超临界水氧化轧钢含油污泥减量无害化处理

轧钢含油污泥含有大量油类、复杂有机物、氧化铁及重金属等有害固体废弃物,常规方法如焚烧法、填埋法不仅占地面积大,而且造成生态环境的二次污染。依据超临界水氧化(supercritical water oxidation,简称SCWO)技术对有机废物处理效果明显的优势,对宝钢轧钢含油污泥进行降解试验。采用单因素分析确定工艺参数,在反应温度为440℃、反应压力为25MPa、停留时间为330s和过氧倍数为300%时,反应结束后出水COD去除率接近98%,剩余固体容积减少了98.5%左右。此外,固体中氧化铁质量分数达30%以上,可深度提纯实现资源化利用。采用SCWO技术处理轧钢含油污泥,减量化、无害化效果显著,达到了预期目标,对国内同类型的轧钢含油污泥处理提供了一定的参考和借鉴意义。

Reduction and harmless treatment for rolling oily sludge by supercritical water oxidation

The oily sludge of steel rolling contains a large amount of oil, complex organic compound, iron oxide and heavy metals, which are recognized as a hazardous solid waste. Conventional methods have limitations, such as incineration and landfill, which not only occupy a large area, but also cause the secondary pollution of the ecological environment. Based on the advantages of supercritical water oxidation (SCWO) technology for the treatment of organic waste, the test of the degradation of the oily sludge of steel rolling in Baosteel was conducted. Single factor analysis was used to determine the process parameters, the result showed that the reaction temperature was 440 ℃, the reaction pressure was 25 MPa, the time was 330 s, and the O2 excess was 300%, the removal rate of outflow COD was close to 98%, and the remaining solid volume decreased by about 98.5% after the reaction. In addition, the mass fraction of iron oxide in solids reached more than 30%, which can be used to achieve the resource utilization. In short, the reduction and harmless effects were obvious by using the SCWO technology for the treatment of the oily sludge of steel rolling, which achieved the exceptive goal and can provide a certain reference for the same type of oily sludge of steel rolling treatment in China.