高分子量多环芳烃--苯并[a]芘的生物降解研究进展

多环芳烃(PAHs)是一类广泛分布于海洋环境中的含有两个以上苯环的有机化学污染物.苯并[a]芘(BaP)是一种由5个苯环组成的分布广泛、致癌性极强的多环芳烃化合物,人们将其作为多环芳烃的指示物,通过研究其在环境中的产生、迁移、转化、降解及毒理作用来判断多环芳烃的污染情况.BaP已成为国内外环境监测的重要指标之一.本文综述了不同环境中BaP的来源与分布,BaP在环境中的行为,微生物对BaP的代谢途径,以及微生物降解BaP的相关限制因子,并结合作者在这方面研究的部分工作与目前国际研究的热点,提出值得进一步探究的有关问题.图4表3参51     

代谢活化作用对多溴代联苯类污染物类/抗甲状腺激素活性的影响

选用大鼠肝匀浆(S9)和鼠肝癌细胞(H4ⅡE)两种体系代谢活化多溴代联苯醚混标(BDEs)和十溴联苯醚(BDE209),采用重组甲状腺激素受体基因酵母检测BDEs和BDE209母体及其代谢产物的类/抗甲状腺激素效应.结果表明,BDEs和BDE209母体均不表现甲状腺激素效应(p>0.05);但是经S9和H4ⅡE细胞代谢活化后,其代谢产物表现出明显的类甲状腺激素活性和抗甲状腺激素活性(p<0.05),BDEs和BDE209的干扰甲状腺激素效应需要经过代谢活化步骤.比较不同代谢活化体系,重组酵母细胞本身的代谢活化作用并不显著,而H4ⅡE细胞和S9代谢活化体系均能够导致活性中间体.     

Nitrogen and phosphorus removal in an airlift intermittent circulation membrane bioreactor

A new airlift intermittent circulation integrated bioreactor was developed for simultaneous nitrogen and phosphorus removal of wastewater, in which, circulation of mixed liquid between mixing zone and aeration zone was realized by aeration power, alternately anaerobic/anoxic bio-environment in mixing zone was realized by intermittent circulation and simultaneous nitrogen and phosphorus removal was obtained through strengthened denitrifying phosphorus removal process. Removal performance of the reactor was investigated and pollutant removal and transfer mechanism in one operation circle was analyzed. The experiment results indicated that under the influent condition of chemical oxygen demand (COD) concentration of 642.1 mg/L, total nitrogen (TN) of 87.4 mg/L and PO₄^3--P of 12.1 mg/L, average removal efficiencies of COD, TN and PO₄^3--P reached 96.4%, 83.2% and 90.5%, respectively, with the hydraulic residence time of 22 hr and operation circle time of 185 min. Track studies indicated that the separation of aeration and mixing zones and intermittent circulation of mixed liquid between the two zones provided distinct biological environments spatially and temporally, which ensured the occurrence of multifunctional microbial reactions.     

PM2.5污染对我国健康负担和经济损失的影响

开展全国范围归因于PM_2.5污染的健康负担和经济损失研究,对于污染防控政策至关重要.首先利用空气质量模型（WRF-Chem）模拟结果,分析2016年PM_2.5的时空分布和暴露水平;同时结合环境健康风险及环境价值评估方法,评估PM_2.5污染引起的健康负担和经济损失;最后基于情景分析方法,预估实现具体PM_2.5控制目标的健康经济效益.结果表明,2016年,我国PM_2.5污染主要集中在京津冀及周边地区、长三角地区、四川盆地以及西北沙漠地区,且71.49%的人口暴露在PM_2.5浓度高于35 μg·m^-3的环境空气中;PM_2.5污染造成约106.04万人过早死亡,约占总死亡人数的10.9%,其中冠心病和中风约占80%;PM_2.5污染造成健康经济损失7059.31亿元,约占国内生产总值（GDP）的0.95%.PM_2.5污染造成的健康负担和经济损失存在显著空间差异,主要分布在PM_2.5浓度和人口密度高的中东部地区;情景分析表明,我国所有地区PM_2.5浓度降至35 μg·m^-3,只能避免17.11%的健康经济损失,而降至10 μg·m^-3可以带来80.47%的健康经济效益.建议环境管理者进一步加强控制力度,更好地保障居民的健康和财富利益,尤其是心脑血管疾病患者等敏感人群以及归因死亡率高的地区.     

有机化合物生物富集因子的计算机预测研究

有机化合物在生物体内的富集,通常用生物富集因子(bioconcentration factor,简称BCF)来表达,这是化合物生态环境毒性评估的重要指标。为合理预测有机化合物是否易于生物富集,首先从美国环保局网站收集了624个具有不同BCF值的化合物,然后采用7种分子指纹结合5种机器学习方法(包括支持向量机、C4.5决策树、k最近邻法、随机森林法和朴素贝叶斯法),构建了化合物BCF的分类预测模型,所有模型均采用独立外部验证集进行验证。其中,使用Chemo Typer分子指纹结合支持向量机方法得到的二分类模型,整体预测准确度最好,达到了85.4%。通过采用信息增益、频率分析等方法,进一步确定了化合物中易于引起生物富集的关键子结构,包括芳基氯、二芳基醚、氯代烷烃等。研究中所用到的方法为有毒化学品的生态风险评价提供了良好可靠的预测工具。     

Sediment characteristics,phosphorus types and phosphorus release rates between river and lake sediments

The Han river is 469.7 km long with 26219-km2 area watershed, and is the primary drinking water source for the 20 million people that live in Seoul, Kangwon-Do and Kyunggi-Do, Korea. Phosphorus release from sediments impacts water quality, and is endangering the beneficial use of the river. This research measures phosphorus release and predicts future releases from bottom sediments of two tributary areas (Chungpyung Lake (CPL) and Jamsil submerged dam (JSD) area in the Han river). Sediment samples were taken over a 4-year period from four points in the Jamsil dam area and from 92 points in CPL. The sediments were analyzed for total phosphorus, the form of the phosphorus and release rates under different conditions to the water column. Sediment phosphorus distribution from CPL was 3-5% adsorbed-P (Ads-P), 15-20% non-apatite-P (NAI-P), 25-30% apatite-P (A-P) and 45-57% residual-P (R-P). In the JSD area, the phosphorus distribution ranges were 1-3% Ads-P, 22-39% NAI-P, 26-40% A-P and 30-39% R-P. Laboratory experiments showed that phosphorus release rates from 60 to 80 mg/m2 week in JSD area and ranged from 25 to 40 mg/m2 week in CPL sediments.     

Evaluation of PCDD/Fs characterization in animal feed and feed additives

Safety control of feed and feed additives is necessary to have safe food of animal origin. Based on media reports, nine incidents regarding dioxins and/or PCBs contaminations occurred worldwide during the last decade. Korea is a country which imports feed and feed additives. In this study, various kinds of feed and feed additives were analyzed to monitor the contamination level of dioxins. The level of PCDD/Fs in fish oil was the highest with a concentration of 23.33ngkg(-1), which is equivalent to a toxicological concentration of 4.68ngWHO-TEQ/kg. Feed from animals origin such as chicken meal, animal fat, fish meal, fish oil, and shell powder showed relatively higher concentrations of PCDD/Fs. Feed from plants origin, minerals, and additives ranged from non-detects for bit pulp and ethoxyquin to 8.28ngkg(-1) for dl-methionine. From a toxicological point of view, the highest concentration in vitamins was 0.08ngWHO-TEQ/kg among the feed additives. 2,3,4,7,8-PeCDF was the dominant congener in samples of fish oil, fish meal, and shell powder. Animal fat showed that the pattern of PCDD/Fs depends on the sources of contamination. A sample of animal fat showed 1,2,3,4,7,8-HxCDF and the other sample showed 1,2,3,4,7,8-HxCDD as a primary congener. Generally, low levels of PCDDs were detected in feed additives. Patterns of PCDD/Fs in choline chloride were different with that in choline chloride from an incident in Europe in 2000.     

Heavy metals and polycyclic aromatic hydrocarbons in sediments from the Shenzhen River,South China

With the analysis of eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and sixteen polycyclic aromatic hydrocarbons (PAHs) in sediments from the Shenzhen River, South China, the ecological risks associated were evaluated using Hakanson’s method (for the metals) and the Effect Range Low/Effect Range Median (ERL/ERM) method (for the PAHs). The result shows concentrations of heavy metal in the order Zn?>?Cu?>?Cr?>?Ni?>?Pb?>?As?>?Cd?>?Hg, and among which the Zn, Cu, Ni, and Pb are exceeding the maximum contaminant level for sediments while those of PAHs are far below. The potential ecological risk index value for the heavy metals in the sediment samples was 261.90, which is in the moderate risk category. Total PAH concentrations in the sediments ranged from 1,028 to 1,120 ng/g, which are all far lower than the sediment guideline concentration of 4,022 ng/g, indicating that the risks of biological impacts caused by PAHs in Shenzhen River sediments are, therefore, relatively low. Besides, the fluorene concentration was above the ERL, and would potentially cause negative biological effects in the Shenzhen River. Heavy metals risks are suggested among the most important concerns that the environmental recover measures pay attention to.     

Effects of activated carbon types and service life on removal of endocrine disrupting chemicals: amitrol, nonylphenol, and bisphenol-A

Removal performances of endocrine disrupting chemicals (EDC) such as amitrol, nonylphenol, and bisphenol-A were evaluated in this study using granular activated carbon (GAC) adsorption. This study found that GAC adsorption was effective in removal of EDCs with high K_ow value. Nonylphenol and bisphenol-A were effectively adsorbed onto all carbons (including the used carbons) tested in this study. As indicated by K_ow value, nonylphenol was more effectively adsorbed than bisphenol-A. The coal-based carbon was found more effective than other carbons in the adsorption of nonylphenol and bisphenol-A due to its larger pore volume. The adsorption capacity reduced with the operation year, and the extent of the reduction was different depending upon the carbon type and the operation year. Amitrol was effectively removed by biological degradation, but was poorly adsorbed. Since the microbes residing at the used carbons already accustomed to amitrol, the used carbons removed amitrol better than the virgin carbons. Although the coal-based carbon showed the best removal performance of amitrol, GAC adsorption could not be recommended for amitrol removal because considerable portion of incoming amitrol (9–87%) passed through GAC adsorption column. According to this study, pore volume mainly influenced the adsorption capacity, but the surface charge was also important due to electrical interaction. The adsorption parameters for nonylphenol and bisphenol-A provided by this study could be valuable when GAC adsorption was considered to handle an accidental spill of nonylphenol and bisphenol-A.     

重大灾害现场消防应急通信保障方法初探

针对四川汶川8.0级地震,探讨了承担着地震等自然灾害抢险救援任务的消防部队如何加强应急无线通信能力,为救援任务顺利完成提供必要保障.