湿式氧化降解高氯化工废水实验研究及经济性分析  

Research on wet air oxidation of high-chloride chemical wastewaters and economic analysis

作　　者：李艳辉[1] 王树众[1] 孙盼盼[1] 杨闯[1] 王来升 张拓[1] 郭洋[1] 

机构地区：[1]西安交通大学能源与动力工程学院热流科学与工程教育部重点实验室,陕西西安710049

出　　处：《化工进展》2017年第5期1906-1913,共8页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51406146);中国博士后科学基金(126540);江苏省自然科学基金(BK20140406);陕西省自然科学基金(BK20140406)项目

摘　　要：高氯化工废水污染物浓度高、腐蚀性极强是工业废水处理的一大难点。本文研究了温度、停留时间、催化剂Fe^(2+)含量对湿式氧化去除该废水总有机碳(TOC)的影响规律,以及最优反应温度+20℃下候选材料的腐蚀特性;并据此进行了综合处理工艺构建及其经济性评估。结果表明:最佳处理工况(温度280℃、停留时间60 min、催化剂Fe^(2+)量100mg/L)下TOC去除率高达97.9%。300℃、pH=13时,镍基合金N10276与N06625发生严重腐蚀,其可归结为氧化性强碱溶液中铬、钼的过钝化溶解,固态镍氧化物或者氢氧化物的碱性溶解以及高浓度氯根对保护性氧化膜的攻击破坏;钛合金TA10表面氧化膜的轻微破坏主要源自溶液的强碱性诱发钛氧化物溶解。废水pH下调至7.5时,各合金腐蚀程度减弱,且TA10呈现出令人满足的抗蚀性能。针对该高氯化工废水,30 t/d湿式氧化综合处理工艺的总投资2078万元,处理费用470.2元/t废水。High-chloride chemical wastewaters with higher organics concentration and strong causticity, is a great challenge in industrial wastewater treatment. We have investigated the effects of reaction temperatures, residence time, and catalyst Fe^2＋ content on TOC removal of the wastewater during wet air oxidation, and corrosion characteristics of candidate materials under atmospheres higher 20℃ than obtained optimal reaction temperature. On the basis of the above research, a comprehensive treatment process for this wastewater was also built. The results showed that a residence time of 60 min, a reaction temperature of 280℃, and catalyst Fe^2＋ amount of 100 mg/L was the optimum set of technological parameters for the degradation of the high-chloride chemical wastewater, under which the TOC removal rate was as high as 97.9%. For condition of 300℃, pH= 13, nickel alloys（N 10276 and N06625） suffered serious corrosion due to trans-passivation dissolution of alloying elements such as chromium and molybdenum in strong oxidizing ＆ alkaline solutions, alkaline dissolution of solid nickel oxides or hydroxides, along with attacks of chloride ions against protective oxides film produced on alloys surface, while surface damage of titanium alloy TA10 also occurred, which mainly derived from strong alkalinity of environmental mediums （pH=13） causing chemical dissolution of the protective titanium oxides. If initial pH value of the corrosion media was adjusted to about 7.5, the corrosion rate of three alloys decreased obviously, and alloy TA10 showed satisfactory corrosion resistance. The economic analysis of wet air oxidation process for the high-chloride chemical wastewater with a capacity of 30 tons per day, indicated that the project total investment is 20.78 million Yuan, while the wastewater processing cost is 470.2 Yuan per ton.

关 键 词：湿式氧化 废水 高氯化工废水 废物处理 镍基合金 钛合金 腐蚀 经济性分析 

分 类 号：X52[环境科学与工程—环境工程] TG17[金属学及工艺—金属表面处理]