水合氧化铁负载D418树脂对磷的吸附性能研究

摘要利用原位沉淀法将水合氧化铁(HFO)负载于氨基膦酸树脂D418上,制备一种对污水中磷具有良好吸附性能的复合吸附剂(HFO-D418),研究了pH、共存离子对HFO-D418去除水中磷的影响,结合红外光谱对HFO-D418吸附磷的机制进行探讨。结果表明,D418与HFO-D418对磷的吸附均在pH为7.0时达到最佳,最大吸附量分别为9.21、36.12mg/g。共存离子的存在将降低两种吸附剂对磷的吸附量,相比而言,HFO-D418受共存离子的影响较D418小,4种共存离子中,CO_3^2-对吸附的影响最大,NO_3^-的影响最小。HFO-D418再生性能优异,以4%(质量分数,下同)NaOH+4%NaCl为解吸剂,经5次再生循环后HFO-D418解吸率仍为80%左右。D418与HFO-D418对磷的吸附过程符合准一级动力学方程,D418离子交换作用及HFO与磷的络合反应、静电吸引是HFO-D418吸附磷的主要作用机制。

Phosphorus adsorption capacity of D418 resin loaded with hydrated ferric oxide

Hydrated ferric oxide(HFO)was loaded on amino phosphonic acid resin D418 by using in-situ precipitation method,the obtained composite adsorbent(HFO-D418)presented perfect performance for the removal of phosphorus from wastewater.The influence of different parameters such as pH,coexisting ions on phosphorus removal by HFO-D418 was investigated,and the mechanism of adsorption was analyzed based on infrared spectroscopy.The results showed the optimum phosphorus adsorption pH of D418 and HFO-D418 were both 7.0 and the maximum adsorption capacities were 9.21,36.12 mg/g,respectively.The presence of coexisting ion could reduce the adsorption capacity of phosphorus by D418 and HFO-D418,whereas the effect of HFO-D418 was less than that of D418.Among the four coexisting ions,CO 2-3 had the greatest effect and NO-3 was the least.HFO-D418 presented excellent regeneration property and the regenerated efficiency,after five times of regeneration by 4%(mass ration,the same below)NaOH+4%NaCl,the desorption rate of HFO-D418 was still about 80%.The kinetic equation fitted well with first order kinetic equation for both sorbent.Ion exchange of D418,complexation between HFO and phosphorus and their electrostatic interaction were the main adsorption mechanisms of phosphorous on HFO-D418.