Journal of Environmental Sciences - Volume 16, issue 5

Authors: DONG, Xu-hui | SAKAMOTO, Kazuhiko | WANG, Wei | GAO, Shi-dong | ISOBE, Yugo

Article Type: Research Article

Abstract: The bio-briquette technique which mixes coal, biomass and sulfur fixation agent and bio-briquettes under 3–5 t/cm^2 line pressure has aroused people's attention in view of controlling the air pollution and the acid rain. In this paper, the physicochemical properties of bio-briquette and its ash were investigated. And the acid soil was improved by the bio-briquette combustion ash, which contained nutritive substances such as P, N, K and had the acid-neutralizing capacity (ANC). The pH, …EC, effective nutrient elements (Ca, Mg, K, P and N), heavy metal elements (Al, Cu, Cd, Cr, Zn and Mn) and acid-neutralizing capacity change of ash-added soils within the range of 0%–10%, were also studied. Specially, when 5% bio-briquette combustion ash was added to the tested soil, the content of the effective elements such as Ca, Mg and K rose by 100 times, 7 times and twice, respectively. The total nitrogen also increased by about twice. The results showed the oxyanions such as that of Al, Cu, Cd, Cr, Zn and Mn were not potentially dangerous, because they were about the same as the averages of them in Chinese soil. It is shown that the ANC became stronger, though the ANC hardly increases in the ash-added soil. On the basis of the evaluation indices, it is concluded that the best mixture ratio is to add 2.5%–8% of the bio-briquette combustion ash to the tested soil. Show more

Keywords: bio-briquette combustion ash, soil improvement, ANC, heavy metal element, nutrient element

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 705-711, 2004

Authors: LIU, Huai-pan | LIU, Jun | ZHANG, Yan-yan | LIU, You-liang

Article Type: Research Article

Abstract: The effects of osmotic stress on the ATPase activity, the contents of -SH group and conjugated polyamines in mitochondrial membrane from wheat seedling [Triticum aestivum L. cv. Yumai No.18 (drought-tolerant) and cv. Yumai No.9(drought-sensitive)] roots were investigated. The results showed that ATPase activity and -SH group content decreased with polyethylene glycol (PEG) 6000 (−0.55 MPa) treatment for 7 d, in concert with the decrease of the ratio of noncovalently conjugated spermidine (NCC-Spd)/noncovalently conjugated …putrescine (NCC-Put) and increase of the covalently conjugated putrescine (CC-Put). Osmotic stress injury to Yangmai No.9 seedlings was alleviated greatly with 1 mmol/L exogenous spermidined (Spd), in concert with marked increases of the ratio of NCC-Spd/NCC-Put, -SH group contents and ATPase activity in mitochondrial membrane. Under osmotic stress, the concomitant treatment of Yumai No.18 seedlings with methylglyoxyl bis (guanylhydrazone) (MGBG), an inhibitor of S-adenosyl methionine decarboxylase (SAMDC), and phenanthrolin (o-Phen), an inhibitor of transglutaminase (TGase), caused a significant decrease of the ratio of NCC-Spd/NCC-Put, CC-Put contents, respectively, in concert with the marked decreases of ATPase activity, -SH group content and its tolerance to osmotic stress. All the results above suggested that osmotic stress tolerance of wheat seedlings was associated with the ATPase activity, the contents of -SH group, NCC-Spd and CC-Put in mitochondrial membrane. Show more

Keywords: ATPase, conjugated polyamines, mitochondria, osmotic stress, wheat (Triticum aestivum L.)

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 712-716, 2004

Authors: FAN, Zhi-jin | HU, Ji-ye | AI, Ying-wei | QIAN, Chuan-fan | YU, Wei-qiang | LI, Zheng-ming

Article Type: Research Article

Abstract: HPLC-UV residue analytical method for monosulfuron [N-[(4'-methyl) pyrimidin-2'-yl]-2-nitrophenylsulfonyl urea] in soil and wheat was developed. Monosulfuron residues were recovered by solvent extraction, followed by liquid-liquid partition, and C_{18} column clean-up. Excellent method recoveries ranging from 95%–104% for both fortified soil and wheat grain were obtained with coefficients of variation 1.5%–11.8%. The minimum detectable quantities in soil and wheat were both 4 ng, the limit of detection was 0.02 mg/kg. When …monosulfuron was applied according to double dosage of maximum recommended use direction (120 g ai/hm^2 of 10% monosulfuron wettable powder sprayed for once during development of wheat) in field studies conducted in Shandong Province and near Beijing, monosulfuron residues was not detected in soil and wheat samples collected 75 d after application. Laboratory soil degradation studies showed that monosulfuron degraded faster in acidic soil and strong alkaline soil than in neutral or weak alkaline soil. Half lives in Jiangxi soil, Shijiazhuang soil, Jiangsu soil and Heilongjiang soil were 41, 48, 87 and 84 d respectively. Monosulfuron residues dissipated rapidly in Shandong and Beijing field test sites with half-lives of less than 14 d. Show more

Keywords: monosulfuron, wheat (Triticum, aestivum L.), soil degradation, residue analysis

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 717-721, 2004

Authors: SHAN, Bao-qing | WANG, Wei-dong | YIN, Cheng-qing

Article Type: Research Article

Abstract: Streamwater chemistry and spatial flow dynamics from a subalpine Abies fabri forest in an experimental watershed located in the east slope of Gongga Mountain were analyzed to gain insights into the gradient effect of primary community succession on the stream biogeochemical process. Results showed that high sand content (exceeding 80%) and porosity in the soil (exceeding 20% in A horizon and 35% in B horizon), as well as a thick humus layer on the soil surface, …made the water exchange quickly in the Huangbengliu (HBL) watershed. Consequently, no surface runoff was observed, and the stream discharge changed rapidly with the daily precipitation. The flow trends of base ions in the stream water were influenced by the Abies fabri succession gradient. Ca^{2+} , HCO_3^- and SO_4^{2-} were the dominant anions in the streamwater in this region. A significant difference of Ca^{2+} , HCO_3^- and SO_4^{2-} concentration exported between the succession stages in the watershed can be found. But they had the similar temporal change in the stream flow. Ca^{2+} , HCO_3^- and SO_4^{2-} showed significantly negative correlations with the daily precipitation and the stream discharge. Concentrations of Cl^- , Na^+ , K^+ , and Mg^{2+} were low in all streamwaters monitored and we observed no differences along the Abies fabri succession gradient. Low ratios of Na: (Na+Ca) (range from 0.1 to 0.2) implied cations were from bedrock weathering(internal source process in the soil system) in this region. But, a variance analysis showed there were almost no differences between rainwater and streamwaters for Mg^{2+} , Na^+ , K^+ , and Cl^- concentrations. This indicated that they might be come from rainfall inputs (external source). We suggest that the highly mobile capacity, rapid water exchange between precipitation and discharge, and long-term export lead to this observed pattern. Show more

Keywords: water chemistry, succession, subalpine coniferous forest, Abies fabri, watershed, Gongga Mt

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 722-729, 2004

Authors: SHU, Wen-sheng | ZHAO, Yun-lin | YANG, Bing | XIA, Han-ping | LAN, Chong-yu

Article Type: Research Article

Abstract: A field experiment was conducted to compare the growth and metal accumulation of Vertiveria zizanioides, Paspalum notatum, Cynodon dactylon and Imperata cylindraca var. major on the tailings, amended with 10 cm domestic refuse + complex NPk fertilizer (Treatment A), 10 cm domestic refuse (Treatment B) and complex NPK fertilizer (Treatment C) respectively, and without any amendment used as control(Treatment D). The results indicated that V. zizanioides was a typical heavy metal excluder, because the concentrations …in shoots of the plants were the lowest among the four plants tested. The most of metal accumulated in V. zizanioides distributed in its root, and transportation of metal in this plant from root to shoot was restricted. Therefore, V. zizanioides was more suitable for phytostabilization of toxic mined lands than P. notatum and C. dactylon, which accumulated a relatively high level of metals in their shoots and roots. It was also found that I. cylindraca var. major accumulated lower amounts of Pb, Zn and Cu than C. dactylon and P. notatum, and could also be considered for phytostalilisaton of tailings. Although the metal (Pb, Zn and Cu) concentrations in shoots and roots of V. zizanioides were the lowest, the total amounts of heavy metals accumulated in shoots of V. zizanioides were the highest among the four tested plants due to the highest dry weight yield of it. The results indicated that V. zizanioides was the best choice among the four species used for phytoremediation (for both phytostabilization and phytoextraction) of metal contaminated soils. Show more

Keywords: Pb/Zn tailings, heavy metals, phytoremediation, Vertiveria zizanioides, Paspalum notatum, Cynodon dactylon, Imperata cylindraca var. major

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 730-734, 2004

Authors: FAN, Xiao-hui | Tsuruta, Haruo

Article Type: Research Article

Abstract: The aim of this work was to examine the emission of N_2 O from soils following addition of nitrogen fertilizer with a nitrification inhibitor (+inh) or without the nitrification inhibitor (−inh) at different soil water regime. Higher soil moisture contents increased the total N_2 O emissions in all treatments with total emissions being 7 times larger for the CK and >20 times larger for the fertilizer treatments at 85% WFPS (soil water filled pore …space) than at 40% WFPS. The rates of N_2 O emissions at 40% WFPS under all treatments were small. The maximum emission rate at 55% WFPS without the nitrification inhibitor (−inh) occurred later (day 11) than those of 70% WFPS (−inh) samples (day 8). The inhibition period was 4–22 d for 55% WFPS and 1–15 d for 70% WFPS comparing the rates of N_2 O emissions treated (+inh) with (−inh). The maximum emission rates at 85% WFPS were higher than those at the other levels of soil water content for all treatments. The samples (+inh) released less N_2 O than (−inh) samples at the early stage. Nevertheless, N_2 O emissions from (+inh) samples lasted longer than in the (−inh) treatment. Changes in mineral N at 55%, 70% and 85% WFPS followed the same pattern. NH_4^+ -N concentrations decreased while NO_3^- -N concentrations increased from the beginning of incubation. NH^+_4 -N concentrations from 40% WFPS treatment declined more slowly than those of the other three levels of soil water content. Nitrification was faster in the (−inh) samples with 100% NH_4^+ -N nitrified after 22 d (50% WFPS) and 15 d (70% and 85% WFPS). N_2 O emissions increased with soil water content. Adding N-fertilizer increased emissions of N_2 O. The application of the nitrification inhibitor significantly reduced total N_2 O emissions from 30.5% (at 85%WFPS) to 43.6% (at 55% WFPS). Show more

Keywords: N_2O emission, nitrification inhibitor, soil water content, upland soil samples

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 735-737, 2004

Authors: LIAO, Min | XIE, Xiao-mei

Article Type: Research Article

Abstract: Adsorption of phenthoate and acetochlor onto kaolin, montmorillonite, bentonite clays and respective organoclays prepared by the exchange of quaternary ammonium as tetradecyltrimethyl ammonium bromide (TTAB), dodecyltrimethylammonium bromide (DTAB), and cetylpyridinium chloride (CPC) were studied. The adsorption equilibrium data points were fitted to Freundlich isotherm equations. The adsorption of phenthoate and acetochlor were significantly enhanced by surfactant treatment of the clays. The amount of both pesticides adsorbed per unit mass of organoclay followed …the order of TTA-kaolin < TTA-montmorillonite < TTA-bentonite, which is inconsistent with the organic carbon content of the clays. The removal efficiency of organomontmorillonite to treat acetochlor is in the order of CP(C_{16} )-montmorillonite > TTA(C_{14} )-montmorillonite > DTA(C_{12} )-montmorillonite. Phenthoate is adsorbed to greater extent than acetochlor by each adsorbent, which may be due to the higher hydrophobicity of phenthoate, indicating considerable hydrophobic interaction between adsorbent/adsorbate systems. Show more

Keywords: adsorption, clays, organoclays, phenthoate, acetochlor

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 738-741, 2004

Authors: ZHAO, Zhong-qiu | ZHENG, Hai-lei | ZHU, Yong-guan

Article Type: Research Article

Abstract: The salt-secreting mangrove, Avicennia marina, and non-salt-secreting mangrove, Kandelia candel were cultivated in sand with various salinities (0‰, 10‰, 20‰, 30‰, 40‰) for 60 d. Plasma membrane vesicles of high-purity in leaves and roots of A. marina and K. candel seedlings were obtained by two-phase partitioning. The function of the plasma membranes, the activity of ATPase, membrane potential and transmembrane proton gradient, at various salinities were investigated. The results showed that within …a certain range of salinity (A. marina and roots of K. candel: 0–30‰; leaves of K.candel: 0–20‰), the activity of ATPase increased with increasing salinity, while high salinity (above 30‰ or 20‰) inhibited ATPase activity. In comparison with A. marina, K. candel appeared to be more sensitive to salinity. The dynamics of membrane potential and transmembrane proton gradient in leaves and roots of A. marina and K. candel seedlings were similar to that of ATPase. When treated directly by NaCl all the indexes were inhibited markedly: there was a little increase within 0–10‰ (K. candel) or 0–20‰ (A. marina) followed by sharp declining. It indicated that the structure and function of plasma membrane was damaged severely. Show more

Keywords: salinity, A. marina, K. candel, plasma membrane, H-ATPase, Ca-ATPase, membrane potential, transmembrane proton gradient

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 742-745, 2004

Authors: LIN, Tao | CUI, Fu-yi | LIU, Dong-mei | AN, Dong

Article Type: Research Article

Abstract: Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this paper, a full-scale study of chlorine dioxide preoxidation cooperating with routine clarification process for Cyclops removal was conducted in a waterworks. The experimental results were compared with that of the existing prechlorination process in several aspects: including the Cyclops removal efficiencies …of water samples taken from the outlets of sedimentation tank and sand filter and the security of drinking water etc. The results showed that chlorine dioxide might be more effective to inactivate Cyclops than chlorine and Cyclops could be thoroughly removed from water by pre-dosing chlorine dioxide process. The GC-MS examination and Ames test further showed that the sort and amount of organic substance in the treated water by chlorine dioxide preoxidation were evidently less than that of prechlorination and the mutagenicity of drinking water treated by pre-dosing chlorine dioxide was substantially reduced compared with prechlorination. Show more

Keywords: Cyclops of zooplankton, chlorine dioxide, chlorine, preoxidation, water treatment

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 746-750, 2004

Authors: Abas, M. Radzi Bin | Omar, Nasr Yousef M. J. | Maah, M. Jamil

Article Type: Research Article

Abstract: PM_{10} airborne particles and soot deposit collected after a fire incident at a chemical store were analyzed in order to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs). The samples were extracted with 1:1 hexane-dichloromethane by ultrasonic agitation. The extracts were then subjected to gas chromatography-mass spectrometric (GC-MS) analysis. The total PAHs concentrations in airborne particles and soot deposit were found to be 3.27 ± 1.55 ng/m^3 and 12.81 …± 24.37 μg/g, respectively. Based on the molecular distributions of PAHs and the interpretation of their diagnostic ratios such as PHEN/(PHEN + ANTH), FLT/(FLT + PYR) and BeP/(BeP + BaP), PAHs in both airborne particles and soot deposit may be inferred to be from the same source. The difference in the value of IP/(IP + BgP) for these samples indicated that benzo[g,h,i]perylene and coronene tend to be attached to finer particles and reside in the air for longer periods. Comparison between the molecular distributions of PAHs and their diagnostic ratios observed in the current study with those reported for urban atmospheric and roadside soil particles revealed that they are of different sources. Show more

Keywords: airborne particles, soot deposit, PAHs

Citation: Journal of Environmental Sciences, vol. 16, no. 5, pp. 751-754, 2004