| 摘要 |
<p>Purifying waste water mixture originating partly from (a) baths contg. organic solvents or alkaline emulsifiers for fats and partly (b) other baths for metal surface treatment, for example waste waters from phosphatising, electroplate rinsing or lacquering plants, takes place by adding clay of 20 mu particle size followed by an inorganic salt, pref. Fe2(SO4)3, homogenising mixture, adjusting to pH 7-9 and treating with a flocculating auxiliary, such as "Sedipur" (RTM) or "Praestol" (RTM). Pref. waste waters (a) and (b) are mixed in ratio =1:9. (i) A mixture of degreasing waste water is mixed with waste water of (b) to pH 8-9, treated with 3 g/l. clay, then with 0.15-0.2 g/l inorganic salt, brought back to pH 8-9 and treated with 1 mg/l sedimentation promoter, pref. in a settling cyclone; or (ii) mixture of phosphatising bath waste water with (b) is set to pH 7, treated with 0.25 g/l clay, and then with 0.1 g/l inorganic salt, brought back to pH 7 and treated with sedimentation promoter.</p> |
