REMOVAL OF CHROMIUM BY SAW-DUST; CONTINUOUS OPERATION

Abstract

Mvance in diaxcel t.dmo3o have bro4t aver increasing az gam th*tie compoisids in waste as both i an rejected bye products of industrial processes end/©r as residue of coixn co nerd al pcoducta. It has resulted in the degradation deedrnion of quality of rec.tving - bodies of water and land and thery impairing this beneficial use. Pure chroian is a steel grey mew., Zt is prpsred from the a ui.oxide for in by ruction with powdered aluminium and Mg by vacua, reduction with carbon or et lice. She metal he* a variety 09 £ndwi ai applicatLon which ,include its use In htgh tensile corroaon resistant s and in cutting tools, in plating* in aticc*rosicn paints and waØd preservativess and in htoephic indust*.,. Chromiumhas been canal dared to be a tod.I matel for many yds. Its to4 city have reported both in ht beings as well me in the animals. The exposure *A hen beings to air borne chromium end chip c acid mists pct, culerly in hexavalent form has been observed to produce irritation. derm►ati ea, perforation of the nsal septum. ulcers end cancer of the respiratory tract. .larly its t .c effects have been soon In rats and rabbits and some of aquatic tale like fiah. Its also effects the biological activity Whim tea place in the biological reactcas and thereby a them r*sUit for pry functioning. Thera ere various methods available for the reel of chromium tram air and water , W+ scrubbers and 1*)ric filters are generally used for r ing d omium ftoe air,. Methods used for removing from water are redu tioni i.cn-*changes electr odwmLoali adsorption on coal eel. - veted carbon, fly e#h etc. Redd.on method in the most commly used method in Which the hexevelant form of chromium is reduced to trivalent form which is lee* to*ic * Hevcr. u. adsorption process is also very irnad used because of its *e** in operation and low cost involved. There has been h r, en effort to find out a material which to cost and largely available with great - ad sari t ive capacity........