活性炭负载TiO2催化臭氧氧化去除水中酚的研究

本文采用活性炭负载TiO2作催化剂对臭氧氧化去除含酚废水进行了研究．研究了不同的酚初始浓度、pH值及臭氧浓度对苯酚去除率的影响，获得了反应动力学常数．实验结果表明：苯酚初始浓度越小，去除率越高．在本实验条件下，向150mL苯酚溶液中通入浓度为3．48mg/L、流量为0．05m^3／h的臭氧化空气反应30min去除率即可达到99％以上。     

磷酸二氢钠去除铀的效果与机理

通过静态实验,研究了不同反应时间、p H值、初始铀浓度、磷酸二氢钠用量、温度等因素对磷酸二氢钠去除溶液中铀的效果的影响,并结合红外光谱、扫描电镜和热重分析等测试结果,探讨了磷酸二氢钠去除铀的机理.结果表明,一定质量的磷酸二氢钠对铀的去除量随着铀初始浓度的增大而增大,随着温度的升高而减小;在p H值为5,磷酸二氢钠用量为2.0 mg时,磷酸二氢钠去除铀的效果最好,铀的去除率高达99%以上;反应在120 min基本达到平衡.红外光谱分析说明磷酸二氢钠主要是通过磷酸二氢根与UO2+2发生络合反应去除溶液中的铀,扫描电镜分析显示反应生产了矿物晶体,热重分析可知该矿物晶体具有很好的热稳定性.     

苯酚的超临界水氧化试验

以自建的一套连续式超临界水氧化装置的温度，压力，溶氧量和流量等参数的可控性进行了实验，并在此基础上进行了苯酚的超临界水氧化研究。结果表明：所建立的装置能比较精确控制各种条件参数，是可靠的超临界水氧化试验研究装置。在氧气过量的条件下，停留时间是影响苯酚在超临界水中氧化分解的主要因素，反应的温度和压力升高导致苯致苯酚去除率的增大，只要有足够的氧气，苯酚起始浓度的增加对苯酚的转化率影响不明显，在实验条件下，溶液中苯酚的去除动力学对苯酚是一级，氧气是零级。     

六方水钠锰矿对罗丹明B的去除效果及机理

六方水钠锰矿作为环境中一种具有较强氧化与吸附能力的氧化锰矿物,对环境中的有机染料有着一定的去除作用。采用常压回流法一步合成纳米六方水钠锰矿,运用X射线衍射(XRD)、电感耦合等离子体光谱仪(ICP-AES)、BET氮气吸附法、场发射扫描电镜(FESEM)和透射电镜(TEM)对其矿物晶体结构、化学组成、比表面积、孔径分布和微观形貌进行表征,选用罗丹明(RB)作为目标有机染料,研究反应条件对纳米六方水钠锰矿对RB的去除效果的影响(包括pH值、六方水钠锰矿浓度、染料浓度和温度)。进而研究六方水钠锰矿对RB的去除机制,通过在反应后的溶液中加入盐酸羟胺,使矿物溶解,吸附在矿物上的染料重新释放到溶液中,以区分吸附去除率和氧化去除率。结果表明,降低反应pH、增加六方水钠锰矿浓度、减小染料浓度以及提高温度均有利于六方水钠锰矿对罗丹明B(RB)的去除。其中影响最大的pH,反应体系pH为2.87时,RB的去除率达到99.9%,而pH为10.29时,RB的去除率仅为8.33%。通过去除机制实验结果表明,在pH为4.5时,RB的氧化去除率是36.3%,吸附去除率为4.6%,六方水钠锰矿去除RB以氧化去除为主。纳米六方水钠锰矿材料的重复利用效果很好,重复使用3次去除率,RB的去除率仅从90.6%降至85.9%。合成的纳米六方水钠锰矿有着很好的去除有机染料的效果,并且有一定的重复利用性,机制的研究也有利于提升对有机染料的去除效果。     

Fe0.5Zn0.5Al2O4 尖晶石催化剂催化湿式氧化降解苯酚的稳定性

研究了Fe0.5Zn0.5Al2O4尖晶石型复合氧化物催化剂在催化湿式氧化处理苯酚废水中的性能.结果表明,在150℃下苯酚就能完全被去除,COD去除率达到94%.催化剂中铁的溶出量随着反应时间的增加经历了一个先增加后减小的过程;而且最终出水铁离子浓度随催化剂用量、氧分压、苯酚溶液pH值的增加而减少,随苯酚浓度的增加而增加.     

菲在硅酸盐矿物上的吸附与光化学降解行为

选用高岭石和蒙脱石为对象研究次生硅酸盐矿物对菲光降解过程产生的影响,并以石英砂作为对照.由于3种矿物的表面积、结构组成、表面电荷、阳离子交换能力不同,导致吸附性能不同,对菲的吸附能力呈现出蒙脱石高岭石石英砂.以发射波长为254 nm的紫外灯为光源,在3种矿物中进行菲光化学降解实验,探讨不同矿物中菲光化学降解行为的区别.紫外光辐射对3种矿物中菲的去除都符合一级反应动力学,24 h后菲的去除效果为:石英砂高岭石蒙脱石,与矿物吸附能力的大小有密切关系.与避光对照组相比,去除率整体上呈现出光照避光,表明紫外光辐射可以显著促进自然环境中菲的转化和降解.通过GC-MS检测到菲光降解的主要产物为邻苯二甲酸二(2-乙基己基)酯、烷烃、苯酚等,表明菲经过紫外光辐射会逐渐变成低毒或无毒物质,最终被矿化.     

壳聚糖改性沸石吸附废水中的苯酚

开发新型低成本苯酚吸附剂是含酚废水处理技术的重点.采用90%脱乙酰度壳聚糖制备改性沸石,在与天然沸石对比的基础上,研究了改性沸石去除废水中的效果.并对影响去除率的主要因素,包括壳聚糖与斜发沸石质量比、废水pH值,吸附时间,改性沸石用量,苯酚的质量浓度等进行研究.通过正交试验确定吸附废水中苯酚最佳工艺条件是:壳聚糖与沸石质量比为1∶20.沸石-壳聚糖颗粒吸附剂用量为12 g·L-1,废水中苯酚质量浓度不大于40mg·L-1,pH值为4～6,吸附平衡时间为35 min,苯酚去除率为90%;吸附适合用Langmuir吸附等温方程来模拟.     

漆酶对水中氯酚类物质的去除

利用漆酶对2,5-二氯苯酚(2,5-DCP)、2,6-二氯苯酚(2,6-DCP)、2,4,5-三氯苯酚(2,4,5-TCP)、2,4,6-三氯苯酚(2,4,6-TCP)等4种物质进行去除研究,考察了温度、时间、pH及漆酶添加量对去除效果的影响,并基于最佳条件下的去除效果,探讨了底物结构对漆酶转化氯酚类物质的影响.结果表明,温度升高,去除率呈先升高后降低再升高的现象;pH增大,去除率有增加的趋势;漆酶添加量在一定范围内与去除率呈正相关,当添加量高于20%后,去除率降低;在较短时间(0.5 h)内,漆酶对4种氯酚类物质的去除均能达到较好的效果.最佳条件下,漆酶对2,5-DCP、2,6-DCP、2,4,5-TCP和2,4,6-TCP的去除率分别为86.2%、45.3%、98.7%、84.8%;氯原子取代位置与取代数目相比对去除效果具有更重要的影响.     

β-环糊精对对硝基苯酚微生物降解的影响

通过对对硝基苯酚微生物降解过程的研究，探讨了在降解过程中加入环糊精对对硝基苯酚降解的影响。研究表明，对硝基苯酚不能单独被降解；葡萄糖能与对硝基苯酚产生共代谢作用；环糊精不能单独与对硝基苯酚产生共代谢作用。在葡萄糖存在的情况下，加入环糊精能影响对硝基苯酚的降解率，且影响的程度与对硝基苯酚的浓度和环糊精的浓度有关，在对硝基苯酚浓度较低时，加入环糊精会延缓对硝基苯酚的降解；当对硝基苯酚浓度较高时，加入环糊精会促进对硝基苯酚的降解。     

有机膨润土吸附垃圾渗滤液中苯酚的研究

以溴化十六烷基三甲铵为改性剂制备有机膨润土，研究了有机膨润土吸附垃圾渗滤液中典型有机污染物苯酚的性能、条件及改性条件对吸附效果的影响。结果表明，有机膨润土对苯酚有很好的吸附效果，实验条件下对苯酚的去除率可达90％以上，pH值是影响有机膨润土吸附能力的主要因素，绘制了不同初始浓度的苯酚溶液在平衡浓度达国家工业废水的第二类污染物三级排放标准时，改性膨润土的用量曲线及吸附等温线，并得到投样量方程：y＝0．1959x－0．2458，R^2＝0．9751。     

冰相中双氧水体系罗丹明B的光解机理

研究了模拟太阳光作用下冰相中双氧水体系罗丹明B(RhB)光转化规律,考察了光照时间、温度、RhB初始浓度、pH值和双氧水剂量对RhB光解的影响.对照冰相与水相中RhB在双氧水体系中的光解效果,发现冰相中RhB的去除率远远低于水相,说明冰相中晶格的笼子效应限制了RhB与H2O2之间的反应.同时,研究了外加3种无机阴离子(还原性Cl-、氧化性SO42-和S2O82-)对冰相中RhB降解的影响,结果表明,3种离子都能促进冰相中双氧水体系RhB的光解,其中S2O82-能显著提高RhB的去除率.S2O82-和Cl-加入剂量越高,RhB去除率越高,而SO42-加入剂量增加会阻碍RhB的光解.依据研究结果,推测了冰相中RhB在双氧水体系中的光解历程与机理,为深入了解冰相中污染物自由基降解规律提供依据.     

天然锰矿-次氯酸钠光催化氧化处理分散蓝2BLN废水

采用天然锰矿和次氯酸钠在紫外光的照射下处理分散蓝2BLN废水，探讨了影响水溶液中分散蓝2BLN染料的光催化降解的各种影响因素。当通入氧气时，天然锰矿用量为20g／L、次氯酸钠的用量为20mL／L、光强2000W、光距10cm、反应时间为60min、pH值在7．5-9．5，废水的COD去除率达52％，脱色率达93％。     

Biodegradation of phenol by native microorganisms isolated from coke processing wastewater

The present investigation was undertaken to assess the biodegradation of phenol by native bacteria strains isolated from coke oven processing wastewater. The strains were designated ESDSPB1, ESDSPB2 and ESDSPB3 and examined for colony morphology Gram stain characters and biochemical tests. Phenol degrading performance of all the strains was evaluated initially. One of the strains namely ESDSPB2 was found to be highly effective for the removal of phenol, which was used as sole carbon and energy source. From an initial concentration of 200 mg I(-1) it degraded to 79.84 +/- 1.23 mg l(-1). In turn the effect of temperature (20 to 45 degrees C), pH (5-10) and glucose concentration (0, 0.25 and 0.5%) on the rate of phenol degradation by that particular strain was investigated. Observations revealed that the rate of phenol biodegradation was significantly affected by pH, temperature of incubation and glucose concentration. The optimal conditions for phenol removal were found to be pH of 7 (84.63% removal), temperature, 30 degrees C (76.69% removal) and 0.25% supplemented glucose level (97.88% removal). The main significance of the study is the utilization of native bacterial strains from the waste water itself having potential of bioremediation.     

乙烯菌核利在水溶液中的光解动力学

以高压汞灯和太阳光为光源,研究乙烯菌核利在重蒸水、自来水、湖水及pH缓冲液中的光解动力学。高压汞灯下,乙烯菌核利在重蒸水中的光解半衰期约为28 m in,而在太阳光下为3.86 h。自来水和湖水中溶解性物质对乙烯菌核利在高压汞灯下的光解动力学仅有微弱的淬灭效应,但在太阳光下表现出显著的敏化效应,照光3 h的敏化效率分别为138%和126%。2种光源下,pH 5.0和pH 7.0缓冲液对乙烯菌核利的光解均表现为光淬灭效应,高压汞灯照光60 m in的淬灭效率分别为69%和57%,太阳光照光7 h的淬灭效率分别为77%和33%;pH 9.0缓冲液则表现出显著的敏化效应,高压汞灯照光20 m in的敏化效率为58%,而太阳光照光1 h的敏化效率则达到了415%。     

乙烯菌核利在水溶液中的光解动力学

以高压汞灯和太阳光为光源，研究乙烯菌核利在重蒸水、自来水、湖水及pH缓冲液中的光解动力学。高压汞灯下，乙烯菌核利在重蒸水中的光解半衰期约为28min，而在太阳光下为3．86h。自来水和湖水中溶解性物质对乙烯菌核利在高压汞灯下的光解动力学仅有微弱的淬灭效应，但在太阳光下表现出显著的敏化效应，照光3h的敏化效率分别为138％和126％。2种光源下，pH5．0和pH7．0缓冲液对乙烯菌核利的光解均表现为光淬灭效应，高压汞灯照光60min的淬灭效率分别为69％和57％，太阳光照光7h的淬灭效率分别为77％和33％；pH9．0缓冲液则表现出显著的敏化效应，高压汞灯照光20min的敏化效率为58％，而太阳光照光1h的敏化效率则达到了415％。     

Contaminants in drinking water and its mitigation using suitable adsorbents: an overview

Various options are applicable for the removal of water pollutants included reverse osmosis, ion exchange, coagulation, co-precipitation, catalytic reduction, herbal filtration, electrodialysis and adsorption. This paper deals with the sorption phenomena for the removal of pollutants from drinking water. Attempts have been made to use low cost sorbents developed by pretreatment/activation/impregnation with alkalis, acids, iron oxide, manganese dioxide, ferric chloride, alum, lime, aluminum salts with natural products/indigenous minerals viz. activated alumina, activated carbon, groundnut husk, saw dust, chemically coated sand, fly ash, zeolites, clay minerals and other plant products. Application of Freundich and Langmuir isotherms were used to assess the adsorption capacity. Equilibrium isotherms were determined at optimum temperature and pH to characterize the sorption process. Statistical parameters such as mass transfer coefficients, multiple regression analysis were applied to establish the mechanism. It is suggested that the characterization of suitable, and exhausted sorbent through the application of fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF) is essential to establish its surface bonding. Scope for safety evaluation and risk assessment to human and biosphere may provide the guideline and predication to the regulatory agencies for its sustainable use and safe disposal The ecotoxicological assessment of the leachates and low cost removal technology are discussed in this paper.     

Occurance and control of manganese in a large scale water treatment plant

The continuous variations of dissolved oxygen (DO), manganese (Mn), pH, and their effect on manganese removal by different water treatment processes are investigated. The results show that the declined DO concentration and pH value in the bottom of reservoir results in the increasing release of Mn from sediment to source water. Manganese concentration increased from 0.1 to 0.4 mg·L^-1 under the condition that DO concentration decreased from 12.0 to 2.0 mg·L^-1 in raw water. The different water treatment processes exhibited different efficiency on manganese removal. The processes with recycling of the suspended sludge, low elevation velocity in settling tank and slow filter rate, will benefit the manganese removal. During a high release of manganese in raw water, traditional coagulation-sedimentation and filtration could not completely remove Mn, although granular activated carbon filtration (GAC) had been applied. At that case, preoxidation with chlorine or potassium permanganate (KMnO₄) was necessary to address the high manganese concentration.     

Microbial metabolism of chlorobiphenyls

Photochemical reactions induced by sunlight contribute to the overall chemistry of natural water systems in many ways. The degradation of pollutants, dissolution of iron and manganese sediments, cycling of trace metal nutrients, and reactions of aquatic nitrogen and oxygen species are some of the many processes having solar photolysis pathways. This paper reviews recent research concerned with photo‐decomposition of pollutants, photolysis of nitrite and nitrate, photosensitization by humic materials and the generation of reactive intermediates. In addition, background material is presented concerning the basic principles of photochemistry and the limited wavelength range of effective solar radiation.     

石英砂负载氧化铁吸附除锑的研究

考察了石英砂负载氧化铁(IOCS)在不同的实验条件下(无机阴离子种类及其离子强度、 pH值、IOCS投加量、温度等)对水溶液中锑的去除效果.结果表明:三种无机阴离子(NO-3,Cl-,SO2-4)对IOCS吸附锑的去除率、吸附容量以及反应速率几乎没有影响;在pH3-9范围内,锑的去除率达到90%.二级反应动力学模型及Langmuir等温吸附模型可分别较好地描述锑的吸附动力学及吸附等温线实验结果.随着温度的增加,反应速率以及吸附容量也随之增加.