Cationic polymers which have been seen to enhance granulation include chitosan [104–106,185], the cationic fraction of Sapindus trifoliata extract [104], synthetic polymers AA 184 H and Percol 763. The efficiency of chitosan has been found to be better than the synthetic polymer Percol 763 and the S. trifoliata extract [104], but the results are not consistent and some authors have found polymer-assisted granules to be smaller than those of a granular sludge. This has been attributed to the polysaccharide structure of chitosan, which is similar to ECP [187] and the water-absorbing nature of the polymer.