锰铁改性针簇莫来石对水中BPA和EE2的去除

Removal of BPA and EE2 from Water by Mn-Fe Embedded in Acicular Mullite

为提高传统水处理工艺对内分泌干扰物的去除效果,本研究合成了锰铁二元金属氧化物改性的针簇莫来石陶粒(MnFe-M),对其理化性质进行了表征,并以黏土陶粒为对照,结合批次吸附实验研究其对水中典型内分泌干扰物双酚A(bisphenol A,BPA)和17α-乙炔雌二醇(17α-ethinylestradiol,EE2)的去除效果和溶液环境对其吸附效果的影响,并对其再生效果进行了研究.结果表明,锰改性后,针簇莫来石陶粒上负载了平均粒径为450 nm的水锰矿,使针簇莫来石陶粒的比表面积、累积孔体积和介孔比表面积均显著增加.未改性针簇莫来石陶粒对BPA和EE2几乎没有去除能力,锰铁改性后的针簇莫来石陶粒对BPA和EE2的去除效率显著增加.针簇莫来石陶粒比黏土陶粒更适合做改性滤料的载体材料.锰铁改性针簇莫来石陶粒对BPA和EE2的吸附动力学符合颗粒内扩散模型,颗粒内扩散是影响吸附速率的重要因素.等温吸附数据与LangmuirFreundlich模型拟合效果较好,基于该模型计算出的BPA和EE2最大吸附量分别为5.043 mg·g^-1和3.990 mg·g^-1.热力学研究表明锰铁改性针簇莫来石陶粒对BPA和EE2的吸附为自发的吸热反应.锰铁改性针簇莫来石陶粒对BPA和EE2的吸附量随pH值的升高而降低.离子强度的增加有利于锰铁改性针簇莫来石陶粒对BPA和EE2的吸附去除,共存阴离子中SO4^2-对BPA和EE2的吸附均有促进作用,而CO3^2-和PO4^3-则会抑制BPA和EE2的吸附.吸附剂再生实验表明锰铁改性针簇莫来石陶粒是易于再生可循环使用的吸附剂.因此,锰铁改性针簇莫来石陶粒对水中典型内分泌干扰物有较好的去除效果,其推广应用可有效解决传统水处理工艺中过滤单元对内分泌干扰物去除效率低的问题.

Acicular mullite was modified by ferromanganese binary metal oxide(Mn-Fe)to improve the removal efficiency of endocrine disruptors by traditional water treatment practices,using the commercial ceramsite for comparison.The physicochemical properties of synthesized samples were characterized,and batch adsorption experiments were carried out to study the adsorption efficiency of bisphenol A(BPA)and 17α-ethinylestradiol(EE2)on synthesized samples,investigating how solution chemistry and regeneration may affect the adsorption efficiency.Results show that the manganese oxide loaded on the acicular mullite was manganite with an average particle size of 450 nm.After Mn-Fe impregnation,the specific surface area,cumulative pore volume,and mesoporous ratio of the acicular mullite were significantly increased.The virgin acicular mullite had no removal ability for BPA and EE2,and the removal efficiency of BPA and EE2 by Mn-Fe impregnated acicular mullite were significantly increased.Acicular mullite was more suitable as support material for modified filter material.The adsorption kinetics of BPA and EE2 on Mn-Fe-M were fitted with the intra-particle diffusion model,and found to be mainly affected by intra-particle diffusion.The isothermal adsorption data was best fitted to the Langmuir-Freundlich model,and the maximum adsorption capacities of BPA and EE2 were 5.043 mg·g^-1 and 3.990 mg·g^-1,respectively.Thermodynamic experiments showed that the adsorption of BPA and EE2 by Mn-Fe embedded in acicular mullite was an endothermic reaction,and the temperature increase is beneficial to the adsorption.The adsorption amount of BPA and EE2 on Mn-Fe embedded in acicular mullite decreased with increasing pH.The increase of ionic strength favored the adsorption removal of BPA and EE2.The co-existing anion of SO4^2-promoted the adsorption of both BPA and EE2,while CO32^-and PO43^-inhibited the adsorption of both BPA and EE2 on Mn-Fe embedded in acicular mullite.The adsorbent regeneration test showed that Mn-Fe embedded acicular mullite was an easily recyclable adsorbent.Mn-Fe embedded in high-porosity acicular mullite can effectively remove typical endocrine disruptors in water,and it can be potentially extensively used to alleviate the problem of low removal efficiency of endocrine disrupting chemicals in traditional water treatment practice.