Journal of Environmental Sciences - Volume 18, issue 1

Authors: SUN, Fu-hong | ZHOU, Qi-xing | ZHANG, Qian-ru

Article Type: Research Article

Abstract: Using the exposure simulation experiment, the action of petroleum affecting the accumulation of the trace metals including copper (Cu) and cadmium (Cd) in littoral polychaete Nereis diversicolor collected from the Shuangtaizi Estuary in Liaoning Province, China was examined. The results showed that there was a markedly non-linear relationship between the accumulation of Cu in worms and the experimental concentration of Cu in exposure solutions when the concentration of petroleum remained at 0, 100, and …220μl/L, respectively. However, significantly non-linear relationship for worms exposed to Cd was observed only when the concentration of added petroleum was 0 and 220μl/L. The accumulation of Cu in worms did not differ significantly among the three different levels of petroleum concentrations combined with various concentrations of Cu. So was the accumulation of Cd in worms (p>0.05). However, the addition of petroleum in exposure solutions brought about an increase in the accumulation of Cu in Nereis diversicolor, in comparison with single Cu pollution. On the other hand, when the concentration of added petroleum remained at 100μl/L, the accumulation of Cd in worms was lower than that in worms exposed to various concentrations of only cadmium. However, the worms exposed to Cd and petroleum 220μl/L did not show obvious and identical increase in the accumulation of Cd, compared with single Cd exposure. The accumulation of both Cu and Cd in worms did not increase significantly with the increases in concentrations of Cu or Cd in exposure solutions combined with petroleum (0, 100, and 220μl/L) under the experimental conditions. Although Nereis diversicolor is exposed to very high Cu and Cd in exposure solutions, accumulation and detoxification mechanisms are sufficient to cope with the extra metal influx in order to survive. Show more

Keywords: Nereis diversicolor, copper, cadmium, petroleum, combined pollution

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 109-114, 2006

Authors: MU, Huan-zhen | ZHENG, Tao | HUANG, Yan-chu | ZHANG, Chun-ping | LIU, Chen

Article Type: Research Article

Abstract: The rainfall system was set up on a slope land, which was used with some materials to enhance soil infiltration. The results showed that it was effective to enhance the infiltration of rainwater in soil and reduce the pollutants of surface runoff. After the soil meliorated by the lignin polymer and zeolite, runoff was delayed about 10 min and reduced by 44.40%–50.00%, synchronously, the pollutant loads, such as total suspended solids (TSS), chemical oxygen demand by …ditromate (CODCr), total nitroger (TN) and total phosphorus (TP), were reduced on averages by 44.58%, 37.80%, 51.62% and 44.11%, respectively. It is an available technique to control the pollution of non-point source from sources. Show more

Keywords: runoff, enhancing infiltration, lignin polymer, non-point source pollution

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 115-119, 2006

Authors: LIU, Jian-guo | WANG, De-ke | XU, Jia-kuan | ZHU, Qing-sen | WONG, Ming-hung

Article Type: Research Article

Abstract: In order to understand the mechanisms on the variation between rice cultivars in Cd uptake and accumulation, two pot soil experiments were conducted with typical rice cultivars that varied greatly in soil Cd uptake. The experiments with six rice cultivars showed that the root oxidation abilities of rice differed with rice cultivars and also with types of the cultivars, the cultivars with indica consanguinity were significantly higher than the cultivars with japonica consanguinity. Root oxidation abilities …of the rice cultivars correlated positively and significantly (P<0.01) with their Cd concentrations and Cd quantity accumulations in rice plants. The experiments with two rice cultivars showed that significant differences also existed between the two cultivars in pot soil redox potentials, which of Shan you 63 (higher soil Cd accumulator) were significantly higher than that of Wu yun jing 7 (lower soil Cd accumulator) under different soil Cd levels, but the degrees of the differences varied with soil Cd levels. The differences were larger under soil Cd treatments than the control. The results indicate that root oxidation ability, especially in Cd contaminated soil, is one of the main mechanisms which dominate Cd uptake and accumulation by rice plant. Show more

Keywords: cadmium (Cd), uptake and accumulation, root oxidation, soil redox potential

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 120-124, 2006

Authors: LIANG, Chan-juan | HUANG, Xiao-hua | TAO, Wen-yi | ZHOU, Qing

Article Type: Research Article

Abstract: Effect of cerium (Ce^{3+} ) on the growth, photosynthesis and antioxidant enzyme system in rape seedlings (Brassica juncea L.) exposed to two levels of UV-B radiation (T_1 : 0.15 W/m^2 and T_2 :0.35 W/m^2 ) was studied by hydroponics under laboratory conditions. After 5 d of UV-B treatment, the aboveground growth indices were obviously decreased by 13.2%–44.1%(T_1 ) and 21.4%–49.3%(T_2 ), compared to CK, …and except active absorption area of roots, the belowground indices by 14.1%–35.6%(T_1 ) and 20.3%–42.6%(T_2 ). For Ce+UV-B treatments, the aboveground and belowground growth indices were decreased respectively by 4.1%–23.6%, 5.2%–23.3%(Ce+T_1 ) and 10.8%–28.4%, 7.0%–27.8%(Ce+T_2 ), lower than those of UV-B treatments. The decrease of growth indices appeared to be the result of changes of physiological processes. Two levels of UV-B radiation induced the decrease in chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency by 11.2%–25.9%(T_1 ) and 20.9%–56.9%(T_2 ), whereas increase in membrane permeability and activities of antioxidant enzymes including superoxide dismutase(SOD), catalase (CAT) and peroxidase (POD) by 6.9%, 22.8%, 21.5%, 9.5%(T_1 ) and 36.6%, 122.3%, 103.5%, 208.9%(T_2 ), respectively. The reduction of the photosynthetic parameters in Ce+UV-B treatments was lessened to 3.2%–13.8%(Ce+T_1 ) and 4.9%–27.6%(Ce+T_2 ), and the increase of membrane permeability and activities of antioxidant enzymes except POD in the same treatments were lessened to 2.4%, 8.4%, 6.6%(Ce+T_1 ) and 30.1%, 116.7%, 75.4%(Ce+T_2 ). These results indicate that the regulative effect of Ce on photosynthesis and antioxidant enzymatic function is the ecophysiological basis of alleviating the suppression of UV-B radiation on growth of seedlings. Furthermore, the protective effect of Ce on seedlings exposed to T_1 level of UV-B radiation is superior to T_2 level. Show more

Keywords: cerium (Ce^{3+}), UV-B radiation, rape, growth, photosynthesis, antioxidant enzyme system

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 125-129, 2006

Authors: ZHANG, Yun | DENG, Li-bin | YE, Wan-Hui

Article Type: Research Article

Abstract: In order to test whether the long-term application of calcium superphosphate leads to an increase of the soil rare earth element contents, superphosphate fertilized soils were sampled and compared with superphosphate-free soils. Spectrophlame inductively coupled argon plasma atomic emission spectrophotometer (ICP-AES) was applied to quantify the rare earth elements (REEs). The total rare earth element contents in calcium superphosphate from Zhijin County, west part of Guizhou Province, China (produced by the sulphuric …acid treatment of the apatites) are about 2.54 mg/g. Between 38 and 189 gREEs/hm^2 per year (available for plants, estimated by 2% citric acid) will be introduced into the soil solution when applying 320 kg superphosphate/hm^2 per year. The long-term application of the latter will increase the REE content by about 18% in the soil surface layer in these areas. A statistically significant increase of the content of the rare earths in some cultivated soils should not be neglected. Show more

Keywords: rare earth elements, calcium superphosphate, soil

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 130-134, 2006

Authors: XIAO, Neng-wen | LIU, Xiang-hui | LI, Wei | GE, Feng

Article Type: Research Article

Abstract: To assess the sublethal toxicity of the herbicide acetochlor to earthworms and to find out biomarkers possible inducted under acetochlor exposure, Eiseniafetida was exposed to artificial soils supplemented with different concentrations of acetochlor (5, 10, 20, 40 and 80 mg/kg soil). Effects of the acetochlor on cytochrome P450 monooxygenases p-nitroanisole O-demethylase (ODM), aldrin epoxidase(AE) and glutathione-S-transferases (GSTs) activities were determined. The results revealed cytochrome P450 monooxygenases were elevated with increasing concentrations of …acetochlor, and the AE activity increased significantly compared with control at the concentration of 80 mg/kg (P<0.05). However, ODM activity from E. fetida was not induced significantly by acetochlor at all treatments (P>0.05). Sodium dodecyl sulfate-polyacryamide gel electrophoresis(SDS-PAGE) showed that one protein band was visualized and no evident differences were found in protein profiles between treatments and control. The GST activity increased significantly with longer duration (P<0.05) and increasing concentrations of acetochlor exposure (P<0.05). This study showed that the monooxygenases and GSTs activities in E. fetida could be induced by acetochlor, and thus, the AE and GST could be used in sublethal assays for soil contamination surveys and GST could be used as biomarkers ofacetochlor exposure in E. fetida. Show more

Keywords: acetochlor, Eiseniafetida, p-nitroanisole O-demethylase, aldrin epoxidase, GST

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 135-140, 2006

Article Type: Other

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 140-140, 2006

Authors: YAO, Xiao-hua | MIN, Hang

Article Type: Research Article

Abstract: An aerobic bacterium, capable of degrading the new chloronicotine pesticide acetamiprid, was isolated from the sludge of pesticide factory after successive enrichment cultures and named strain FH2 which is a Gram-negative, rod-shaped, obligate aerobic organism with ((0.5–0.7) × (1.5–3.0))μm of cell size and with monotrichous flagellum. It was identified as a member of Pseudomonas sp. based on morphology, physio-biochemical properties, Biolog GN2, 16S rDNA sequence and phylogenetic characteristic analysis. The isolate could …grow optimally at pH 7.0 and 30°C in acetamiprid-mineral medium with 800 mg/L concentration. About 53.3% acetamiprid was degraded by strain FH2 after incubation for 14 d in acetamiprid-mineral medium and nearly 96.7% degraded when incubated in acetamiprid-yeast mineral medium at 30°C for 14 d. This paper describes phylogenetic and degradation characterization of a pure bacterium being able to mineralize acetamiprid for the first time. Show more

Keywords: acetamiprid, biodegradation, characterization, isolation, Pseudomonas sp., 16S rDNA

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 141-146, 2006

Authors: LIU, Xiang | MAO, Xiao-min | YANG, Jian-gang | Barry, D.A. | LI, Ling

Article Type: Research Article

Abstract: Pollution by polycyclic aromatic hydrocarbons (PAHs) is widespread due to unsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phenanthrene, a typical PAH, was selected as the target in this paper. The PAH-degrading mixed culture, named ZM, was collected from a petroleum contaminated river bed. This culture was injected into phenanthrene solutions at different concentrations to quantify the biodegradation process. Results show near-complete removal …of phenanthrene in three days of biodegradation if the initial phenanthrene concentration is low. When the initial concentration is high, the removal rate is increased but 20%–40% of the phenanthrene remains at the end of the experiment.The biomass shows a peak on the third day due to the combined effects of microbial growth and decay. Another peak is evident for cases with a high initial concentration, possibly due to production of an intermediate metabolite. The pH generally decreased during biodegradation because of the production of organic acid. Two phenomenological models were designed to simulate the phenanthrene biodegradation and biomass growth. A relatively simple model that does not consider the intermediate metabolite and its inhibition of phenanthrene biodegradation cannot fit the observed data. A modified Monod model that considered an intermediate metabolite (organic acid) and its inhibiting reversal effect reasonably depicts the experimental results. Show more

Keywords: biodegradation model, phenanthrene, microbial growth and decay, Monod growth model

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 147-153, 2006

Authors: ZENG, Jun | GUO, Hua-fang | HU, Yue-ming

Article Type: Research Article

Abstract: As being an effective real-time method of monitoring vehicle emissions on-road, a remote sensing system based on the tunable diode laser (TDL) technology was presented, and the key technologies were discussed. A field test in Guangzhou (Guangdong, China) was performed and was found that the factors, such as slope, instantaneous speed and acceleration, had significant influence on the detectable rate of the system. Based on the results, the proposal choice of testing site was presented.

Keywords: remote sensing, tunable diode laser, vehicle emission, detectable rate

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 154-157, 2006

Authors: JIANG, Yan-li | LIU, Hui-ling | WANG, Qun-hui | JIANG, Zhao-hua

Article Type: Research Article

Abstract: A new method of determining the cumulate concentration of hydroxyl radicals in the TiO_2 /Ti photoelectrocatalytic (PEC) oxidation system was established by o-phenanthroline-Fe(II)(Fe(phen)_3^{2+} ) spectrophotometry and using anion exchange membrane. Fe (phen)_3^{2+} can be oxidized to o-phenanthroline-Fe(III)(Fe(phen)_3^{3+} ) by strong oxidization of hydroxyl radicals (·OH). Then the cumulate concentration of hydroxyl radicals can be calculated through determining the change of the Fe(phen)_3^{3+} …absorbency at 509 nm. In addition, the research results showed the production rate of hydroxyl radicals was affected obviously by pH of solution, the cumulate concentration of hydroxyl radicals was the largest at nearby the initial pH 6.3 (isoelectric point), and the change direction of pH after illumination tended to nearby isoelectric point. Show more

Keywords: TiO_2/Ti catalyst, photoelectrocatalysis, o-phenanthroline-Fe, hydroxyl radical, anion exchange membrane

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 158-161, 2006

Authors: WANG, Ying-hong | WANG, Yue-si | SUN, Yang | XU, Zhong-jun | LIU, Guang-ren

Article Type: Research Article

Abstract: Combining improved injector, gas line and valve-driving modules, a GC equipped with FID and ECD, could simultaneously measure CH_4 , CO_2 and N_2 O in an air sample within 4 min. Test results showed that the system has high sensitivity, resolution and precision; the linear response range of the system meets the requirement of in situ flux measurements. Thus, the system is suitable for monitoring fluxes of main greenhouse gases in terrestrial …ecosystem since it is easy to use, efficacious, stable and reliable to collect data. Show more

Keywords: GC, valve, emission of greenhouse gases, ecosystem

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 162-169, 2006

Authors: WU, Xiao-qin | WU, Zhong-biao

Article Type: Research Article

Abstract: A novel utilization way of the sludge from wet calcium-based flue gas desulfurization (FGD) processes has been developed in this paper. This study focused on the conversion of the FGD gypsum into α-hemihydrate calcium sulfate by a hydrothermal salt solution method at atmospheric pressure. Experimental study has been carried out in a batch reactor. Qualitative and quantitative analyses were made by DSC/TG thermal analysis, SEM, XRD, metalloscope and chemical analysis. The experimental …results showed that the modification of FGD gypsum was controlled by the dissolution and recrystallization mechanisms. With the introduction of FGD gypsum the salt solution was supersaturated, then crystal nucleus of α-hemihydrate calcium sulfate were produced in the solution. With the submicroscopic structure of FGD gypsum crystal changed, the crystal nucleus grew up into α-hemihydrate calcium sulfate crystals. Thus, the modification of FGD gypsum was fulfilled. Show more

Keywords: FGD gypsum, modification, hydrothermal mixed salt solution, atmospheric pressure

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 170-175, 2006

Authors: HE, Pin-jing | QU, Xian | SHAO, Li-ming | LEE, Duu-jong

Article Type: Research Article

Abstract: Landfill is the major disposal route of municipal solid waste (MSW) in most Asian countries. Leachate from landfill presents a strong wastewater that needs intensive treatment before discharge. Direct recycling was proposed as an effective alternative for leachate treatment by taking the landfill as a bioreactor. This process was proved not only considerably reducing the pollution potential of leachate, but also enhancing organic degradation in the landfill. However, as this paper shows, although direct leachate recycling …was effective in landfilled MSW with low food waste fraction (3.5%, w/w), it failed in MSW containing 54% food waste, as normally noted in Asian countries. The initial acid stuck would inhibit methanogenesis to build up, hence strong leachate was yielded from landfill to threaten the quality of receiving water body. We demonstrated the feasibility to use an assisted bioreactor landfill, with a well-decomposed refuse layer as ex-situ anaerobic digester to reducing COD loading in leachate. By doing so, the refuse in simulated landfill column (2.3 m high) could be stabilized in 30 weeks while the COD in leachate reduced by 95% (61000 mg/L to 3000 mg/L). Meanwhile, the biogas production was considerably enhanced, signaling by the much greater amount and much higher methane content in the biogas. Show more

Keywords: bioreactor, landfill, leachate recycling, organics, enhancement, leachate, pretreatment

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 176-179, 2006

Authors: YANG, Shi-ying | LOU, Li-ping | WU, Xiao-na | CHEN, Ying-xu

Article Type: Research Article

Abstract: For TiO_2 heterogeneous reaction, the reaction site and the detailed mechanism are interesting and controversy topics. In this paper, effects of surface fluorination of TiO_2 on the photocatalytic degradation of an azo dye, Orange G(OG) under UV or visible light irradiation were investigated, and the possible reaction site and mechanism were elucidated. The adsorption of OG on TiO_2 was nearly inhibited by fluoride but its UV light induced photodegradation rate …was greatly increased by a factor of about 2.7, which was due to the more generated free hydroxyl radicals. It supported the views that fluoride could desorb the oxidant species from surface and that the reaction sites could move to the bulk solution. In TiO_2 /Vis system, the observed inhibition effects of fluorination could be interpreted by the competitive adsorption, which provided additional evidences that the visible light sensitized photodegradation of dye pollutants on the catalyst surface. Show more

Keywords: photocatalytic degradation, mechanism, adsorption, fluorination, dye pollutants

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 180-183, 2006

Authors: SULTAN, Khawar | DOWLING, Kim

Article Type: Research Article

Abstract: This paper reports on the major cations (Ca, Mg, Na and K) and arsenic (As) compositions of surface waters collected from major creeks, rivers and lakes in Central Victoria (Australia). The surface waters were found to be neutral to alkaline (pH 6.7–9.4), oxidised (average redox potential (Eh) about 130 mV) and showed variable concentrations of dissolved ions (EC, about 51–4386μS/cm). The concen- trations of dissolved major cations in surface waters were found to be in the …order of Na>>Mg>Ca>K and in soils the contents of metals followed an order of abundance as: Ca>Mg>>K>Na. While Na was the least abundant in soils, it registered the highest dissolved cation in surface waters. Of the four major cations, the average concentration ofNa (98.7 mg/L) was attributed to the weathering of feldspars and atmospheric input. Relatively highly dissolved concentrations of Na and Mg compared with the world average values of rivers reflected the weathering of rock and soil minerals within the catchments. The As soil level is naturally high(linked to lithology) as reflected by high background soil values and mining operations are also considered to be a contributory factor. Under relatively alkaline-oxidative conditions low mobility of dissolved As (average about 7.9μg/L) was observed in most of the surface waters with a few higher values (>15 μg/L) around a sewage disposal site and mine tailings. Arsenic in soils is slowly released into water under alkaline and/or lower Eh conditions. The efficient sink of Fe, Al and Mn oxides acts as a barrier against the As release under near neutral-oxidising conditions. High As content (average about 28.3 mg/kg) in soils was found to be associated with Fe-hydroxides as revealed by XRD and SEM analysis. The dissolved As concentration was found to be below the recommended maximum levels for recreational water in all surface waters (lakes and rivers) in the study area. Catchment lithology exerted the fundamental control on surface water chemistry. Sites impacted by mining waste dumps showed a decline in water quality. Show more

Keywords: surface water, major cations, arsenic, soil, Australia

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 184-192, 2006

Authors: Lee, Jae-Wook | Kwon, Tae-Ouk | Thiruvenkatachari, Ramesh | Moon, Il-Shik

Article Type: Research Article

Abstract: This study evaluates the adsorption ability of bisphenol A (BPA) on titanium dioxide (TiO_2 ) and its effect on the photocatalysis by advanced oxidation process using UV radiation and TiO_2 photocatalyst. Degradation of BPA was also evaluated for the system without adsorption prior to photocatalytic reaction. The separation of TiO_2 from BPA solution treated by pilot-scale photocatalytic reactor (capacity 0.16 m^3 ) was studied using submerged …ultrafiltration (UF) membrane. It was found that although adsorption capacity of BPA was not high, adsorption played an important role in improving the efficiency ofphotocatalysis. On the other hand, during the separation of TiO_2 particles from aqueous suspension, the permeate flux of the membrane was strongly affected by transmembrane pressure and TiO_2 dose. The permeate turbidity was decreased below 1 NTU. Show more

Keywords: bisphenol A, TiO_2, adsorption, membrane, photocatalysis

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 193-200, 2006

Authors: HUANG, Can | LI, Ji | KANG, Wen-li | TANG, Xin-yan

Article Type: Research Article

Abstract: Manure odor, which results in the increasing complaints and lawsuits, has increased the tension among swine producers and surrounding residents. The effects of Lactobacillus plantarum and different rates of soluble carbohydrates additions to swine manure on odorous compounds, chemical compounds and indigenous flora were evaluated. Additions were calculated on dried manure weight basis. Variables monitored included ammonia (NH_3 ), hydrogen sulfide (H_2 S), odor offensiveness, pH, ammonium nitrogen(NH_4^+ -N), …volatile fatty acids (VFAs), urease and indigenous flora. The results indicated that the combination of L. plantarum and soluble carbohydrates dramatically reduced manure pH. Lower pH resulted in the reduction of NH_3 volatilization (34.6%–92.4%, P<0.01), the increases of H_2 S (P< 0.05) and NH_4^+ -N (5.3%–17.5%, P<0.05). In addition, L. plantarum and soluble carbohydrates additions significantly reduced odor offensiveness, those VFAs related to malodor indicators(valeric acids, 12.3%–47.7%, P<0.05; iso-valeric, 3.5%–23.8%) and the main microorganisms responsible for odor production, with the number of Eubacteria in swine manure reducing by 4.9%, 11.6%, 17.4%, 34.1% and 32.2% respectively. Show more

Keywords: Lactobacillus plantarum, soluble carbohydrates, swine manure, odorous compounds, indigenous flora

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 201-206, 2006

Article Type: Other

Citation: Journal of Environmental Sciences, vol. 18, no. 1, pp. 207-207, 2006