Mercury adsorption by different modifications of furfural adsorbent

Adsorption of mercury from aqueous solutions using three types of furfural-based carbon adsorbents was studied. After activation with water vapor and air, carbon adsorbents with basic and acidic characters, respectively, were obtained. The results from the study showed that all modifications of the adsorbents (with both basic and acidic characters, as well as an adsorbent from mixture of furfural and apricot stones tar) are efficient sorbent materials for mercury removal from aquatic solutions. Mercury adsorption follows a Langmuir isotherm. Adsorbents with good adsorption capacities (174 mg/g for the basic adsorbent, 154 mg/g for the adsorbent from a mixture of furfural and tar, and 132 mg/g for the adsorbent with acidic character) were obtained. The pH was determined to be the most crucial parameter. The mercury removal increases with an increase in pH from 2 to 5. It was found that the adsorption capacities of the produced carbons are significantly higher than those of commercial activated carbons. A desorption study was performed with hot water. The percentage of the recovery was 6% for the basic furfaral adsorbent, 1% for the furfural adsorbent with acidic character, and 4% for the adsorbent from the mixture of furfural and tar.