水滑石及其焙烧产物对水中苯甲酸根的吸附研究

Study of hydrotalcite and its calcined products absorbing benzoic acid in water

为了脱除水中的苯甲酸根,以苯甲酸作为吸附质,研究了水滑石及其焙烧产物的吸附作用。考察了吸附剂的镁铝摩尔比、初始pH值、苯甲酸浓度、吸附剂添加量、吸附时间和温度对吸附效果的影响,并对比考察水滑石和焙烧水滑石对苯甲酸的吸附。结果表明,水滑石及其焙烧产物对苯甲酸的最优吸附条件均为酸性环境下,镁铝摩尔比3∶1,吸附质浓度220 mg/L,吸附剂的量0.06 g;水滑石吸附时间20 h,吸附温度为60℃时,对苯甲酸的去除效果最好;而焙烧水滑石在室温下吸附苯甲酸8 h达到最高去除率;在同样条件下,水滑石焙烧产物比水滑石对苯甲酸的吸附大得多。

In order to remove benzoic acid in the water,the adsorptions of hydrotalcite and its calcined products with benzoic acid as adsorbent were studied.The factors were investigated as follows：the molar ratio of Mg to Al,initial pH,the concentration of benzoic acid,the quantity of adsorbent,temperature and adsorptive time.Most attention was paied to the different impacts of hydrotalcite and its calcined products on benzoic acid being adsorbed.The results show that,the optimal conditions of hydrotalcite and its calcined products adsorbing benzoic acid are both that,in acidic solution the molar ratio of Mg to Al being 3∶1,adsorbate concentration of 220 mg/L,adsorbent quantity of 0.06 g.Benzoic acid is removed most after 20 h at the temperature of 60 ℃,while calcined hydrotalcite adsorbs benzoic acid most in 8 h at room temperature.And under the same conditions,calcined hydrotalcite adsorbs benzoic acid much more than hydrotalcite does.