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含有氯霉素(CM)、抗菌素增效剂(TMP)和磺胺新诺明(SMZ)的合成制药废水对生物处理有较强的抑制作用.研究表明,通过对厌氧菌和好氧菌的驯化、筛选和复配采用吹脱-厌氧-好氧串联工艺可有效降低废水的有机污染指标:经吹脱和厌氧水解酸化处理后,CODCr去除率为70%,再经好氧生化系统处理,CODCr去除率可达60%.试验结果表明装置运行效果稳定,为实际废水处理提供了一定设计依据. 相似文献
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The aim of this study was to determine for the first time in Poland, levels of exposure to synthetic pyrethroids in preschool and school age children and their parents living in urban and rural areas. For this purpose concentrations of pyrethroid metabolites: 3-phenoxybenzoic acid (3-PBA), 2,2-dibromovinyl-2,2-dimethylcyclopropanecarboxylic acid (Br2CA), cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-Cl2CA) and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (trans-Cl2CA) were determined in 374 urine samples using a validated GC–MS method. 相似文献
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Photodegradation mechanism of deltamethrin and fenvalerate 总被引:1,自引:0,他引:1
To understand the degradation and environmental fate of pyrethroids, the process of their photodegradation under simulated natural
conditions was investigated. The results showed that the degradation process follows first-order kinetics. The degradation intermediates
were identified with gas chromatography-mass spectrometry. A plausible mechanism was discussed to explain the process. Several
influences on degradation process were investigated and reported such as the e ects of initial concentration of pyrethroids, total time
of light irradiation, solvents, and light source, as well as the e ect of a few substances that exist in the environment. This study could
be a good reference for the degradation of pyrethroids in practical circumstances. 相似文献
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巢湖流域和太湖流域沉积物中苄氯菊酯和高效氰戊菊酯的生态风险评价 总被引:2,自引:0,他引:2
分析了巢湖流域和太湖流域表层沉积物中苄氯菊酯和高效氰戊菊酯,并结合毒性单元法(Toxic Unit,TU)和物种敏感性分布法(Species Sensitivity Distributions,SSD)评价了两种拟除虫菊酯的生态风险.结果显示,两大流域沉积物中均广泛检测出两类污染物.总体而言,巢湖流域苄氯菊酯含量较高,而太湖流域高效氰戊菊酯含量较高.同时,两种污染物在巢湖流域呈现显著的正相关,但太湖流域二者之间没有相关关系.3种风险评价方法(TU法、沉积物SSD法、水体SSD法)均揭示苄氯菊酯对巢湖流域水生环境影响较大,而高效氰戊菊酯对两个流域影响均较大.因此,需要加强对流域高效氰戊菊酯污染的关注.其中,TU法预测的风险最小,沉积物SSD法预测的风险最大,主要原因在于TU法采用的毒性数据为LC50,而SSD法则选用了NOEC/LOEC,同时沉积物SSD法是出于保护大部分底栖生物为目的的方法.各种方法对于评价沉积物毒害污染物的生态风险均存在不足,尽管沉积物SSD法最为合理,但由于其毒性数据较少,最终预测结果存在一定的不确定性.因此,需要进一步加强对底栖生物毒性的研究和数据积累. 相似文献
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7种拟除虫菊酯农药对卤虫的急性毒性研究 总被引:1,自引:0,他引:1
为了研究7种拟除虫菊酯农药对美国大盐湖卤虫(GSL Artemia)的急性毒性效应,挑选18~24 h内孵出的卤虫,继续培养24 h后得到Ⅱ~Ⅲ龄卤虫无节幼体,将其暴露于所设浓度梯度的拟除虫菊酯溶液中进行24 h急性毒性实验,记录卤虫无节幼体在各浓度溶液中的死亡情况,并将所得数据进行Probit分析。结果表明,卤虫对不同拟除虫菊酯的敏感性相差较大。氯菊酯、氯烯炔菊酯、炔咪菊酯、胺菊酯、联苯菊酯、高效氯氟氰菊酯和溴氰菊酯对卤虫的24 h半致死浓度(24 h-LC50)分别为4.68、14.82、18.12、38.21、>100、>100和>100 mg.L-1。因此,在含有卤虫的盐水环境中,应尽量避免使用毒性较高的氯菊酯,而选择使用联苯菊酯、高效氯氟氰菊酯和溴氰菊酯等毒性较低的农药。 相似文献
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粉煤灰合成沸石同步脱氨除磷特性的研究 总被引:18,自引:1,他引:18
利用粉煤灰合成沸石,研究其在同步去除氮、磷方面的特性.合成沸石对氨氮和磷酸盐的吸附净化均随时间增加而变化,但均在24h后基本达到平衡.随合成沸石投加量的增加,同步去除污水中氮磷的效果越好,但在投加量为8 g·L-1以上时去除率的增加明显放慢.在pH为7~9时氨氮去除率最高(约60%),超过此pH范围时去除率降低.在pH 7~9范围磷去除率达最低(约为85%),超过此pH范围时去除率增加(最高达到近100%).合成沸石对氨氮的吸附为放热反应,对磷的吸附为吸热反应.不同阳离子饱和的合成沸石对氨氮的吸附顺序依次为:Al>Mg>Ca>Na>Fe,对磷的吸附顺序则为:Al>Fe>Ca>Mg>Na.合成沸石的氨氮吸附机理为阳离子交换作用,对磷的去除除化学沉淀作用外尚有吸附机制. 相似文献
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本文研究了有机磷农药甲基1605和毒死蜱对~1O_2探针性物质二乙基二硫酸(DES)、萜品烯(α-terp)及ROO和RO探针性物质2.6-二叔醒基-4-甲基苯酚(BHT)和1,2,3,4-四氢萘(tetra)光降解的敏化作用.结果表明基态氧直接参与了DES和α-terp的光解;在甲基1605的作用下,1/K_(exptl)与[α-terp]的关系表明,α-terp的降解不为~1O_2历程;同时BHT和tetra的敏化降解说明ROO的量子产率为~1O_2量子产率的5倍;对氯氰菊酯的光敏降解产物的检测表明,在甲基1605存在下,产物仍然以~3O_2氧化产物为主. 相似文献
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Monitoring of Pesticide Residues in Fruits 总被引:1,自引:0,他引:1
Fruit samples of ber, grapes and guava analysed for pesticide residues employing multiresidue analysis by gas liquid chromatography equipped with ECD and NPD detectors and capillary columns showed contamination with organochlorine, synthetic pyrethroid and organophosphate insecticides. Among organochlorines, HCH, DDT and endosulfan were detected in almost all the samples. Residues of HCH and DDT were maximum in ber followed by grapes and guava where as of endosulfan were maximum in guava followed by grapes and ber. All the fruit samples showed the presence of residues with one or the other group of pesticides. Residues of none of the pesticides exceeded the MRL values in any sample. On the basis of these studies, it is suggested that monitoring studies should be extended to other fruits grown in different agro climatic regions which may serve as basis for future policy in chemical use. 相似文献