Enhanced dewatering of sludge with the composite of bioflocculant MBFGA1 and P(AM-DMC) as a conditioner

Bioflocculant MBFGA1 was investigated to be used as a conditioner for sludge dewatering, and the response surface methodology (RSM) was employed to study the enhancing performance of the dewatering process by the composite of MBFGA1 and poly(acrylamide [2-(methacryloyloxy)ethyl]-trimethylammonium chloride) (P(AM-DMC)). Results showed that dry solids (DS) and specific resistance to filtration (SRF) of sludge treated by MBFGA1 alone appeared as 21.7 % and 3.6 x 10(12) m kg(-1), respectively, which were much better than FeCl3, Al-2(SO4)(3), and polyaluminum chloride (PAC), but poorer than P(AM-DMC) in sludge dewatering. Apart from this, the optimized conditioning process for improving the dewaterability of the sludge conditioned by the composite is MBFGA1 of 1.4 g L-1, P(AM-DMC) of 0.13 g L-1, CaCl2 of 56.1 mg L-1, pH value of 7.5, and agitation speed of 149 rpm. Under this optimal condition, DS and SRF appeared as 29.9 % and 2.2 x 10(12) m kg(-1), respectively. Thus, it is feasible and meaningful to enhance the dewaterability of the sludge by the compound uses of MBFGA1 and P(AM-DMC).