污水厌氧处理微生物的固定化方法及硬化处理

本文阐述了污水厌氧处理微生物的固定化方法及硬化处理的试验研究。正交试验结果表明,经胺处理及醛交联后的固定化微生物的酶活力,强度及稳定性均是令人满意的。试验经过半年的连续运转,粒子性能仍然完好。     

B掺杂TiO2/ITO薄膜电极的MOCVD制备及其可见光催化活性研究

采用金属有机物化学气相沉积方法,制备出了具有可见光催化活性的B掺杂TiO2/ITO薄膜电极。利用X射线衍射(XRD)、X射线光电子能谱(XPS)以及紫外-可见漫反射吸收光谱(UV-Vis-DRS)分析等方法对所得材料的晶型、组成、化学态和光响应等特性进行了表征。同时,在模拟可见光照射条件下,通过在光电催化反应体系中降解偶氮染料甲基橙的实验,验证和评价了材料的光电催化性能。结果表明:所制备的B掺杂TiO2/ITO纳米薄膜电极在可见光条件下具有良好的光电催化性能,其催化活性在一定范围内(B∶Ti<15%(原子比))随着B掺杂量上升而提高。光电催化甲基橙的去除率达到82.7%,并且经过连续实验,证实了材料具有良好的稳定性和可重复使用性。     

金属有机物化学气相沉积法制备负载型纳米TiO2光催化剂及性能评价

纳米粉末TiO2是有效的光催化剂，但存在回收困难、分散性差、颗粒易团聚等问题，极大地限制了其在废水处理中的实际应用。为解决上述问题，采用常压金属有机物化学气相沉积技术在活性炭表面沉积构成纳米TiO2固定化非均相光催化剂。XRD图谱表明煅烧温度为773K时负载的TiO2晶型结构为锐钛矿，873K时出现金红石相。TEM分析表明负载量为8％(wt)时负载的TiO2颗粒的粒径为10～20nm；载体负载前后BET面积减少仅为6％。以对氯苯酚(4-CP)为污染物进行了光催化降解实验，结果表明制备的负载型TiO2的光催化活性不仅接近商业粉末光催化剂P25，而且可以重复使用10次其光催化活性保持不变，显示了较好的废水处理应用前景。     

US/H2O2组合工艺催化降解苯酚水溶液的研究

研究了苯酚水溶液在超声波/过氧化氢(US/H2O2)复合氧化工艺条件下的降解效果及机理.详细讨论了H2O2体积质量、苯酚初始体积质量、溶液初始pH和外加Fe2+等因素对US/H2O2工艺氧化降解苯酚的影响.结果表明:在单独的超声波辐照或者过氧化氢氧化下苯酚去除率很小,而在组合氧化过程US/H2O2工艺中有显著的提高;苯酚降解的拟一级动力学速率常数增强因子可达到6.904,存在明显的协同效应     

有机物质对铁还原降解四氯化碳的影响

为探寻土壤和地下水中广泛存在的醌和表面活性剂等有机物质对铁用于环境中有机氯污染修复的影响,实验采用在零价铁还原体系中,加入增强电子转移的醌类物质和铁表面负载表面活性剂,以提高铁对四氯化碳的吸附来增强铁还原脱氯.结果表明：分别加入4.0×10^-3mol/L蒽醌-2,6-二磺酸钠和1,4-二羟基蒽醌,四氯化碳的降解速度提高70%和52%.用阳离子表面活性剂负载的零价铁对四氯化碳降解有很好的增强效果,最佳的增强效果在临界胶束浓度附近,十六烷基三甲基溴化铵和溴代十六烷基吡啶处理的铁比未处理的铁可提高四氯化碳的降解速率分别为81%和130%,2种阴离子表面活性剂没有协同增强效果.     

用修正的Polanyi-Dubinin方程描述有机蒸气-水蒸气在活性炭上的吸附平衡

活性炭吸附法用于低浓度有机废气的治理,具有脱除率高、可以回收有机溶剂等优点。但由于废气中或多或少混有水蒸气,导致吸附能力降低,这种情况在相对湿度较高的南方地区尤为严重。定量地估计水蒸气对活性炭吸附容量的影响,对吸附装置的设计和操作,具有重要的指导意义。     

高压脉冲介质阻挡放电降解土壤中芘的研究

针对我国土壤多环芳烃的污染问题,通过自研的介质阻挡脉冲反应器处理土壤中的芘,研究了放电电压、放电频率、土壤湿度、土壤厚度、空气流速和土壤pH等条件对降解效果的影响。结果表明,随着放电电压和放电频率增加,芘的降解率提高,空气流速和土壤湿度在适宜的范围内,有利于芘的降解,增加土壤厚度和降低pH会降低芘的降解率。最适降解条件为：放电电压12.6 kV、放电频率1.0 kHz、土壤湿度3.0%、土壤厚度1 mm、空气流速2 L/min、土壤pH≥7,芘的降解率为97.04%。通过HPLC-MS和FT-IR分析,间接证明放电产生的活性物质O₃、·OH、NO _x 等导致了芘的降解,提出了芘可能的降解途径。     

Wet oxidation of PVA-containingdesizing wastewater

Polyvinyl alcohol (PVA)-containing desizing wastewater was treated by various wet oxidation methods.Parameters such as reaction temperature, initial solution pH, and the dosage of H2O2 were investigated in terms of chemical oxygen demand (CODcr) and total organic carbon (TOC) removal rate. Up to 90% of the initial CODcr was removed by wet air oxidation(WAO) at 270℃ with stoichiometric oxygen supply, while at temperature of 200℃, the CODcr removal rate was found to be 80%. Similar results were obtained by Promoted WAO (PWAO) and wet peroxide oxidation(WPO) at a lower temperature of 150℃. Reaction temperature was found to have a significant effect on the oxidation performance for all the methods. Initial solution pH was observed to play a significant role in PWAO and WPO where H2O2 was employed. Comparison of WAO, CWAO(catalytic wet air oxidation), PWAO and WPO shows that the rate of CODcr removal increases in the order: WAO, CWAO, PWAO and WPO.     

High Conductivity Water Treatment Using Water Surface Discharge with Nonmetallic Electrodes

Although electrohydraulic discharge is effective for wastewater treatment,its application is restricted by water conductivity and limited to the treatment of low conductivity water. For high conductivity water treatment,water-surface discharge is the preferred choice.However. the metallic electrodes are easily corroded because of the high temperature and strong oxidative environment caused by gas phase discharge and the electrochemical reaction in water.As a result. the efficiency of the water treatment might be affected and the service life of the reactor might be shortened.In order to avoid the corrosion problem,nonmetallic electrode water-surface discharge is introduced into high conductivity water treatment in the present study.Carbon-felt and water were used as the high voltage electrode and ground electrode,respectively.A comparison of the electrical and chemical characteristics showed that nonmetallic electrode discharge maintained the discharge characteristics and enhanced the energy efficiency,and furthermore,the corrosion of metal electrodes was avoided.     

Oxidation of S（IV） in Seawater by Pulsed High Voltage Discharge Plasma with TiO2/Ti Electrode as Catalyst

Oxidation of S（IV） to S（VI） in the effluent of a flue gas desulfurization（FGD） sys- tem is very critical for industrial applications of seawater FGD. This paper reports a pulsed corona discharge oxidation process combined with a TiO2 photocatalyst to convert S（IV） to S（VI） in artificial seawater. Experimental results show that the oxidation of S（IV） in artificial seawater is enhanced in the pulsed discharge plasma process through the application of TiO2 coating electrodes. The oxidation rate of S（IV） using Ti metal as a ground electrode is about 2.0x10-4 mol. L 1. min-1, the oxidation rate using TiO2/Ti electrode prepared by annealing at 500 ~C in air is 4.5x 10-4 tool. L-a ~ min-1, an increase with a factor 2.25. The annealing temper- ature for preparing TiO2/Ti electrode has a strong effect on the oxidation of S（IV） in artificial seawater. The results of in-situ emission spectroscopic analysis show that chemically active species （i.e. hydroxyl radicals and oxygen radicals） are produced in the pulsed discharge plasma process. Compared with the traditional air oxidation process and the sole plasma-induced oxidation process, the combined application of TiO2 photocatalysts and a pulsed high-voltage electrical discharge process is useful in enhancing the energy and conversion efficiency of S（IV） for the seawater FGD system.