基于吸附与电化学氧化双功能磁性生物碳对17ß-雌二醇降解机理研究

The contamination of various water environments by 17ß-estradiol (E2) is serious these days. Biochar adsorption method is well known for high adsorption capacity and treatment efficiency. However, with single adsorption method, the complete E2 elimination and continuous reuse for E2 adsorption are difficult. In this sense, this study, based on the high conductivity and high adsorption properties of biochar, suggests a novel E2 remediation principle by magnetically “on-off” control of the dual-functional magnetic biochar for adsorption and low voltage electrochemical oxidation combined method, and to make the magnetic biochar regenerable for continuous remediation of E2 polluted environmental water. This research would firstly study on the method of synthesizing high conductivity and high E2 adsorption efficiency magnetic biochar, and then perform E2 adsorption with magnetic biochar followed by magnetic controlled concentration of the E2 adsorbed magnetic biochar on the electrode for a low voltage electrochemical degradation. The remediation efficacy, mechanism and various environmental factors effect on the remediation efficacy would also be revealed. This research would provide theoretical evidences and techniques for the adsorption and electrochemical oxidation combined continuous E2 remediation mechanism, for developing potential capability of biochar, and for the continuous remediation of E2 polluted water.

目前国内外各种水环境中17ß-雌二醇（E2）污染问题突出，生物碳吸附法因吸附容量大、处理效率高而广受青睐，然而用单一的吸附法难以对E2彻底消除及连续去除利用。本研究拟基于生物碳的高导电性和高效吸附特性，提出通过磁场“关-开”式控制将双功能磁性生物碳吸附和低电压电化学氧化相结合的新型E2修复机理，达到对污染水环境中E2的高效连续修复以及磁性生物碳可再生利用的效果。研究具备高导电性和E2高效吸附性的磁性生物碳合成方法的基础上，进行磁性生物碳对E2的吸附、电极表面上的磁控制富集和低电压电化学氧化降解，揭示修复效果、修复机理、以及各种环境影响因素。该研究为揭示吸附法和电化学氧化法相结合连续修复E2污染环境的机理、生物碳的潜能开发、E2污染水体的修复提供理论依据和技术。

本研究基于磁场“关-开”式控制双功能磁性生物碳吸附和低电压电化学氧化相结合修复E2为目的，建立了高导电性和E2高效吸附性的纳米大小磁性生物碳合成方法，揭示了甘蔗渣来源生物碳的电导性可通过控制制备参数而调节，且较高热解温度制备的生物碳具有更优越的电子转移能力。证明了磁性生物碳具有大的比表面积和多孔结构，可对E2以Langmiur模型快速高容量吸附，相比π-π结合，氢键为主导吸附作用力。揭示了磁控富集下吸附－电化学氧化协同E2去除机制，利用0.3 mg•mL-1 磁性生物碳（Mag-BC800）在0.7 V 电压下，60小时可降解92.70%的1 mg•L-1E2，优越于无磁场富集时的效率（71.93％），由此，明确了电极上磁富集通过提升电子转移速率增强电氧化降解的效应。利用吸附和电氧化一体化连续E2去除研究中，第４次吸附－电氧化去除率保留初始的60%以上。.　 本研究获得了高导电、高效吸附性磁性生物碳，明确了材料电化学特性和E2吸附机理，初步阐明了生物碳结构特性与性能的相关关系，实现了吸附和原位低电压氧化的有效耦合，为低成本绿色修复E2污染提供了借鉴和参考。