焦化废水中COD的沉淀预处理及资源化利用研究

Study on the Pretreatment and Beneficial Use of COD Sediment in Coking Wastewater

高浓度焦化废水经生化处理后COD难以达标并浪费大量资源。采用实验室自制的无机絮凝剂PAC和助凝剂PAM对焦化废水原水进行了预处理。结果表明,PAC+PAM的投加量分别为2.5 g/L和0.025 g/L,搅拌时间8 min,温度25℃,pH值为6时可取得最佳的絮凝效果;对COD的最佳去除率为37.5%。GC-MS分析结果表明,焦化原水经PAC和PAM混凝预处理后主要去除物为苯酚类有机物,可采用碱沉淀法对其进行分离和资源化回收。

COD in high concentration coking wastewater after the biological treatment is difficult to reach the standard and cause enormous waste of resources. The raw coking wastewater was pretreated by using laboratory-made inorganic flocculants PAC and coagulant aid PAM.The results show that the best flocculation effect can be achieved when the dosage of PAC and dosage of PAM were 2.5 g/L and 0.025 g/L respectively, the blending time was 8 min with the temperature of 25 ℃ and the pH value of 6, and the best removal rate of COD was 37.5%. The results of GC-MS analysis indicate that the main removed materials from the raw cock wastewater after PAC and PAM coagulation treatment were organic phenols, which can be separated and recycled as resources by using alkali precipitation.