Waste water filtration process - which does not block the filter, effected by sequential addn of aluminate, silicate and ammonium/polyvalent cation source

摘要

A waste water system is purified by first adding 0.004-0.04 moles/l of of an alkali aluminate (I) then 0.006-0.2 moles/l of an alkali silicate (II) and 0.001-0.2 moles/l of a sol. ammonium ion source and/or a source of Ca, Mg, Fe, Al, Ba, Co, Cd, Sr and/or Cu ions (III) so as to form solids which are then filtered, the pH of the system being >5.5 when (I) is added. The system is readily filterable and does not block the filter. The process is universally applicable, uses readily available chemicals, is rapid and economical and yields a liq. which is free from particulate matter and many (in)org. solutes (incl. micro-organisms) and yields a highly dewatered unique complex of recovered solids which can safely be stored, handled and beneficially used.