酚油共萃协同解毒技术及其在煤化工高浓废水中的应用

Co-extraction and synergistic detoxification technology and its application in high-concentration wastewater from coal chemical industry

煤化工高浓废水因成分复杂、污染物浓度高、毒性大、可生化性低等特点受到环保行业广泛关注,废水中含有高浓度的氨氮、酚类和油类物质及杂环化合物和多环芳烃等高毒性污染物,高效脱酚和深度解毒是该类废水处理的两大瓶颈。本工作从过程污染控制角度提出了酚油共萃协同解毒技术,配合研发的酚油联合脱除专用萃取剂IPE-PO,有针对性地处理云南某企业的煤化工高浓废水。用GC-MS检测了处理前后废水中的有机物种类,并与工业应用广泛的甲基异丁基酮萃取剂(MIBK)萃取体系进行对比。预处理后废水中的化学需氧量(COD)、总酚、氨氮(NH4+-N)、有机物的吸光度(UV254)平均脱除率分别为77.69%,90.45%,97.10%和82.19%,去除了大部分有毒污染物,废水的可生化性显著提高。处理后废水中的有机物种类从原水中的101种减至74种,展现了该技术在处理有毒物质方面的优势。经生化和深度处理,废水COD从31000~37000 mg/L降至100 mg/L以下,UV254从197cm-1降至0.5cm-1,可直接排入污水厂,运行成本不超过10元/t。IPE-PO萃取剂酚油协同共萃解毒技术在煤化工废水处理上是一种可行且高效的预处理方法。

High-concentration wastewater from coal chemical industry has attracted widespread attention because of complex composition,high concentration of pollutants,high toxicity and low biodegradability.It not only contains ammonia nitrogen,phenols and oil compounds with high concentration,but also contains highly toxic pollutants such as heterocyclic compounds and polycyclic aromatic hydrocarbons(PAHs).High-efficiency dephenolization and deep detoxification are the two major bottlenecks in wastewater treatment.In this work,the phenolic-oil co-extraction synergistic detoxification technology was proposed from the perspective of process pollution control,and the special extractant IPE-PO was used to treat the high-concentration wastewater from coal chemical industry in Yunnan.The organic matter in the wastewater before and after treatment was detected by GC-MS,and compared with methyl isobutyl ketone(MIBK)extraction system which was used in industrially widely.After treatment using IPE-PO extractant,the average removal rates of chemical oxygen demand(COD),total phenol,ammonia nitrogen(NH4+-N)and absorbance of organic matters at 254 nm(UV254)were 77.69%,90.45%,97.10%and 82.19%,respectively.Most of the toxic pollutants were removed,and the biodegradability of the wastewater was improved significantly.There were 101 kinds of organic matters in the raw water,after IPE-PO process,the types of organic compounds were reduced to 74 kinds.The process showed ascendancy in the treatment of toxic matters.After biochemical and advanced treatment,the COD of wastewater reduced from 31000~37000 mg/L to less than 100 mg/L,and the UV254 of wastewater reduced from 197 cm-1 to 0.5 cm-1,which meet the wastewater discharge standard of China.Compared with the MIBK extraction system,the deep detoxification ability of the technology was proved.The operating cost does not exceed 10 yuan/t wastewater.The phenol-oil synergistic co-extraction detoxification technology with IPE-PO extractant is a feasible and efficient pretreatment method for coal chemical wastewater treatment.