Electrocoagulation coupled with electrooxidation for the simultaneous treatment of multiple pollutants in contaminated sediments

In situ and simultaneous remediation of a variety of pollutants in sediments remains a challenge. In this study, we report that the combination of electrocoagulation (EC) and electrooxidation (EO) is efficient in the immobilization of phosphorus and heavy metals and in the oxidation of ammonium and toxic organic matter. The integrated mixed metal oxide (MMO)/Fe anode system allowed the facile removal of ammonium and phosphorus in the overlying water (99% of 10 mg/L NH₄⁺-N and 95% of 10 mg/L P disappeared in 15 and 30 min, respectively). Compared with the controls of the single Fe anode and single MMO anode systems, the dual MMO/Fe anode system significantly improved the removal of phenanthrene and promoted the transition of Pb and Cu from the mobile species to the immobile species. The concentrations of Pb and Cu in the toxicity characteristic leaching procedure extracts were reduced by 99% and 97% after an 8 hr operation. Further tests with four real polluted samples indicated that substantial proportions of acid-soluble fraction Pb and Cu were reduced (30%–31% for Pb and 16%–23% for Cu), and the amounts of total organic carbon and NH₄⁺-N decreased by 56%–71% and 32%–63%, respectively. It was proposed that the in situ electrogenerated Fe(II) at the Fe anode and the active oxygen/chlorine species at the MMO anode are conducive to outstanding performance in the co-treatment of multiple pollutants. The results suggest that the EC/EO method is a powerful technology for the in situ remediation of sediments contaminated with different pollutants.     

燃煤产生的有毒金属沉降对重庆水环境影响研究

本文将水、气、土壤视为一个统一的系统,选用WH TM模型,从机理着眼,分析了非点源有毒重金属在大气、土壤和水体中的迁移过程;研究预测了煤炭消耗量对环境造成的影响;模拟了能源消耗与转换过程排入环境中的气态或固态污染物、随水文循环最终以液态形式增加了水环境的污染负荷。特别着重于在酸性沉降条件下对水环境的危害。     

燃煤电厂排放细微灰粒中痕量元素的分布与富集规律

本文测定了武汉市青山热电厂５＾＃锅炉在两种不同燃烧工况条件下，除尘器入口烟道灰的四种不同粒径灰粒中的Ｃｕ，Ｃｏ，Ｎｉ，Ｐｂ，Ｃｄ，Ｃｒ和Ｂｅ等七种痕量元素的含量。发现大部分元素有在细微粒子中富集的倾向，富集程度与颗粒物粒径大小、元素性质、元素存在形态及燃烧工况条件有密切关系。这种富集倾向可用痕量元素在燃烧过程中的蒸发－凝集作用来解释。     

江西省食管癌与岩石类型

利用江西省大量岩石类型和食管癌死亡调查资料，对食管癌死亡率与人群生存区岩石类型的相关性进行了研究。结果表明，江西省食管癌死亡率与岩石类型密切相关。食管癌死亡率与变质岩、碳酸盐岩、第四系松散岩、红色碎屑岩呈正相关，与岩浆岩呈负相关，与碎屑岩相关不显著。     

痕量汞的分析现状

本文系统地综述了自1975年以来分光光度法、催化法、电极溶出伏安法、冷原子吸收和荧光法以及其它方法分析痕量汞的发展状况,并对稀浓度汞标液的保存方法作了介绍。     

固定化微生物技术及其在重金属废水处理中的应用

固定化微生物技术是一种有效的废水生物处理技术.较为全面地介绍了其定义、分类及载体选择.全面系统地介绍了固定化微生物(主要是菌类和藻类)技术近年来在重金属废水处理中的应用现状,分析认为,固定化微生物技术对于处理含各种重金属离子的废水均有很广阔的应用前景,并对今后的研究方向做了探讨.     

Effect of photosensitizer riboflavin on the fate of 2,4,6-trinitrotoluene in a freshwater environment

The effect of riboflavin (1 microM) on the fate of TNT (20 mg/l) in a natural water environment was studied. The relative contribution of photolysis, microbial assemblages and freshwater matrix to TNT degradation was examined. The rates, extent and products of TNT and riboflavin transformation were compared under different experimental conditions. It was found that riboflavin significantly enhanced the degradation of TNT in natural water environment. Thus it is a potentially useful photosensitizing agent for the treatment of TNT-contaminated surface water. Furthermore, in the presence of riboflavin, two new intermediates with max. absorption wavelength of 230 nm were found, demonstrating that transformation of TNT in the presence of riboflavin undergoes different pathways.     

Detection limits of optical gas imagers as a function of temperature differential and distance

Optical gas imaging (OGI) is an effective tool for detecting gas leaks from process equipment. Despite the fact that OGI has been used for leak detection for over a decade, its detection limit is an elusive performance metric and has not been systematically characterized and quantified like other detection instruments. A substantial body of research has been performed that has shed some light on the OGI detection limits and the factors that dictate the detection limits. The OGI detection limit expressed as ppm-m and ppm now can be quantified as a function of ΔT (differential temperature between the gas plume and the background), the OGI camera type, and the specific gas in question. Furthermore, the OGI detection limit expressed as grams per hour can be calculated based on the ΔT and the distance from the OGI camera to the leak location under common leak survey conditions. For the same OGI camera, the detection limit can vary by several orders of magnitude due to ΔT and distance. The present work has demonstrated how different OGI detection limits can be. More importantly, this work has, for the first time, formulated equations that can be used to determine OGI detection limits with a given set of leak detection conditions. Being able to quantify OGI detection limit and understand the variables that dictate the detection limit is a significant advancement. It will help OGI to become accepted as a mature field instrument. The variables characterized in this work should have an impact on the development of OGI leak survey protocols, such as Appendix K to Code of Federal Regulations 40 CFR Part 60 in the United States. Established detection limits will also help emission inventory for fugitive emissions when OGI is used as the sole leak detection method.

Implications: Optical gas imaging (OGI) has been used for leak detection and control of fugitive volatile organic compound (VOC) emissions and methane emissions due to equipment leaks. However, detection limits of OGI have not been characterized and quantified like other detection instruments. The lack of well-understood detection limits has hindered broader applications of OGI. The work presented in this paper represents important steps that will enable OGI users and policymakers to establish (1) OGI detection limits under various conditions, (2) OGI leak survey criteria for a desired minimum detectable leak size, and (3) maximum potential emissions from the nondetect sources in emission inventory studies.     

两级SBR与传统SBR工艺的对比研究

用两级SBR工艺（TSSBR）处理COD与氮浓度较高的工业废水，SBR1去除有机物，SBR2主要进行硝化反硝化。TSSBR与传统SBR工艺相比，COD降解速率和硝化反应速率明显提高，COD去除率由84％提高到93％，2种工艺的反硝化速率没有明显差别。在原水COD浓度较高的情况下，TSSBR可有效克服高COD浓度对硝化反应的抑制，硝化反应速率是传统SBR的2倍。对于COD和氮浓度较高的工业废水，TSSBR明显优于传统SBR，是一种理想的处理工艺。     

富氧尾气中NOx催化净化的研究进展

本文对富氧条件下NOx 催化净化的研究现状进行了综述 ,并对其存在的问题进行了探讨