Purificn. of pretreated waste water - contg. heavy metals and/or nitrite(s), by anaerobic treatment

摘要

The COD and pollutant content of waste water that contains heavy metals and/or nitrites and has been pretreated by permeation, adsorption, heat treatment, neutralisation, detoxification and/or filtration are reduced by: (a) introducing the waste water into a reactor; (b) maintaining the waste water under anaerobic conditions until biological activity sets in; (c) continuing the anaerobic treatment in such a way that the biological activity of the waste water is sustained; (d) discharging the treated waste water from the reactor after a preselectable treatment time, and filtering it; (e) disposing of the pollutant-enriched filtrate (sic); and (f) passing the treated waste water to a clarification plant. USE - The process is esp. applicable to waste water from the metal-working industry.