Fenugreek mucilage for solid removal from tannery effluent

Fenugreek mucilage, a food grade natural polysaccharide, has been reported as a flocculant for tannery effluent treatment, for the very first time. The flocculation efficiency of the mucilage has been tested under various conditions by standard jar test method. The effects of polysaccharide concentration, contact time and pH on percent solid removal have been studied. The maximum suspended solid (SS) and dissolved solid (TDS) removal were nearly 85% and 40%, respectively using flocculant dose of 0.08 mg/l. The suitable pH range was neutral for maximum efficiency of mucilage as flocculant. Time required for maximum TDS removal was 3 h whereas it was only 1 h for SS removal. Wide-angle X-ray diffraction patterns of powder samples of the solids, before and after treatment, have also been reported to suggest the interaction of tannery waste with the mucilage. The flocculation efficiency of this mucilage was found at par with that of a commercial flocculant. (C) 2004 Published by Elsevier B.V.