生物絮凝剂γ-聚谷氨酸絮凝性能研究

Characteristics of bioflocculant poly(γ-glutamic acid)produced by Bacillus subtilis NX-2

研究了枯草芽孢杆菌NX 2制备的生物絮凝剂γ 聚谷氨酸 (γ PGA)的絮凝活性。γ PGA对高岭土、活性炭等悬浮液具有较高的絮凝活性 ,絮凝活性稳定 ,热稳定性好 ,用量高于 10mg/L时适用pH范围宽 ,最适投加浓度为2 0mg/L ,加入Ca2 +、Mg2 +、Fe3 +、Al3 +、Fe2 +、Na+等金属离子能不同程度增强γ PGA的絮凝活性 ,其中Ca2 +助凝效果最高。使用Ca2 +作助凝离子可降低γ PGA用量 ,但Ca2 +浓度过高会明显降低γ PGA的絮凝活性。还研究了γ PGA对电镀废水的处理效果 ,实验证明γ PGA能有效降低电镀废水中Cr+3 、Ni+2 等离子的浓度。

Poly(γ glutamic acid) (γ PGA) produced by Bacillus subtilis NX 2 had a high flocculating activity to some organic and inorganic suspension and its flocculating properties was investigated In kaolin suspension, the flocculating activity got highest at the γ PGA concentration of 20 mg/L and was steady to pH with the concentration above 10 mg/L, and decreased upon heating at 70℃ The flocculating activity was synergistically simulated by the addition of cations, Ca 2+ was the optimum cation that remarkably promoted the flocculating activity and could lower the cost by dropping the dosage of γ PGA, while the excessive Ca 2+ can restrain the flocculating activity γ PGA was tested to treat the electric plating waste water that it could remarkably remove the heavy metal ions, such as Cr +3 , Ni +2