To obtain the subject coagulant comprising a water-soluble vinylic polymer containing a specific monomer as an essential unit monomer and capable of exhibiting an excellent dehydration rate on the centrifugal dehydration treatment or belt-pressing hydration treatment of organic sludges generated on the microorganism treatments of sewages or excrements.
This coagulant comprises a water-soluble vinylic polymer containing a radical-polymerizable (meth)acrylic monomer having a primary amine base group, preferably a monomer of the formula (R is H, CH3; X is O, NH; Q is CH2CH2, CH2CH2CH2, etc.; Z is Cl, Br, I, NO3, etc.) as an essential unit monomer. The colloid equivalent values (a), (b) and (c) of the polymer at pHs of 4, 7 and 10 satisfy the inequalities: (b)/(a)=0.1 to 0.5, and (c)/(a)=0 to 0.1. The coagulant thereby exhibits high adsorptivity to suspended particles in water to show effective coagulability (flock formability), and especially exhibits a remarkable effect to high organic substance-containing sludges difficult in dehydration.
SATO MASAAKI
KAWAGUCHI SHINOBU
