铁氧化物对模拟印染废水中锑的去除性能研究

Sb(Ⅴ)removal by different iron oxides from simulated textile-wastewater

含锑化合物常作为纺织工业的催化剂,易引发锑(Sb)污染问题.本文以针铁矿、四方纤铁矿与水铁矿等3种常见的铁氧化物作为吸附剂,比较了不同铁氧化物对Sb(Ⅴ)的去除性能,探究了印染废水中各类因素对锑吸附性能的影响.研究结果显示,3种铁氧化物均可使锑浓度为200μg·L^(-1)的模拟印染废水的出水Sb(Ⅴ)浓度小于50μg·L^(-1),满足相应排放标准.铁氧化物的锑吸附过程更符合准二级动力学方程与Freundlich吸附模型,表明其可能以多层吸附与化学吸附为主.铁氧化物的吸附性能主要受到废水pH值、材料比表面积、共存离子等因素的影响.BET、SEM与TEM结果显示,水铁矿具有更大比表面积与更小粒径,在3种铁氧化物中具有最佳的Sb(Ⅴ)吸附容量,在酸性条件下具有更好的吸附性能;共存的含氧阴离子对锑的吸附影响比较大,尤其是磷酸根,但在实际印染废水的水质特征下,3种铁氧化物对Sb(Ⅴ)均具有较高的去除效果.

Antimony compounds are often used as catalysts in textile industry,which may cause antimony pollution.In this paper,the Sb(Ⅴ)adsorption performances by goethite,akaganeite and 2-line ferrihydrite were compared.And the influences of various factors from textile wastewater on adsorption process were investigated.results showed that the Sb(Ⅴ)concentration of simulated textile wastewater with initial Sb(Ⅴ)concentration of 200μg·L^(-1)was less than 50μg·L^(-1)after adsorption,meeting the corresponding discharge standard.The antimony adsorption process was fitted well by the pseudo-second-order kinetic equation and the Freundlich isotherms model,indicating that Sb(Ⅴ)adsorption might be mainly involved in the multilayer and chemical adsorption.Sb(Ⅴ)adsorption was mainly affected by a combination of the pH values,specific surface area and coexisting ions.According to the results of BET,SEM and TEM,2-line ferrihydrite possessed the largest specific surface area and the highest adsorption capacity among the iron oxides.Coexisting oxyanions had a great impact on the adsorption of antimony,especially the phosphate.However,all the three kinds of iron oxides had a high removal efficiency of antimony in the actual printing and dyeing wastewater.