The Screening And Culture Conditions Optimizing Of Flocculant-producing Strains And Study On Flocculation Characteristic Of The Flocculant

Microbial flocculant is a kind of high molecular substance which is produced by microorganisms. It is nontoxic, high-efficient and widely-used. Nowadays the reserches on microbial flocculant are more and more.The influence of PO43- and Ca2+ was investigated in traditional assay of flocculating efficiency. In this article, when pH exceeded 7.0, with PO43- and Ca2+ and without any microbial flocculant on traditional beaker experiment, the flocculation activity of the two irons enhanced with the increasing of the two irons concentrations and pH. When the Ca2+ concentration was 0.4mmol/L and the PO43- concentration was 0.043mol/L, pH exceeded 7.0, the flocculation activity retained above 80% stably, and when pH was 8.0, the flocculation activity achieved 91%, the mostly. The experiments indicated that the traditional assay of flocculating efficiency could not estimate the flocculation activity correctly when the two irons existed, so it needed some modification.Seven strains were screened and isolated from active sludge from waterworks and soil from a garden and pond. The microbial flocculants produced by them showed high and stable flocculation activity for Gaoling clay suspension. And two of them named Z-J and Z-4, which flocculated Gaoling clay suspension best, was...