Fe^0体系降解2,4二氯酚的影响因素及其反应机理

Factors Affecting Dechlorination of 2,4-Dichlorophennol Contaminated Wastewater by Zero-Valent Iron System and Reaction Mechanisms

采用铁屑、炉渣及河砂混合介质降解2,4-二氯酚(2,4-DCP)模拟废水,研究铁屑粒径、铁屑投加量、铁屑与炉渣配比、pH值等因素对2,4-DCP脱氯效果的影响,探讨Fe0体系降解2,4-DCP的反应机理。结果表明,铁屑粒径、铁屑投加量、铁屑与炉渣配比、pH对2,4-DCP脱氯效果均有显著影响,在铁屑粒径为2～5 mm、不改变废水pH、铁屑与炉渣质量比为31∶9条件下,Fe0体系对2,4-DCP去除率高达97%。2,4-DCP经脱氯后主要产物为2-氯酚、4-氯酚和苯酚,反应后废水的可生化性明显提高,利于后续的生物处理。

An experiment was carried out using mixture of iron filings,furnace slag and river sand to dechlorinate simulated 2,4-DCP-contaminated wastewater,with a view to exploring its affecting factors,like particle-size and rate of iron filings,ratio of iron filings to furnace slag,pH,etc.,and its reaction mechanism.Results show that all the above-listed factors had significant effects on dechlorination.The Fe0 system could remove as much as 97% of the contaminant when its iron filings was 2-5 mm in particle size,pH of the wastewater remained unchanged,and the ratio of iron filings to furnace slag was 31∶9.After dechlorination 2,4-DCP in the wastewater was turned mainly into 2-CP,4-CP and phenol,leaving the water be much improved in biodegradability for further treatment.