【摘要】 采用微生物絮凝方法高效净化重金属废水并回收重金属离子以便循环利用的研究正受到业界的广泛关注.本文研究胶质芽孢杆菌（Bacillus mucilaginosus）K02菌株制得的微生物吸附剂对重金属离子Pb²⁺、Zn²⁺、Cd²⁺、Cu²⁺和Cr³⁺的吸附与解吸作用.采用原子吸收法测定不同处理条件下各重金属离子的浓度,发现该吸附剂对单一金属离子的吸附可在2 h内达到平衡,10 min即可达到吸附平衡时吸附量的60%;对5种金属离子的吸附率均随吸附剂用量增加而呈现不同程度的升高趋势;对Zn²⁺的吸附率在p H值4⁷的范围内均较高,但对Pb²⁺、Cd²⁺、Cu²⁺和Cr³⁺的吸附率受酸性影响较大;设置的起始离子浓度会显著影响吸附率.在对混合金属离子的吸附中,该吸附剂能同时吸附上述5种金属离子,并显示出对Pb²⁺较强的选择性,吸附率能达到90%以上.采用草酸、草酸铵、乙二胺四乙酸二钠（EDTA-2Na）和硝酸钠对吸附后的吸附剂进行解吸,发现草酸对Cu²⁺解吸效果最好,解吸率能达到42.238%;EDTA-2Na对Pb²⁺解吸率能达到64%以上.试验结果为该菌在处理重金属污染废水中的实际应用提供了基础资料.更多还原

【Abstract】 The methods for efficient treatment of heavy metal wastewater and recovery of heavy metal ions by adopting the microbial flocculant have received extensive attention of the industry.In this paper,the microbial adsorbents produced by the culture of Bacillus mucilaginosus K02 strain were used to study the characteristics of adsorption and desorption of heavy metal ions like Pb²⁺,Zn²⁺,Cd²⁺,Cu²⁺and Cr³⁺.Atomic adsorption method was used to determine the concentration of heavy metal ions under different treatment conditions.It was found that the adsorption on the single metal ion could reach equilibrium within 2 hours,and the adsorption capacity of the adsorbent could reach 60%in 10 minutes.The results also showed that the adsorption rate of microbial flocculant to the five metal ions increased by the amount of adsorbents’increasing,and the optimum p H of adsorption was 4⁷.The original concentration of ions could affect the adsorption rate greatly.For the adsorption of mixed metal ions,the adsorbent could simultaneously adsorb the five kinds of ions and show a strong selectivity to Pb²⁺,in which the adsorption rate can reach more than 90%.Oxalic acid,EDTA-2Na ammonium oxalate,and sodium nitrate were used to desorb the adsorbent after adsorption.It was found that oxalic acid had the best desorption effect on Cu²⁺and the desorption rate was 42.238%.In addition,ammonium oxalate,EDTA-2Na has a selectivity to Pb²⁺that desorption rate can reach more than 64%.The results provides basic data for the microbial adsorbents prepared by the K02 strain in the practical application of heavy metal wastewater treatment.更多还原