Journal of Environmental Sciences - Volume 16, issue 3

Authors: Verma, R.J. | Vasu, Archana | Saiyed, Abdul Alim

Article Type: Research Article

Abstract: Oral administration of arsenic trioxide (3 and 6 mg/kg body weight/d) for 30 d caused, as compared with vehicle control, dose-dependent significant reductions in body weight, absolute weight, protein, glycogen, as well as, total, dehydro and reduced ascorbic acid contents both in the liver and kidney of arsenic-treated mice. Succinic dehydrogenase (SDH) and phosphorylase only in the liver activities were significantly reduced in a dose-dependent manner. Acid phosphatase activity was significantly decreased in …the liver of low dose arsenic-treated animals; however, significant rise in its activity was observed in high dose group. As compared with vehicle control, treatment also caused significant dose-dependent reductions in SDH, alkaline phosphatase and acid phosphatase activities in the kidney of mice. Vitamin E cotreatment as well as, 30 d withdrawal of arsenic trioxide treatment with or without vitamin E caused significant amelioration in arsenic-induced toxicity in mice. Administration of vitamin E during withdrawal of treatment also caused significant amelioration as compared from only withdrawal of the treatment. It is concluded that vitamin E ameliorates arsenic-induced toxicities in the liver and kidney of mice. Show more

Keywords: arsenic toxicity, mice, oral administration, amelioration

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 447-453, 2004

Authors: LI, Ning | CHEN, Xiao-yong | SHEN, Lang | LI, Yuan-yuan | CAI, Yue-wei

Article Type: Research Article

Abstract: The genetic composition of Poa annua L. populations with a series of traffic pollution was studied by starch electrophoresis. Five enzyme systems were stained. The results showed that: (1) Traffic pollution can dramatically change genotypic frequencies at some loci of P. annua populations. Significant deviations from Hardy-Weinberg equilibrium were observed on loci Fe-1 and Me due to the excess of heterozygote in some populations. (2) The effective number of alleles per locus, and the observed and …expected heterozygosity were higher in the pollution series than in the clear control site (Botanic Park population), but the increase was not related with the pollution extent. (3) Most genetic variation was found within populations, and only 6.21% was among populations of the polluted series. Slightly higher differentiation (F_{ST} =7.98%) was observed when the control population was included. (4) The calculated gene flow (Nm) is 2.8841 per generation. The mean of genetic identity is 0.9864 and the genetic distance average to 0.0138. Show more

Keywords: genetic composition, traffic pollution, allozyme analysis, Poa annua L

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 454-457, 2004

Authors: WANG, Shu-guang | LIN, Xian-gui | YIN, Rui | HOU, Yan-lin

Article Type: Research Article

Abstract: The effect of inoculation with arbuscular mycorrhiza (AM) fungi (Acaulospora lavis) on the degradation of di (2-ethylhexyl) phthalate (DEHP) in soil was studies. Cowpea plants (Pigna sinensis) were used as host plants and grown in a specially designed rhizobox. The experimental results indicated that, both in sterile and non-sterile soil, mycorrhizal colonization rates were much higher in the mycorrhizal plants than in the non-mycorrhizal plants. Addition of 4 mg/kg DEHP slightly affected mycorrhizal colonization, but the …addition of 100 mg/kg DEHP significantly decreased mycorrhizal colonization. DEHP degradation in the mycorrhizosphere (Ms) and hyphosphere (Hs), especially in the Hs, increased after inoculation with Acaulospora lavis. It is concluded that mycorrhizal hyphae play an important role in the plant uptake, degradation and translocation of DEHP. The mechanism might be attributed to increased numbers of bacteria and actinomycetes and activity of dehydrogenase, urease and acid phosphatase in the Ms and Hs by mycorrhizal fungi. Show more

Keywords: AM fungi, inoculation, DEHP, concentration, degradation

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 458-461, 2004

Authors: LIN, He | GAO, Xiang | LUO, Zhong-yang | GUAN, Shi-pian | CEN, Kefa | HUANG, Zhen

Article Type: Research Article

Abstract: In this paper, removal of NOx (namely DeNOx) from flue gas by radical injection combined with NaOH solution (26% by weight of NaOH in water) scrubbing was investigated. The experimental results showed that the steady streamer corona occurs through adjusting the flow rate of the oxygen fed into the nozzles electrode. The vapor in the oxygen has influence on the V-I characteristics of corona discharge. Both HNO_2 and HNO_3 come into being …in the plasma reactor and the DeNOx efficiency in the plasma reactor is more than 60%. The overall DeNOx efficiency of the whole system reaches 81.7% when the NaOH solution scrubbing is collaborated. Show more

Keywords: radical, plasma reactor, DeNOx process, absorb

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 462-465, 2004

Authors: Das, Biplob | Khan, Yusuf Sharif Ahmed | Das, Pranab

Article Type: Research Article

Abstract: Nutrient loadings were measured for surface seawater and bottom sediments of semi-intensive and improved extensive shrimp culture pond, adjacent estuary, and fallow land in the south-east coastal region of Bangladesh during August, 2000 – January, 2001 to evaluate the impact of shrimp culture. The mean levels of nutrients found in the pond surface water were 108.780 mg/L for CaCO_3, 0.526 mg/L for NH<FORMULA>_4^+ -N, 3.075 wt% for organic carbon, 7.00 mg/L for …PO_4 -P, 5.57 mg/L for NO_3 -N, and 7.33 mg/L for chlorophyll-a. The maximum mean value of H_2 S (0.232 mg/L) was found in estuarine water. Nutrients loading were found to be decreased with distance from the shrimp farm discharge unit in estuarine water. The mean level of organic matter, total nitrogen, and organic carbon were found in higher concentrations in sediments of cultured pond compared to bottom soil of adjacent fallow land at the same elevation. Extractable Ca values were found in higher concentration (550.33 ppt) in adjacent fallow land, as; the shrimps for molting in shrimp ponds use extractable Ca. The relation between seawater H_2 S value and sediment pH (r = -0.94); sediment organic carbon and sediment pH values (r = -0.76), sediment total nitrogen and sediment pH (r = -0.74) were found to be highly negatively correlated. Whereas the relation between seawater H_2 S value and sediment total nitrogen (r = 0.92), water NH_4^+ -N and sediment pH (r = 0.66) were found to be positively correlated. The results revealed that load of nutrients at eutrophic level in estuarine water, and decrease of soil pH; leading to acid sulphate soil formation indicates a negative impact of shrimp culture. Show more

Keywords: environment, eutrophication, impact, nutrients, shrimp culture

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 466-470, 2004

Authors: LIU, Fu-qiang | CHEN, Jin-long | CHENG, Xiu-mei | GE, Jun-jie | LI, Ai-min | ZHANG, Quan-xing

Article Type: Research Article

Abstract: An aminated hypercrosslinked macroporous polymeric adsorbent was synthesized and characterized. Adsorption isotherms for 1-amino-2-naphthol-4-sulfonic acid (1, 2, 4-acid) and 2-naphthol obtained from various binary adsorption environments can be well fitted by Freundlich equation, which indicated a favorable adsorption process in the studied range. Adsorption for 1, 2, 4-acid was an endothermic process in comparison with that for 2-naphthol of an exothermic process. 2-naphthol molecules put a little influence on the adsorption capacity …for 1, 2, 4-acid. However, the adsorption to 1, 2, 4-acid depressed that to 2-naphthol in a large extent for the stronger electrostatic interaction between 1, 2, 4-acid and adsorbent. The predominant mechanism can be contributed to the competition for adsorption sites. And the simultaneous environment was confirmed to be helpful to the selective adsorption towards 1,2,4-acid based on the larger selectivity index. Show more

Keywords: aminated hypercrosslinked macroporous polymeric adsorbent, 1, 2, 4-acid, 2-naphthol, competitive adsorption

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 471-475, 2004

Authors: SHI, Lei | WANG, Bao-zhen | CAO, Xiang-dong | Wang, Jin | LEI, Zhi-hong | WANG, Zhi-ren | LIU, Zheng-ying | LU, Bing-nan

Article Type: Research Article

Abstract: The operational performance of a full-scale subsurface-flow constructed wetland, which treated the mixed industrial and domestic wastewater with BOD_5 /COD mean ratio of 0.33 at Shatian, Shenzhen City was studied. The constructed wetland system consists of screens, sump, pumping station, and primary settling basin, facultative pond, first stage wetland and secondary stage wetland. The designed treatment capacity is 5000 m^3 /d, and the actual influent flow is in the range of < …2000 to > 10000 m^3 /d. Under normal operational conditions, the final effluent quality well met the National Integrated Wastewater Discharge Standard (GB 8978-1996), with the following parameters (mean values): COD 33.90 mg/L, BOD_5 7.65 mg/L, TSS 7.92 mg/L, TN 9.11 mg/L and TP 0.56 mg/L. Seven species of plants were selected to grow in the wetland: Reed, Sweetcane flower Silvergrass, Great Bulrush, Powdery Thalia and Canna of three colours. The growing season is a whole year-round. The seasonal discrepancy could be observed and the plants growing in the wetland are vulnerable to lower temperature in winter. The recycling of the effluent in the first stage of the wetland system is an effective measure to improve the performance of the wetland system. The insufficient DO value in the wetland system not only had significant effect on pollutants removal in the wetland, but also was unfavourable to plant growth. The recycling of effluent to the inlet of wetland system and artificial pond to increase DO value of influent to the wetland is key to operate the subsurface constructed wetland steadily and effectively. Show more

Keywords: subsurface-flow constructed wetland, operational performance, marsh plants, pre-treatment, facultative pond

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 476-481, 2004

Authors: HE, Fei | JIA, Zhi-qian | PENG, Yue-lian | WANG, Pei-jing | LIU, Zhong-zhou

Article Type: Research Article

Abstract: Al_{13} or Al_b is usually regarded as the most efficient species of polyaluminum chloride (PAC), the performance flocculant for water treatment. This paper was intended to report a new method to synthesize PAC with high content Al_b , by using the membrane reactor. NaOH solutions were managed to permeate slowly through the micropores of ultrafiltration membrane into AlCl_3 solutions under the suitable transmembrane pressure (TMP). …Meanwhile NaOH drops size was limited to nano-scale, resulting in dramatical reduction of the characteristic diffusion time and great increment of contact interface between the strong base and Al ions in solution to favor the formation of Al(OH)_4^- , the precursor of Al_{13} , so little precipitates and much Al_b are produced. When the initial concentration of AlCl_3 /NaOH is 0.40/2.0 (mol/L), MWCO=10000, TMP=0.0085 MPa, T=305K and B (molar ratio of OH^- /Al^{3+} )=2.25, the quantity of Al_b attains about 80%. The results of ^{27} Al-NMR determination show that the Al_{13} content is equal to Al_b content. And our PAC product has shown better flocculation effects than the commercial product. Show more

Keywords: membrane reactor, polyaluminum chloride

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 482-486, 2004

Authors: SUI, Hong | LI, Xin-Gang | XU, Shi-Min

Article Type: Research Article

Abstract: Trichloroethylene (TCE), a common groundwater pollutant, was cometabolized by microorganisms in the presence of toluene as a growth substrate. The effect of concentrations of toluene and TCE and temperature on biodegradation was discussed. Acclimated microorganisms degraded TCE after a lag period of 5 to 22 h depending on toluene concentrations. Approximately 60%, 90% and 64% of TCE were degraded at toluene to TCE concentration ratios of 23:1, 115:1 and 230:1, respectively. At a TCE concentration of …1.46 μg/ml, 80% of TCE and 98.4% of toluene were removed. But less degradation of TCE and toluene was observed when TCE concentration was above 48.8 μg/ml. The lag time of TCE decreased and the TCE biodegradation rates increased with the increase of temperature. Show more

Keywords: cometabolism, microbial degradation, toluene, trichloroethylene

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 487-489, 2004

Authors: PENG, Jian | WANG, Yang-lin | JING, Juan | LI, Wei-feng | DING, Yan

Article Type: Research Article

Abstract: Littoral zone is a special land/landscape type. As an important kind of land resource in support, the use of littoral zone is vital to eastern coastal areas in China. And the research on littoral zone relates to the key theory of landscape ecology. Based on the theory of landscape ecology, the littoral zone was divided into four types: mud flat, sand beach, bench, and biological flat. The distribution of each type in China is pointed out. As a …typical open system, littoral zone has six landscape ecological characteristics: (1) high sensitivity to disturbance; (2) distinct edge effect; (3) spatial aggregation of natural resources; (4) frequently spatial oscillation; (5) obviously spatial heterogeneity; and (6) noticeably spatial differentiation. Some proposals are also put forward on the land use and development of littoral zone for environmental protection and environmental management. Show more

Keywords: landscape eco-environment, littoral zone, China

Citation: Journal of Environmental Sciences, vol. 16, no. 3, pp. 490-496, 2004