加速溶剂萃取-固相萃取净化-气相色谱法测定土壤中17种有机氯农药

建立了加速溶剂萃取(ASE)-固相萃取净化(SPE)-气相色谱法测定土壤中17种有机氯农药(OCPs)的方法。采用ASE技术对土壤中OCPs进行提取,选用二氯甲烷∶丙酮=1∶1作为萃取溶剂,减少了组分的损失,17种OCPs的提取回收率达71.7%~113.4%。以弗罗里硅土小柱为净化载体,选择不同的淋洗溶剂形成4种方案进行净化试验,结果表明:方案1采用丙酮∶正己烷=1∶1为淋洗溶剂时的净化效果最好,17种OCPs的回收率为71.0%~97.6%,方法的检出限为0.16~0.28μg/kg。利用所建立的方法进行3个水平(0.01 mg/kg、0.02mg/kg、0.05mg/kg)的加标回收试验,结果表明:除了添加水平为0.01mg/kg时异狄氏剂和环氧七氯的回收率较差外,其余OCPs的回收率均达到72.3%~108.2%,相对标准偏差RSD小于15.6%,方法的回收率和相对标准偏差均满足土壤农药残留检测中准确度和精密度的要求。     

东莞市工业危险废物污染防治对策研究

危险废物具有腐蚀性、毒性、易燃性、反应性和感染性等特性,对公众健康或环境构成重大或潜在的威胁.基于东莞市危险废物产生、处理、处置情况的调查分析,归纳出该市危险废物监管难点和污染防治存在的主要问题,借鉴国内外危险废物管理经验,结合东莞市实际情况,提出危险废物污染防治的对策与建议.建议加强危险废物信息管理系统建设;强化危险废物源头管理;提升处理、处置综合技术能力;发展循环经济,提高资源利用率;加强技术支撑体系建设,提升危险废物监管能力.     

农业作业者的听力防护

农业领域作业者的听力防护问题极少被关注,以农机噪声、养殖场噪声及其对作业者伤害调查数据看,农业噪声对作业者的危害不容忽视,给予作业特点和需求,需要选择合适的听力保护装备,并建立听力保护计划,保护在噪声环境中工作的农业作业者。     

Prenatal diagnosis of a fetus harboring an intermediate load of the A3243G mtDNA mutation in a maternal carrier diagnosed with MELAS syndrome

We prenatally diagnosed MELAS syndrome in a fetus whose mother and older brother had the MELAS-specific A3243G mutation. The mutant mtDNA level of the amniotic fluid cells was not significantly different from that of the postnatal peripheral blood and hair follicle samples. The obstetrical course was uncomplicated except for transient exacerbation of the mother's diabetes, which required insulin control. At term, the infant was macrosomic, and the delivery was complicated by shoulder dystocia. MELAS syndrome in itself does not influence either the prenatal course of the mother or the fetal outcome. In contrast to the fulminating clinical course of this mother's first child, MELAS symptoms did not develop in her second child until age four, despite similar high tissue levels of mutant mtDNA. The phenotypic diversity in two offspring with similar higher levels of mutant mtDNA suggests that prenatal genetic diagnosis of cultured amniotic cells may yield results that are poor prognosticators of fetal outcome. Copyright © 2004 John Wiley & Sons, Ltd.     

现场总线技术在烟气脱硫控制系统中的应用

阐述了一种将FCS与DCS相结合的控制系统-FDCS，并将其应用在火电厂烟气脱硫过程控制系统中。解决了液位控制易失灵、pH值难控制等问题，提高了系统的稳定性，保证了脱硫效率，降低了综合投资成本。     

A risk assessment system for alien plant bio-invasion in Xiamen, China

Bio-invasion has caused serious ecosystem damage and enormous economic losses in China,and it has been the greatest factor to island bio-diversity reduction.Xiamen,as an important seaport with a relatively high conservation value,is particularly vulnerable to bio-invasion for its typical island ecosystem as well as frequent human-made disturbance.As a result of field surveys,literature review, and consultation with experts,a list of 67 alien plants identified as major invaders(12 species)and emerging inv...     

一株菲高效降解菌的环境适应性研究

生物降解是多环芳烃从环境中去除的主要途径,菲是一种典型的三环芳烃。本研究考察了一株能高效降解多环芳烃菲的鞘氨醇单胞菌GY2B在含河沙环境及不同盐度的人工海水环境中的生长特性与降解菲的情况。结果表明：河沙的加入对菌株GY2B的生长及其高效降解菲的性能均无明显影响,65 h可将起始浓度为100 mg/L的菲降解99.5%以上;而经过驯化后在添加85%人工海水的条件下该菌也仍可正常生长并高效降解菲,66 h可将起始浓度为100 mg/L的菲几乎完全降解。本研究结果可为菌株GY2B在受多环芳烃污染的河滩、河口及近海海洋环境修复中的应用提供参考依据。     

环己酮肟槽风险控制技术

运用危险与可操作研究(HAZOP)和故障失效模式分析方法(FMEA),对己内酰胺装置的环己酮肟贮槽及其物料输送过程存在的危险有害因素进行了系统分析,并针对存在火灾爆炸等风险性,从工艺、设备及安全管理等方面提出了对策措施.     

Reductive transformation and detoxification mechanism of 2,4-dinitrochlorobenzene in combined zero valent iron and anaerobic-aerobic process

A combined zero valent iron (ZVI) and anaerobic-aerobic process was adopted for the treatment of 2,4-dinitrochlorobenzene (DNCB)-containing wastewater. The transformation pathway, reduction of acute toxicity and enhancement of biodegradability were investigated. After pretreatment by ZVI, DNCB in wastewater could be completely converted into 2,4-diaminochlorobenzene (DACB). The ratio of BOD₅/COD increased from 0.005 ± 0.001 to 0.168 ± 0.007, while EC_{50, 48 hr} (V/V) increased from 0.65% to 5.20%, indicating the enhancement of biodegradability and reduction of acute toxicity with the pretreatment by ZVI. DACB was further dechlorinated to m-phenylenediamine during the anaerobic process using methanol as electron donor, with EC_{50, 48 hr} increasing from 5.20% to 48.2%. After the subsequent anaerobic-aerobic process, m-phenylenediamine was degraded completely, with effluent COD of 67.5 ± 10.8 mg/L. This effluent of the subsequent anaerobic-aerobic process was not toxic to zebrafish. The combined ZVI and anaerobic-aerobic process offers bright prospects for the treatment of chlorinated nitroaromatic compound-containing wastewater.