超临界水氧化处理棉纺织品印染废水

在温度400~600℃、压力25 MPa、停留时间10~45 s、过氧比0%~400% 条件下,用超临界水氧化(SCWO)法在连续管式反应器中处理棉纺织品印染废水。分析了工艺条件对总有机碳(TOC)及氨氮(NH3-N)降解效率的影响。研究表明,温度是影响TOC降解的最重要因素,不同温度下,降解率随过氧比变化的趋势不同。在450℃、停留时间20 s、过氧比300% 时,废水TOC降解达98.94%。NH3-N的降解与反应温度和氧化剂量密切相关。当过氧比300%,温度从400℃上升到600℃时,NH3-N的浓度从55.42 mg/L下降到3.31 mg/L,而600℃没有氧化剂存在时氨不易降解。450℃时随着过氧比增大NH3-N浓度略有下降,在该温度下停留时间延长对NH3-N降解无显著影响。

Supercritical water oxidation of cotton textiles dyeing wastewater

Cotton textiles dyeing wastewater was treated by supercritical water oxidation (SCWO) in a continuous flow tubular reactor using hydrogen peroxide (H2O2) as an oxidant. The degradation of total organic carbon(TOC)and the ammonia and nitrogen(NH3-N)were studied at the temperature range of 400~600℃,25 MPa,residence time bewteen 10~45 s and excess oxygen varying from 0%~400%. The results showed that temperature is the most important factor influencing TOC degradation. The TOC degradation efficiency varies with excess oxygen at different temperatures. At 450℃, 20 s and excess O2 300％, the degradation efficiency of TOC is 98.94％. The degradation of NH3-N is closely related to temperature and excess oxygen of the reaction. When excess oxygen of 300%, the NH3-N concentration decreases from 55.42 mg/L to 3.31 mg/L as the temperature increases from 400℃ to 600℃. When oxidizing agent is absent at 600℃, the degradation of NH3 is difficult. The effects of excess oxygen and residence time of the reaction on the NH3 degradation are not obvious at 450℃.