质子化剩余污泥作为生物吸附剂去除水溶液中活性红4的研究

以城市污水处理厂的剩余污泥为材料,经过质子化处理制备成生物吸附剂,进行了吸附水溶液中活性红4(RR4)的研究.同时考察了吸附时间、溶液pH值、染料浓度、盐的浓度等因素对RR4吸附的影响.生物吸附剂对RR4的吸附所需平衡时间短(约22h),酸性条件利于吸附,碱性条件下则会发生解吸附(解吸附率高于87%),吸附等温曲线符合Langmuir和Freundlich模式,pH=1条件下生物吸附剂、活性碳、硅藻土对RR4的最大吸附量qm分别为35.66,20.48,1.82mg·g-1.RR4低浓度时盐对吸附不产生明显影响,当RR4高浓度时,盐对吸附有促进作用.研究结果表明,用质子化剩余污泥作生物吸附剂去除染料废水中RR4有实际应用的潜力,为剩余污泥的资源化提供了新途径.

Study on the removal of RR4 in aqueous solution by protonated sewage sludge

The protonated sewage sludge biomass discharged from a sewage treatment plant was used as a new type of biosorbent for the removal of anionic dye Reactive Red 4. Various experimental parameters (e.g. pH, contact time, salt concentration, dye concentration etc.) were investigated. Adsorption reached equilibrium after 22 hours. The dye uptakes increased with the declining of solution pH, and under alkaline conditions desorption was dominating. The desorption efficiencies were higher than 87% at pH8. The isothermal data of biosorption followed the Langmuir and Freundich models well, and the maximum sorption capacities of the biosorbent, activated carbon and diatomite were 35.66,20.48 and 1.82 mg·g^-1 respectively. The uptake of RR4 was not significantly affected by a high concentration of salt when RR4 concentration was lower, and salt promoted sorption when RR4 concentration was higher. The results indicated that protonated sewage sludge was an attractive substance for removing dyes from wastewater, and it was a new way to resource reutilize sewage sludge.