Suspended org. and inorg. solids are removed from aq. soln. by adding an improved water-sol. acryloguanamine copolymer flocculant with mol. wt. >2000 and contg. 0-1000 units each of acrylamide, vinyl guanamine, acrylic acid, trimerized acrylonitrile structure I, and acrylonitrile groups in an acid aq. soln. at pH > 2 and temp. above the f.p., optionally with inorg. flocculants. Thus, when the copolymeric flocculant was added at 5, 10, 12, 17, 21, 30, and 50 mg/L to a soln. contg. suspended solids 0.05-1.2 g/L, clarification was 90% in 10 min, 95 in 10, 97 in 10, 100 in 11, 100 in 10, 100 in 7, and 100% in 5 min, resp. [on SciFinder (R)]