印染污泥的超临界水氧化实验研究

Study on the Supercritical Water Oxidation of the Dyeing Sludge

通过间歇式反应器和小型盘管式反应器进行了印染污泥的超临界水氧化特性实验研究。在明确污泥输运特性的基础上,探索反应温度、氧化系数、污泥含水率及辅助燃料对超临界水氧化反应的影响规律,评估反应后污泥中重金属元素的浸出毒性。研究结果表明,常温条件下,91%含水率的污泥粘度满足高压污泥隔膜泵的输运要求。温度与氧化系数对超临界水氧化反应起积极作用,而含水率对有机物分解是不利的,在585℃、5 min、含水率91%及氧化系数3.0条件下,污泥COD去除率达到99.61%。另外,2.57%的异丙醇对污泥具有明显的共氧化作用,在400℃时,COD去除率增加至98.54%。最后,重金属在反应过程中可转化为稳定的结合态。综上所述,超临界水氧化技术可实现对印染污泥的无害化处置。

The experimental investigation on supercritical water oxidation of dyeing sludge was carried out using a batch reactor and a small coil reactor.On the basis of understanding the transport characteristic of sludge, the influences of reaction temperature, oxidation coefficient, moisture content and auxiliary fuel on the supercritical water oxidation of sludge were examined, and the leaching toxicity of heavy metal in sludge after reaction was evaluated. The research results showed that, the viscosity of sludge with moisture content of 91% met the transport requirement of high-pressure sludge diaphragm pump under ambient condition. The reaction temperature and oxidation coefficient showed positive effects on supercritical water oxidation of sludge, whereas increasing the moisture content was disadvantageous to the decomposition of organics. At conditions of 585 ℃, 5 min, moisture content was 91% and oxidation coefficient was 3.0, the COD removal rate achieved 99.61%. Moreover, the 2.57 vol% isopropanol presented obvious co-oxidative behavior for the degradation of sludge, the COD removal rate increased to 98.54% at 400 ℃. Finally, the heavy metal elements could be converted into the stable binding state. In conclusion, the supercritical water oxidation process is an environmentally friendly approach for harmless treatment of dyeing sludge.