Effect of initial pH control on biological phosphorus removal induced by the aerobic/extended-idle regime

Recently, it has been reported that biological phosphorus removal (BPR) can be induced by an aerobic/extended-idle (AEI) regime. This study further investigated the effect of initial pH ranging from 6.6 to 8.2 on BPR in the AEI process, and compared the BPR performance between the AEI and the anaerobic/oxic (A/O) regimes under their optimal initial pH value. Experimental results firstly showed that phosphorus removal linearly increased with initial pH increasing from 6.6 to 7.8, but slightly decreased when initial pH increased from 7.8 to 8.2. The optimal initial pH should be controlled at 7.8, and the phosphorus removal at initial pH 7.8 was approximately 1.7-time than that at initial pH 6.6. The mechanism studies showed that the biomass cultured at initial pH 7.8 contained more polyphosphate accumulating organisms (PAOs), lower glycogen accumulating organisms (GAOs), and had higher activities of exopolyphosphatase and polyphosphate kinase than that cultured at initial pH 6.6. Cyclic studies revealed that initial pH control affected the transformations of intracellular polyhydroxyalkanoates and glycogen, which might thereby influence microbial competition between PAOs and GAOs. Then, BPR performance between the AEI and the A/O regimes by adjusting initial pH at 7.8 was also compared. The results showed the AEI regime could drive a better BPR than the generally accepted A/O regime (98% vs 88%). Finally, controlling initial pH at 7.8 to promote BPR in the AEI process was confirmed for a municipal wastewater.     

铬盐工业污染防治对策与建议

在对全国铬盐工业多家企业调研的基础之上,对铬盐工业的生产现状、主要生产工艺及排污节点、污染物排放特征、污染控制技术等进行了论述,指出了污染防治存在的问题,并提出了对策和建议。     

磁性壳聚糖凝胶微球对水中Pb(Ⅱ)的吸附性能

以壳聚糖为原材料,通过原位共沉淀法和柠檬酸钠交联法制备了一种新型多孔磁性壳聚糖凝胶微球吸附剂CS-citrate/Fe₃O₄.利用扫描电镜（SEM）、透射电镜（TEM）、傅里叶红外光谱（FTIR）、热重分析（TG）对吸附剂进行了表征.结果表明,吸附剂内部具有发达的孔隙结构,并均匀分布有平均直径为（4.79±1.09）nm的Fe₃O₄纳米颗粒;吸附剂中引入Fe₃O₄后,仍存在羟基、氨基和羧基等功能基团,且吸附剂磁性良好可用于磁场分离;吸附剂对Pb（Ⅱ）的吸附等温线和动力学研究表明,吸附过程以化学吸附为主,最大吸附容量可达178.25mg/g.     

包装印刷的环境性能及绿色化对策探讨

绿色环保已成为新世纪的发展主题，包装印刷的绿色化问题已成为阻碍包装印刷工业持续发展的大问题。对此，在研究了现行各种包装印刷技术的环境性能，及包装印刷材料中油墨的环境性能的基础上，从总体上探讨了包装印刷绿色化五个方面的发展对策：发展无醇印刷和无水胶印技术，发展环保柔性版印刷技术，发展环保油墨，发展直接制版技术(CTP)和数字化印刷技术，发展废弃物处理技术。     

青弋江流域不同级别河流底栖动物群落结构研究

2013年8月对青弋江流域不同级别河流底栖动物进行了调查。共采集到底栖动物60种,隶属于39科58属。从1级到4级河流,种类数表现出逐渐减少的趋势,分别为46、39、36和16种。1~3级河流中种类数最多的均是水生昆虫,4级河流中种类数最多的是软体动物。整个流域底栖动物密度和生物量分别为382 ind./m2和3643 g/m2。不同级别河流中,2级河流底栖动物密度最大,4级河流密度最小,且二者存在显著差异;2级和4级河流底栖动物生物量都较高,且显著高于1级河流。在功能摄食类群方面,整个流域以刮食者和过滤收集者为主。随着河流级别的增加,刮食者相对密度和相对生物量表现出先增加后下降的趋势;撕食者在1、2级河流所占比例较高;直接收集者和过滤收集者在1级和4级河流中所占比例较高     

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.     

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     

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.     

曝气生物滤池效能关键影响因素研究进展

曝气生物滤池（BAF）是一种新型的生物氧化处理工艺,已被广泛应用于城市废水处理、中水回用及微污染源水的预处理。详细论述了目前国内外对BAF效能的关键影响因素,如填料、水力停留时间、进水底物、水温、曝气量与进水量比、反冲洗工艺、化学除磷药剂等的研究现状,并探讨了其今后的研究方向。     

采用氢氧化钠溶液循环浸出法脱除高砷阳极泥中的砷

采用氢氧化钠溶液循环浸出法处理高砷阳极泥（简称阳极泥）,考察了氢氧化钠溶液与阳极泥质量比（简称液固比）等因素对限极泥中砷、锑、铅浸出率的影响。在液固比为5、氢氧化钠浓度为2．0moL／L、反应温度为70～85℃、反应时间为8h的条件下,砷浸出率可达95％以上;含砷浸出液经硫化钠沉砷后可返回浸出工序重复使用,在硫化钠与砷质量比大于3时,浸出液沉砷率维持在80％以上,同时回用浸出工序后,砷浸出率达95％以上,且铅、锑流失率较低。