Han Yun, Hu Yu-Jie, Lian Jie, Yang Si-Zhe, Qi Ze-Ning
School of Municipal and Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Key Laboratory of Environmental Engineering of Shaanxi Province, Xi'an 710055, China.
Huan Jing Ke Xue. 2019 Aug 8;40(8):3660-3667. doi: 10.13227/j.hjkx.201901013.
To improve the capacity for phosphorus removal and to reduce the cost of treatment, alum sludge from a water supply plant was obtained to prepare modified zeolite coated with layered double hydroxide (LDHs), which was synthesized using an acidified extraction liquid. The surface characteristics and chemical composition of raw zeolites, Al-Zn modified zeolites, and alum sludge modified zeolites were determined, and the isothermal adsorption and adsorption kinetics were analyzed. The performance and mechanism of phosphorus removal by the alum sludge modified zeolites were evaluated. The results showed that the optimum conditions for acidification extraction were 60 min treatment time, 150 r·min, and pH 1.0, which achieved 77 mg aluminum extraction rate per gram of alum sludge. Compared to raw zeolites, the maximum saturated adsorption capacity and the desorption performance of the zeolites were significantly increased by this modification. In addition, the theoretical maximum adsorption capacity of alum sludge modified zeolites was increased from 30.24 mg·kg to 170.40 mg·kg. The modification changed the main mode of phosphate adsorption by zeolite from physical adsorption to chemical adsorption. Alum sludge modification could improve the efficiency of phosphate adsorption and the regeneration capacity of zeolite, which could reduce the risk of water eutrophication caused by high phosphate concentrations, and could achieve the purpose of waste control by waste.
为提高除磷能力并降低处理成本，获取了某供水厂的明矾污泥，用以制备负载层状双氢氧化物（LDHs）的改性沸石，该LDHs使用酸化提取液合成。测定了原生沸石、铝锌改性沸石和明矾污泥改性沸石的表面特性与化学成分，并分析了等温吸附及吸附动力学。对明矾污泥改性沸石的除磷性能及机理进行了评估。结果表明，酸化提取的最佳条件为处理时间60分钟、转速150转·分钟、pH值1.0，此时每克明矾污泥的铝提取率达到77毫克。与原生沸石相比，经此改性后沸石的最大饱和吸附容量和解吸性能显著提高。此外，明矾污泥改性沸石的理论最大吸附容量从30.24毫克·千克提高到了170.40毫克·千克。该改性将沸石对磷酸盐的吸附主要方式从物理吸附转变为化学吸附。明矾污泥改性可提高磷酸盐吸附效率及沸石的再生能力，既能降低高磷酸盐浓度导致水体富营养化的风险，又能实现以废治废的目的。
