Biodegradation of benzo[a]pyrene in soil by Mucor sp. SF06 and Bacillus sp. SB02 co-immobilized on vermiculite

Two indigenous microorganisms, Bacillus sp. SB02 and Mucor sp. SF06, capable of degrading polycyclic aromatic hydrocarbons （PAHs） were co-immobilized on vermiculite by physical adsorption and used to degrade benzo[a] pyrene （BaP）. The characteristics of BaP degradation by both free and co-immobilized microorganism were then investigated and compared. The removal rate using the immobilized bacterial-fungal mixed consortium was higher than that of the freely mobile mixed consortium. 95.3% of BaP was degraded using the co-immobilized system within 42 d, which was remarkably higher than the removal rate of that by the free strains. The optimal amount of inoculated co-immobilized system for BaP degradation was 2%. The immobilized bacterial-fungal mixed consortium also showed better water stability than the free strains. Kinetics of BaP biodegradation by co-immobilized SF06 and SB02 were also studied. The results demonstrated that BaP degradation could be well described by a zero-order reaction rate equation when the initial BaP concentration was in the range of 10--200 mg/kg. The scanning electronic microscope （SEM） analysis showed that the co-immobilized microstructure was suitable for the growth of SF06 and SB02. The mass transmission process of co-immobilized system in soil is discussed. The results demonstrate the potential for employing the bacterial-fungal mixed consortium, co-immobilized on vermiculite, for in situ bioremediation of BaP.     

离子色谱法测定碳酸锶产品中的氯杂质

讨论了在单柱离子色谱仪上用ＴＳＫｇｅｌＩＣ－Ａｎｉｏｎ－ＳＥ柱为分离柱，１ｍｍｏｌ／Ｌ邻苯二到（ＰＨ５．４）作流动相，以电导检测器检测，测定沸水提取碳酸锶产品中的杂质氯的方法。该法简便、快速、准确、无干扰，在测定范围内有良好的线性。最小检出量为０．１μｇ，ＩＣ法与比色法的测定结果基本一致，ＣＩ＾－的含量为０．１６６％，相对标准偏差为２．８％，回收率为９７．９％～１００％。     

120t转炉除尘水处理存在问题及对策

以宝钢集团新疆八一钢铁有限责任公司为例，介绍了120t转炉除尘浊环水系统的运行情况，分析转炉除尘水处理存在的问题及原因，结合现场实践提出改进措施及解决此类问题的思路。经实际运行考核，斜板沉淀器出水悬浮物小于100mg/L，系统节约新水60m^3/h，满足了生产要求，达到了回收尘泥、保护环境、节能降耗、水资源综合利用的目的。     

六株真菌对土壤中芘和苯并芘的降解及其动力学

研究了6株真菌对土壤中芘和苯并芘(BaP)的降解动态,用Michaelis-Menton和Monod动力学模型对结果进行拟合.结果表明,6株真菌对芘和BaP的降解速率有显著性差异,降解率相差不大.产黄青霉(Penicillium chrysogenum,SF04),在42d内对BaP的降解能力最强,可达71.31%,对芘的降解能力相对最弱.镰刀菌(Fusariumsp.,SF11),黑曲霉(Aspergillusniger,SF05),木霉(Trichodermasp.,SF02)和毛霉(Mucorsp.,SF06)42d对芘的降解率分别为86.22%,86.18%,85.41%,85.04%,对BaP的降解率分别为71.11%,69.44%,69.05%,69.72%.木霉(Trichodermasp.,SF02)和毛霉(Mucorsp.,SF06)对芘和BaP的降解速率均很快.     

基于DALYs的北京市大气PM2.5载带苯并[a]芘疾病负旦研究

苯并[a]芘(BaP)是一类兼具强致癌性和非致癌毒性的物质,可随PM_(2.5)经呼吸途径进入人体而威胁健康.本文采集2016年北京城区监测点PM_(2.5)样品并采用气相色谱质谱联用仪测定其载带BaP浓度.通过BaP的流行病学及动物毒理学数据的检索和分析,确定BaP呼吸暴露的致癌和非致癌毒效应评价终点及其剂量效应关系.运用伤残调整生命年(DALYs)指标估算了呼吸途径人群PM_(2.5)载带BaP暴露导致的疾病负担.结果显示北京市BaP导致总疾病负担为431.36 DALYs·a~(-1),每千人DALYs为0.03 a~(-1).其中非致癌效应的疾病负担为1.98 DALYs·a~(-1),致癌效应为429.39 DALYs·a~(-1).不同毒效应的疾病负担排序为:癌症(99.54%)发育毒性(0.41%)生殖毒性(0.04%).不同季节的疾病负担贡献差异较大.北京市BaP暴露导致疾病负担的主要贡献季节为冬季,疾病负担贡献的顺序为冬季(88.01%)秋季(4.91%)春季(4.34%)夏季(2.74%).     

Laboratory-scale study of the suppression of PCDD/F emission during coal and MSW co-incineration

The experimental test of co-incinerating Chinese raw municipal solid waste （MSW） and coal in a laboratory-scale tubular reactor was first reported in present study, and the emission of normal gas components and the effects of the S/Cl molar ratio or coal mixing percentages on polychlorinated dibenzo-p-dioxins and dibenzofurans （PCDDs/Fs） emission were investigated and discussed. The results indicated that OCDD was the only PCDD homologues since others like TCDD-HpCDD was hardly detected, while as the categories of PCDF homologues were comparatively much more general. The amount of PCDD was much larger than that of PCDF in all operating conditions. Since ZPCDF/∑PCDD〈〈1, the dominant role of the precursor formation was proven in our experimental conductions. With increasing the coal addition to MSW （from 0 to 16%）, PCDD and PCDF were reduced considerably. Coal and MSW may suppress the PCDD/F emissions efficiently （over 95%） during the MSW incineration process. The PCDD/F suppression results of the present study could be helpful guidance to the industrial application of Chinese MSW and auxiliary coal co-incineration processes. The PCDD/F stack emission data of two industrial incinerators using co-incineration technology in China seem to have a great positive reduction of PCDDs/Fs.     

Spatial population structure in forest voles of the genus <Emphasis Type="Italic">Clethrionomys</Emphasis> in the southern taiga of the Middle Irtysh region

A comparative analysis of spatial population structure in the northern red-backed vole (Clethrionomys rutilus Pall.) and large-toothed red-backed vole (Cl. rufocanus Sund.) has been performed in the middle taiga zone of the Middle Irtysh region (Omsk oblast). Populations of these species are represented by sets of territorial groups whose numbers and spatial distribution change from year to year depending on the ratio of these species in a biotope and their population density. There is no significant interspecific competition between cohabitant Cl. rutilus and Cl. rufocanus. In particular, this follows from the fact that the population density and distribution pattern of one species are independent of those of the other species. It has been found that the size of home ranges in Cl. rutilus inversely depends on its population density, with that in Cl. rufocanus remaining approximately the same at different population densities, and that the structure of the resident part of the population in both species changes during the season, as voles from neighboring habitats or dispersing voles settle in the study area.     

表面活性剂对苯并[a]芘在黑炭表面吸附解吸的影响

通过静态吸附实验,研究了3种不同类型的表面活性剂(阳离子∶十六烷基三甲基溴化铵,CTAB;阴离子∶十二烷基苯磺酸钠,SDBS∶非离子,曲拉通100,TX100)对苯并[a]芘(BaP)在黑炭表面吸附解吸的影响.结果表明,3种表面活性剂的存在均会增加BaP在黑炭表面吸附的非线性程度.CTAB的存在可以促进BaP在黑炭表面的吸附同时抑制了BaP的解吸,然而SDBS的存在降低了BaP在黑炭表面的吸附并增加了吸附过程的可逆性.与CTAB和SDBS不同,TX100对BaP在黑炭表面吸附解吸的影响取决于其添加浓度.低浓度的TX100(50 mg.L-1)能够促进BaP在黑炭上的吸附并抑制BaP的解吸,吸附能力参数Kd值(在ce=50μg.L-1下)从188 062 mL.g-1增大到264 179 mL.g-1,解吸滞后指数HI从0.44降低到0.39.随着TX100浓度增加到150 mg.L-1和200 mg.L-1,TX100对BaP的吸附表现出抑制作用并能够促进BaP的解吸,Kd值(在ce=50μg.L-1下)从188 062 mL.g-1分别降低到182 751 mL.g-1和178 730 mL.g-1,解吸滞后指数从0.44分别升高到0.65和0.70.本研究为预测多环芳烃在表面活性剂污染的环境中的分布特征和最终归趋提供了理论依据.     

杯[4]芳烃修饰Amberlite XAD-4树脂去除水中双氯芬酸

通过偶氮化反应将合成的去叔丁基杯[4]芳烃连接到Amberlite XAD-4树脂上,并且采用FTIR、SEM和TG/DTA法表征了杯[4]芳烃修饰Amberlite XAD-4树脂的结构.结果表明,水溶液中杯[4]芳烃修饰Amberlite XAD-4树脂对双氯芬酸的去除率远大于单独Amberlite XAD-4树脂和杯[4]芳烃.双氯芬酸的浓度为20mg/L时,随着杯[4]芳烃修饰AmberliteXAD-4树脂投加量的增加,双氯芬酸的去除率增加很快.当吸附剂量增加到80mg/L时,双氯芬酸的去除率为92.8%,并且达到吸附平衡,吸附的双氯芬酸量为34.02mg/g. Langmuir和Freundlich等温线与实验数据均有很好的拟合度.对热力学参数的计算表明,△H与△G负值显示出反应的放热和自发过程.     

离子液体[C_8 mim]Cl对泥鳅胚胎和仔鱼的毒性

以泥鳅的胚胎及仔鱼为试验材料,选择胚胎发育的4个不同时期(囊胚期、原肠胚中期、神经胚期、尾芽期)及仔鱼期为处理开始的时间点,探讨了离子液体[C8mim]Cl的毒性作用。结果表明,随着[C8mim]Cl浓度增加,泥鳅胚胎的孵化率下降,畸形率上升,具有明显的剂量-效应关系,67~150 mg·L-1的[C8mim]Cl对泥鳅胚胎均表现出明显的致畸毒性效应;随着[C8mim]Cl浓度增加,泥鳅仔鱼死亡率上升,而100~225 mg·L-1的[C8mim]Cl对泥鳅仔鱼具有明显的致畸、致死作用。其中,[C8mim]Cl对孵出期泥鳅仔鱼的24 h、48 h的半致死浓度分别为97.95和86.77 mg·L-1;而[C8mim]Cl对孵出后3 d泥鳅仔鱼的24 h、48 h的半致死浓度分别为73.77和40.98 mg·L-1。由上可知,在一定的剂量内,[C8mim]Cl对泥鳅胚胎及仔鱼的发育有明显的致畸、致死作用,这为离子液体[C8mim]Cl的合理使用提供了理论依据。