自来水厂脱水铝污泥对水中磷的吸附去除研究

Adsorption Removal of Phosphorus from Wastewater by Dewatered Alum Sludge from Waterworks

选取两种自来水厂铝污泥,以配制的含磷水和实际污水作为研究对象,考察了铝污泥对磷的吸附去除效果及吸附特征。结果表明,铝污泥投量的增加提高了对磷的去除效果,铝污泥吸附磷的机理主要是配体离子交换反应,随着溶液pH值的升高,铝污泥对磷的吸附容量减小。铝污泥对磷的吸附更符合Langmuir吸附等温线模型,而拟二级反应动力学模型对吸磷数据的拟合效果更好。采用铝污泥处理实际污水,出水总磷浓度达到了一级A排放标准。这不仅提供了一种新的除磷方法,而且也为自来水厂铝污泥的资源化利用提供了一个途径。

Two alum sludge samples from waterworks were selected to adsorb and remove phosphorus from simulated phosphorus-containing wastewater and real wastewater from a WWTP. The adsorption characteristics were also investigated. The results show that the removal effect of phosphorus is improved with the increasing dosage of alum sludge. Ligand exchange is the dominating mechanism of phosphorus adsorption by alum sludge. The adsorption capacity decreases with the increasing pH. The adsorp- tion isotherm fits Langmuir model while the adsorption kinetics fits pseudo second-order reaction kinetics. After the treatment of the real wastewater by alum sludge, the TP concentration in the effluent meets the first level A criteria. The application of alum sludge in the treatment of wastewater offers a novel method for the phosphorus removal from wastewater and a new way for the resource utilization of alum sludge from waterworks.