Research on Flocculation Property of Bioflocculant PG . a 21 Ca

This paper investigates the flocculation performance of polyglutamic acid-based bioflocculant PG.a21 Ca by processing kaolin suspension, studies the effects on the flocculation efficiency from the amount of flocculant, pH, temperature, hydraulic condition and etc. The results show that the flocculation rate of PG.a21 Ca to 1 g/L kaolin suspension is 95.8% under the condition that the amount of PG.a21 Ca is 300 mg/L, pH is 7, temperature is 25 oC, stirring speed of mixing is 350 r/min, stirring time of mixing is 50 s, stirring speed of reaction is 80 r/min, and stirring time of reaction is 4 min. Effects from wastewater processing show that bioflocculant PG.a21 Ca has better effects in treating domestic wastewater and higher removal rate of total phosphorus and ammonia nitrogen than the common chemical flocculants such as PAC and PFS. Meanwhile, PG.a21 Ca can effectively remove chlorophyll A in algae-contained lake water and make water clear, and partially remove COD and TP in wastewater from beer brewing.