METHOD OF HEAVY METALS REMOVAL FROM MUNICIPAL WASTEWATER

A method of removing one or more heavy metals from municipal wastewater b y use of a membrane separation process is disclosed. Specifically, the follo wing steps are taken to remove heavy metals from municipal wastewater: (a) c ollecting a municipal wastewater containing heavy metals in a receptacle sui table to hold said municipal wastewater; (b) adjusting the pH of said system to achieve hydroxide precipitation of said heavy metal in said municipal wa stewater; (c) adding an effective amount of a water soluble ethylene dichlor ide- ammonia polymer having a molecular weight of from about 500 to about 10 ,000 daltons that contain from about 5 to about 50 mole percent of dithiocar bamate salt groups to react with said heavy metals in said municipal wastewa ter system; (d) optionally clarifying the treated wastewater from step c; (e ) passing said treated municipal wastewater through a submerged membrane, wh erein said submerged membrane is an ultrafiltration membrane or a microfiltr ation membrane; and (f) optionally back-flushing said membrane to remove sol ids from the membrane surface.