镧-钙双金属凝胶微球对水中低磷含量的去除性能

以粉煤灰为基本骨架,将镧、钙双金属作为交联剂对海藻酸钠进行交联制备得到镧-钙双金属凝胶微球,并通过批量吸附实验和表征分析研究了镧-钙双金属凝胶微球对水中低含量磷的去除性能和去除机理。结果表明,镧-钙双金属凝胶微球具有不规则多孔结构,镧和钙2种金属被交联在了微球上,磷主要通过与微球上的La³⁺和Ca²⁺发生化学沉淀而被去除。随着微球投加量的增加,磷的去除率也随之增加;强酸性条件下微球的除磷效果较差;与磷共存的SO₄^2-和F^-会抑制微球对磷的吸附去除。微球对水体中低含量磷的吸附去除过程符合准2级动力学模型和Freundlich等温吸附模型,属于非均相、化学吸附过程。

Removal Performance of Low Content Phosphorus in Water by Lanthanum-Calcium Bimetallic Gel Microspheres

With fly ash as the basic framework,lanthanum and calcium bimetals were used as crosslinking agents to cross-link sodium alginate to prepare lanthanum-calcium bimetallic gel microspheres.The removal performance and mechanism of low content phosphate in water by lanthanumcalcium bimetallic gel microspheres were investigated through batch adsorption experiments and characterization analysis.The results showed that,the lanthanum-calcium bimetallic gel microspheres had irregular porous structure,and lanthanum and calcium were crosslinked onto the microspheres.The phosphate was removed by chemical precipitation with La³⁺and Ca²⁺on the microspheres.The phosphate removal rate increased with the increase of the microspheres dosage.The strong acidic conditions had negative effect on phosphate adsorption onto the microspheres.The SO₄^2-and F-coexisting with phosphorus would inhibit the adsorption and removal of phosphorus by the microspheres.The adsorption and removal process of microspheres for low-content phosphorus in water conformed to the pseudo-second-order kinetic model and the Freundlich isotherm adsorption model,which was a heterogeneous and chemical adsorption process.