嘉兴市印染行业中水回用率影响因素及对策研究

Study on influencing factors and countermeasures of reuse rate of reclaimed water in dyeing industry in Jiaxing

对嘉兴市3类印染企业中水回用率影响因素进行了全面调查,并对废水排放量大的化纤印染企业开展了典型调查。结果表明:嘉兴市印染企业共354家,小型企业占65.3%,微型企业占16.1%。化纤印染企业占57.6%,其原料和助剂用量最大,废水排放量最高。不同染色工艺中,溢流染色工艺COD产污系数最大,31家化纤印染、22家棉印染企业采用此工艺;卷染染色工艺氨氮和TN产污系数最大,6家棉印染企业采用此工艺。典型化纤印染企业水解池BOD/COD(B/C,质量比)≤0.3,膜浓缩液盐分高,总溶解固体(TDS)为5620~8803 mg/L,COD去除率为5.1%~75.0%,氨氮去除率为39.8%~59.2%,TN去除率为-12.9%~8.4%。生化出水中主要残留有机物是难降解的邻苯二甲酸酯类,苯胺类和芳香烃化合物。活性污泥菌群中土微菌属(Pedomicrobium)和unclassified_f_Rhodocyclaceae功能菌群相对丰度低于1.6%。针对嘉兴市小微印染企业占比高,染色工艺产污系数大,废水处理生化效果差,膜浓缩液盐分高等问题,提出了加快行业整合淘汰提升,采用先进的气流(气液)染色的清洁生产工艺,推广废水深度削减技术等对策。

A comprehensive investigation was carried out on the factors affecting the reuse rate of reclaimed water of 3 types of dyeing enterprises in Jiaxing,and a typical investigation was carried out on chemical fiber dyeing enterprises with large wastewater discharge.The result showed that there were 354 dyeing enterprises in Jiaxing,small enterprises accounted for 65.3%,micro-enterprises accounted for 16.1%.The ratio of chemical fiber dyeing enterprises was the largest,accounted for 57.6%,and chemical fiber dyeing enterprises used the largest amount of raw materials and auxiliaries,and had the highest waste water discharge.The COD pollution coefficient of overflow dyeing process was the largest,but there were 31 chemical fiber dyeing enterprises and 22 cotton dyeing enterprises still using this process,the ammonia nitrogen and TN pollution coefficient of jigger dyeing process were the largest,but there were 6 cotton dyeing enterprises still using this process.The B/C ratio of hydrolytic acidification tank of a typical chemical fiber enterprises was≤0.3,the salinity of membrane concentrated liquid solution was high,TDS was 5620-8803 mg/L,the removal rate of COD,ammonia nitrogen and TN was 5.1%-75.0%,39.8%-59.2%,-12.9%-8.4%respectively.The main residual organic matter in the effluent of biochemical tank were phthalate,anilines and aromatic compounds.The relative abundance of Pedomicrobium and unclassified_f_Rhodocyclaceae in the activated sludge flora was less than 1.6%.For the problems such as the small and micro dyeing enterprises in Jiaxing accounted for a higher proportion,the pollution coefficient of the dyeing process and the salinity of membrane concentration was high,the effect of biochemical treatment was poor,countermeasures about accelerating industry integration,promotion and elimination,using the cleaner production process such as the air flow(air-liquid)dyeing process,and promoting wastewater deep reduction technology were proposed.