Ecological risks and potential sources of heavy metals in agricultural soils from Huanghuai Plain, China

A total of 224 agricultural soil samples from Huanghuai Plain in China were investigated for the concentrations of seven heavy metals (As, Cd, Cr, Hg, Ni, Pb, and Zn). The mean concentrations of the metals were 12, 0.17, 79, 0.04, 35, 25, and 74 mg/kg, respectively. These values are similar or slightly higher than background values in this region, except for Cd with a mean nearly twice the background value. The estimated ecological risks based on contamination factors and potential ecological risk indexes are also mostly low, but considerable for Cd and Hg. Multivariate analysis (including Pearson's correlation analysis, hierarchical cluster analysis, and principal component analysis) clearly revealed three distinct metal groups, i.e., Cr/Ni/Zn, As/Cd/Pb, and Hg, whose concentrations were closely associated with the distribution and pollution characteristics of industries in and around the plain. The main anthropogenic sources for the three metal groups were identified as atmospheric deposition, sewage irrigation/fertilizers usage, and atmospheric deposition/irrigation water, respectively. The present results are well suited for planning, risk assessment, and decision making by environmental managers of this region.     

高压脉冲放电等离子体处理含偶氮染料活性红195废水

采用高压脉冲放电等离子体处理含偶氮染料活性红195 废水,实验结果表明:当电极间距为10 mm、空气流量为0.10 m3 / h、溶液初始pH 为3.05,放电反应时间为21 min 时,活性红195 去除率为98.72%;废水中加入Cu2+时,随Cu2+加入量的增加,活性红195 的去除率先减小后增大;加入自由基抑制...     

超声波辅助萃取—气质联用色谱法测定活性污泥中的多溴联苯醚

建立了活性污泥中多溴联苯醚(PBDEs)的分析方法。活性污泥经超声波辅助萃取,用酸性硅胶、铜粉及复合硅胶柱纯化后,采用气质联用色谱(GC/MS)对7种PBDEs单体进行测定,内标法定量。结果表明,该方法具有很好的精密性和准确性,方法检测限为17～121 pg/g,加标回收率为84.5%～109.0%,相对标准偏差(RSD)为0.5%～2.8%,回收率指示物3,3’,4,4’-四溴联苯醚(BDE-77)的回收率平均值为89.2%,RSD为0.8%,能够满足活性污泥中PBDEs的测定要求。采用所建立的方法对杭州和台州的活性污泥样品进行了测定,结果显示,台州样品中PBDEs含量高于杭州样品,但两者都低于相关文献所报道的北美及欧洲国家活性污泥中PBDEs的含量。     

活性炭-微波辐射法去除苯酚的机理研究

通过微波辐射前后水样的紫外分光扫描分析，以及微波辐射后水样中的苯酚浓度和COD浓度之间线性相关性分析表明，活性炭-微波辐射强化除酚效率的主要机理是微波使反应体系温度升高导致的活性炭加速吸附作用，而不是微波诱导催化氧化作用。通过对微波辐射前后活性炭的SEM扫描电镜分析说明，活性炭在微波场中由于“微域爆炸”导致其表面及内部孔隙结构的变化， 吸附性能得到改善，是强化苯酚去除的另一原因。 研究还表明，在较短的作用时间内，活性炭-微波辐射法的除酚效率高于常温吸附，但低于沸腾条件下的高温吸附。活性炭-微波辐射去除苯酚的规律遵循其吸附特性，温度越高，吸附反应速度越快。     

复合混凝法处理高浓度聚丙烯酰胺生产废水

采用聚合氯化铝(PAC)混凝和活性炭吸附的复合混凝法处理高浓度聚丙烯酰胺(PAM)生产废水.实验结果表明,最佳处理条件为:废水 pH 6.5,废水温度 35℃,先加入 PAC 混凝后再加入活性炭,PAC 加入量250 mg/L,活性炭加入量 200 mg/L.在此最佳条件下,废水 COD 去除率达 52.0%.该复合混...     

The leaching of additive-derived flame retardants (FRs) from plastics in avian digestive fluids: The significant risk of highly lipophilic FRs

The exposure to plastic debris and associated pollutants for wildlife is of urgent concern,but little attention has been paid on the transfer of plastic additives from plastic debris to organisms. In the present study, the leaching of incorporated flame retardants(FRs),including polybrominated diphenyl ethers(PBDEs), alternative brominated FRs(AFRs), and phosphate flame retardants(PFRs), from different sizes of recycled acrylonitrile-butadienestyrene(ABS) polymer were investigated in avian digestive fluids. The impact of co-ingested sediment on the leaching of additive-derived FRs in digestive fluids was also explored. In the recycled ABS, BDE 209(715 μg/g) and 1, 2-bis(2,4,6-tribromophenoxy) ethane(BTBPE,1766 μg/g) had the highest concentrations among all target FRs. The leaching proportions of FRs were higher in finer sizes of ABS. The leaching proportions of FRs from recycled ABS increased with elevated logK OWof FRs. In the tests with coexisted ABS and sediment, hexato deca-BDEs, BTBPE, and decabromodiphenyl ethane(DBDPE) migrated from ABS to sediment, which resulted in the less bioaccessible fractions of these FRs in gut fluids. More lipophilic chemicals tended to be adsorbed by sediment from ABS. The results suggest the migration of additive-derived FRs from plastics to other indigestible materials in digestive fluids. The findings in this study provide insights into the transfer of additive-derived FRs from plastics to birds, and indicate the significant contribution of FR-incorporated plastics to bioaccumulation of highly lipophilic FRs.     

膜法A／O工艺处理炼油污水的探讨

应用生物膜法Ａ／Ｏ系统这项新技术处理炼油废水近三年来，已取得了初步成果；它对ＣＯＤ、酚、硫化物、ＮＨ３－Ｎ的去除效果明显，但对总氮的去除效果较差。对我厂Ａ／Ｏ系统的运行进行了分析，对其存在问题进行了探讨，且提出了可行性的建议。     

SBR法对焦化废水生物脱氮研究

采用SBR工艺对焦化废水的有机物降解和生物脱氮进行了研究。试验结果表明。焦化废水的生物脱氮是以短程硝化／反硝化的途径存在的，而且在好氧阶段存在同时硝化／反硝化（sND）过程。好氧阶段的反硝化效率约占整个反应周期脱氮效率的37．0％。SBR反应器对NH3-N的去除效率在95．8％-99．2％．CODCr的去除效率在85．3％～92．6％。由于出水中NO2-N的积累。NO2—N对CODCr浓度贡献值得关注。     

冷原子吸收法测定工业废水中的汞

应用WGC-200型微分测汞仪，研究石化工业外排废水样品中汞的测定技术。将水样以适量的硫酸酸化，加高锰酸钾使汞成为离子状态，再以氯化亚锡为还原剂，在酸性介质中测定汞，回收率为：95％～116％，最低检出限可达0．00001ug／mL。     

地质环保方法在百色油田污水治理中的应用

运用地质环保方法 ,从源头控制地层出水量 ,并将处理后的油田污水替代以往注入油层的清水 ,回注地层 ,解决了油田污水的出路问题 ;同时也成功地解决了注入水与地层的配伍性难题 ,极大地减小了注入水对油层的伤害 ,为水驱油藏的采收率提高提供了有效的技术措施 ;此外每年节约注入地层用清水30×104 m3,取得了良好的综合经济效益。