Characterization studies of a semi‐automated separation method for analysis of non‐ortho substituted polychlorinated biphenyl (PCB) congeners in environmental samples

Non‐ortho substituted polychlorinated biphenyl (PCB) congeners can account for the majority of the dioxin‐like toxicity in environmental samples, yet analysis for these congeners is difficult because other PCB congeners co‐elute with them in most Chromatographic methods. An automated method was developed which incorporates a porous graphitic carbon (PGC) column which is commercially available. Non‐ortho substituted congeners were successfully separated from interfering PCB congeners. Recoveries of non‐ortho substituted congeners were consistently reproducible (CV < 9%) when chicken eggs were fortified with individual congeners.     

Persistent organochlorine contaminants in human tissues of the Czech and Slovak populations

The persistence of lipophilic organochlorine substances leads to their incorporation into the food chain and subsequent uptake by humans. Due to their use in the past, Czech and Slovak countries belong to the countries with a relatively high body burden of organochlorines. Levels of PCBs in human tissues based on the congener‐specific analysis are reported in this paper. Samples were analysed for the most abundant PCB congeners. Prevalent persistent organochlorine pesticides and their isomers/metabolites have also been included. The present study is focused on following areas: i) distribution of analysed substances in the various human tissue samples from selected regions of the Czech and Slovak Republic and ii) comparison with the results from other foreign and local studies.     

中和—絮凝法回收硝酸型退锡废水中的锡

将传统的中和法和絮凝法相结合,采用中和—絮凝法回收硝酸型褪锡废水中的锡,考察了反应终点体系pH、碱液浓度、絮凝剂浓度等因素对锡回收效果的影响。实验结果表明,在NaOH溶液浓度为6 mol/L、反应终点体系pH为0.8、聚丙烯酰胺溶液质量浓度为3 g/L的工艺条件下,可得到干基锡含量54.6%（w）的高品位锡泥。与传统的单一中和/絮凝法相比,采用中和—絮凝法不仅可以有效提高生产效率,而且减少了碱液和絮凝剂用量,回收锡之后体系中大量的硝酸可进一步回收利用。     

水解酸化-外循环(EC)厌氧-接触氧化工艺处理啤酒废水

内蒙古自治区某啤酒厂采用水解酸化-外循环(EC)厌氧-接触氧化工艺处理啤酒废水。经过4个月的调试达到满负荷运行,系统稳定可靠,出水水质远优于GB19821-2005《啤酒工业污染物排放标准》。COD、BOD5、NH3-N、TN和TOC的去除率分别达97.5%、98.5%、85%、75%和98.5%。     

硝酸浸提拆解废印制电路板元器件技术

研究了废印制电路板在不同浓度硝酸溶液中焊锡完全溶解的时间,以及Sn,Pb,Zn,Fe和Cu的溶解规律及循环利用浸提液的可行性. 结果表明:废印制电路板最佳剥离硝酸浓度为2 mol/L左右,该条件下210 min内废印制电路板上的焊锡完全溶解,元器件能够全部拆除;稀硝酸作为浸提液,可重复利用4次以上,各次循环对焊锡均具有较好的溶解效果;循环利用过程中,Cu反应速率逐次增加,易造成Cu的流失.      

销毁含多氯联苯废弃物焚烧炉的二噁、类二噁和多氯联苯排放

我国正在研制专用于销毁高浓度多氯联苯（ＰＣＢｓ）的焚烧炉,主要处理废旧的含（ＰＣＢｓ）的电力电容器和变压器,应用可靠准确的监测方法测定了试验性焚烧炉渣、烟灰排气和废水中的二口恶口英（ｄｉｏｘｉｎｓ）,类二口恶口英多氯联苯（ｄｉｏｘｉｎｌｉｋｅＰＣＢｓ）和ＰＣＢｓ含量,结果表明该炉试烧高浓度ＰＣＢｓ时,焚毁率可以达到９９．９９９９％,炉渣中的２,３,７,８ＴＣＤＤ毒性当量为８７．８６ｐｇＴＥＱ／ｇ,烟灰中残留二口恶口英和类二口恶口英的总２,３,７,８ＴＣＤＤ毒性当量为４７．２３ｎｇＴＥＱ／ｇ．     

Polychlorinated biphenyls (PCBs) in indoor air originating from sealants in contaminated and uncontaminated apartments within the same housing estate

Twenty-four congeners of polychlorinated biphenyls (PCBs) were measured in 83 air samples and 20 elastic sealants samples of apartments with PCB-containing sealants. In addition, PCBs were measured in 21 air samples from reference apartments located in an uncontaminated section of the same estate. The PCB_tot levels in the air of the contaminated section were 168-3843 ng m⁻³ (mean: 1030 ng m⁻³), while the mean levels in the reference apartments were 6.03 ng m⁻³. The sum of the 24 measured PCB congeners in sealants from the contaminated section was 187-221 680 mg kg⁻¹. Principal component analysis revealed four groups among the sealant samples with different congener compositions, only two of which were clearly similar to known PCB mixtures, while two were not. Significant correlations and intercorrelations were observed between the lower chlorinated congeners in air and sealant, e.g. for PCB 28_air and 28_seal (p = 0.04) and for PCB 28_air and 52_air, 52_seal. However, no correlation was observed between the lower chlorinated congeners and the sums of PCB (∑PCB₆ or ∑PCB₂₄) or the higher chlorinated congeners. Analysis of air concentrations in relation to questionnaire data indicated that the indoor air levels could be reduced by increased cleaning and airing frequencies.     

Comparative distribution, sourcing, and chemical behavior of PCDD/Fs and PCBs in an estuary environment

PCDD/F and PCB field data (1041 samples) in five media (dissolved, suspended sediment, bed sediment, catfish, and blue crab) were studied to explore dual contaminant patterns in the Houston Ship Channel, Texas, USA. PCDD/Fs showed greater concentration than PCBs in suspended sediments while PCBs were higher in apparent dissolved (truly dissolved + DOC-associated), fish, and crab. PCDD/Fs at nearly all locations contributed more strongly to dioxin-like toxicity. The fraction of PCB TEQ was, however, enriched in biotic over abiotic media due in large part to the presence of PCB 126, which was mostly undetected in water and sediment and yet exhibited a BAF three times greater than 2,3,7,8-TCDD. Dissolved-suspended sediment and suspended-bed sediment relationships showed that (1) observed apparent dissolved concentration differences (as fraction of total water were mean 10% PCDD/Fs and 63% PCBs) can reasonably be explained by a four-phase partition model (truly dissolved, DOC-associated, suspended OC, and suspended BC) for PCBs but not for PCDD/Fs and (2) the contaminants behaved similarly in bed to suspended sediment concentration ratios (C_bed/C_susp) upstream of a major confluence but not downstream. PCA-cluster analysis pointed to the possibility that suspended sediment PCB contamination originates from resuspended bed sediment while PCDD/Fs in suspended sediment originates more probably from other sediment sources such as upstream wash load or air deposition. Finally, examinations of a congener marker ratio (PCB 209/206) seemed to indicate that a source of pure PCB 209 may exist in bed sediment near Patrick Bayou though the source was not completely localized.     

Incidence of thyroid disease following exposure to polybrominated biphenyls and polychlorinated biphenyls, Michigan, 1974-2006

Thyroid hormones, which influence body metabolism and development, could be affected by persistent organic pollutants. We sought to examine the relationship between polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) and thyroid disease. We employed incidence density sampling to perform a nested case control analysis of the Michigan Long-Term PBB Cohort. Cohort members (n = 3333) were exposed to PBBs through contaminated cattle feed in 1973-1974 and to PCBs through daily life. Those with detectable serum PBB and PCB concentrations at enrollment were categorized into tertiles of PBB and PCB exposure. Case-patients were cohort members answering “Yes” to “Has a healthcare provider ever told you that you had a thyroid problem?” during follow-up interviews; control-patients were cohort members answering “No”. We used odds ratios (OR) with 95% confidence intervals (CI) to compare odds of thyroid disease by PBB and PCB exposure and by various risk factors. Total cumulative thyroid disease incidence after 33 years was 13.9% among women and 2.6% among men. After adjusting for body mass index, we found no statistically significant differences in odds of any type of thyroid disease among women or men with elevated PBB or PCB exposure. Compared to control-patients, women with thyroid disease had increased odds of being overweight/obese (OR = 2.82, 95% CI: 1.94-4.11) and developing infertility (OR = 1.71, 95% CI: 1.08-2.69), diabetes (OR = 1.61, 95% CI: 1.04-2.51), or arthritis (OR = 1.71, 95% CI: 1.18-2.50) during follow-up. Additional research should explore potential associations between PBBs/PCBs and thyroid disease among children exposed in utero.     

Accumulation of organochlorine contaminants in loggerhead sea turtles, Caretta caretta, from the eastern Adriatic Sea

We analyzed 15 polychlorinated biphenyls (PCBs) and five organochlorine pesticides (OCPs) in fat tissue of 27 loggerhead sea turtles (Caretta caretta) from eastern Adriatic Sea with the curved carapace length ranging from 25.0 to 84.5 cm. The PCB profile was dominated by hexa- and hepta-chlorinated congeners, with PCB-153 (median: 114.9 ng g⁻¹ wet mass), PCB-138 (80.0 ng g⁻¹ w.m.), and PCB-180 (26.7 ng g⁻¹ w.m.) detected with the highest levels. Toxic mono-ortho congeners PCB-118, PCB-105 and PCB-180 with dioxin-like toxicity were found in >70% samples. 4,4′-DDE (81.0 ng g⁻¹ w.m.) prevailed the OCP signature, accounting for 80% of the total DDTs. A significant increasing trend in accumulation with size was found for PCB-52 (r_s = 0.512, p < 0.01) and PCB-114 (r_s = 0.421, p < 0.05). Comparison of our results with organochlorine contaminant (OC) pattern in some prey taxa suggest that contamination occurs primarily through the food web, with biomagnification factors of 0.14-6.99 which were positively correlated with the octanol-water partition coefficient (log K_ow; p < 0.05). This study, based upon a fairly large sample size collected mostly from incidentally captured animals over a short time period (June 2001-November 2002), present a temporal snapshot of OC contamination in wild, free-ranging loggerheads from Adriatic feeding grounds and provide a baseline for monitoring the regional OC trends in this endangered species.