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1.
微氧颗粒污泥工艺能够同时进行好氧氧化和厌氧还原过程,是处理五氯酚（pentachloro-phenol,PCP）的理想方法。对微氧颗粒污泥降解PCP限制性生态因子pH的作用规律进行了研究。实验结果表明,在pH值在6.7-7.5范围,PCP和CODCr有较高的去除率,产气量较高,出水氯酚浓度达到较低的水平。而pH值低于6.7或高于7.5,PCP和CODCr去除率降低,且产生低氯代酚的积累。 相似文献
2.
闫晔 《化工职业技术教育》2009,(Z1)
以纳米TiO_2为催化剂的光催化氧化技术是一种新型的废水处理技术,具有高效、价廉、无二次污染、成本低等优点,受到广泛关注。本文利用纳米TiO_2催化剂对模拟苯酚废水进行光催化处理,研究了光源种类、pH值、苯酚初始浓度、催化剂的用量、添加H_2O_2对降解过程的影响。通过实验确定:改变催化剂的投加量,调节适当的pH值,减小溶液的初始浓度,适当加入H_2O_2氧化剂等方法,可以提高含酚废水的处理效率。当苯酚溶液初始溶度为100mg/L,催化剂的用量为1.5g/L,溶液pH=4,氧化剂H_2O_2用量为2.5ml/L时,紫外光照反应4hr,苯酚降解率可达56%。苯酚浓度不高时,光催化降解反应符合一级动力学方程。 相似文献
3.
在强碱性环境中高锰酸钾和苯酚反应后的溶液在800～900mm范围内的吸收与苯酚初始浓度正相关,该范围内的吸收几乎全部来自于反应后生成的MnO4^2-反应后溶液在845nm处的吸收与苯酚初始浓度之间具有良好的线性关系：Abs=0．03292C＋0．07034（R=0．9954）。该法能直接用于测定苯酚光催化降解过程中的浓度变化。 相似文献
4.
研究UV254光照下,Fe(Ⅲ)-EDTA/H2O2对苯酚的催化光降解效能。首先考察反应时间、溶液初始pH值、Fe(Ⅲ)与EDTA的浓度比值对UV/Fe(Ⅲ)-EDTA催化光降解苯酚的影响,进而考察UV/Fe(Ⅲ)-EDTA/H2O2体系对苯酚的降解效能。结果表明:当溶液pH为7,Fe(Ⅲ)/EDTA浓度比值为1:1时,经过1h反应,UV/Fe(Ⅲ)-EDTA体系对苯酚的催化光降解效率达61.13%。在溶液初始pH为37时,UV/Fe(Ⅲ)-EDTA对苯酚的降解率均可达60%以上。在中性条件下,UV/Fe(Ⅲ)-EDTA体系添加H2O2后可把苯酚的降解率从61.13%提高到91.30%。反应前后溶液的紫外扫描光谱表明光降解过程中苯酚的苯环共轭结构被破坏。最后对UV/Fe(Ⅲ)-EDTA/H2O2体系催化光降解机理进行了初步探讨。 相似文献
5.
采用二氧化钛光催化结合掺硼金刚石电催化来提高污染物氧化效率.以苯酚作为模型废水污染物,分别比较了采用BDD电催化和TiO2光催化以及两者结合方法的降解过程,研究了电流密度和初始浓度等条件对降解效果的影响,并进行了反应动力学讨论.实验结果表明：与单独处理相比, BDD和TiO2组合处理方法拥有较优的苯酚去除效果,尤其是先电解后光催化的方式,其最优工作电流密度为25.48mA/cm2,并且随着苯酚初始浓度增加,去除率随之下降.动力学研究表明反应符合准一级动力学方程. 相似文献
6.
利用硅藻土基负载Fe^3+/Mn^2+双金属催化剂对对氯苯酚溶液进行氧化降解,以TOC值考察其降解效果,研究了不同初始pH值、催化剂用量和H 2O 2投加量条件下,对对氯苯酚降解效果的影响。 相似文献
7.
文章研究了高铁酸钾协同365 nm紫外光降解对氯苯酚,考察了高铁酸盐投加量、pH值和初始浓度对对氯苯酚去除率的影响并对比了单独高铁酸钾和复合体下的矿化率.实验结果表明:在高铁酸钾与对氯苯酚的摩尔比为4:1,对氯苯酚初始浓度为8 mg/L,pH为4时去除率为49%,比单独高铁酸盐处理降解率提高了11%.矿化率提高了6%.动力学结果表明降解过程为准一级动力学过程. 相似文献
8.
溶剂萃取法处理苯酚废水 总被引：1，自引：0，他引：1
以生物柴油为萃取剂,苯酚有机废水为对象,研究了废水初始浓度、pH值、温度以及油水相比等因素对苯酚废水萃取效果的影响。正交实验结果表明,影响生物柴油萃取苯酚的因素显著性依次为相比、温度、初始浓度和pH值,较适宜的萃取条件是:相比2∶1、温度20.0℃、初始浓度1250.0mg/L、pH5.5,一级萃取率为94.1%。在正交实验所得的适宜萃取条件下,进行了单因素实验。结果表明,萃取率随着相比的增大而增加,分配系数随之降低;初始浓度的影响在浓度小于6.98g/L时显著,萃取率和分配系数均随之增加;萃取10min就可以达到平衡。在相比2∶1、温度20.0℃、pH5.5的条件下处理浓度为6.98g/L的苯酚水溶液,五级错流萃取后苯酚浓度降为1.8mg/L,萃取率99.97%,改善了苯酚水溶液的可生化性,可实现苯酚的循环利用。 相似文献
9.
《绵阳师范学院学报》2017,(11):70-75
以从绝缘材料厂的活性污泥中筛选到的1株苯酚降解菌作为试验对象,以聚乙烯醇(PVA)为包埋剂,氯化钙(CaCl_2)为固定剂制成固定化小球,通过研究不同包埋条件对固定化小球性能的影响来确定最佳包埋条件.结果表明,该菌株包埋的最适条件:聚乙烯醇的质量浓度12%、Ca Cl2的质量浓度5%、菌胶比0.8/30、交联时间12 h,苯酚降解率达到82.5%,且包埋后的小球机械强度和传质性能都比较好.这将为进一步采用固定化包埋技术处理含酚废水的深入研究提供了实验依据. 相似文献
10.
以苯酚作为唯一碳源和能源的无机盐培养液对从绝缘材料厂排放的活性污泥进行驯化,从中分离筛选到1株苯酚降解菌,编号为JY04.采用正交实验设计方法优化了该菌株固定化条件,并且考察了该固定化细胞降解苯酚的最适条件.结果表明:在固定化条件为海藻酸钠(SA)浓度为5%,湿菌重/包埋剂为6/30,CaCl2浓度为3%时,固定化时间为8 h,降解率可达82.6%,并具有较好的机械强度.确定其对苯酚降解最适条件为pH 7.0,苯酚浓度为400 mg/L,温度32℃,接种量为25 g,培养时间42 h,其苯酚的降解率可达97.3%.该菌株固定化细胞的降解苯酚能力和耐受苯酚能力均大于游离细胞.固定化菌株对苯酚有较强的降解和耐受能力,是处理苯酚废水的良好菌种资源. 相似文献
11.
To understand the feasibility of its application to the in situ remediation of contaminated groundwater, the dechlori-nation of 2,4-dichlorophenol (2,4-DCP) by Ni/Fe nanoparticles in the presence of humic acid (HA) was investigated. We found that, as high performance liquid chromatography (HPLC) was used, the 2,4-DCP was first quickly reduced to o-chlorophenol (o-CP) andp-chlorophenol (p-CP), and then reduced to phenol as the final product. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles, as the HA concentration increased, the removal rate decreased evidently. It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP, and that the sequence of the tendency in dechlorination of intermediates was p-CP>o-CP. Transmission electron microscope (TEM) showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate. Also we con-cluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination. 相似文献
12.
Lei Li Nai-yun Gao Yang Deng Juan-juan Yao Ke-jia Zhang Hai-jun Li Di-di Yin Hua-se Ou Jian-wei Guo 《浙江大学学报(A卷英文版)》2009,10(11):1660-1669
The degradation of Microcystin-LR （MC-LR） in water by hydrogen peroxide assisted ultraviolet （UV/H2O2） process was investigated in this paper. The UV/H2O2 process appeared to be effective in removal of the MC-LR. MC-LR decomposition was primarily ascribed to production of strong and nonselective oxidant-hydroxyl radicals within the system. The intensity of UV radiation, initial concentration of MC-LR, MC-LR purity, dosages of H2O2, the initial solution pH, and anions present in water, to some extent, influenced the degradation rate of MC-LR. A modified pseudo-first-order kinetic model was developed to predict the removal efficiency under different experimental conditions. 相似文献
13.
To understand the feasibility of its application to the in situ remediation of contaminated groundwater, the dechlorination of 2,4-dichlorophenol （2,4-DCP） by Ni/Fe nanoparticles in the presence of humic acid （HA） was investigated. We found that, as high performance liquid chromatography （HPLC） was used, the 2,4-DCP was first quickly reduced to o-chlorophenol （o-CP） andp-chlorophenol （p-CP）, and then reduced to phenol as the final product. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles, as the HA concentration increased, the removal rate decreased evidently. It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP, and that the sequence of the tendency in dechlorination of intermediates was p-CP〉o-CP. Transmission electron microscope （TEM） showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate. Also we concluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination. 相似文献
14.
采用表面印迹技术制备了磁性分子印迹聚合物（Fe3O4@SiO2@MIPs）,使用扫描电镜（SEM）、透射电镜（TEM）和红外光谱（FT-IR）对产物的结构进行了表征。通过吸附性能实验研究证实了制备的Fe3O4@SiO2@MIPs对目标分子2,4-二氯酚（2,4-DCP）具有快速的吸附动力学特征和较高的吸附容量;与非印迹聚合物（Fe3O4@SiO2@NIPs）比较,Fe3O4@SiO2@MIPs对2,4-DCP表现出显著的亲和性;吸附选择性实验表明,Fe3O4@SiO2@MIPs对2,4-DCP具有较强的特异结合性能。此外,5次的重复使用后,制备材料的吸附效率仍可达80%以上,说明该材料具有可重复使用性。 相似文献
15.
INOUE Yasushi MIZOGUCHI Takuya SIMIZU Yohei YOSHIDA Naoko KATAYAMA Arata 《天津大学学报(英文版)》2012,18(6):441-449
In order to design and predict the dechlorination processes for remediating the halogenated aromatic compounds in the biobarrier system applied in situ,an anaerobic continuous-flow column was set up with the introduction of an enriched 2,4,6-trichlorophenol(TCP) reductive dechlorinating consortium.The fates of TCP and its metabolites were simulated according to the first-order sequential dechlorination kinetic model.The enriched TCP anaerobic dechlorinating consortium dechlorinated 100 μmol/L TCP to 4-chlorophenol(4-CP) via 2,4-dichlorophenol(DCP) in 10 d.The consortium was predominated with the phylum of Firmicutes and Bacteroidetes,based on the PCRdenaturing gradient gel electrophoresis(DGGE) analysis.After the consortium was applied to the column,the experimental data in the steady state were fitted by the least square method,and the first-order dechlorination kinetic constants from TCP to 2,4-DCP,from 2,4-DCP to 4-CP and from 4-CP to phenol,were 1.58 d-1,2.23 d-1 and 0.206 d-1,respectively.According to the fitting results,the required biobarrier width for the complete remediation of TCP,2,4DCP and 4-CP were 126 cm,130 cm and 689 cm,respectively.The dechlorination/degradation of 4-CP must be increased when the technology is applied to the real site. 相似文献
16.
INTRODUCTIONAsasinkandaninnersourceofnutrients,sedimentsplayanimportantroleinlakeeutroph ication.TheeutrophicationstatusofWestLakeisstillcriticalinrecentyearsevenaftermostpollutionsourcesaroundWestLakehavebeencontrolled(Peietal.,1998) ,mainlythroughtherel… 相似文献
17.
Effects of pH and Eh on release of nitrogen and phosphorus from sediments of West Lake 总被引：1，自引：0，他引：1
The effects of pH and Eh on release of nitrogen and phosphorus from sediments of West Lake under different conditions were investigated by simulation test. Results showed that the net flux of NH4+-N release from sediments increased with pH, but NO3--N showed negative-going release at all tested pH levels. The net flux of NH4+-N release from sediments was higher under anaerobic or aerobic condition of the overlying water, but only under aerobic condition would net release of NO3--N occur. It was also shown that phosphorus released was mainly in its inorganic form, higher pH and anaerobic conditions of overlying water greatly stimulated release of phosphorus. In situ measurement at several West Lake locations indicated that sediment resuspension induced by boat propeller stimulated nutrients release from sediment into overlying water. 相似文献
18.
INTRODUCTION Chlorinated phenols compounds used widely in industry were intentionally or inadvertently released into environment in large quantities. These chlorin-ated aromatic compounds have strong resistance to physical, chemical and biological treatments and have been listed as a priority pollutant by the U.S. Envi-ronmental Protection Agency (Lin and Tseng, 1999). Wastewater containing chlorophenols has malodor-ous odor, high toxicity, bioaccumulation and car-cinogenic potential. … 相似文献
19.
通过砂培实验探讨了Ca(H2PO4)2、NH4HCO3、(NH2)2CO对氯磺隆降解的影响．实验中用直接气相色谱检测氯磺隆．结果表明：Ca(H2PO4)2的加入使砂样呈酸性，促进氯磺隆的降解，降解曲线遵从抛物线方程；而NH4HCO3的加入使砂样呈碱性，阻碍氯磺隆的降解，降解曲线同样遵从抛物线方程．砂样添加尿素后，氯磺隆高浓度组中氯磺隆的降解曲线遵从抛物线方程，半衰期为30．5天；氯磺隆低浓度组中氯磺隆降解曲线先迅速下降，然后上升，在20天左右出现一顶峰，最后缓慢下降．理论分析认为，这是因为氯磺隆与尿素先形成结合态形式，使可测定氯磺隆浓度迅速下降，然后在微生物等原因的作用下又逐渐破坏其结合，使氯磺隆又释放出来；高浓度组形成的结合态浓度相对较低，不足以显现下凹趋势，只表现出降解曲线平缓．尿素与氯磺隆形成结合态，可能对后茬作物造成危害，应引起高度重视． 相似文献
20.
The remediation of groundwater which contains chlorinated organic compounds （COCs） by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dichlorophenol （2,4-DCP） by Pd-Fe bimetallic nanoparticles in the presence of humic acid （HA） to investigate the feasibility of using Pd-Fe for the in situ remediation of contaminated groundwater. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Pd-Fe nanoparticles. The rate constant k values of 2,4-DCP dechlorination were 0.017, 0.013, 0.009, 0.006 and 0.004 min^-1 for HA concentrations of 0, 5, 10, 15 and 20 mg/L, respectively. The relationship between HA dosage and k values can be described as a linear model. 相似文献