Treatment of municipal rinsing water involving the removal of heavy metals etc and the recovery of useful salts using, inter alia, ion-exchangers

摘要

A process and apparatus for treatment of rinsing water involving abduction of burnishing (Bruenier) and de-fatting baths containing salts. Water treatment is effected by: (i) removing heavy metals, silicates and carbonates from municipal water; (ii) subjecting to spray rinsing; (iii) removing emulsified oils and fats as well as organic and synthetic oils from the saved rinse water using a special exchanger (18) such that there is no further efflorescence (bloom); (iv) using UTF, NF, RO or A-carbon to remove the organic products from the rinse water (defatting), there being an A-carbon purification before each ion-exchange unit; (v) recovering useful materials in the units T1 and T2 (14) which collect the eluate, these materials being recycled to the process bath and the evaporation losses being compensated for using e.g. Na3PO4.12H2O, this material also being used with the eluate (A2) on the burnishing side (Bruenierseite); (vi) regenerating the A2 to give NaNO3 or NaNO2 on the burnishing side; (vii) improving the quality by using chemically-pure water (clean rinsing); (viii) cutting down on the amount of water by permanent uniform recycling of the rinsing water; and (ix) processing in the absence of waste water.