Experimental study on Rhodopseudomonas spheroides as coal microbial flocculant

Rhodopseudomonas spheroides were used to investigate the flocculating effects of coal slurry with orthogonal experiments. The study results indicate that Rhodopseudomonas spheroides have a good effect on flocculating fine coal slurry,the flocculating rate up to 90. 3% in the flocculanting test; the best technology parameters of flocculanting test as following: the culture time is 2 d,coagulant of flocculant is 1 mL1,Bacilli volume is 4 mL,the type of flocculant is broken liquid,and the pH value is 6. The result of FTIR and SEM tests show that the biological extract of Rhodopseudomonas spheroides contains a lot of acidic polysaccharides that has the effect of flocculation,the flocculant structure compact,which consist of large number of spheroids,and has much more adsorption sites. The flocculant occurred between the biomacromolecule and fine particle of coal slurry mainly by means of "absorption and bridge"effect.