Abstract:

A high temperature wet air oxidation experiment was carried out to study the organic process wastewater with high concentration of phenol and difficulty in biodegradation, and the impact of reaction temperature and residence time on the remove rate of pollutants such as phenol, COD, TOC and the wastewater biodegradability was mainly studied. The results show that the removal rate of various contaminants in wastewater is positively correlated with reaction temperature and residence time, and which is mainly affected by reaction temperature. When the reaction temperature is lower than 230 ℃, the initial organic phenol mainly is converted to intermediate products(benzoquinone), while with the increase of temperature, phenol tends to convert to final products(CO₂ and H₂O). At the operating conditions of 270 ℃, 9.0 MPa and residence time of 120 min, the removal rates of S^2-, phenol, COD and TOC in the oxidized effluent are 100.0%, 99.4%, 83.5% and 71.9% respectively, and B/C value is increased to 0.69, the biodegradability is significantly improved, which could be directly sent to the sewage treatment plant for further treatment.

Key words: high temperature wet oxidation process, high phenol-containing waste water, reaction temperature, residence time, phenol removal rate, COD removal rate, TOC removal rate, B/C value

摘要：

针对炼油过程产生的高浓度含酚、难生物降解有机废水，开展了高温湿式氧化试验研究，考察了反应温度和停留时间对苯酚、化学需氧量(COD)和总有机碳(TOC)去除率以及废水可生化性的影响。结果表明，各污染物的去除率与反应温度和停留时间均正相关，且主要受反应温度的影响。当反应温度低于230℃,苯酚主要转化为中间产物(苯醌),随着温度的提高，苯酚更趋向于向最终产物(CO₂和H₂O)转化。在操作温度270℃、操作压力9.0 MPa、停留时间120 min时，出水S^2-、酚、COD和TOC的去除率分别为100%,99.4%,83.5%和71.9%,B/C值提高至0.69,可生化性显著提高，可直接送污水处理场进行处理。

关键词: 高温湿式氧化工艺, 高浓度含酚废水, 反应温度, 停留时间, 酚去除率, COD去除率, TOC去除率, B/C值