基于孔结构调控强化生物增强活性炭吸附与生物降解协同效能的机理研究

Bio-Enhanced Activated Carbon (BEAC) process has been proved to be a mature technology for drinking water depth treatment. Synergy effect between adsorption and biodegradation is the critical factor which can cause stable and high effective operation. Previous studies confirmed that adsorption and biodegradation can be well strengthened by carbons with synchronously well-developed meso--porous and micro-porous structures. It provides a novel way to further strengthening the BEAC efficiency. However, studies focusing on pore-structure regulation and mechanism of synergy effect between biodegradation and adsorption are still big challenges. In order to solving the technical problems of pore-structure regulation for bio-degradation process, invention of in-situ modification methods will be proposed in this project, aiming at the establishment of ideal surficial micro-circumstance for functional bacteria in BEAC process. Directional regulation of pore structure and optimization of surface physical and chemical properties will be consequently conducted. To clarify mechanism of synergy effect between adsorption and biodegradation caused by pore structure regulation, studies focusing on influencing mechanism of adsorptive property, function bacteria immobilization, biodegradation and key enzyme activity will be intensively studied. Through the combination of molecular biology and mathematical model, quantification method for synergy effect and bio-regeneration will be determined. Based on above research findings, fundamental performance evaluation index system of carbons focusing on bio-enhancement will be proposed. And comprehensive quantitative indicators system will be consequently established and improved. Research findings in this project can provide new material and theoretical-technical support to depth water treatment process using activated carbon. The research can provide a reliable theory base and reference for stable operation of BEAC process.

生物增强活性炭（BEAC）工艺是饮用水深度处理的成熟技术，其稳定高效运行的关键在于吸附与生物降解作用的协同。前期研究证实，同步发达的中、微孔结构可促进活性炭吸附及生物降解效能的提高，这为进一步强化BEAC工艺效能提供了新途径。但孔结构调控及吸附与生物降解协同作用机制仍属亟待揭示科学问题。本项目将通过研发活性炭原位改性方法，实现对孔结构的定向裁制及表面物化特性的优化，构建利于功能菌生长的表面微环境，解决适合生物强化的活性炭改性技术难题。开展孔结构对吸附、功能菌固定特征、生物降解效能、关键酶活性及作用途径的影响机制研究，阐明孔结构分布调控对吸附与生物降解协同作用的影响途径。通过净水特性、分子生物学与数理模型相结合的方法，解决生物再生及协同效能的量化难题。在上述研究的基础上，构建适宜BEAC工艺的高效活性炭选用技术指标体系。本项目将为保障我国饮用水供水安全提供新材料、新理论和运行调控关键技术。

本项目提出的碳素前体物复配、物化耦合催化活化及深度活化相结合的原位同步调控方法，显著提升了压块净水活性炭的总孔容积、中孔结构的孔径分布范围及中孔孔隙率（60%以上）。催化活化和深度活化过程则显著增强了炭表面含氧基团含量及酸性有机官能团丰度。通过本项目提出的改进工艺，成功制备了具有同步发达的大、中、微孔结构的新型高效煤质净水炭XHIT-8162。通过快速吸附实验体系（RSSCT）及生物增强活性炭小试体系的试验研究证实：对于活性炭中微孔结构的同步调控显著提升了净水炭对大分子天然有机物及无机离子的同步吸附效能，合理的大、中孔结构及表面微环境更加适宜功能菌负载及生物降解活性的发挥，炭表面循环负载生物量及增殖性能提升显著。在长期生物增强活性炭中试工艺净水效能跟踪研究的基础上，进一步明确了孔结构调控强化生物增强活性炭工艺中生物降解与活性炭吸附协同作用的机制。通过RSSCT计算的物化吸附量变化曲线与中试工艺净水效能曲线，提出了以污染物累积去除总量为量化指标的生物降解及吸附协同效能量化方法。针新型活性炭净水寿命及饱和炭的再生回用则研究表明，吸附与生物降解协同效能的提升增强了炭表面吸附点位的原位同步再生效率，功能菌活性及稳定性较微孔型炭显著增高，从而有效的提升了炭寿命及饱和炭的再生及回用效能。在对净水厂现行选用活性炭指标体系进行技术就绪度等级评价的基础上，完善了适宜BEAC工艺的活性炭基础指标体系，建立并完善了加权综合评价指标体系。研究同时阐明了原位调控方法制备的铁/钙原位改性炭GL100/200及FGL4实现对大分子天然有机物及类金属离子的高效同步吸附机理。