Degradation of phenol in an upflow anaerobic sludge blanket(UASB) reactor at ambient temperatureKE

A synthetic wastewater containing phenol as sole substrate was treated in a 2.8 L upflow anaerobic sludge blanket(UASB) reactor at ambient temperature. The operation conditions and phenol removal efficiency were discussed, microbial population in the UASB sludge was identified based on DNA cloning, and pathway of anaerobic phenol degradation was proposed. Phenol in wastewater was degraded in an UASB reactor at loading rate up to 18 gCOD/(L·d), With a 1:1 recycle ratio, at 26(1℃, pH 7.0-7.5. An UASB reactor was able to remove 99% of phenol up to 1226 mg/L in wastewater with 24 h of hydraulic retention time(HRT). For HRT below 24 h, phenol degradation efficiency decreased with HRT, from 95.4% at 16 h to 93.8% at 12 h. It further deteriorated to 88.5% when HRT reached 8 h. When the concentration of influent phenol of the reactor was 1260 mg/L(corresponding COD 3000 mg/L), with the HRT decreasing(from 40 h to 4 h, corresponding COD loading increasing), the biomass yields tended to increase from 0.265 to 3.08 g/(L·d). While at 12 h of HRT, the biomass yield was lower. When HRT was 12 h, the methane yield was 0.308 L/(gCOD removed), which was the highest. Throughout the study, phenol was the sole organic substrate. The effluent contained only residual phenol without any detectable intermediates, such as benzoate, 4-hydrobenzoate or volatile fatty acids(VFAs). Based on DNA cloning analysis, the sludge was composed of five groups of microorganisms. Desulfotomaculum and Clostridium were likely responsible for the conversion of phenol to benzoate, which was further degraded by Syntrophus to acetate and H2/CO2. Methanogens lastly converted acetate and H2/CO2 to methane. The role of epsilon-Proteobacteria was, however, unsure.     

Use of rural energy resources and eco-environmental degradation in Tibet

IntroductionReportedasthethirdpoleoftheearth(Zheng ,1996) ,theTibetregionisthemainbodyoftheQinghai TibetPlateau.Itcrosses 9°50′oflatitudefromsouthtonorthand2 0°30′oflongitudefromeasttowest,withavastareaof1 2millionkm2 andahighaverageelevationofover40 …     

Catalytic degradation of methylene blue by Fenton like system: model to the environmental reaction

To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe( Ⅲ ) and H2O2 in the absence of light instead of Fe( Ⅱ ) and H2O2 was studied. Results showed that use of Fe ( Ⅲ ) is more promising than Fe( Ⅱ ). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount of salicylic acid is added which is a one of the priority pollutant.     

水中内分泌干扰物-壬基酚的去除研究进展

壬基酚是一种内分泌干扰物,主要来源于NPEO,能通过生物富集作用进入生物体内并造成危害。当前检测水样中壬基酚的主要方法是采用GC—MS,预处理采用固相萃取。研究表明自来水厂的常规处理工艺对于壬基酚的去除有限;而活性炭、有机蒙脱土吸附等物理方法,超声声化、电化学氧化、光分解等化学方法可有效降解水中的壬基酚。     

烟酰胺降解菌的筛选及其降解特性

采用HPLC对某烟酰胺生产废水的主要成分进行分析,并模拟废水中的主要成分烟酰胺(nicotinamide)的浓度,对以烟酰胺为唯一碳源配制的培养基进行降解实验,获得有较佳降解率和生长能力的菌株YSI-1和YSI-2.结果表明,YSI菌株的混合菌降解效果优于单株菌,混合菌在初始OD600值为0.4,pH为7.0时,对浓度为2000 mg/L的烟酰胺降解2 d的降解率可达32.8%.延长处理时间或提高菌种的初始OD600值,烟酰胺的去除率均有较大的增加.     

臭氧光催化降解地下水中天然有机物的研究

在现场开展了中试规模的臭氧光催化降解天然有机物的研究.研究表明,对大分子天然有机物占很大比例且重碳酸盐含量较高的地下水,臭氧投加量10 mg/L和反应时间10 min条件下,TOC的去除率不到20%,但UV254和三卤甲烷生成潜力(THMFP)去除率分别达到近60%和33.5%.臭氧光催化与活性炭吸附相连,能显著提高UV254的THMFP的去除率,但TOC去除率并不明显高于单独活性炭吸附.臭氧光催化使大分子有机物转化为小分子有机物,后者在活性炭上的吸附性提高且生化性改善,可望在生物活性炭上更有效地去除.     

等离子体与光催化复合技术净化污水处理泵站臭气

用一种等离子体-光催化复合技术净化污水处理泵站臭气,研究表明该复合技术具有较显著的协同促进效应,通过改变等离子体发生单元与光催化单元的距离以及在两者之间放置去静电网,可消除等离子体单元产生的负电荷对光催化单元的不利影响,进一步提高其复合效应.同时还对这一复合技术产生协同效应的机理进行了分析,并在污水处理泵站实地考查了这种复合技术对臭气的净化效果.该技术对臭气中NH3的降解率可达46.1%,对H2S的降解率可达67.3%.     

超声波技术降解水中氯代有机物的研究进展

介绍了超声波技术的基本原理,概述了超声波和各种超声联用（超声波与紫外光、过氧化氢、臭氧、Fenton试剂等联用）技术降解氯代有机物的效果和影响因素,总结了氯代有机物降解机理与动力学的研究进展,并在此基础上提出了今后超声波及其联用技术降解水中氯代有机物的研究方向。     

负载型纳米TiO2光催化剂的制备及其光催化活性

采用悬浮聚合法制备粉煤灰-聚苯乙烯微珠载体,通过矿化接枝技术将水热法制备的纳米TiO2负载在粉煤灰-聚苯乙烯微珠载体上,制成负载型纳米TiO2光催化剂。用x射线衍射仪、扫描电子显微镜对负载型纳米TiO2光催化剂进行了表征;通过光催化降解甲醛实验评价了负载型纳米TiO2光催化剂的活性。实验结果表明,纳米TiO2在载体上分散良好,平均粒径为36．4nm;该催化剂活性较高,明显优于粉体纳米TiO2光催化剂,重复使用10次左右,该催化剂的活性无明显下降。     

PTA高效降解菌制备与PTA废水生物处理研究

筛选出了4株对苯二甲酸(TA)的高效降解菌,利用诱变技术,使菌种的DNA结构发生突变,提高了菌种降解性能,并对优化后的菌种进行固定化包埋,形成高效菌对苯二甲酸(PTA)废水生物处理技术,处理负荷达到5kgCOD/m3·d以上。