Fe(Ⅲ)改性耐锑芽孢杆菌吸附处理含锑废水的影响机制及其机理研究

The serious water environment pollution of heavy metals in mining area was caused by the discharge of antimony-containing wastewater in China. And the present drawback for autimony wastewater treatment contains the following: low efficiency, high cost, complex control, easy to produce secondary pollution. Therefore, the new method for treating antimony wastewater by high-efficient biosorption of Fe(Ⅲ)-Modified antimony-resistant Bacillus.Sp is proposed in this project, which takes into account the merits of antimony-resistant Bacillus.Sp consisting of large adsorption capacity, strong selectivity, environment-friendly, better regeneration, and low cost，and the merits of Fe (III) consisting of making the surface of the microorganism to be protonated, the activation adsorption site. Antimony-resistant Bacillus.Sp will be isolated from samples of the antimony mine soil and water, as subsequently identified; the optimum cultivation conditions and the nutritional factors will be obtained through isolation technology, physiological and biochemical experiments, molecular biology statistical analysis. Based on high adsorption and good sedimentation performance of ferric salt, Fe-modified antimony-resistant Bacillus.Sp adsorbent is prepared and their structures were characterized. Than influence mechanism of factors on the removal efficiency of Fe-modified antimony-resistant Bacillus.Sp adsorbent are be studied in detail using statistical analysis and batch test. The modern advanced morphology, physical, chemical and biological characterization techniques, as combined with theoretical cell biology, will be used for revealing the adsorption mechanisms, migration and transformation and trandference of antimony-resistant Bacillus.Sp and Fe-modified antimony-resistant Bacillus.Sp. This project intends to provide technical support and theoretical guide for biological treatment of wastewater from heavy metal antimony ore. This project is significant with providing technical reference for water pollution control of antimony.

针对锑矿区含锑废水排放会造成的矿区流域水环境重金属严重污染、及如何强化微生物吸附处理含锑废水性能并解析其影响机制与机理的问题，基于芽孢杆菌选择性强、环境友好、成本低、重金属易回收和Fe(Ⅲ)使微生物表面去质子化、活化吸附位点等优点，以湖南锡矿山宝大兴矿区含锑废水和合成含锑废水为处理对象，本项目提出Fe(Ⅲ)改性耐锑芽孢杆菌吸附处理含锑废水的新方法。运用抗性筛选分离方法和分子生物学技术，从锑矿污染土壤中筛选鉴定出耐锑芽孢杆菌；以氯化铁为改性剂，采用侵泡/固化方法改性制备Fe(Ⅲ)改性耐锑芽孢杆菌吸附剂，对其结构表征；运用序批试验，采用统计学分析方法，得出主要影响因素对其除锑的影响机制；引入经典吸附理论，构建其除锑吸附模型，结合形貌、物理、化学及生物等表征技术，解析其化学与物理吸附过程及机理。研究有望形成较为完备的Fe(Ⅲ)改性耐锑芽孢杆菌吸附除锑理论体系，为锑矿区含锑废水提供技术与理论支撑。

针对锑矿区含锑废水排放会造成的矿区流域水环境重金属严重污染等问题，基于微生物吸附和铁盐吸附锑等优点，以含锑废水为处理对象，提出Fe(Ⅲ)改性耐锑菌株吸附处理含锑废水的新方法。获得主要结论：①筛选获得了Proteus cibarius、Rhodotorula glutinis等耐锑菌株，其液体极限耐Sb(Ⅲ)浓度MIC达400 mg/L，并获得其优化培育方法；②耐锑菌株的抗性基因存在于染色体上，通过细胞排锑、解毒作用、代谢调控等途径对锑发挥抗性；③获得Fe(Ⅲ)铁盐改性耐锑菌株吸附剂（FMPAs）的最优制备条件：Fe(Ⅲ)浓度0.1 mol/L、pH=3、温度35 ℃、改性时间24 h；④获得了FMPAs吸附去除锑的最佳吸附条件：Sb(Ⅲ)的最优吸附条件：吸附时间2.0 h，投加量3432 mg/L，pH =6，温度44.41℃，Sb(Ⅲ)初始浓度27.7 mg/L；Sb(V)的最优吸附条件：吸附时间3.0 h，投加量1910 mg/L，pH =2.31，温度44.96℃，Sb(V)初始浓度24.80 mg/L，FMPAs对Sb(Ⅲ)和Sb(V)的最大吸附容量分别为30.61和60.51 mg/g。适当延长吸附时间、增加吸附剂投加量、提高反应温度以及降低Sb(V)或Sb(Ⅲ)的初始浓度都对提高FMPAs的吸附率是有利的；⑤揭示了FMPAs吸附去除Sb(Ⅲ)和Sb(V)的机理：FMPAs吸附Sb(Ⅲ)和Sb(V)的吸附过程可用朗姆等温模型和准一级动力学模型拟合，主要为化学吸附。铁在FMPAs中主要以FeOOH和Fe2O3形态存在，Fe-O-OH和多糖里的-OH被Sb(Ⅲ)和Sb(V)取代而生成了新的配合物Fe-O-Sb，X≡Fe-OH里的-OH被Sb(Ⅲ)取代生成X≡Fe-Sb配合物，从而达到吸附去除Sb(Ⅲ)及Sb(V)的目的。本研究为锑矿区含锑废水提供技术与理论支撑。