聚硅酸铁去除焦化废水生化尾水有机物的效能研究

Study on removal efficiency of polyferric silicate for organic matters in biochemical tail water of coking wastewater

采用共聚法制备聚硅酸铁(PSF)混凝剂,与助凝剂聚丙烯酰胺(PAM)搭配构成PSF+PAM混凝体系处理焦化废水生化尾水,并与PAC(聚合氯化铝)+PAM混凝体系进行有机物去除性能的对比分析。结果表明,混凝剂质量浓度为1500~3500 mg/L、PAM质量浓度为10 mg/L、初始pH=7.8的条件下,PSF+PAM混凝体系对有机物去除的性能更优;混凝剂质量浓度为3000 mg/L时,PSF+PAM体系对废水COD、色度、UV_(254)的去除率较PAC+PAM体系分别提高了8.53%、3.68%、11.17%。紫外-可见分光光谱分析结果表明,PSF+PAM体系对尾水中单环芳香族化合物、多环芳烃与含氮杂环化合物的去除效果优于PAC+PAM体系;三维荧光光谱表征结果表明,PSF+PAM体系对尾水中色氨酸等类芳香性蛋白质、类富里酸、类腐殖酸的去除效果优于PAC+PAM体系。PSF+PAM体系对焦化废水生化尾水有机物有较好的去除性能。

Polyferric silicate(PFS)coagulant prepared via copolymerization is combined with polyacrylamide(PAM)to form PSF+PAM coagulation system to treat bio-treated effluents of coking wastewater.The capability of removing organic matters by PSF+PAM is investigated in comparison with that by polyaluminum chloride(PAC)+PAM coagulation system,which is the most widely used system in factories.The results show that PFS+PAM coagulation system has a better performance in removing organic matters when the dosage of coagulant is in the range of 1,500-3,500 mg·L^(-1),the dosage of PAM is 10 mg·L^(-1),and the initial pH is 7.8.The removal rates of PSF+PAM coagulation system for COD,chroma and UV_(254)are 8.53%,3.68%,and 11.17%respectively higher than those of PAC system when the dosage of the coagulant is 3,000 mg·L^(-1).It is indicated from analysis by UV-Vis spectroscopy that PFS+PAM coagulation system performs better than PAC+PAM coagulation system in removing monocyclic aromatic compounds,polycyclic aromatic hydrocarbons and nitrogen-containing heterocyclic compounds.In addition,three-dimensional fluorescence spectra characterization results demonstrate that PFS+PAM coagulation system also shows better removal performance for aromatic proteins such as tryptophan,fulvic acid and humic acid than PAC+PAM coagulation system.PSF+PAM coagulation system can deliver good removal performance to organic matters in biochemical tail water of coking wastewater.