Metagenomic insights into responses of microbial population and key functional genes to fulvic acid during partial nitritation

The long-term impact of fulvic acid (FA) on partial nitritation (PN) system was initially examined in this study. The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulation rate (NAR nearly 100%) and ammonium removal rate (ARR 56.85%), while FA over 50 mg/L decreased ARR from 56.85% to 0.7%. Sludge characteristics analysis found that appropriate FA (<50 mg/L) exposure promoted the settling performance and granulation of PN sludge by removing Bacteroidetes and accumulating Chloroflexi. The analysis of metagenomics suggested that the presence of limited FA (0-50 mg/L) stimulated the generation of NADH, which favors the denitrification and nitrite reduction. The negative impact of FA on the PN system could be divided into two stages. Initially, limited FA (50-120 mg/L) was decomposed by Anaerolineae to stimulate the growth and propagation of heterotrophic bacteria (Thauera). Increasing heterotrophs competed with AOB (Nitrosomonas) for dissolved oxygen, causing AOB to be eliminated and ARR to declined. Subsequently, when FA dosage was over 120 mg/L, Anaerolineae were inhibited and heterotrophic bacteria reduced, resulting in the abundance of AOB recovered. Nevertheless, the ammonium transformation pathway was suppressed because genes amoABC and hao were obviously reduced, leading to the deterioration of reactor performance. Overall, these results provide theoretical guidance for the practical application of PN for the treatment of FA-containing sewage.     

降雨氢离子浓度的参数化研究

对酸雨模式中降雨的物理过程进行了简化假设，在此基础上研究了大气中影响降雨氢离子浓度的几种主要污染物（ＳＯ２ ，ＶＯＣｓ ，ＮＨ３ ，ＮＯｘ） 及温度、天顶角、雨强等因素同降雨氢离子浓度的参数关系     

聚四氟乙烯生产中副产氯化氢及盐酸处理的安全技术措施

简要介绍聚四氟乙烯生产中副产氯化氢及盐酸的处理方法.根据氯化氢和盐酸的特性,设计了相应的安全技术措施,以保证安全生产.     

用废盐酸和劣质高岭土生产聚合氯化铝的研究

采用废盐酸和劣质高岭土生产聚合氯化铝技术，对试验原料、设备、内容等作了介绍，结果表明，该项技术不仅解决了某化工厂副产 浓度含氟盐酸的出路问题，而且综合利用了当地的矿产资源，实现了经济效益、环境效益和社会效益的统一。     

电渗析治理糠醛废水过程性能的研究

糖醛废水含１．０％－２．５％的乙酸，直接外排，污染环境，浪费资源，通过３０－８０对膜，４００ｍｍ×８００ｍｍ隔板组装的电渗析器中型试验，脱除其中９５％以上的水，回收得到浓度为２０％的乙酸，再经萃取，精馏得到９９％工业乙酸，治理后的废水含酸量小于０．０２％，可安全排放或回用。对影响极限电流，过程效率的因素进行了探讨，导出工艺特性的经验式，提出相应特性常数。     

凝胶化改性尼龙-6渔网的防生物附着性能研究

采用对渔网尼龙-6纤维进行接枝丙烯酸的方法,制备防止海洋污损生物附着的表面凝胶化改性渔网材料.以小球藻、杜氏藻、金藻为实验海藻,研究了三种海藻在改性材料表面的生物附着性能.结果表明,三种海藻在聚丙烯酸凝胶改性尼龙-6纤维表面的附着量明显少于普通尼龙-6纤维.改性纤维的接枝率越高,海藻的附着量越小,接枝率16.1%以上时纤维具有优良抗生物附着性能.     

铬渣的细菌解毒实验研究

采用从铬渣堆埋场附近的污泥中分离到的高效还原Cr(Ⅵ)的Ch-1菌进行细菌浸出的摇瓶实验,分别考察了不同液固比,温度,初始pH值情况下浸出液的pH值变化,Cr(Ⅵ)浓度变化及浸出过程铬渣中六价铬的浸出率变化和最终渣浸出毒性.实验结果表明,在细菌的作用下,浸出液Cr(Ⅵ)浓度均能解毒为0ppm,同时,浸出液pH值降低到8～9之间, 细菌浸出渣毒性降低到0.05ppm以下,远低于GB5085.3-1996危险废物浸出毒性鉴别标准1.5ppm.同时,渣中的Cr(Ⅵ)也大部分被有效浸出后还原为Cr(Ⅲ) 沉淀.特别是在液固比10:1,温度28℃,初始pH＝10.0的条件下,铬渣中六价铬浸出率达到了95.43%,同时浸出液pH值＝8.20,Cr(Ⅵ)浓度为0ppm,浸出渣浸出毒性0.007 ppm,均达到国家排放标准,取得了较好的解毒效果.     

氯化钙对聚合氯化铝混凝去除腐植酸的影响作用研究

研究了ＣａＣｌ２对ＰＡＣ混凝去除腐植酸的影响作用，发现ＣａＣｌ２可以改善混凝效果和沉淀性能。探讨了ｐＨ值、投加量、温度等因素的影响，对药剂费用进行了经济分析，为今后的实际应用提供了基本数据。     

饮用水致突变前体物水生腐殖酸研究进展

腐殖质是水体中常见的有机物，也是饮用水主要致突变前体物质之一。本文拟对水生腐殖酸的来源、分析方法、环境效应与健康效应以及去除方法作一简要介绍。