Evaluation of atmospheric sources of PCDD/Fs, PCBs and PBDEs around a steel industrial complex in northeast China using passive air samplers

The concern about emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) from steel industrial parks has increased in the past decades. In this study, polyurethane foam (PUF)-disk based passive air samples were collected in and around a big steel industrial park of Anshan, Northeast China from June 2008 to March 2009. The levels, seasonal variations and potential sources of PCDD/Fs, PCBs and PBDEs in the atmosphere around the steel industrial complex were investigated, and potential contribution of these three groups of persistent organic pollutants (POPs) from iron and steel production was also assessed. The air concentrations of ∑₁₇PCDD/Fs (summer: 0.02-2.77 pg m⁻³; winter: 0.20-9.79 pg m⁻³), ∑₁₉PCBs (summer: 23.5-155.8 pg m⁻³; winter: 14.6-81.3 pg m⁻³) and ∑₁₃PBDEs (summer: 2.91-10.7 pg m⁻³; winter: 1.10-3.89 pg m⁻³) in this targeted industrial park were relatively low in comparison to other studies, which implied that the industrial activities of iron and steel had not resulted in serious contamination to the ambient air in this area. On the whole, the air concentrations of PCDD/Fs in winter were higher than those of summer, whereas the concentrations of PCBs and PBDEs showed opposite trends. The result from principal component analysis indicated that coal combustion might be the main contributor of PCDD/F sources in this area.     

Increased urinary 8-hydroxy-2��-deoxyguanosine levels in workers exposed to di-(2-ethylhexyl) phthalate in a waste plastic recycling site in China

Background

Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited.

Methods

The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender?Cage matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2??-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed.

Results

Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 ??g/l; well water: 14.20 vs. 0.79 ??g/l, pond water: 135.68 vs. 0.37 ??g/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p?p?p?Conclusions The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers.     

医疗废弃物焚烧挥发性氯含量与热值测试与估算

通过测定上海某医疗废弃物处置公司设定燃烧工况条件下某时间段内烟气中HC l的平均排放速率,估算出上海地区医疗垃圾废物中的可燃烧转化氯含量在2.33%~2.64%左右;通过测定各较小采样时间段(2 m in)的烟气HC l浓度测定发现批次进料造成烟气中HC l浓度近4倍的波动,通过初步的热平衡估算得到医疗废弃物的热值大致在21.8 M J/kg,得到的结果可为我国医疗废弃物的焚烧工艺设计提供基础依据。     

初始pH值对泔脚发酵产氢余物甲烷化的强化研究

以城市生活垃圾厌氧消化污泥为接种物,考察了初始pH值为5、6、7和8时对泔脚发酵产氢余物中温（36℃）批式厌氧消化的影响。结果表明,当初始pH值低于7时,随着初始pH值的增大,产氢余物的产甲烷能力也随之增大;而当初始pH值高于7时,体系的产沼能力却受到了极大的抑制。结合Gompertz模型拟合结果,初始pH值为7为泔脚发酵产氢余物沼气化的最佳初始pH值,其沼气化的延迟时间λ、产甲烷率、生物气中甲烷的最高体积含量分别为： 4.02 d,379.28 mL/g VS,82.2％。厌氧消化结束后,除初始pH值为5的以外,厌氧消化余物的pH值在 6.8～6.9之间,这为沼气中甲烷的高体积含量（高于常规厌氧消化的最高甲烷体积含量75%）提供了证据。     

试论江苏省国土资源与区域可持续发展

国土资源是区域可持续发展的基础,国土资源的合理开发利用是区域持发展的必由之路。首先详细地分析了江苏国土资源的优势条件,然后着重阐述了江苏国土资源的劣势,指出 一个资源约束型省份人地关系紧张、气候灾害频敏、环境问题突出已严重制约着区域的可持续发展;最后,根据江苏省情,对江苏可持续发展提出如下建议;加强对地理区位的开发和利用,促进力的合理布局,严格控制人口增长,努力提高人口素质,严格保护耕地,高效利用     

城市小区分散式生态污水处理

针对目前我国城市集中式污水处理方法的弊端，提出将小型人工湿地运用于城市小区的污水处理，形成分散式生态污水处理系统，实现环境目标与经济效益的结合。     

Migration of manufacturing industries and transfer of carbon emissions embodied in trade: empirical evidence from China and Thailand

Environmental Science and Pollution Research - At present, China’s carbon emissions rank first in the world, which not only brings huge challenges to the sustainable development of...     

Comparative study on the removal efficiency of hydrogen sulfide (H2S) using three different packings

To improve the removal efficiency on hydrogen sulfide (H₂S), a biofilter was developed and was made of polyvinyl chloride (PVC) pipes. The effects of three different packings (i.e., packing A, packing B, and packing C), containing different proportions of activated carbon, sawdust, wormcast, perlite, and pig manure compost, based on different biofilter parameters on H₂S removal efficiency, were investigated. With the extension of running time, the H₂S removal rate of packing A reached up to 90.12%, that of packing B reached a peak at 92.96%, and that of packing C was highest at 87.21%. The contribution rate of each packing at the bottom of the device was significantly greater (p < 0.01) than that of other parts, and those of the top of the devices were all greater than those of the middle of the devices. The H₂S removal rate increased with greater filler layer height. The removal rate of group B increased first with humidity, and then declined, with the optimal humidity level for the removal of H₂S 50–65% in this study. With the prolongation of the run, the pH of packing A was reduced from 7.1 to 5.91, while the pH of packing B and C remained within the range of 6.53–7.10. An increase was found in the number of bacteria and fungi over time. The count of bacteria in packing B and C and following a decreasing order was bottom > middle > top, whereas that for fungi was the opposite. In conclusion, it is thought that packing B (comprising wormcast + sawdust + activated carbon) is more efficient in the removal of H₂S than the other packings and may thus be utilized in biofilters. These results hope to provide useful information for future related research on the removal efficiency of H₂S using packings.

Implications: Wormcasts use as biological filter packing to remove H₂S is limited and needs yet to be explored. A comparative study on the removal efficiency of H₂S using three packings showed the packings that included wormcast were more efficient than others, and showed the combined features of physical absorption and biological removal with long sustainability and good efficiency, although these were largely influenced by environmental factors and nutrient content for the microorganisms. In summary, wormcast could be utilized in biological filters in the future in related research beacuse of its good efficiency and low cost.     

Performance of hybrid vertical up- and downflow subsurface flow constructed wetlands in treating synthetic high-strength wastewater

The performance and temporal variation of hybrid vertical-subsurface flow constructed wetlands (VFCWs) in response to two-stage combinations of vertical upflow (VUF) and vertical downflow (VDF) were analyzed in this research. The results of high carbon (C) treatment and high nitrogen (N) treatment were similar. The Lythrum salicaria treatment showed higher removal efficiency than CWs planted with Acorus calamus. Under high C- and N-loading treatments, the optimum two-stage combination was VDF-VUF VFCWs planted with A. calamus. Furthermore, the highest nutrient removal efficiencies were achieved in late summer (July and August) and early autumn (September). The chemical oxygen demand and total nitrogen removal efficiencies were significantly affected (P?<?0.05) by season, system, and wetland plant.     

Potential biodiesel-producing microalgae: two new strains of Amphikrikos sp.

BH32 and BH43 were isolated and identified as Amphikrikos sp. based on morphological characteristics and phylogenetic trees. They shared the same 18S rRNA sequences, but possessed different amounts of introns in their 18S rDNAs. The specific growth rate, cellular component and fatty acid profile under different growth stages have been surveyed. Their main fatty acids were found to be C16 and C18 groups. Our results indicated that both of them could be taken as excellent candidates of biodiesel. Moreover, the intra-genus polymorphism of 18S rDNA caused by intron presence/absence can provide valuable information for the study of intron evolution.