脱硫废水处理系统污泥资源化除磷技术研究

Phosphorus Removal by Reusing Sludge from Flue Gas Desulfurization Wastewater Treatment System

针对脱硫废水水质和"三联箱"处理工艺的特点,提出了将脱硫废水处理系统污泥(脱硫污泥)用于除磷的方案。以模拟含磷废水为处理对象,对脱硫污泥除磷技术进行了深入研究,考察了不同污泥浓度及污泥含钙量对除磷效果的影响,通过吸附热力学和吸附动力学的研究探索除磷机理。结果表明,含钙污泥除磷主要通过化学反应和吸附作用共同实现,化学反应产物为CaHPO_4·2H_2O;在一定污泥浓度和含钙量条件下,磷去除率可达99%以上;污泥含钙量越高,对磷的吸附容量越大,所需污泥量越少;适当升高温度可以促进污泥对磷的吸附。由X射线衍射(XRD)和扫描电子显微镜(SEM)表征分析可知,反应后的污泥表面有透钙磷石生成,进一步验证了实验结果。

This paper proposes a scheme for the utilization of sludge from the FGD wastewater treatment system(desulfurization sludge)according to the characteristics of flue gas desulphurization(FGD)wastewater and the"triple box"process,The phosphorus removal technology on desulphurization sludge is studied using the simulated wastewater as the processing object.Effects of the sludge dosage and its calcium content on phosphorus removal efficiency are discussed,and the mechanism is explored with the study on adsorption thermodynamics and kinetics.The results show that phosphorus removal using calcium-containing sludge is mainly realized through chemical reaction and adsorption,and the product is CaHPO4·2H2O.The phosphorus removal rate is over 99%under a certain sludge concentration and calcium content.The higher the calcium content in the sludge,the greater the adsorption capacity for phosphorus and the less the sludge demand will be.In addition,the appropriate raising temperature can promote the adsorption of phosphorus to the sludge.The characterization analysis of X ray diffraction(XRD)and the scanning electron microscope(SEM)show that calcium phosphate rocks generate on the surface of the sludge,which further verifies the experimental results.