铁改性凹凸棒土对甲醛废水的处理

Adsorption of Formaldehyde by Ferric Ion Modified Attapulgite

以凹凸棒土为载体,硝酸铁为活性前躯体,通过浸渍-焙烧法制得铁改性凹凸棒土,并将其应用于废水中甲醛的吸附。研究了不同负载化合物、硝酸铁含量、焙烧温度、吸附剂加入量、吸附时间对铁改性凹凸棒土吸附甲醛效果的影响。结果表明:以凹凸棒土为载体,硝酸铁含量为20%,500℃下焙烧3 h得到吸附剂;在25℃、吸附剂加入量为12 g/L、吸附76 h时,铁改性凹凸棒土对甲醛的去除率为92.22%。该吸附过程符合Langmuir吸附模型,饱和吸附量为3.8399 mg/g。并且吸附过程符合准二级动力学模型。

With attapulgite as the carrier, ferric nitrate as the active precursor, the iron-modified attapulgite adsorbent was prepared by impregnation-calcination method and was applied to the adsorption of formaldehyde in wastewater. The effects of different loading compounds, ferric nitrate content, calcination temperature, addition amount of adsorbent and adsorption time on the removal rate of formaldehyde were respectively analyzed. The results indicated that： the optimal iron-modified attapulgite adsorbent was obtained by taking attapulgite as the carrier, calcinating it at 500℃ for 3 hours, with the ferric nitrate content of 20%. When the addition amount of adsorbent was 12 gEL and the adsorption time was 76 hours at 25℃, the removal rate of formaldehyde was 92.22%. The adsorption behavior could be depicted by Langmuir equations, and the saturated adsorption capacity was 3.8399 mg/g. And, the adsorption behavior follows a pseudo-second-order kinetic model.