Purifying waste waters contg. (in)organic colouring materials - by passing over adsorbent waste prods. and/or by introducing filter ash or flue dust

摘要

Waste waters contg. up to 20 kg/m3 dissolved and/or colloidally distributed inorganic and/or organic colouring materials are purified by adjusting pH 1-14 to esp. pH 6-8 and (a) passing over adsorbing waste prods., (A), pref. at a surface loading of 10 (3 to 0.6) m3/m2 adsorber surface hr. and/or (b) introducing dry electrostatic filter ash or flue dust in quantities of 10-150 kg/m3 waste water, whereby the colouring materials are flocked and electrochemically bonded. (A) consists of wet ash, xylite, wet ash xylite, partly coked ash xylite and thermally or chemically activated xylite. Pre-purified waste waters can be discoloured economically to form clear water. O2-consumption in main drainage stream is reduced. Discolouration can reach 100%.