US/H2O2系统协同降解苯酚的动力学研究

超声波/过氧化氢（US/H₂O₂）复合氧化过程在废水处理领域有很广泛的应用前景，但在动力学方面的研究很少，为此研究了US/H₂O₂工艺降解苯酚的动力学.结果表明，苯酚在单独超声波辐射（US）、过氧化氢（H₂O₂）氧化和超声波/过氧化氢（US/H₂O₂）协同下的降解均符合表观一级动力学.在单独的超声波辐射或者过氧化氢氧化下苯酚去除率很小，而在复合氧化过程US/H₂O₂工艺中有显著的提高，表明协同效应存在.苯酚去除的速率常数增强因子可达到6.904.进一步从US/H₂O₂系统中存在US、H₂O₂和羟基自由基（•OH）3部分协同作用的降解机理，推导出了简化的机理动力学模型，很好地反应过氧化氢浓度过量条件下苯酚的降解.     

负载型二氧化钛光电催化降解苯酚废水的反应动力学

采用浸渍提拉法制备发泡镍载二氧化钛薄膜电极,并以其为工作电极,建立三电极光电催化体系,对该体系降解苯酚的动力学进行了研究.考察了反应液初始pH值、反应物初始浓度、催化剂用量、光辐照强度、外加直流偏压值对光电催化反应速率的影响,采用幂指数方程描述反应动力学,得到方程C=C₀exp(-0.5430 C ^-0.4241 ₀ E ^0.2968 Q ^0.5418 I ^0.5877 t).方程计算值与实验值吻合较好,误差基本在15％以内.     

线板式脉冲电晕反应器放电特性研究

为了实现废气处理中低能耗与高处理效率问题，研究了气体流速、气体温度及反应器并联操作因素对线板式电晕反应器放电特性的影响.采用Blumlein 脉冲形成网络（BPFN）型窄脉冲高压电源，考察了这些操作因素对脉冲波形及电参数的影响，分析了并联反应器与脉冲电源的匹配关系，得出了反应器充电电压对峰值阻抗和电源能量效率的影响.结果表明:提高处理废气的流速可以有效的提高电源能量效率.一定范围内的温度改变对能量转换效率的影响不大.与单个电晕反应器相比，反应器并联后的电源最大能量转换效率从96%降为88%.     

响应面法优化湿式氧化处理阳离子红X-GRL废水

以偶氮染料阳离子红X-GRL为模拟污染物，采用单因素法筛选出温度、氧气分压、搅拌速度、pH、染料质量浓度5个相对重要的影响因素，利用响应面法在60～180 ℃、氧气分压为0～2倍理论需氧量、搅拌速度为100～700 r/min、pH值为 2～10、染料质量浓度为500～2 931 mg/L范围内探讨了操作条件对染料去除率的影响，并分析了这些影响因素之间的相互作用.采用响应面法对实验结果进行了模型拟和，并对模型进行了实验验证.结果表明，响应面法的预测值与实验值吻合较好，在通过响应面法得到的优化工艺条件下处理X-GRL废水，染料去除率接近100％.     

均相Fenton氧化降解苯酚废水的反应机理探讨

以苯酚为模拟污染物,通过Fenton、类Fenton及其光助体系光谱变化和动力学常数的比较,说明Fenton氧化反应不是单纯的自由基反应体系,高价铁配合降解是其重要的中间反应途径.Fe(Ⅱ)和H₂O₂配合生成高价配合物,通过配合物的电子转移使污染物得到氧化,从而对传统的Fenton自由基氧化反应理论提出了修正.     

天然纤维脱浆废水湿式空气氧化动力学

This work described the application of wet air oxidation (WAO) to the treatment of desizing wastewater from natural fiber processing. A two-liter autoclave batch reactor was used for the experiments. The range of operating temperature examined was between 150 and 290℃, and partial pressure of oxygen ranged from 0.375 to 2.25 MPa standardized at 25℃. Variations in Chemical Oxygen Demand(COD) and Total Organic Carbon(TOC) were monitored during each experiment and used to assess the performance of the process. Experimental results showed that WAO can be an efficient method for the treatment of desizing wastewater. Furthermore, Catalytic Wet Air Oxidation (CWAO) was applied to reduce the reaction temperature and pressure in WAO process. A higher COD removal ratio was achieved under more mild reaction condition with the aid of CWAO. A mathematical model was also proposed to simulate the WAO process of desizing wastewater, in which three distinct kinetics steps were considered to describe the degradation of starch. The model simulations were in well agreement with the experimental data.     

旋流澄清/涂膜硅藻土过滤处理电镀废水

为解决传统化学沉淀砂滤工艺的金属沉淀物固液分离不完全、出水COD难以达标的问题,将旋流澄清与硅藻土预涂膜技术相结合,开发出一种新型的处理中小规模电镀废水的后处理技术。电镀废水总铬、总铜、总氰化物浓度分别为6. 72、18. 40、22. 10mg/L,COD为240mg/L,在处理水量为100m3 /d、阳离子聚丙烯酰胺(PAM)投量为3mg/L、硅藻土预涂膜过滤强度为12. 5m3 /(m2·h)的工艺条件下,对总铬、总铜、总氰化物去除率分别达到93. 3%、97. 4%、99. 9%。和传统沉淀砂滤相比,在取得较高的重金属离子去除率的同时,出水COD为60mg/L,达到《污水综合排放标准》(GB8978—1996)的一级标准。     

Characteristics of Electrode-Water-Electrode Discharge and its Application to Water Treatment

Atmospheric air discharge above the surface of water is an effective method for water treatment.The leakage current and Joule heating of water are reduced by the air gap,which raises the energy efficiency of the water treatment.However,the application of this kind of discharge is limited by a pair of conflicting factors：the chemical efficiency grows as the discharge gap distance decreases,while the spark breakdown voltage decreases as the gap distance decreases.To raise the spark breakdown voltage and the chemical efficiency of atmospheric pressure water surface discharge,both the high-voltage electrode and the ground electrode are suspended above the water surface to form an electrode-water-electrode discharge system.For this system,there are two potential discharge directions：from one electrode to another directly,and from the electrodes to the water surface.The first step in utilizing the electrode-water-electrode discharge is to find out the discharge direction transition criterion.In this paper,the discharge direction transition criterions of spark discharge and streamer discharge are presented.By comparing the discharge characteristics and the chemical efficiencies,the discharge propagating from the electrodes to the water surface is proved to be more suitable for water treatment than that propagating directly between the electrodes.     

The Catalytic Effect of Metal Ions on the Degradation of 4-Chlorophenol Induced by an Aqueous Pulsed Discharge Plasma

The influence of metal ions, such as Fe2+ , Fe3+ , Cu2+ and Mn2+ , on 4-CP degrada- tion was investigated in an aqueous pulsed discharge plasma system with or without the addition of a TiO 2 photo-catalyst. From an analysis of the pseudo first-order rate constant (k CP ) and energy efficiency (G 50% ) for 4-CP degradation, the experimental results show that the degradation of 4-CP is much enhanced in the presence of ferrous ions at the optimal concentration of 0.2～0.8 mmol/L or 0.2 mmol/L in an aqueous pulsed discharge plasma without or with the TiO2 system, respectively, and the enhancement is ascribed to plasma induced Fenton and photo-Fenton reactions. Meanwhile, the rank of such metal ions for catalytic effect on 4-CP degradation was Fe2+ > Fe3+ > Cu2+ > Mn2+ and Fe2+ > Fe3+ > Mn2+ > Cu2+ for the former and the latter systems, respectively, and the reasons behind this were discussed through the analysis of active species, especially hydrogen peroxide.