Fabrication of three bio-adsorbents from different parts of rape straw

Abstract

Three kinds of bio-adsorbents are fabricated from the different parts of rape straw, which are adsorbent core, adsorbent hull, and adsorbent stalk, respectively. As the adsorbates, kerosene, paraffin, rapeseed oil, and dibutyl phthalate are employed to evaluate the adsorption performance of the three kinds of bio-adsorbents. The results suggest that adsorbent core has much higher adsorption quantity to all the four adsorbates (27.37, 32.23, 33.37, and 39.28 g/g, respectively) than adsorbent hull (7.39, 8.37, 8.85, and 10.30 g/g) and adsorbent stalk (6.75, 7.25, 7.92, and 9.32 g/g). The adsorption mechanism of the three bio-adsorbents is investigated. The results illustrate that different bio-adsorbents own different micromorphologies. The special microchamber structure is found in the bio-adsorbent of the adsorbent core, which is seen as the main reason for its excellent adsorption performance. The adsorption volume of unit mass (Va) was proposed to evaluate the intrinsic adsorption properties of the bio-adsorbents. The recovery performance of the bio-adsorbents is investigated by using of two different treatment methods. The effect of treatment on recovery rate is discussed.