催化湿式氧化法处理酸性红B模拟染料废水的研究

【作者】 张凯；

【导师】 赵彬侠；

【作者基本信息】 西北大学 ， 化学工程， 2009， 硕士

【摘要】 有机染料废水的处理是现阶段国内外环保领域亟待解决的一个重大问题,此类废水具有强烈的生物毒性、色度深、酸性强且难降解,若直接排放会严重污染环境,但采用传统的生化和物化等方法处理效果不佳,湿式空气氧化工艺（Wet Air oxidation,简称WAO）是处理此类废水的有效方法。但传统WAO工艺反应条件苛刻、处理成本高、对设备要求严格,大大限制了该技术的推广应用。本文以氧化能力更强的过氧化氢为氧化剂,采用自制催化剂,以COD去除率、金属离子溶出量作为催化剂活性和稳定性的评价指标,优化了催化剂的制备条件,系统地研究了催化湿式过氧化氢氧化工艺,同时对其动力学进行了初步探讨。采用溶胶凝胶法制备了二氧化钛催化剂,分别考察了乙醇用量、凝胶的焙烧温度等因素对催化剂催化活性的影响,筛选出适宜的制备工艺,并在其基础上添加其他活性组分对其改性,发现在添加铈的情况下活性只是稍有提高,COD去除率可以达87.2%,但是,相比于二氧化钛在光催化方面的催化能力,在CWPO中的催化活性稍显不足。以γ-Al₂O₃为载体,采用浸渍法制备了Fe₂O₃/γ-Al₂O₃催化剂,考察了浸渍液浓度、焙烧温度、焙烧时间等对于催化剂活性的影响,筛选出适宜的制备工艺。添加催化剂助剂Ce制备了Fe₂O₃/CeO₂/γ-Al₂O₃催化剂,使COD去除率有所提高,但是铁离子溶出未能明显降低,因此,在其基础上又添加催化剂助剂Ni制备了Fe₂O₃/CeO₂/NiO₂/γ-Al₂O₃催化剂,使得铁离子溶出降低至15mg/L。在催化湿式过氧化氢氧化（CWPO）处理酸性红B废水实验中,考察了催化剂用量、废水初始pH值、过氧化氢用量及反应温度对处理效果的影响。并将所研制催化剂用于CWPO工艺,用于处理实际染料废水,取得了理想的处理效果。根据所得实验数据,对CWPO法处理酸性红B模拟染料废水过程进行了动力学研究,结果显示,适量催化剂的加入使得该反应的活化能比WPO过程分别降低了73.5%和17.4%。更多还原

【Abstract】 The disposal of organic dye wastewater is an important problem which is desiderated to solve in domestic and international environmental protection at present,the dye wastewater has strong biologic toxicity,acidity and deep chroma as well as difficult to be resolved.The wastewater will pollute the environment seriously if discharged directly,and the result by traditional biochemical and physicochemical process is not good.Wet Air Oxidation（WAO） is an effective way to dispose this kind of wastewater.However,the traditional WAO technique requires exacting reaction condition,high cost,and strict requirement on equipment, which restrict the popularizing and application of this technique.This thesis discussed to use H₂O₂,which is stronger on oxidation,as the oxidant,and self-made catalyst,also to use the COD removing rate,dissolving of metal ion as the evaluation criteria of catalyst activity and stability.So the preparation condition of the catalyst was optimized.And the technique of CWPO was fully researched.Meanwhile,there was preliminary research on the dynamics of the CWPO.In the experiment,we made titanium dioxide catalyst by sol-gel technique;observed the effects on catalytic activity by Ethanol usage and gel calcination temperature;screened out suitable preparation technique;and on this basis we added other active components to change its nature.When adding Ce,the activity increased slightly and COD removing rate reached 87.2%.However,the catalytic activity of titanium dioxide in CWPO was weak compared to its in photocatalytic reaction.γ-Al₂O₃ being the carrier,we made Fe₂O₃/γ-Al₂O₃ catalyst by dipping;observed the effects on catalytic activity by calcination time and temperature;screened out suitable preparation technique.Ce was added to get Fe₂O₃/CeO₂/γ-Al₂O₃ catalyst,which improved the removing rate of COD,but the dissolving of metal ion decreased unobviously.On this basis, we added Ni to get Fe₂O₃/CeO₂/NiO₂/γ-Al₂O₃ catalyst and the dissolving of metal ion reduced to 15mg/L.During the process of disposing Acid Red B wastewater by CWPO,observed the effects on disposing result by catalyst usage,initial pH value,hydrogen peroxide usage and reaction temperature.We put the prepared catalyst into CWPO technique,then disposed the actual dye wastewater and achieved a desirable result.Combined the experimental datum,we researched the dynamics of the process of disposing Acid Red B wastewater by CWPO.It showed that, when adding suitable catalyst,the activation energy for the reaction decreased respectively by 73.5%and 17.4%comparing with its in the WPO process.更多还原