Abstract: A flocculant composition includes an aqueous solution of a mixture of titanyl sulfate or titanium tetrachloride with a water-soluble, neutral alkali or alkaline earth metal salt at a titanium to alkali or alkaline earth metal salt ratio calculated as TiO.sub.2 of from 0.25:1 to 0.0002:1 by weight. The flocculant composition may further contain a water soluble iron salt at a titanium to iron ratio calculated as TiO.sub.2 and Fe.sub.2 O.sub.3 of from 1:1 to 40:1 by weight, or a water-soluble zirconium salt at a titanium to zirconium ratio calculated as TiO.sub.2 and ZrO.sub.2 of from 1:1 to 40:1 by weight, or a water soluble aluminum salt at a titanium to aluminum ratio calculated as TiO.sub.2 and Al.sub.2 O.sub.3 of from 1:1 to 40:1 by weight.

Abstract: A composition comprises a cellulose acetate or other cellulose ester, and an anatase-type titanium oxide having (1) a specific surface area of not less than 30 m.sup.2 /g, (2) a primary particle size of 0.001 to 0.07 .mu.m, or (3) a specific surface area of not less than 30 m.sup.2 /g and a primary particle size of 0.001 to 0.07 .mu.m. For improving the photodegradability and the dispersibility, the surface of the titanium oxide may be treated with a phosphoric acid salt or other phosphorus compound, a polyhydric alcohol, an amino acid or others. Use of a low-substituted cellulose ester with an average substitution degree not exceeding 2.15 insures high biodegradability. The composition may further contain a plasticizer and/or an aliphatic polyester, a biodegradation accelerator (e.g. organic acids or esters thereof). The degradable cellulose ester composition is highly photodegradable and moldable and hence useful for the manufacture of various articles.