Emission characterization of unintentionally produced persistent organic pollutants from iron ore sintering process in China

Emission of unintentionally produced persistent organic pollutants (Unintentional POPs), including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychorinated biphenyls (PCBs), hexachlorobenzene (HxCBz) and pentachlorobenzene (PeCBz), were investigated in four typical iron ore sintering plants in China. The emission factors and annual mass releases of the Unintentional POPs were calculated. The results indicated that PCDFs contributed more than 60% to the overall toxic equivalent quantity (TEQ) values, while the contribution of the dl-PCBs is relatively low, and only in the range of 8-9%. The dominant congeners of PCDD/Fs and dl-PCBs contributing most to the total TEQ were 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and PCB-126. With regard to the TEQ contributions, the most abundant homologues were PeCDFs and HxCDD/Fs, followed by PeCDDs and non-ortho dl-PCB, whereas HpCDD/Fs, OCDD/Fs and mono-ortho dl-PCBs almost made no contributions. Due to the massive use of recycled waste in the feeding materials, the average emission factor of PCDD/Fs and dl-PCBs of the four plants was 3.95 μg WHO-TEQ ton⁻¹. Based on the results, the annual release of PCDD/Fs and dl-PCBs in 2007-2009 were estimated to be 2070 g, 2212 g, and 2307 g WHO-TEQ, respectively.     

Environmental Technology Verification (ETV) test of dioxin emission monitors

The performance of four dioxin emission monitors, including two long-term sampling devices, the Dioxin-MonitoringSystem (DMS) and AMESA (the adsorption method for sampling dioxins and furans), and two semireal-time continuous monitors, the resonance ionization with multimirror photon accumulation time-of-flight mass spectrometer (RIMMPA-TOFMS) and the jet resonance-enhanced multiphoton ionization (jet-REMPI) system were tested. A package boiler burning a simulated chlorinated hazardous waste was used for a total of nine tests. Reference samples were collected during each test and analyzed for polychlorinated dibenzodioxins and dibenzofurans (PCDDs/Fs) using gas chromatography mass spectrometry. The PCDD/F concentrations of the reference samples measured by EPA Method 23 ranged from 0.9 to 6.0 ng toxic equivalence (TEQ)/dry standard cubic meter. The relative accuracies achieved by DMS, AMESA, and jet-REMPI varied from 22.6% to 78.2%, with 100% data completeness. The RIMMPA-TOFMS produced no quantifiable results due to various difficulties associated with the instrument during the testing. The two long-term samplers were easy to install and operate and provided a cumulative, averaged emission for the sampling period. The operations of the two semi-real-time continuous monitors were relatively complex, but one of them provided on-site, real-time data for PCDD/F emissions from measurement of a TEQ correlative indicator compound. This article summarizes results from the individual Environmental Technology Verification reports for the four dioxin monitors. This work was presented, in part, at the Fourth International Conference on Combustion, Incineration/Pyrolysis and Emission Control (i-CIPEC)     

停留时间对滴滴涕农药热处理特性的影响研究

利用高温管式炉研究停留时间对滴滴涕农药热处理特性的影响。结果表明,600℃时ηDDT在15 min内迅速增长,在15 min后稳定在85%上下;900℃时,当停留时间≥15 min,ηDDT≥99%;1 200℃时,各时段的ηDDT≥99.9%。在滴滴涕农药残渣中,DDTs在600℃和900℃时的配比随停留时间的增加变化甚微,在1 200℃时,p,p’-DDD、DDT和o,p’-DDT分别占DDTs总量的比例随时间增加明显降低,p,p’-DDE则大幅增加。在尾气中,DDTs在600℃时的配比随停留时间的增加无明显变化,DDT为主要尾气残留物质,900℃时DDTs在尾气中配比变化混乱,1 200℃时,p,p’-DDE的比例随停留时间的增长迅速增加,并成为尾气中的主要DDTs残留物质。     

Apparent relationships between anthropogenic factors and climate change indicators and POPs deposition in a lacustrine system

Climate change and anthropogenic activities are expected to impact the environmental behaviors and fates of persistent organic pollutants(POPs), however, quantitative studies on these combined factors are scarce. In this study, dichlorodiphenyltrichloroethane(DDTs), polycyclic aromatic hydrocarbons(PAHs), and polychlorinated biphenyls(PCBs)were used as examples to identify how and when those factors may be related to the deposition of POPs in the sediment of Lake Chaohu, China, using generalized additive models(GAMs). Three historical trends of DDT, PAH, and PCB deposition were delineated in a dated sediment core encompassing ～100 years of historical record: a steady state or gradually increasing stage, a rapidly increasing stage, and a declining stage. The GAM results showed that aquatic total phosphorus(TP) concentrations and regional GDP(anthropogenic factors) were dominant contributors to POP accumulation rates in the lake sediment. The fitted relationships between air temperature and sedimentary DDT and PAH concentrations were linear and negative, while a positive linear relationship was found for PCBs, suggesting that Lake Chaohu may have become a net source for DDTs and PAHs, and a sink for PCBs, under a progressively warming climate.     

油料作物对土壤老化残留DDT的吸收积累

油料作物对亲脂性DDT的吸收富集能力是否会更强是一个值得研究的问题。采用DDT老化残留土壤,温室盆栽油料作物花生(Arachishypogaea),大豆(Glycinemax)和芝麻(Sesamumindicum)。果实成熟后将植株分成根、茎、果壳和果仁四部分,GC-ECD测定各部位中的DDT浓度。研究了油料作物对土壤老化残留DDT的吸收积累情况,结果表明,∑DDT在三种作物不同部位中的浓度顺序都是:根>茎>果壳>果仁。含油量高的花生果仁和芝麻果仁中∑DDT浓度都明显高于大豆果仁的∑DDT浓度,这种差异有可能是由果仁含油量的差异造成的。单株植物吸收积累∑DDT的总量顺序为:花生>芝麻>大豆。花生、大豆和芝麻三种作物的根和茎的生物富集系数都比较高,特别是花生的,说明这三种油料作物根部从土壤中吸收积累老化残留DDT的能力以及从根部向茎部运输DDT的能力都是相当强的。     

臭氧-生物活性炭对微污染原水中典型持久性有机物的去除效果

以长三角地区J市典型有机微污染水源P水厂为研究对象,考察了臭氧-生物活性炭深度处理工艺对微污染水源水中有机物的去除效果.结果表明,臭氧-生物活性炭深度处理使高锰酸盐指数、总有机碳(TOC)和UV254的平均去除率分别提升19. 2%、10. 4%和23. 0%.水厂原水中检出8种多环芳烃(polycyclic aromatic hydrocarbon,PAHs)、16种有机氯农药(organochlorine pesticides,OCPs)、5种卤乙酸(haloacetic acids,HAAs),其总浓度分别为53. 9~100. 0、6. 5~41. 8、2. 5×103~1. 1×104ng·L~(-1),臭氧-生物活性炭深度处理对多环芳烃和有机氯农药的平均去除率分别为32. 5%和25. 9%,比常规处理工艺出水的水质有显著提升.卤乙酸的去除率为33. 8%~87. 0%,主要通过常规处理工艺去除;臭氧-生物活性炭深度处理对氯代乙酸略有去除,溴代乙酸有少量生成.     

包埋类脂的吸附剂制备及吸附POPs性能

用丙酮作溶剂将三油酸甘油酯分散到醋酸纤维(CA)基体中,采用悬浮聚合的方法制备出了一种兼具亲水性,又能高倍富集持久性有机污染物的球形复合吸附剂。通过对分散剂的种类及其用量、悬浮介质的种类及其用量的研究,获得了球形复合吸附剂的最佳合成路线与工艺.球形吸附剂粒径为1～2mm。通过荧光分析和电镜扫描分析,表明三油酸甘油酯已被包埋到醋酸纤维基体中,并得到了均匀分散。采用七氯、狄氏剂、异狄氏剂、灭蚁灵为代表性的持久性有机污染物(POPs)。动力学吸附实验表明,当初始浓度为1μg/L时,在快速吸附阶段,溶液中80%的氯、狄氏剂、异狄氏剂可得到有效去除,但并没有达到吸附平衡。快速吸附完后,还在持续地进行慢速吸附。而对于灭蚁灵,吸附速度远远低于其他几种POPs。实验证明了吸附速度不仅与辛醇/水系数有关,而且还与有机污染物的分子结构有关。     

珠江口水环境中多溴联苯醚生态风险分析

以多溴联苯醚(PBDEs)作为研究对象,对珠江口水环境中多溴联苯醚进行了生态风险问题形成、生态风险分析及生态风险表征。研究结果表明,珠江口水环境中多溴联苯醚的生态风险主要来自五溴联苯醚,其在水相和沉积物相中的计算结果分别为0.000057和0.0073,目前珠江口水环境中多溴联苯醚的生态风险水平较低,暂无生态风险。     

持久性有机污染物(POPs)生物修复研究进展

持久性有机污染物(POPs)具有高毒性和低可降解性的特征,通过先进的生物修复技术来治理POPs污染正受到公众普遍的关注.而提高生物可利用性则可以突破原位生物修复的瓶颈;宏基因组技术可以获得大量的降解基因资源;利用生物工程手段,可以大幅度提高降解菌的能力这3个方面是目前POPs生物修复领域的研究热点.