Water purificn. contg. tenside for industrial water - by addn. of organic flocculant, inorganic precipitant, and removing coagulated solids, for soil purifin. or textile washing water dispersed solid particle sepn.

摘要

(a) 1-1000 ppm of an organic flocculant is added to the water in a 1st pptn. stage, (b) 5-2000 ppm of an inorganic precipitant is added in a 2nd pptn. stage, (c) the coagulated solids are removed by filtration or centrifuging, and opt. (d) the pretreated water is re-used or is cleaned by reverse osmosis. Pref. before stage (a) the pH of the water is brought to 6-9 (7.5-8.5). (a) An anionic or cationic flocculant, (an acrylamide copolymer), esp. an acrylamide-acrylic acid copolymer with mol. wt. above 100,000 and with 10-70 mols.% of acrylic acid, is used in amt. of 1-100 ppm. (b) The flocculant is a salt of Al, Ca, Mg or Fe, the aq. salts of which give water-insol. pptes. on reaching the pH of the contaminated water, or salts which on addn. of other salts, e.g. Na carbonate or phosphate, give fine pptes. are used and Al2(OH)5Cl.2-3H2O is esp. used. The amt. is 10-800 ppm. To remove residual turbidity, 5-5000 (10-2000) ppm of an adsorbent may be added after the 2nd pptn. stage. The adsorbent has a large surface and is esp. active C or zeolite 4A. After (c), the water may be disinfected, esp. by heating or addn. of chemical disinfectants, esp. substances liberating O2, e.g. peracids or H2O2 or Cl2. USE/ADVANTAGE - The treated surfactant bath can be reused or is easily disposed of. It contains residual tensides, and may be used to wash or clean contaminated hard surfaces, or as consumption water, or to make up a washing and cleaning bath