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比较4种金属氧化物纳米颗粒(nMgO,nAl_2O_3,nTiO2和nFe_2O_3)对水体P的吸附性能,并探讨了pH、吸附时间、共存离子等因素对nMgO吸附P的影响,用XRD和XPS分析了nMgO对P的吸附机制,最后通过小青菜盆栽实验法探讨nMgO从养殖废水中吸附回收P的应用潜力.结果发现,在pH3.0~8.0范围内,nMgO对P的吸附量显著高于nAl_2O_3、nTiO_2和nFe_2O_3,4种纳米颗粒对P的吸附量分别可达40、31.77、15.93和13.08mg/g.吸附后P的解吸可逆性较差.nMgO对P的吸附能在0.5h内达到吸附平衡,P的吸附符合准二级动力学过程.体系共存的等量F~-、Cl~-、NO_3~-、SO_4~(2-)、Na~+、K~+和NH_4~+离子对nMgO吸附P无显著影响,Mg~(2+)和Ca~(2+)离子对P吸附具有促进作用.nMgO对P的吸附等温线可用Langmuir模型描述,最大吸附量达139.3mg/g.XRD和XPS分析表明,nMgO对P的吸附是伴有静电吸引的以表面络合沉淀反应为主的吸附过程.nMgO能有效地从养殖废水中吸附回收P,吸附P的nMgO作为肥料,能使小青菜干物质量从0.31g/kg土增加到0.96g/kg土.
The adsorption properties of nMgO, nAl_2O_3, nTiO2 and nFe_2O_3 on water P were compared. The effects of pH, adsorption time and coexisting ions on the adsorption of nMgO on P were investigated. The effects of nMgO The adsorption mechanism of P was studied.At last, the potential of nMgO adsorbing and recovering P from aquaculture wastewater was discussed through the potted experiment of small cabbage.It was found that the adsorption capacity of nMgO to P was significantly higher than that of nAl 2 O 3 and nTiO 2 And nFe_2O_3, 4 kinds of nanoparticles on the P adsorption capacity of up to 40,31.77,15.93 and 13.08mg / g respectively.The reversible desorption of P after adsorption is poor.NMgO adsorbed on P adsorption equilibrium within 0.5h, The adsorption of P accords with the quasi-second-order kinetic process and the adsorption of nMgO on the same amount of F ~ -, Cl ~ -, NO_3 ~ -, SO_4 ~ (2 -), Na ~ +, K ~ + and NH_4 ~ P had no significant effect, and Mg 2+ and Ca 2+ promoted the adsorption of P. The adsorption isotherm of nMgO to P could be described by Langmuir model with the maximum adsorption of 139.3 mg / g.XRD and XPS The analysis shows that the adsorption of P by nMgO is an electrostatic adsorption-dominated adsorption process with surface complexation. NMgO can effectively adsorb P from aquaculture wastewater P recycled, adsorption nMgO P as fertilizer, to make a small amount of dry vegetables from 0.31g / kg soil increased to 0.96g / kg soil.