Study On The Multiple Microorganisms With Functions Of Producing Microbial Flocculants And Degrading Lignin

It was studied that the multiple microorganisms were constructed and used totreat papermaking wastewater which was difficultly degraded because of containingmany kinds of pollutants, such as lignin. In terms of the principle of ecologyposition's separation, three arbitrary strains were mixed and cultivated on base of twostrains, to construct the multiple microorganisms(TD-1+GS-2+CS-1) with doublefunctions that producing flocculant and degrading lignin. After flocculation anddegradation, the CODcr of the wooden grinding paste papermaking wastewater falledfrom 1821mg/L to 345mg/L.The optimal cultivating condition is listed as follows: 0.3ml for each strain(germsolution) per 50ml cultivating medium, pH 7, temperature 30℃, shaking speed160rpm and operating time 72h, under which, the flocculating activity of the MBFproduced by multiple microorganisms is up to 97.7%.The MBF produced by multiple microorganisms excels at treating the turbid ofpapermaking wastewater and can even remove more than one third CODcr. Theoptimized removing turbid scheme is listed here. 1.0ml MBF and 4ml 1%CaCl₂ wereput into 100ml papermaking wastewater in 100ml test tube, and pH of the system wasadjusted to 9, then the test tube was stirred and left for 10 min to settle. Under thatcircumstance, the efficiencies of removing turbid degree and CODcr are 87.5% and36.1%, respectively. The experience speed equation of removing turbid degree frompapermaking waste water with the MBF is C_{t, OD}(A)=C_{0, OD} (1-t／(1.6191+1.0428t)).After flocculated by MBF, the experience speed equations of removing CODcrand lignin from papermaking wastewater with the multiple microorganisms areq₁=86.4875e^{-1.8854／t} and u₁=1／(0.9925e^-t-0.0324), respectively. The efficiencies ofremoving CODcr and lignin are 68.6% and 38.8%, respectively.At the same condition, the efficiencies of removing CODcr and lignin degreefrom papermaking wastewater with fixed multiple microorganisms are 66.9% and 37.8%. The efficiencies are close to multiple microorganisms, yet they are ahead oftime for 2 days. The experience speed equations of removing CODcr and Lignin areq₂=74.5671e^{-0.904／t} and u₂=1／1.5257e^-t-0.0487, respectively.