Green and efficient degradation of cefoperazone sodium by Bi4O5Br2 leading to the production of non-toxic products: Performance and degradation pathway

Photocatalytic process represents a promising approach to overcome the pollution challenge associated with the antibiotics-containing wastewater. This study provides a green, efficient and novel approach to remove cephalosporins, particularly cefoperazone sodium (CFP). Bi₄O₅Br₂ was chosen for the first time to systematically study its degradation for CFP, including the analysis of material structure, degradation performance, the structure and toxicity of the transformation products, etc. The degradation rate results indicated that Bi₄O₅Br₂ had an excellent catalytic activity leading to 78% CFP removal compared with the pure BiOBr (38%) within 120 min of visible light irradiation. In addition, the Bi₄O₅Br₂ presents high stability and good organic carbon removal efficiency. The effects of the solution pH (3.12 - 8.75) on catalytic activity revealed that CFP was mainly photocatalyzed under acidic conditions and hydrolyzed under alkaline conditions. Combined with active species and degradation product identification, the photocatalytic degradation pathways of CFP by Bi₄O₅Br₂ was proposed, including hydrolysis, oxidation, reduction and decarboxylation. Most importantly, the identified products were all hydrolysis rather than oxidation byproducts transformed from the intermediate of β-lactam bond cleavage in CFP molecule, quite different from the mostly previous studies. Furthermore, the final products were demonstrated to be less toxic through the toxicity analysis. Overall, this study illustrates the detailed mechanism of CFP degradation by Bi₄O₅Br₂ and confirms Bi₄O₅Br₂ to be a promising material for the photodegradation of CFP.     

Nanomaterials for environmental burden reduction, waste treatment, and nonpoint source pollution control: a review

Nanomaterials are applicable in the areas of reduction of environmental burden, reduction/treatment of industrial and agricultural wastes, and nonpoint source (NPS) pollution control. First, environmental burden reduction involves green process and engineering, emissions control, desulfurization/denitrification of nonrenewable energy sources, and improvement of agriculture and food systems. Second, reduction/treatment of industrial and agricultural wastes involves converting wastes into products, groundwater remediation, adsorption, delaying photocatalysis, and nanomembranes. Third, NPS pollution control involves controlling water pollution. Nanomaterials alter physical properties on a nanoscale due to their high specific surface area to volume ratio. They are used as catalysts, adsorbents, membranes, and additives to increase activity and capability due to their high specific surface areas and nano-sized effects. Thus, nanomaterials are more effective at treating environmental wastes because they reduce the amount of material needed.     

钙钛矿型烯土复合氧化物及其在汽车尾气净化工程中的应用

本文介绍了钙铁矿型烯土复合氧化物的结构特征、制备方法与催化性能；分析了该类氧化物对汽车尾气环境的适应性，并与现有的贵金属催化剂作了比较．     

上海高密度居民区合流制系统雨天溢流水质研究

城市面源污染已成为上海城区河道的主要污染源.为此,研究了上海市合流制排水区域SA雨天溢流的水质特性,并探讨了溢流水质的主要影响因素.结果表明,该区域雨天溢流COD、BOD、SS、NH₃-N、TN、TP事件平均浓度的均值分别为614mg/L、208.5 mg/L、684 mg/L、17.6 mg/L、29.8 mg/L、3.0 mg/L,远高于国外的一些研究结果;分析事件平均浓度的对数正态概率分布表明,BOD的对数正态分布性最好;此外,研究还发现COD和SS溢流浓度和前期晴天数与降雨历时的比值呈现出较高的正相关性.     

兰州形变台概况及资料映震能力的探讨

本文介绍了兰州形变台的台址条件及其资料的基本情况，并对1987年以来水管倾斜仪（FSQ）、石英伸缩仪（SSY-11）、石英水平摆倾斜仪（SQ-70B）观测资料以及与地震之间的对应关系进行了详细的分析总结。结果表明，观测资料可靠稳定，具有良好的映震能力。     

生物浮选法处理含油污泥

利用从石油污染物中分离的一组微生物菌株对胜利油田含油污泥进行了生物浮选处理,探讨了处理过程中温度、稀释率、投加菌量及加糖量等因子对油去除率的影响及组合菌株与单一菌株处理效果的差异。通过实验获得生物浮选最佳运行参数为:温度40℃,稀释率98%,加菌量3.75%,加糖量0.25%,在该参数运行条件下,原油去除率可达95%以上。使用混合菌株进行生物浮选有利于回收原油中含油量的提高。     

BAC生物活性炭法及其在水处理中的应用

介绍了生物活性炭(BAC)法去除有机物的方式,不同进水水质条件下的特征穿透曲线。总结了BAC法的优缺点以及国、内外对BAC生物再生的研究与观点,以及BAC技术的研究与应用进展。     

生态足迹理论对生态城市建设的启示

介绍了生态足迹理论基本概念和计算模型,并运用该模型,对上海市生态足迹进行了计算和分析。在此基础上探讨了生态足迹理论对生态城市建设的启示,提出应在不降低人们生活水平的前提下,减少生态足迹,提高城市的可持续发展能力。     

电极配置和操作条件对静电油烟净化效率的影响

以有机气溶胶发生器产生的0.02～2.02μm癸二酸二辛酯颗粒模拟餐饮业排出的油烟PM2 5组分,利用静电低压撞击器颗粒物检测仪测定各粒径范围的颗粒个数和质量浓度,并系统研究了电极配置、电场风速和供电电压等因素对静电油烟净化效率的影响.结果表明:油烟荷电量以及荷电颗粒迁移距离是影响净化效率的关键因素,优化电极配置的增效...     

基于碳数分段法的石油烃污染土壤异位热脱附工艺的优化

针对石油烃污染土壤成分复杂、污染严重、修复难度高的问题,采用适用性广、效率高且去除彻底的异位热脱附技术修复石油烃污染土壤。利用碳数分段法及室内模拟实验,探究在热脱附过程中的土壤粒径、含水率和有机质对石油烃及各组分热解吸效率的影响;另外,还采用响应面法对各影响因素进行了优化,以获得异位热脱附修复石油烃污染土壤的最优工艺参数。结果表明,当污染土壤粒径高于1 mm时,石油烃脱附效率均可达90%以上,且粒径越大土壤颗粒中石油烃去除率越高。其中,润滑油段(ORO, C28~C40)组分的脱附效率随粒径变化最为明显。当土壤含水率为15%、脱附时间为50 min时,石油烃脱附效率最大为52.63%。另外,土壤中有机质含量越低,越利于石油烃的脱除,且高温(400~500 ℃)条件下可基本消除土壤中高含量有机质(3.82%)对石油烃脱除的阻碍作用。响应面优化实验得到的最佳工艺参数条件为,粒径2 mm、有机质含量1.44%、含水率为17.68%,在此条件下的石油烃脱附去除效率可达65.32%。该研究结果可为热脱附技术在石油烃污染场地的实际应用提供参考。