摘要：

为提高活性炭对Pb²⁺的吸附效果,用硝酸铁对活性炭进行了改性处理。采用BET、SEM、Boehm等方法对改性前后活性炭的理化特性进行了表征,考察了吸附时间、pH、吸附剂投加量对改性前后活性炭吸附Pb²⁺效果的影响。结果表明,相比于未改性活性炭(GAC),硝酸铁改性活性炭(Fe-GAC)比表面积减少,酸性含氧官能团增加,极性增强。对于质量浓度为10 mg/L的Pb²⁺溶液,Fe-GAC的最佳投加量为2.0 g/L,此条件下Pb²⁺去除率可达到98.73%,比采用GAC提高了30.15%。吸附剂吸附Pb²⁺过程与Langmuir吸附等温线方程拟合较好,相关系数R²在0.99以上。

关键词: 硝酸铁, 改性活性炭, 吸附, Pb(Ⅱ)

Abstract:

In order to improve the adsorbing capacity of activated carbon for Pb²⁺,activated carbon has been modified with iron nitrate,and the physiochemical characteristics of activated carbon before and after the modification are characterized by BET,SEM,Boehm,etc. The influences of adsorption time,pH,and dosage of adsorbent on the adsorbing effect of activated carbon before and after modification on Pb²⁺ are investigated. The results show that compared with unmodified activated carbon(GAC),the specific surface area of iron nitrate modified activated carbon(Fe-GAC) is reduced,but acidic oxygen-containing functional group is increased and polarity enhanced. For the Pb²⁺ solution whose mass concentration is 10 mg/L,the optimal dosage of Fe-GAC is 2.0 g/L. Under these conditions,the Pb²⁺ removing rate can reach 98.73%,it is 30.15% higher than that of using GAC. The Pb²⁺ adsorbing process by using the adsorbent is fitted with Langmuir adsorption isotherm equation quite well,and the correlation coefficient R² is above 0.99.

Key words: iron nitrate, modified activated carbon, adsorption, Pb(Ⅱ)

中图分类号: 

• X703.1