STUDY OF PHYSICO-CHEMICAL TREATMENT OF ROLLER FLOUR MILL EFFLUENT

Abstract

Pollution control bodies, set up by the government, have laid• down specific standards of quality for disposal of effluents from industries who are required to treat their efflu-ents to comply with the specified permissible limits of various parameters. This study pertains to the treatment of effluent from Roller Flour Mill. The study reveals that the nature of the effluent from these mills varies from mill to mill and so the treatment stra- tegy will also vary accordingly. This study is confined to physico-chemical treatment of the effluent which consisted of treatment by plain settling followed by chemical treatment in which the effluent was treated with different doses of lime and alum. Different sets of experiments were conducted. Keep-ing dose of one of these constant, the dose of the other was varied in a particular set. Jar test set up was employed to properly mix and apply the lime and alum dosage. The study showed good results. With an aim to reduce the COD further, chemical treatment was further done with chlorine and hydrogen peroxide applica-tions. Different dosage of chlorine and hydrogen peroxide were applied to the supernatant obtained after treatment with optimum dose of lime and alum. The results obtained this time were also favourable. The overall results show that substantial reduction in pollution load can be obtained with physico-chemical treat- ment of the type studied.