改性γ-聚谷氨酸络合重金属离子性能

研究了不同控制条件(温度、Pb2+浓度、pH)对交联改性γ-聚合谷氨酸(γ-PGA)吸附重金属离子所形成的絮凝颗粒性质的影响,对于治理水中重金属污染的相关研究有一定参考价值。实验表明,C-L-γ-PGA絮凝吸附Pb2+的最佳温度段在30℃附近。随着交联度的增加,不同的Pb2+浓度影响絮凝颗粒的大小,当处于较低浓度时,静电引力成为影响絮凝颗粒粒径最主要的因素,当Pb2+浓度增加到一定程度时,重金属的吸附量成为絮凝颗粒的粒径的决定因素。溶液pH达到7附近时,能够形成粒径最大的絮凝颗粒,并出现了最大的Pb2+去除率。C-L-γ-PGA对其他重金属离子也有类似的吸附絮凝作用,且絮凝吸附强弱顺序为Cu2+>Cr3+>Pb2+>Hg2+。吸附絮凝颗粒的粒径反映了重金属被吸附之后分离的难易程度,因此研究不同条件对絮凝颗粒粒径的影响对重金属离子的吸附和去除有重要意义。

Complex capacities of modified y-PGA with heavy metal ions

The influence of granulars properties formed by crosslinking modification γ-glutamic acid(γ-PGA) adsorpting heavy metal ions under different control conditions(temperature,Pb2 + concentration,pH)was researched,which has certain reference value for researches about heavy metal removal in water.Experiments showed that C-L-γ-PGA flocculated and adsorpted Pb2+ had the best effect when the temperature was about 30℃.With the increase of crosslinking,the size of granulars was affected by Pb2+ concentrations,when Pb2+ was in low concentration,the electrostatic force became the most important factor in granulars size,when the Pb2+ concentration increased to a certain extent,heavy metals adsorption became the most important factor in granulars size.The granulars had the largest size when pH was 7,and the Pb2+ removal rate reached maximum.There were similar flocculating adsorption when C-L-γ-PGA adsorpted other heavy metal ions,and the order of flocculating adsorption strength was Cu2+>Cr3+>Pb2+>Hg2+.The difficulty of separating the flocculation-adsorption heavy metals related to the size of flocculation-adsorption granulars,the study on the influence of flocculating granular size under the different conditions had most important significance for the elimination and adsorption of heavy metal ions.