Immobilization of rapeseed press-cake in an alginate matrix for the sorption of atrazine

Due to residual oil retained within it, rapeseed press-cake has been shown to be effective for the removal of atrazine from water through an absorption mechanism. However, it is difficult to put this into practice due to the hygroscopic nature of the press-cake resulting in considerable swelling, together with the formation of a thick paste which hinders phase separation. In order to overcome this, press-cake has been immobilized in an alginate matrix. The kinetics and sorption efficiency of this immobilized press-cake to absorb the model pesticide atrazine, has been studied. The results show that the rate of atrazine removal is slower than for free press-cake, although the total amount of atrazine removed is the same (K-pc/w = 0.25). Phase separation was greatly simplified. The alginate immobilized press-cake could be dried, in order to reduce volume and weight, with no adverse effect on atrazine removal kinetics or sorption properties. (c) 2007 Elsevier Ltd. All rights reserved.