高炉碱矿渣负载纳米零价铁对生活污水中氮磷的去除效果

Given that blast furnace alkali-activated slag has high adsorption performance, and nano zero-valent iron (nZVI) used in sewage treatment has limitations when used alone, therefore, using blast furnace alkali-activated slag as a carrier, 6 kinds of blast furnace alkali-activated slag-supported nano zero-valent iron materials (alkali-activated slag - nZVI) with different mass ratios were prepared, and the adsorption and removal effects of 5 different dosages of materials on nitrogen and phosphorus in water under different reaction times and reaction temperatures were investigated. The results show that the optimal reaction mass ratio of alkali-activated slag to nZVI, m(slag powder)∶m(Fe~(2+)), is 4∶1, and the optimal effective dosage is 1 g; the removal rates of total nitrogen and total phosphorus increase with the increase of temperature. Under the reaction conditions of 25 °C and 1.5 h, the removal rates of total nitrogen and total phosphorus in the effluent both reach more than 65%. The adsorption kinetics, adsorption isotherm, and adsorption thermodynamics of the prepared materials were analyzed. The results show that the adsorption process of the supported materials for nitrogen and phosphorus is an entropy-increasing, endothermic spontaneous process, and the adsorption kinetic characteristics conform to the pseudo-first-order kinetic equation.

鉴于高炉碱矿渣具有高吸附性能,而污水处理中应用到的纳米零价铁(nZVI)在单独使用时具有局限性,因此,利用高炉碱矿渣作为载体,制备了6种不同质量比的高炉碱矿渣负载型纳米零价铁材料(碱矿渣- nZVI),探究了5种不同用量的材料在不同反应时间和反应温度下对水中氮磷的吸附去除效果。结果表明:碱矿渣与nZVI的最佳反应质量比m矿渣粉∶mFe~(2+)为4∶1,最优有效用量为1 g;总氮和总磷的去除率随温度的升高而增大,在25 ℃、1.5 h的反应条件下,出水的总氮和总磷去除率均达到65%以上。对所制备材料的吸附动力学、吸附等温式和吸附热力学进行分析,结果表明,负载材料对氮磷的吸附过程属于熵增、吸热的自发过程,吸附动力学特征符合准一级动力学方程。