRY were the most predominant kindsfollowed by 6-ring PAHs (BP, IN). Show more

Keywords: PAHs, influencing factors, vehicle exhaust, air pollution

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 365-370, 2005

Authors: SHAO, Li-ming | HE, Pin-jing | ZHANG, Hua | YU, Xiao-hua | LI, Guo-jian

Article Type: Research Article

Abstract: When municipal solid waste (MSW) with high content of food waste is landfilled, the rapid hydrolysis of food waste results in the imbalance of anaerobic metabolism in the landfill layer, indicated by accumulation of volatile fatty acids (VFA) and decrease of pH value. This occurrence could lead to long lag time before the initiation of methanogenesis and to the production of strong leachate. Simulated landfill columns with forced aeration, with natural ventilation, and with no aeration, …were monitored regarding their organics degradation rate with leachate recirculation. Hydrolysis reactions produced strong leachate in the column with no aeration. With forced aeration, the produced VFA could be effectively degraded, leading to the reduction in COD of the leachate effluent since the week 3. The CH_4 in the landfill gas from the column with aeration rate of 0.39 m^3 /(m^3 · d) and frequency of twice/d, leachate recirculation rate of 12.2 mm/d and frequency of twice/d, could amount to 40% (v/v) after only 20 weeks. This amount had increased up to 50% afterward even with no aeration. Most of COD in the recirculated leachate was removed. Using natural ventilation, CH_4 could also be produced and the COD of the leachate effluent be reduced after 10 weeks of operation. However, the persistent existence of oxygen in the landfill layer yielded instability in methanogenesis process. Show more

Keywords: MSW landfill, methanogenesis, leachate recirculation, forced aeration, natural ventilation

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 371-374, 2005

Authors: SUN, Shi-lei | CHENG, Shu-pei | WAN, Yu-qiu | ZHANG, Xu-xiang | SHI, Lei | ZHU, Cheng-jun | YU, Hong-xia | LUO, Xiang | LU, Jian-hua | ZHANG, Xiao-chun | WANG, Gui-lin | WANG, Hong-li | YU, Jing-zhou | Chen, Jun

Article Type: Research Article

Abstract: In the pilot study of treating the purified terephthalic acid (PTA) wastewater with the functional Strain Fhhh in the carrier activated sludge process (CASP), the ratio of COD:TN:TP and the concentrations of Cu, Mn, Se and Zn were controlled to improve the manganese peroxidase(MnP) levels for increasing the treatment efficiency. When the ratio of COD: TN: TP was 100: 0.36: 0.15 and the concentrations of Cu, Mn, Se and Zn were 0.54, 5.07, 0.00 and 0.08 …mg/L, the MnP specific activity (MnP-SA) reached 689 U/L, and the sludge loading rate to COD (SLRC) was 1.09 d^{-1} , which was 4–7 fold of that in other processes reported. The data indicated that improving MnP level could enhance the degradability of Fhhh. And the potentials of Fhhh and CASP will be also discussed in this paper. Show more

Keywords: functional strain, PTA wastewater, pilot engineering, MnP-SA, regulation, SLRC

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 375-378, 2005

Authors: WANG, Xiao-fei | ZHOU, Qi-xing

Article Type: Research Article

Abstract: Joint toxicity of methamidophos and cadmium (Cd) on the ornamental Abelmoschus manihot was firstly examined and compared with single-factor effects of the two pollutants using ecotoxicological indexes including the inhibitory rate of seed germination, root elongation and inhibitory concentration 50% (IC_{50} ). The results indicated that methamidophos and Cd had unobvious (p > 0.05) effects on seed germination of the ornamental. There were significant (p < 0.05) inhibitory effects of Cd …on root elongation of the tested plant. When the concentration of added Cd was low (< 20 mg/L), significant antagonistic effects on root elongation were observed. And synergic effects were observed when Cd was added in high dose (> 20 mg/L). However, the analysis of joint effects indicated that there were antagonistic effects between Cd and methamidophos under all the treatments. At the high concentration of Cd, joint toxicity of methamidophos and Cd was more dependent on concentration of Cd. Show more

Keywords: joint toxicity, cadmium, methamidophos, ornamental

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 379-383, 2005

Authors: ZHOU, Ai-min | WANG, Dong-sheng | TANG, Hong-xiao

Article Type: Research Article

Abstract: Typical sediments from Taihu Lake, a meso-to-hypereutrophic lake, were collected and examined on the basis of P-fractionation by sequential extraction scheme. Sedimentary inorganic phosphorus were fractioned into four forms and the rank order according to the mean concentration of P-fractions in Taihu Lake was NaOH-P > BD-P > HCI-P > NH_4 Cl-P. The concentrations of BD-P were linearly correlated with the content of active Fe (R^2 = 0.96). Also, the linear relationship between …the sum of BD-P and NaOH-P and the sum of active Fe and active Al content was observed within the six sediments investigated (R^2 = 0.96). Moreover, the bio-available phosphorus (BAP) content was estimated by the sum of NH_4 CI-P, BD-P, and NaOH-P, viz. BAP = NH_4 CI-P + NaOH-P + BD-P. In Taihu Lake, the BAPcontents are ranging from 0.10 mg/g dw to 1.25 mg/g dw, and average 0.40 mg/g dw for all sediment samples. The relative contributions of BAP to total sedimentary phosphorus (TP) and inorganic sedimentary phosphorus (IP) range from 18.67% to 50.79% (33.61% on average) and from 52.82% to 82.09% (67.81% on average), respectively. Show more

Keywords: phosphorus fractionation, bio-availability, sediment, Taihu Lake

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 384-388, 2005

Authors: ZHANG, Xia | XIE, Ping | LI, Yan-ling | CHEN, Fei-zhou | LI, Si-xin | GUO, Ni-chun | QIN, Jian-hui

Article Type: Research Article

Abstract: Phytoplankton assemblages in the subtrophical oligotrophic Lake Fuxian, the second deepest lake in China, were investigated monthly from September 2002 to August 2003. A total of 113 species belonging to seven phyla were identified, among them, a filamentous green alga, Mougeotia sp., dominated almost throughout the study period and comprised most of the total phytoplankton biomass. Mougeotia sp. has made a substantial development during the past decades: it was absent in 1957, only occasionally present in …1983, increased substantially in 1993, and became predominant in 2002–2003. It is likely that natural invasion of the Taihu Lake noodlefish (Neosalanx taihuensis) has led to a change of dominant herbivorous zooplankton from small to large calanoid, which has increased grazing pressure on small edible algae, and thus has indirectly favored the development of the inedible filamentous Mougeotia sp. Show more

Keywords: phytoplankton community, Neosalanx taihuensis, oligotrophic plateau lake

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 389-394, 2005

Authors: LU, Wei | ZHANG, Xiao-jian

Article Type: Research Article

Abstract: Some parameters, such as assimilable organic carbon (AOC), chloramine residual, water temperature, and water residence time, were measured in drinking water from distribution systems in a northern city of China. The measurement results illustrate that when chloramine residual is more than 0.3 mg/L or AOC content is below 50 μg/L, the biological stability of drinking water can be controlled. Both chloramine residual and AOC have a good relationship with Heterotrophic Plate Counts (HPC)(log value), the …correlation coefficient was −0.64 and 0.33, respectively. By regression analysis of the survey data, a statistical equation is presented and it is concluded that disinfectant residual exerts the strongest influence on bacterial growth and AOC is a suitable index to assess the biological stability in the drinking water. Show more

Keywords: AOC, biological stability, HPC, residual chloramines, regression analysis

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 395-398, 2005

Authors: FAN, Zhi-jin | AI, Ying-wei | QIAN, Chuan-fan | LI, Zheng-ming

Article Type: Research Article

Abstract: Monosulfuron was developed for weed control in the field of wheat (Triticum, aestivum L.) and millet (Panicum miliaceum L.) with the application rate ranging from 15 to 60 g ai/hm^2 . Herbicidal activity of monosulfuron was evaluated systematically by bioassay using maize (Zea mays L.) taproot as indicator and weed fresh weight of Acalypha australis L. and Echinochloa phyllopogon. Maize CAU 3138 was the most tolerant cultivars to monosulfuron with IC_{50} (concentration of …50% inhibition) of 85 μg/kg, Yedan 13 was one of the most sensitive cultivars to monosulfuron with IC_{50} of 6.4 μg/kg. Monosulfuron inhibited the growth of Acalypha australis L. strongly comparing with that of Echinochloa phyllopogon. Monosulfuron was a good acetolactate synthase (ALS) inhibitor in vitro, the I_{50} (50% of inhibition) of monosulfuron, chlorsulfuron, tribenuron-methyl and nicosulfuron for CAU 3138 were 32, 2, 19 and 26 nmol/L respectively, for Yedan 13 the I_{50} were 15, 3, 17 and 65 nmol/L respectively. In vivo ALS inhibition occurred only in higher concentration of 4 sulfonylurea herbicide tested. Comparison study of this test indicated that the mode of action of monosulfuron was the same as that of other sulfonylurea herbicides such as chlorsulfuron, tribenuron-methyl and nicosulfuron, they were all inhibitors targeted at the ALS. Show more

Keywords: monosulfuron, sulfonylurea herbicide, acetolactate synthase (ALS)

Citation: Journal of Environmental Sciences, vol. 17, no. 3, pp. 399-403, 2005