北京大学学报自然科学版 ›› 2017, Vol. 53 ›› Issue (6): 1108-1114.DOI: 10.13209/j.0479-8023.2017.107

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一种磁性剩余污泥的制备及其除磷研究

陶虎春, 张晓, 李金波, 黄帅斌, 马骉   

  1. 深圳市重金属污染控制与资源化重点实验室, 北京大学深圳研究生院环境与能源学院, 深圳 518055
  • 出版日期:2017-11-20 发布日期:2017-11-20
  • 基金资助:
    深圳市科技计划技术开发项目(JSKF20150828173756275)和流域生态工程学学科建设(深发改[2017]542号)资助

Preparation of Magnetic Excess Sludge and Removal of Phosphate

Huchun TAO, Xiao ZHANG, Jinbo LI, Shuaibin HUANG, Biao MA   

  1. Shenzhen Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055
  • Online:2017-11-20 Published:2017-11-20

摘要:

以FeCl3, FeCl2和NH3·H2O为原料, 通过共沉淀法制备磁性Fe3O4纳米颗粒(MNPs), 并将含水率为99%的剩余污泥与其复合, 制备磁性剩余污泥(MES)。采用交变梯度磁强计测定、扫描电子显微镜观察等分析方法对MES进行表征。计算磁分离后的污泥体积浓缩程度, 进行MES对磷的吸附去除研究。结果表明, MES具有超顺磁性, 其饱和磁化强度为42 emu/g, 30秒内可实现固液分离, 且分离后的MES体积为原剩余污泥体积的1/10。MES吸附磷的最适pH为4~6, 最佳磷溶液初始浓度为16 mg/L (以P计), 600分钟后达到吸附平衡。准二级动力学模型对吸附试验数据的拟合程度较高。MES对磷的吸附等温线符合Langmuir方程, 理论最大吸附量为3.00 mg/g (以P计)。磁性剩余污泥可快速、大幅度地缩减剩余污泥体积, 且对磷的吸附性能优于剩余污泥。研究结果可为处理剩余污泥提供新的途径。

关键词: 磁性剩余污泥, 磁分离, 吸附,

Abstract:

MNPs were prepared using coprecipitation method, with FeCl3, FeCl2 and ammonia. MNPs were compounded with excess sludge (moisture content of 99%) to prepare magnetic excess sludge (MES). Alternating gradient magnetometer was used to measure the magnetic response of MES and scanning electron microscope (SEM) to observe morphology of excess sludge and MES. After magnetic separation, the water content of MES was calculated to investigate the degree of sludge thickening. The adsorption property of total phosphorus onto MES was investigated. According to the results, MES had superparamagnetism, and its saturation magnetization was 42 emu/g. Within 30 s it could be separated from liquid. The optimal conditions for adsorption of total phosphorus on MES were the initial pH value of solution ranging in 4-6, an initial concentration of phosphorus solution of 16 mg/L (calculated as P), adsorption equilibrium was achieved within 600 min. The kinetics data were fitted well with the pseudo-second order model. The adsorption fitted the Langmuir isotherm well with the equilibrium data and the theoretical maximum adsorption capacity was 3.00 mg/g (calculated as P). MES could accelerate the separation of sludge and wastewater, and the volume of excess sludge was reduced largely. The adsorption performance of total phosphorus on MES was better than that on excess sludge. The study provided a new handling method of excess sludge for sewage treatment plant whose secondary treatment process was activated sludge process.

Key words: magnetic excess sludge, magnetic separation, adsorption, phosphate