Effects of regional differences in waste composition on the thermal formation of polychlorinated aromatics during incineration

Two artificial wastes (A and B) whose contents reflect regional differences in municipal solid waste composition, were used to investigate the thermal formation of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and naphthalenes (PCNs) during incineration. Flue gas samples were simultaneously collected at three ports in the post-combustion zone corresponding to flue gas temperatures of 400, 300, and 200 °C. The combustion of Waste B, which had a higher chlorine and metal content than Waste A, produced greater levels of highly-chlorinated homologues, as demonstrated by a higher degree of chlorination. The total concentrations of PCDDs, PCDFs, PCBs, and PCNs formed in the combustion of both wastes increased as temperature decreased along the convector. There were no significant differences in total concentrations between Waste A and Waste B combustion at specific temperatures, with exception of PCDFs at 400 °C. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) modeling, used to evaluate the data for all compound groups, suggest that during flue gas quenching at temperatures of 400 °C low-chlorinated homologues are preferentially formed in the presence of copper, which is known to be a very active catalyst for this process. At 300 and 200 °C, the formation of highly-chlorinated homologues is favored.     

Assays of dioxins and dioxin-like compounds in actually contaminated soils using transgenic tobacco plants carrying a recombinant mouse aryl hydrocarbon receptor-mediated β-glucuronidase reporter gene expression system

The transgenic tobacco plant XD4V-26 carrying the recombinant mouse aryl hydrocarbon receptor XD4V-mediated β-glucuronidase (GUS) reporter gene expression system was used for assay of dioxins and dioxin-like compounds consisting of polychlorinated dibenzeno-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls (Co-PCBs) in actually contaminated soils. The transgenic tobacco plant XD4V-26 showed a significant dose-dependent induced GUS activity when cultured on MS medium containing PCB126 [toxic equivalency factor (TEF) = 0.1]. In contrast, PCB169 and PCB180, which have 0.03 of TEF and unassigned TEF values, respectively, did not significantly induce GUS activity under the same conditions as with PCB126. When the tobacco plants were cultivated for up to 5 weeks on actually contaminated soils with dioxins and dioxin-like compounds collected from the periphery of an incinerator used for disposal of residential and industrial wastes, GUS activity in the leaves was dose-dependently increased. The plants clearly detected 360 pg-TEQ g^?1 of dioxins and dioxin-like compounds in this assay. There was a positive correlation between GUS activity and TEQ value of dioxins and dioxin-like compounds in the plants. This assay does not require any extraction and purification processes for the actually contaminated soil samples.     

Microbial Communities in Composite Biofilms Participating in the Degradation of PCB

A moorland soil site polluted with PCB showed a high diversity ofmetabolically active bacteria. Beside frequent types of 16S rRNAsequences similar to those of the species ofSphingomonasand the Acidobacterium phylum an unusual high number ofsequences from the genus Burkholderia were found. Burkholderia was also the main genus in isolates enriched onbiphenyl or various chlorobenzoates. In microcosm experimentssterilized surfaces exposed to PCB polluted soil always showed thepresence of clay aggregates formed by bacteria attached to thesubstratum. The bacteria use the PCB loaded clay colloids astransport medium for the water insoluble substrate to get accessto the carbon source. This is a novel mechanism of how bacteria dealwith hydrophobic substrates.     

PCBs在土壤半野外试验系统中迁移与消失的规律

利用构建的土壤半野外试验系统,在接近野外(半干旱气候)条件下,研究高含量(400mg/kg)高氯代PCBs(以五氯代为主)在系统中的迁移与消失规律.结果表明,在处理后的12个月内,PCBs几乎没有迁移,也几乎没有减少;处理24个月后,仅有不超过2%的PCBs向下层迁移,但迁移不超过10cm;在处理24个月后,处理层PCBs的浓度降低10.19%,这其中包含向下迁移的部分该项研究为PCBs的填埋或其它处理措施提供了科学依据,并为PCBs及其类似污染物的生态风险评价提供了基础资料.     

Distribution of polychlorinated biphenyls in the Fort Edward,New York,water system

Levels of polychlorinated biphenyls (PCBs) have been determined in the water, in the soils and sediments, and in the biota of a small upstate New York public water supply system, which is near the heavily polluted section of the Hudson River and a disposal site for PCB-containing waste. The impounded water exhibits a significant and relatively uniform level of Aroclor 1016, whereas the ground and surface waters supplying the reservoir do not. Rainfall, which exhibits a high level of Aroclor 1016, constitutes a small but significant source of PCB input. Soil and sediment samples exhibit significant median levels of both Aroclor 1016 and Aroclor 1254, but the local concentrations vary widely. The biota exhibit much higher PCB levels than the water or sediments, and show a strong preference for Aroclor 1254. The PCB levels in the macroinvertebrates are particularly high, suggesting that these organisms may provide a useful indicator for monitoring PCB contamination in aquatic systems. Risk assessment indicates that the lifetime incremental risk of cancer associated with the drinking water is below 10^–6. Management of such low levels of PCB contamination is best achieved by reducing the input of PCBs.     

醇类助溶剂去除砂土中多氯联苯作用机制

醇类助溶剂单一使用及复配表面活性剂使用去除砂土中多氯联苯(PCBs)的关键是增溶和降低界面张力.通过降低界面张力实验和振荡增溶实验分析了醇类助溶剂单一使用对多氯联苯界面张力的降低作用和增溶作用,以及醇类复配Triton X-100使用时醇对Triton X-100降低界面张力和增溶PCBs的影响.结果表明,醇-PCBs油的界面张力与醇浓度、醇含碳原子数均呈负相关,甲醇、乙醇、异丙醇的最佳解吸浓度分别为70%、55%、40%,最佳解吸效率达90%以上;Triton X-100-PCBs油界面张力与Triton X-100浓度呈负相关,Triton X-100浓度低于3 000 mg/L时复配10%乙醇、10%异丙醇比单一Triton X-100振荡洗脱效率低,Triton X-100浓度在3 000～7 500 mg/L时3组差异不大,Triton X-100浓度为10 000 mg/L时单一、10%乙醇、10%异丙醇TritonX-100溶液解吸效率分别为80.9%、90.36%、89.36%.表明醇类单一使用对降低界面张力与增溶均有很好的效果,但需要其体积分数达40%以上;醇类复配Triton X-100时醇的存在弱化了Triton X-100增溶和降低界面张力的作用,乙醇与异丙醇弱化作用差异性不大,当Triton X-100浓度高于3 000 mg/L时,弱化作用不显著.     

Determination of 3,4-dichlorinated biphenyl in soil samples by real-time immuno-PCR assay

A real-time fluorescent quantitative immuno-polymerase chain reaction (RT-IPCR) assay was developed for the detection of non-dioxin-like polychlorinated biphenyl (PCB) congener in soil samples. Based on the construction of 3,4-dichlorinated biphenyl (IUPAC PCB12) hapten and its immunogen, the specific polyclonal antibodies (pAbs) to PCB12 was obtained and used to develop a direct competitive RT-IPCR assay. Using the optimized assay, a standard curve for PCB12 was prepared. The linear range for the determination of PCB12 was from 10.0 to 1.0 × 10⁶ fg/mL with a correlation coefficient of 0.98 and a detection limit of 1.53 fg/mL. The RT-IPCR assays were tested for their cross-reactivity profiles using four selected congeners and four Aroclor products. The results for the soil samples correlated with the concentrations of PCBs obtained by gas chromatography/mass spectrometry. This highly specific, sensitive, and robust assay can be applied to on-site tests of PCBs and serve as a model for other pollutant immunoassays.     

浙江省台州市电子垃圾拆解地多溴联苯醚浓度水平分布特征和迁移趋势

本研究分析了浙江省台州市电子垃圾拆解地及其周边表层土壤和大气中多溴联苯醚（PBDEs）的浓度水平.结果表明,台州市峰江和滨海的拆解园区、农田和居住区土壤中∑₁₂PBDEs含量（以dw计）范围分别为21.8~1310 ng ·g^-1和6.19~220 ng ·g^-1,PBDEs单体分布没有显著差异.峰江和滨海两地大气中∑₁₂PBDEs质量浓度范围分别为262~3240 pg ·m^-3和840~2990 pg ·m^-3,浓度中值分别为1410 pg ·m^-3和840 pg ·m^-3（冬季）、1590 pg ·m^-3和1960 pg ·m^-3（夏季）,除去BDE209外的11种PBDEs单体分布在冬夏两季呈现显著性差异.通过土-气交换逸度分析发现峰江和滨海PBDEs在土-气分布迁移趋势上呈现一定的差异性.峰江PBDEs的迁移趋势主要以土壤挥发为主,土壤是大气中3~5溴代BDEs的排放源,温度的升高可以促进这一过程,这说明峰江土壤中PBDEs已成为污染释放源,建议应对峰江电子垃圾拆解园区土壤和附近农田开展土壤修复.滨海PBDEs的迁移趋势则主要以大气沉降为主,土壤是PBDEs主要的汇,说明滨海的拆解园成为PBDEs的新排放源.     

Polychlorinated dibenzo-p-dioxins and related compounds: the blood levels of young Japanese women.

We investigated PCDDs and related compounds in the blood of young Japanese women, approximately 20 years of age, who had not yet had children, and discussed how the TEQ level of PCDDs and related compounds in their blood may affect the next generation. Means of total TEQ levels were 0.063 pg/g for whole blood basis and 21 pg/g for lipid basis. TEQ of PCDDs, PCDFs and coplanar PCBs accounted for about 43, 34 and 23% of the total TEQ in the whole blood basis, respectively. In the lipid basis, their values were about 44, 34 and 22%, respectively. Previously, we investigated PCDDs and related compounds levels in mother's breast milk, lymphocyte subpopulation and thyroid function of their children, and found negative correlations between the TEQ level of PCDDs and related compounds and CD4+/CD8+, and/or the TEQ level of PCDDs and related compounds and the T₄ level in 36 mothers and children. Of these cases, the average age was approximately 28 years. PCDDs and related compounds may be related to immunopathy, such as atopic dermatitis. The effects of PCDDs and related compounds on babies of young Japanese women are important and must be further evaluated.     

焦化废水中几种难降解有机物的厌氧生物降解特性

在试验室条件下,采用厌氧间歇试验,分别研究了焦化废水中几种有代表性的难降解有机物——喹啉、吲哚、吡啶、联苯的厌氧生物降解特性.文中突出了以厌氧预处理改善焦化废水中难降解有机物生物降解性的工程实用背景,对这四种有机物的厌氧处理的动力学特性、共基质作用、厌氧处理下去除效果的改善等,进行了较为深入的研究.