RESUMEN
The mechanism of chromium accumulation and microstructure transformation of the fused yeast were studied in this paper.The result showed that the process of Cr6+ reduction and adsorption was accom-panied by the H+ consumption.The main adsorptive groups on the strain surface included amino,hydroxyl,phosphate group and amide,among which phosphate group played vital role in the chromium accumulation.The removal rate of chromium and reduction rate of hexavalent chromium declined 70% and 46%,respec-tively,when phosphate group was masked.During the adsorption process the chromium ions complexed on the surface of fused yeast was transported into the cell wall and combined with inclusion to form steady spe-cies and this took 90 min to reach the equilibrium.The biosorption and reduction of Cr on the cell surface would alter microstructure of cell surface,reduce cell membrane potential and increase cell membrane per-meability.
RESUMEN
A new experiment curriculum system of environmental microbiology was established centering on applied microbiology in environmental protection field and emphasizing on design and research experi- ments to motivate the students’ interests for the course, which helped them to improve their ability of think- ing independently and creatively as well as their practicing ability.
RESUMEN
The stability of microbial flocculant (MBF) produced by Aspergillus sojae and its application to municipal thickened sludge dewatering were studied. The results showed that the MBF had high heat and acid-base endurance with high flocculating activity in a wide range of pH from 1.5 to 12. The MBF retained 96% of flocculating activity after 35 days preservation at 4℃, but in different pH the flocculating activity difference was very apparent after 35 days store at room temperature. The experimental results also demon- strated that the MBF was better than PAM and PAC in reducing specific resistance filtration. The optimal dose of MBF used for intensifying thickened sludge dewatering is 7%(volume fraction). And the more the volume of sludge is treated, the less the cost of MBF for unit volume sludge treatment.