有机磷农药在土壤环境中的降解转化

有机磷农药是世界上应用最广泛的农药种类之一 ,它属于比较容易降解的、对环境污染较小的农药。从有机磷农药的性质出发 ,着重讨论了有机磷农药的水解、光解和微生物降解 ,这也是有机磷农药在土壤中的主要降解转化过程     

紫外光芬顿-膜分离耦合体系降解金霉素

以金霉素为降解对象，采用沉淀法制备α-FeOOH光催化剂，进一步将其用共价结合法负载在陶瓷膜上，用SEM、XRD、EDS、UV-Vis和FTIR对α-FeOOH和光催化陶瓷膜进行表征.结果表明催化剂α-FeOOH呈针状或纺锤长片状，长宽分别为500~550nm、25~50nm，经α-FeOOH改性的陶瓷膜孔隙率由14.83%变为8.11%.研究光芬顿陶瓷膜耦合体系对金霉素的降解效率和动力学行为，确定了光芬顿陶瓷膜耦合体系的最优降解条件为金霉素初始浓度50mg/L，H₂O₂投加浓度10mmol/L，UV强度为3796.6μW/cm².进一步利用UV-Vis光谱分析了两种体系对金霉素的降解机理，光催化剂体系下，H₂O₂的浓度基本保持不变，而光芬顿陶瓷膜耦合体系下H₂O₂的浓度先升后降，同时后者在同一时间点对TOC和NH₄⁺-N去除率更高，表明光芬顿陶瓷膜耦合体系氧化能力更强，对金霉素的降解更为彻底.     

含氯有机物非生物降解方法的最新研究进展

通过介绍目前国际上对含氯有机物的非生物降解方法的最新研究成果,包括零价金属还原、金属组合体系还原脱氯、含铁化合物还原降解、催化加氢还原以及机械化学方法等.分析了每种技术的具体应用和存在的问题以及这些处理方法的发展方向等.     

膨胀珍珠岩负载TiO2光催化脱色性能的研究

以钛酸四丁酯为原料 ,膨胀珍珠岩为载体 ,用溶胶 -凝胶法制备可漂浮于水面的负载型TiO2 。利用该负载型TiO2 对罗丹明B(RB)进行光催化脱色实验 ,结果表明 ,浸渍 3次的负载型TiO2 光催化活性最高 ,催化剂最佳用量为 5 0 0mg/10 0mLRB ,经 5h光照 ,对 10 0mL浓度为 1mg/L和 2 .5mg/LRB脱色率分别为 76 .6 7%和 4 7.2 7% ;该催化剂使用寿命长 ,2 5h后催化剂脱色性能没有减弱 ,可重复使用 ;经 8h光照 ,染料废水脱色效果好。     

Synergetic effects of anodic-cathodic electrocatalysis for phenol degradation in the presence of iron(II)

A novel electrocatalysis method for phenol degradation was described using a β-PbO₂ anode modified with fluorine resin and a Ni–Cr–Ti alloy cathode. In case of air sparging at the cathodic zone, the techniques of anodic–cathodic electrocatalysis (ACEC) and ferrous ion catalyzed anodic–cathodic electrocatalysis (FACEC) in the presence of iron(II) were developed. Both of ACEC and FACEC were more effective than anodic electrocatalysis (AEC). The percentage of phenol eliminated by FACEC could increase by nearly 30% compared with that of AEC, and the current efficiency could reach to 70%. Important operating factors such as ferrous ion concentration, air-sparging rate and applied current were investigated and it was found that such beneficial effects could be achieved at a suitable current and ratio of the concentration of ferrous ion to the air sparged. The mechanism of phenol degradation is proposed to be the generation of hydroxyl radicals concerned with the two electrodes. Results also indicated that the process provided an efficient way to regenerate ferrous ion compared with the conventional Fenton's system.     

缺氧反硝化-好氧串联系统对难降解PVA退浆废水的试验研究

研究了投加硝态氮NO3^--N对缺氧反硝化-好氧和缺氧水解-好氧串联系统处理印染PVA退浆废水的效果。结果表明，缺氧反硝化投加硝态氮NO3^--N比缺氧水解-好氧对CODCr的去除率在缺氧池、好氧池中均提高了30％，缺氧反硝化-好氧工艺二沉池出水经生物碳处理后，CODCr，的去除率达90％。C：N：P的比例合适与否是处理印染PVA退浆废水成功的关键。     

有机污染物的光催化降解过程中的分析技术进展

本文对有机物的光催化降解动力学研究 ,降解产物的鉴定、定量检测等过程中所使用的一些分析技术和手段 ,尤其是在有机物的光降解机理研究中羟自由基的检测技术和方法进行了综述     

Anaerobic degradation of diethyl phthalate, di-n-butyl phthalate, and di-(2-ethylhexyl) phthalate from river sediment in Taiwan

We investigated anaerobic degradation rates for three phthalate esters (PAEs), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and di-(2-ethylhexyl) phthalate (DEHP), from river sediment in Taiwan. The respective anaerobic degradation rate constants for DEP, DBP, and DEHP were observed as 0.045, 0.074, and 0.027 1/day, with respective half-lives of 15.4, 9.4, and 25.7 days under optimal conditions of 30 °C and pH 7.0. Anaerobic degradation rates were enhanced by the addition of the surfactants brij 35 and triton N101 at a concentration of 1 critical micelle concentration (CMC), and by the addition of yeast extract. Degradation rates were inhibited by the addition of acetate, pyruvate, lactate, FeCl₃, MnO₂, NaCl, heavy metals, and nonylphenol. Our results indicate that methanogen, sulfate-reducing bacteria, and eubacteria are involved in the degradation of PAEs.     

磷钨酸光催化降解甲基橙溶液的研究

以磷钨酸为光催化剂,在紫外灯照射下,对模拟染料废水甲基橙溶液进行光催化降解,并研究了催化剂加入量、pH值、甲基橙初始浓度和外加氧化剂H2O2对光催化降解效果的影响.结果表明,磷钨酸光催化剂加入量为300 mg/100 mL,pH=2.5时,甲基橙溶液的降解率明显高于其他pH值的降解率;在较低浓度下,甲基橙溶液的光催化降解反应符合一级动力学方程;外加氧化剂H2O2可提高光催化反应速率.