磁性吸附材料CuFe2O4吸附砷的性能

根据Cu(Ⅱ)和Fe(Ⅲ)都对砷有较强的亲和性,制备了同时含有Cu(Ⅱ)和Fe(Ⅲ)的、可用磁分离方法进行分离回收的磁性吸附材料CuFe₂O₄,并对其进行了表征及吸附砷的性能研究.结果表明,该吸附剂对砷的吸附能力与溶液pH有关,在弱酸性及中性条件下,吸附砷的能力最强,而对As(V)的吸附能力比对As(Ⅲ)更强些,在平衡浓度为10μg/L时,其吸附容量可达10mg/g左右,可以很容易地将水中浓度为1～20mg/L的As(V)降到10μg/L以下.实验考察了几种无机阴离子对吸附砷的影响,表明较高浓度(砷浓度的20倍)的硫酸盐对As(Ⅲ)和As(V)的吸附均有一定影响,盐酸盐及磷酸盐则影响不明显;负载的As(V)可较容易地用0.1mol/L NaOH洗脱下来,使吸附剂再生,而As(Ⅲ)则难以洗脱,这与2种价态砷的吸附机理不同有关.

Arsenic Adsorption by Magnetic Adsorbent CuFe2O4

By the fact that Cu(II) and Fe(III) have strong affinity toward inorganic arsenic, the present paper reported the preparation of the magnetic adsorbent CuFe2O4 for the removal of arsenic. This adsorbent was composed with Cu(II) and Fe(III) oxides and can be recovered by magnetic separation technique. The characterization and the arsenic adsorption properties of the magnetic adsorbent were also studied. The sorption capacity was related to the pH of arsenic containing solution and the adsorption was more efficient for removing arsenic from acid and neutral solutions. As(V) was found to be more strongly adsorbed than As(III) on the adsorbent, and its adsorption capacity was 10 mg/g at equilibrium concentration of 10 micrograms/L (pH 3.5-6.5). Arsenic adsorption was not influenced by the presence of chloride and phosphate, but slightly influenced by sulfate at 10-20 times concentration of arsenic. As(V) desorption was performed more efficiently than As(III) desorption using 0.1 mol/L NaOH, which was the result of the different adsorption mechanism for the two arsenic species on adsorbent.