拟除虫菊酯气相色谱手性拆分方法及其影响因素分析

拟除虫菊酯具有较强的手性特征,包含多种异构体,不同异构体具有不同的生物活性,因此,其异构体的手性拆分具有重要的意义。气相色谱分析法因其分辨率高,峰容量大,灵敏度高、分析时间短,选择性强等特点,已被广泛应用于拟除虫菊酯的手性拆分中。文章通过阐述基于氢键作用、配位作用、包结络合作用的3种手性固定相的拆分机制,综述了气相色谱用于拟除虫菊酯手性分离的研究状况。此外,文章还分析了有机溶剂、水、温度等对拟除虫菊酯在拆分过程中差向异构现象的影响。     

Facile and Sensitive Spectrophotometric Determination of Synthetic Pyrithroids in Their Formulations, Water and Grain Samples

A novel reagent was introduced for the facile and sensitive spectrophotometric determination of syntheitic pyrethroids in their formulations (fenvalerate, cypermethrin and decamethrin), water and grain samples. These methods were based on the hydrolysis of synthetic pyrethroids under the alkaline conditions to form respective aldehyde groups. These groups were condensation with 3-methyl-2-benzothiazolinone hydrochloride (MBTH) to yield color derivatives having λ_max at 520 nm for fenvalerate, 516 nm for cypermethrin and 512 nm for decamethrin. The proposed method could be successfully applied for the determination of synthetic pyrethroids in their formulations, water and grain samples.     

造粒合成沸石滤料对污水中磷的净化与回收

以粉煤灰为原料,采用水热合成法制备沸石,造粒后合成沸石填充至滤柱中. 研究了不同运行条件下合成沸石对污水中磷的净化与回收效果. 结果表明:合成沸石对模拟污水和城市生活污水经二级生化处理后的排放水中磷的去除能力相近,且在磷含量低的情况下后者高于前者;与造粒前相比,造粒后的合成沸石仍具有良好的固磷能力. 水力负荷明显影响滤柱中磷的去除效果,其在177.9 L/(m2·h)以下时,磷的去除效果较好. 此外,进水pH也明显影响合成沸石的除磷效果,当进水pH调至酸性或碱性范围时,合成沸石的除磷能力显著提高. 该滤柱能够长期有效地净化与回收污水中的磷,达到饱和时合成沸石的w(磷)达20.04 g/kg(以磷元素计),可实际应用于农田改良.      

生物亲和亲水磁性填料在污水生物处理中的应用

采用添加生物亲和亲水物质、活性炭及磁粉并磁化的改性聚丙烯填料,进行挂膜和模拟污水生物降解试验.结果发现,普通聚丙烯填料改性后,水滴静态接触角降低22%,含水率提高3～5倍;改性聚丙烯填料比普通聚丙烯填料具有更快的挂膜速度和更高的COD降解率,并能承受更高的气液比以及气流和水流的冲击.改性聚丙烯填料的挂膜期从普通聚丙烯填料的7 d缩短为3 d;将初始COD为500 mg/L的模拟污水完全降解,改性聚丙烯填料需10.5 h,而普通聚丙烯填料则需22.5 h;在连续处理的操作方式下,当气液比为40:1时,改性聚丙烯填料的COD降解率达到最大,为99%,而普通聚丙烯填料则在气液比为30:1时,达到最大的COD降解率,为79%.     

UASB+AF-生物接触氧化工艺处理皂素-酒精综合废水

采用水解酸化-UASB+AF-接触氧化工艺处理黄姜皂素-酒精综合废水,经调试启动和运行研究,结果表明:当进水COD在10 000~12 800 mg/L时,最终出水COD浓度可降低到200 mg/L以下;水解酸化、UASB+AF和接触氧化各阶段的COD去除率分别达到23%、75%和93.5%,系统总的COD去除率可达到98.4%,出水色度在30~50倍之间;同时该工艺具有运行稳定、耐冲击负荷能力强等特点。     

Pesticides residues in the Prochilodus costatus (Valenciennes, 1850) fish caught in the São Francisco River,Brazil

The objective of this study was to determine the levels of pesticides in the fish Prochilodus costatus caught in São Francisco River, one of most important rivers in Brazil. Thirty-six fish were captured in three different areas, and samples of the dorsal muscle and pooled viscera were collected for toxicological analysis. We evaluated the presence of 150 different classes of insecticides, fungicides, herbicides and acaricides by multiresidue analysis technique using liquid chromatography-tandem mass spectrometry (LC-MS/MS), with the limit of detection of 5 ppb. In this study, organophosphorus and carbamate pesticides were detected at the highest levels in the caught fish. Among the 41 organophosphorus pesticides surveyed, nine types were detected (chlorpyrifos, diazinon, dichlorvos, disulfoton, ethion, etrimfos, phosalone, phosmet and pyrazophos) in the muscle, viscera pool, or both in 22 (61.1%) fish. Sampled tissues of 20 (55.6%) fish exhibited at least one of the eight evaluated carbamate pesticides and their metabolites: aldicarb, aldicarb sulfoxide, carbaryl, carbofuran, carbosulfan, furathiocarb, methomyl and propoxur. Fungicides (carbendazim, benalaxyl, kresoxim-methyl, trifloxystrobin, pyraclostrobin and its metabolite BF 500 pyraclostrobin), herbicides (pyridate and fluasifop p-butyl), acaricide (propargite) and pyrethroid (flumethrin) were also detected. In conclusion, P. costatus fish caught in the São Francisco River contained residues of 17 different pesticides, in both muscles and the viscera pool, indicating heavy environmental contamination by pesticides in the study area.     

Sediment Contaminant Chemistry and Toxicity of Freshwater Urban Wetlands in Southern California1

Brown, Jeffrey S., Martha Sutula, Chris Stransky, John Rudolph, and Earl Byron, 2010. Sediment Contaminant Chemistry and Toxicity of Freshwater Urban Wetlands in Southern California. Journal of the American Water Resources Association (JAWRA) 46(2):367-384. DOI: 10.1111/j.1752-1688.2009.00407.x Abstract: Wetlands provide many critical functions in urban ecosystems, including habitat for wetland-dependent fauna and enhancement of water quality. Interest in restoring or creating wetlands to enhance these functions is increasing due to the scale and extent of wetland loss and water quality problems associated with urbanization. One of the most pressing questions associated with urban wetland restoration is the extent to which urban wetlands tend to concentrate contaminants, and if so, whether an associated risk to wildlife exists. The goal of this study was to better understand these potential risks, and the associated tradeoffs with using wetlands to treat urban runoff. Sediment toxicity, contaminant chemistry, and macroinvertebrate (MI) community metrics were measured in 21 southern California wetlands that receive urban runoff as their primary water source. MI organisms in 18 of the 21 urban wetlands examined were considered to be at risk due to sediment contaminant concentrations and toxicity. Most of the sites were either toxic to the amphipod Hyalella azteca, exceeded a sediment quality guideline, or both. Sediment chemistry and toxicity identification evaluation studies suggest that pyrethroid pesticides may have been responsible for much of the toxicity documented in this study. The mean Probable Effects Concentration quotient (an index of degree of sediment contamination) was found to negatively correlate with MI diversity in these wetlands suggesting that toxicity was affecting organisms at the base of the food chain in these wetlands.     

珠江河口沉积物中拟除虫菊酯类农药污染及毒性评价

拟除虫菊酯农药是一种广谱、高效、低毒、低残留的亲脂性杀虫剂,它会随农田排水、降雨淋洗进入水体,最终进入沉积环境,故沉积物是其最终归宿之一。本研究针对珠江河口沉积物中菊酯类农药的污染状况进行调查,研究它们的含量、组成比例、污染来源及其潜在毒性,为珠江渔业水生生态环境管理及掌握环境中有机污染情况提供依据,对保护渔业环境安全有十分重要的意义。2012年5月采集珠江河口表层沉积物,采用气相色谱法-电子捕获法（GC-ECD）对表层沉积物中联苯菊酯、甲氰菊酯、高效氯氟氰菊酯、氯菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯进行残留检测,并利用其对钩虾的生物毒性来评价沉积物的潜在毒性。结果显示,表层沉积物（以干质量计）中7种菊酯类农药质量分数介于ND~6.59μg·kg-1（ND表示未检出）,平均值为0.75μg·kg-1,其总质量分数与有机碳质量分数呈现一定的正相关性;组成比例表明,氯菊酯最多,占总量的57.63%,它的检出率为61.90%,甲氰菊酯其次,约占总量的16.39%,检出率为28.57%,氯菊酯占主要组成部分,可能与其在珠江三角洲居民生活中被大量使用及其降解速率有关;珠江桥采样点高浓度的菊酯类农药的检出（6.59μg·kg-1）,可能与其靠近人口密集和经济发达的广州有关;与国内外其他地区相比,珠江河口沉积物中菊酯农药处于较低水平;采用毒性单元TU（选用钩虾Hyallela Azteca的LC50）进行毒性评估,∑TU值范围为0~0.09,远远低于1,表明珠江河口拟除虫菊酯不存在生态风险。     

综合客运交通中机场电磁环境影响分析

随着我国国民经济的快速发展,大城市迫切需要建立多层次、立体化综合交通枢纽,将城际铁路、轨道交通引入机场区域已成为越来越多城市交通的发展趋势。但机场电磁环境会否因此受到影响,飞机导航安全性、可靠性是否得到绝对保障成为人们关注的焦点。本文通过某省会城市国际机场的实例,预测分析了两种轨道交通对机场电磁环境的影响。从而为今后综合客运枢纽中,不同交通运输方式间的安全兼容提供了参考和思路,为交通工程规划建设的合理性、可行性提供技术依据。     

Comparative Sensitivity to the Insecticides Deltamethrin and Esfenvalerate of Some Aquatic Insect Larvae (Ephemeroptera and Odonata) and Daphnia magna

Sensitivity to the pyrethroids deltamethrin and esfenvalerate (aqueous solution) and LC₅₀ have been determined in acute (96-h) toxicological tests on mayfly larvae (Cloeon dipterum and Caenis miliaria), damselfly larvae (Lestes sponsa and Cordulia aenea), and juveniles from a laboratory culture of Daphnia magna. Sensitivity to deltamethrin increases in the series C. aenea (Odonata) < D. magna (Cladocera) < L. sponsa (Odonata) < C. miliaria(Ephemeroptera) < C. dipterum (Ephemeroptera), and that to esfenvalerate, in the series C. aenea < D. magna < L. sponsa C. miliaria C. dipterum. The values of LC₅₀ about 0.01 g/l determined for mayfly larvae are below those known for various hydrobionts from the literature, indicating a very high sensitivity of these insects to pyrethroids.