| 摘要 |
<p>Removal of Ag from a photographic processing soln. comprises: (a) adding a mercapto-s-triazine (I), opt. in water-soluble salt form, to form pptes. and fines of the Ag salt of (I); and (b) adding a flocculant (II) to flocculate and agglomerate the fines formed in (a), where (II) is a copolymer of acryloyloxyethyl trimethylammonium chloride (AETAC) and acrylamide and has a reduced viscosity of 21-30 dl/g. When the soln. has an Ag concn. 1 g/l, (II) has an AETAC content of 4-27 (esp. 9-14) mole.%. When the soln. has an Ag concn. of 1-15 g/l, (II) has an AETAC content of 0.1-7 (esp. 0.5-2)mole.%. (II) is added in an amt. of 10-100 ppm.. (I) is trimercapto-s-triazine (TMT) or its trisodium salt. In an example, simulated mini-lab effluent contg. 2.5 g/l Ag was treated (5 gal) with 400 ml of a 15% TMT soln., stirred for 10 min., and pumped into a second reactor at a rate of 200 ml/min. together with 20 ml/min. of a soln. contg. 400mg/l flocculant (1 mole.% AETAC). Precipitated solids were removed in a settling filter.</p> |
