Ecotoxicological and chemical evaluation of phenolic compounds in industrial effluents

The aim of this paper was to evaluate the ecotoxicological response of industrial effluents containing phenolic compounds. All complex effluents collected from a chemical plant and then after both a chemical–physical and biological treatment were characterised with chemical analysis, biodegradability tests and four ecotoxicological tests (Daphnia magna, Artemia salina, Brachionus plicatilis and Vibrio fisheri with Microtox^®). The evaluation of the chemical and ecotoxicological data was useful for predicting the effect of the raw effluent on the treatment plant and the impact of the final treated effluent on the receiving water. Besides the toxicity of the effluent from the chemical plants, the acute toxicity of its main components was also determined. The results of the tests and toxicity data from literature were transformed in Toxic Units (TUs). Effluent toxicity was under- or over-estimated by calculating the sum of the TUs of the individual components, depending on which toxicity data and test organisms were used.     

气-水联合反冲洗膜污染防治技术研究

采用气水联合反冲洗技术,考察了气水比(Qg/Ql)、反冲洗周期及其对膜污染的防治效果。结果表明,气水联合反冲洗较单独气或水反冲洗效果好;在过滤周期20min,反冲洗时间1min,气水比1.5时,气水联合反冲洗能够恢复膜通量到膜清水通量的80%以上。此法可大幅度清除沉积在膜表面的泥饼层,恢复膜通量,维持膜过滤性能的稳定,是一种较为有效的膜污染防治技术。     

悬浮填料对厌氧氨氧化MBR运行的影响特性及机理

向厌氧氨氧化（anammox）膜生物反应器（MBR）投加悬浮填料,考察其对反应器脱氮性能和膜污染的影响特性,并探究了相关机理.试验结果表明,投加填料后,反应器脱氮性能良好.当进水氨氮（NH₄⁺-N）160mg/L、亚硝态氮（NO₂^--N）180mg/L时,出水NH₄⁺-N和NO₂^--N均在15mg/L以下,硝态氮（NO₃^--N）在30mg/L以下,总氮去除率可达90%.投加填料显著减轻了膜污染,跨膜压差（TMP）稳定在8kPa左右.混合液中溶解性微生物产物（SMP）和胞外聚合物（EPS）成分分析结果表明,在第67~149d,蛋白质总量、多糖总量和总有机碳总量分别下降了49%、43%和61%,它们浓度的下降有利于延缓膜污染;此外,悬浮填料对膜组件的机械碰撞也起到了物理清洗作用.高通量测序结果显示,悬浮填料生物膜在anammox菌相对丰度方面显著高于混合液污泥,说明anammox菌更适宜于附着生长,投加填料可以为其提供更加稳定的生长环境.     

曝气强度对膜生物反应器污泥混合液可滤性的影响

主要研究了曝气强度对膜生物反应器(MBR)膜污染的影响.2套MBR采用恒流出水模式连续运行60 d,曝气强度分别为500及100 L/h,应用死端过滤装置来检测不同阶段污泥混合液的可滤性.实验中对不同曝气强度下的溶解性微生物代谢产物(SMP)分子质量分布、颗粒粒径分布、胞外聚合物(EPS)含量进行了测定.结果表明,过高的曝气强度将恶化污泥混合液的可滤性,增加了膜污染速率.进一步研究表明,曝气强度的增加导致了污泥混合液上清液中相对分子质量>10000的SMP浓度的增加,此部分大分子有机物浓度直接影响了污泥混合液的可滤性.过高的曝气强度也导致了污泥絮体中1～10μm细小颗粒和EPS含量的增加.     

两种膜生物反应器处理印染废水的对比试验研究

针对印染废水成分复杂、色度大、浓度高且生物难降解物质多等特点,采用了混凝沉淀法对印染废水进行预处理,而后分别采用新型海藻式膜生物反应器(MBR)和传统帘式膜生物反应器对印染废水进行活性污泥法处理试验研究。通过对化学需氧量(COD)、生化需氧量(BOD)、氨氮(NH3-N)、总氮(TN)、总磷(TP)、色度、浊度等水质指标连续进行测定、分析与处理,考察两种膜生物反应器对印染废水的降解效果,并观察系统运行情况和膜组件污染状况。试验结果表明:海藻式MBR对印染废水的处理效果良好,出水浊度低于0.3NTU,对COD、BOD、色度、氨氮、总氮的去除率分别可达90%、94%、91.4%、87.8%、86.4%。海藻式MBR在各项指标上均明显优于传统帘式MBR,且能够降低MBR膜丝根部的污染,清洗更方便、更有效。     

温度对膜生物反应器运行特性及膜污染的影响

温度对膜生物反应器（MBR）污染物去除效果和膜污染速率都有很大的影响。采用两套相同的MBR蓑置在冬季运行,其中一套维持20℃的恒温,另一套水温与周围环境相同。对两套装置处理效果及膜污染速率进行对比,并通过反应器中溶解性微生物产物（SMF）、胞外聚合物（EPS）含量、污泥粒径分布扣膜面污染物的比较,分析温度对MBR运行的影响。研究结果表明膜对污染物的截留能有效补偿低温时微生物作用的不足,因此低温对出水水质并没有显著的影响。此外,低温时虽然SMP和EPS的释放增加,但并没有引起膜污来的加剧。相反地,低温时污泥粒径较高温时小,而粒径较大的颗粒更易沉积于膜表面,因此低温时膜面固体物质含量较低,膜污染速率反而比高温时低。     

膜生物反应器出水深度处理及回用技术

针对膜生物反应器对难生化降解物质去除率不高,出水中仍残留部分污染物,对水安全和回用造成一定影响这一不足,综述了膜生物反应器出水深度处理及回用技术,并指出了今后的发展方向.     

膜生物反应器亚硝化性能的影响因素研究

利用膜生物反应器成功启动了亚硝化工艺处理人工合成废水.为了确定影响亚硝化工艺效果的因素,先后对温度和溶解氧浓度进行了研究,结果表明,在温度35℃并且NH4+-N负荷平均0.45 kg.(m3.d)-1和溶解氧0.5 mg/L的条件下,可使出水中NO3--N的浓度低于20 mg.L-1,而ρ(NO2--N)∶ρ(NH4+-N)接近1.0.同时发现反应器运行期间,在低溶解氧的情况下,膜组件的污染并不严重.荧光原位杂交分析发现,在膜生物反应器中氨氧化菌成为优势菌种,亚硝酸盐氧化菌的活性受到了抑制.微生物群落分析则进一步提供了实现亚硝化工艺所必需的生物信息.     

TMBR+NF/RO组合工艺处理垃圾渗滤液的工程应用

采用TMBR+NF/RO组合工艺对湖北省宜昌市某垃圾卫生填埋场渗滤液进行处理,介绍了组合工艺的流程、特点、设备规格、技术参数。TMBR系统对可生化降解COD处理后,COD平均质量浓度为822 mg/L,平均去除率为95.8%,对NH_3-N平均去除率为94.9%;经过NF/RO出水的COD平均值为45 mg/L,NH_3-N均小于25mg/L,达到《生活垃圾填埋场污染控制标准》(GB 16889—2008)的排放标准。组合工艺处理成本为29.5元/m3。     

A review of textile industry: Wet processing,environmental impacts,and effluent treatment methods

The word “textile” means to weave and was taken from the Latin word “texere.” Nowadays, textiles not only fulfill humankind's basic necessity for clothing, they also allow individuals to make fashion statements. As one of the oldest industries, the textile industry occupies a unique place in India. It is responsible for 14% of the total industrial manufacture in India. However, the textile industry is also considered to be one of the biggest threats to the environment. Pretreatment, dyeing, printing, and finishing operations are among the various stages of the industrial textile manufacturing process. These fabrication operations not only utilize huge quantities of power and water, they also generate considerable amounts of waste. The textile industry utilizes a number of dyes, chemicals, and other materials to impart the required qualities to the fabrics. These operations produce a significant amount of effluents. The quality of effluents is such that they cannot be put to other uses, and they can create environmental problems if they are disposed of without appropriate treatment. This review discusses different textile processing stages, pollution problems associated with these stages, and their eco‐friendly alternatives. Textile wet processing is described in detail, as it is the key process in the industry and it also generates the greatest amount of pollutants in textile processing. The environmental impact of textile effluents is discussed, as textile effluents not only impose negative effects on the quality of water and soil, they also imperil plant and animal health. In this paper, various methods for treating textile effluents are described. Discussion of physical, chemical, biological, and advanced treatment technologies of effluent treatment are included in this paper.