Water Pollution Abatement by Lignosulfonate-PEI or Protein Complexes

Lignosulfonate alone worked as coagulant of polluted water with clay, if its molecular weight was sufficiently high. It was difficult to obtain the high molecular weight of lignosulfonate which was commercially available, by condensing with formaldehyde. Moreover, the building up molecular weight of lignosulfonate is not economical. Thus, the complexes of lignosulfonate with polyethylenimin or protein were employed for abatement of polluted water with clay. Incorporation of PEI or protein of four percent with lignosulfonate reduced remarkably floc sedimentation time. Also, the coagulation properties of the complexes were better than those of PEI and protein alone.