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811.
DDT污染土壤的植物修复技术 总被引:2,自引:0,他引:2
本文报道用植草方法研究为DDT及其主要降解产物污染土壤的植物修复技术。在污染物的浓度为 0 .2 15mg/kg的土壤中 ,种植 10种草 3个月后DDT及其主要降解产物的总含量分别降低 19.6 %— 73.0 %。种植不同品种的草对土壤中污染物有不同的去除能力 ,其中以种植丹麦产的Taya草 (Per .ryegrass)与美国产的Titan草 (Tallfescue)为最强。用种植草的方法修复受DDT及其主要降解产物污染的土壤是一项可行的技术。在去除土壤中DDT的作用上 ,草的吸收是轻微的 ,只占原施药量的 0 .13%— 1.0 8% ,土壤中污染物消失的主要因素是土壤中生物降解作用的结果。 相似文献
812.
Effects of humic substances on photodegradation of bensulfuron-methyl on dry soil surfaces 总被引:1,自引:0,他引:1
The photodegradation of the herbicide bensulfuron-methyl on dry soil surfaces in the presence and absence of humic substances was investigated under Xe lamp irradiation. A rapid rate of disappearance occurs in the humus-removed soil. The presence of humic acid (HA) and fulvic acid (FA) reduces degradation rates and has a quenching effect on the photodecomposition of bensulfuron-methyl. The quenching effect increases with increasing HA and FA concentration in soil. HA has a slightly greater ability to quenching the photolysis compared to FA. In addition, co-effects of HA and FA on quenching the photolysis are stronger than single effects of HA or FA. 相似文献
813.
Polychlorinated dibenzo-p-dioxins and dibenzofurans in paper making from a pulp mill in China 总被引:2,自引:0,他引:2
An extensive investigation on the input, formation and fate of PCDD/Fs in a pulp mill using reeds as raw materials in China was carried out. The main PCDD/Fs input in the production process came from reeds, which may be contaminated by PCDD/Fs from sodium pentachlorophenate to control snailborne schistosomiasis. High levels of I-TEQ in the products were observed. 相似文献
814.
Petroleum hydrocarbons and polycyclic aromatic hydrocarbons in the surficial sediments of Xiamen Harbour and Yuan Dan Lake, China 总被引:1,自引:0,他引:1
Surficial sediments were sampled from nine stations in Xiamen Harbour and two stations in Yuan Dan Lake during April 2002. Sediment samples were extracted by organic solvents, separated by silica gel column chromatography and analyzed by gas chromatography-mass selective detector (GC-MSD). Selected ion monitoring was at M/Z=57 for petroleum hydrocarbons (PHCs) and individual M/Zs for each of the 15 typical polycyclic aromatic hydrocarbons (PAHs) and nine alkylated PAHs. The results showed that concentrations of PHCs and total PAHs in the sediments of Yuan Dan Lake were 1397 microg g(-1) (dry weight, dw) and 1377 ng g(-1) (dw), respectively. The ranges for PHCs and total PAHs in the sediments from Xiamen Harbour were 133-943 microg g(-1) (dw) and 98-309 ng g(-1) (dw), respectively. Shipping activities, industrial wastewater discharges, fuel oil spillage from ships and vehicles were the main sources of PHCs and PAHs in the Harbour. In addition, the widespread use of coal for industrial processes and domestic consumption accounted for the second largest source of PAHs in the sediments, while atmospheric transport and deposition of PAHs are also important. 相似文献
815.
本文阐述了QSAR研究中常用的几个电子参数σ的定义、测试方法及估算方法,对可利用数据进行了归纳整理,并通过实例阐述了其在QSAR中的重要作用。 相似文献
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819.
Effect of ZnFe2O4 doping on the photocatalytic activity of TiO2 总被引:9,自引:0,他引:9
The photocatalytic oxidation of the organic pollutants with the TiO2 as photocatalyst has been widely studied in the world, and many achievements have been got. The degradation of pollutants is highly related with the photocatalytic activity of TiO2. It is demonstrated that doping ions or oxides to TiO2 is one way to enhance the photocatalytic activity of TiO2. In this paper, the ZnFe2O4-doped TiO2 nanoparticles were prepared from butyl titanate by a sol-gel method and characterized by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that when TiO2 was doped with ZnFe2O4, its particle size will decrease and its crystal structure will partly transform from anatase to rutile. The photocatalytic activity of the elaborated powders was studied following the degradation of Rhodamine B. The results showed that doping ZnFe2O4 to TiO2 will enhance the photocatalytic activity of TiO2 and that ZnFe2O4-doped TiO2 in the coexistence of anatase and rutile has higher efficiency for the degradation of Rhodamine B than that in the anatase phase alone. Also the different role of O2 in the direct photolysis and photocatalysis of Rhodamine B was discussed. 相似文献
820.
BACKGROUND AND OBJECTIVE: Indigenous soil microorganisms are used for the biodegradation of petroleum hydrocarbons in oily waste residues from the petroleum refining industry. The objective of this investigation was to determine the potential of indigenous strains of fungi in soil contaminated with petroleum hydrocarbons to biodegrade polycyclic aromatic hydrocarbons (PAH). MATERIALS AND METHODS: Twenty one fungal strains were isolated from a soil used for land-farming of oily waste residues from the petrochemical refining industry in Singapore and identified to genus level using laboratory culture and morphological techniques. Isolates were incubated in the presence of 30 mg/L of phenanthrene over a period of 28 days at 30 degrees C. The most effective strain was further evaluated to determine its ability to oxidise a wider range of PAH compounds of various molecular weight i.e acenaphthene, fluorene, fluoranthene, chrysene, benzo(a)pyrene and dibenz(ah)anthracene RESULTS AND DISCUSSION: After 28 days of incubation, 18 of the 21 fungal cultures were capable of oxidising over 50% of the phenanthrene present in culture medium, relative to abiotic controls. Fungal isolate, Penicillium sp. 06, was able to oxidise 89% of the phenanthrene present. This isolate could also oxidise more than 75% of the acenaphthene, fluorene and fluoranthene after 30 days of incubation. However, the oxidation of high molecular weight PAH i.e. chrysene, benzo(a)pyrene and dibenz(ah)anthracene by the Penicillium sp. 06 isolate was limited, where the extent of oxidation was inversely proportional to PAH molecular weight. CONCLUSIONS: Fungal isolate, Penicillium sp. 06, was effective at oxidising a range of PAH in petroleum contaminated soils, but higher molecular weight PAH were more recalcitrant. RECOMMENDATIONS AND OUTLOOK: There is potential for the re-application of this fungal strain to soil for bioremediation purposes. 相似文献