Permalink : http://hdl.handle.net/2115/90928

JaLCDOI : 10.14943/bull.fish.73.2.55

KEYWORDS : Biodegradable flocculant;Aluminum;Gelatin;Kaolin;Clarification efficiency;Flocculation-filtration;Floc settling velocity

The flocculation ability of aluminum-gelatin (Al-GL) composite flocculant was examined with kaolin suspensions as functions of Al concentration (CAl) and GL concentration (CGL) at pH 6.5-7.5.　The reagents were added separately to the kaolin suspension in order of Al solution, pH adjuster, and GL solution.　The flocculation performance was evaluated in terms of the clarification efficiency (CE), the settling velocity (v) of kaolin floc on flocculation experiment, and the specific cake resistance (α) on filtration experiment.　The settling velocity was determined by an in-situ measurement of transmitted light intensity through the kaolin suspension using a self-made apparatus.　Based on the obtained parameters, CE, v, and α, the optimum conditions were found to be CAl = 0.5 mM and CGL = 0.05 g/L for the flocculation of kaolin suspension of 10 g/L.