基于多Agent仿真解析处理剩余污泥的微生物电解池种群互作关系

Multi-agent simulation predicts interspecies interaction in microbial electrolysis cell using waste sludge

摘要:

【背景】微生物电化学系统耦合了电化学反应和厌氧消化过程，在处理剩余污泥同时实现能源回收，成为具有应用前景的技术之一。揭示电活性生物膜和活性污泥种群互作机制，有助于进一步调控和强化系统性能。高通量核酸测序技术研究微生物群落具有投入大、耗时长和不可预测的缺点，开展微生物群落动态仿真可以更有效地预测群落结构与功能。【目的】研究厌氧消化和生物电化学系统的微生物种间热力学与动力学的演化规律。在考虑电子供体、电子受体、温度、pH值等生态条件下，分析底物的电子流向及微生物群落结构的动态变化。【方法】通过对剩余污泥处理的微生物电解池(Microbial electrolytic cell，MEC)建立一个多Agent仿真(Multi-agent-based simulation，MAS)模型，评估MEC对底物氧化电子转移的能量效率和传质效率，模拟微生物群落结构实时变化，同时耦合动力学和热力学分析；揭示影响MES运行的电子流向决定性因素及相应的微生物种群，为复杂污染物生物处理系统中种间互作和动力学研究提供基础依据。【结果】通过MAS模拟，确定MEC污泥处理工艺的最佳能量传递效率与传质效率为η=0.2，ε=0.5，MAS结合热力学与动力学参数模拟微生物的群落动态与实验组有较高的吻合性。在长期的运行中，微生物电化学系统中丙酮酸没有积累。【结论】证实了MAS结合热力学与动力学参数可以预测微生物的群落动态，并进行实时监测。研究表明多Agent仿真为微生物群落结构动态变化提供了一种新的研究方法，该方法与高通量核酸测序技术进行校验和联用，为人工和自然生态系统中微生物种群预测与评估研究提供一个新的手段。

Abstract:

[Background] Microbial electrochemical system (MES) is coupled with electrochemical reaction and anaerobic digestion process. It is one of the technologies for implementing simultaneously energy recovery and waste sludge treatment. Understanding the syntrophic interaction in electroactive biofilm and activated sludge will be helpful to enhance the ability and regulation of bioreactors. High-throughput nucleic acid sequencing technology has the disadvantages of high cost, long time consumption and unpredictability. Therefore, dynamic simulation of microbial community will effectively predict structure and function. [Objective] The evolution of thermodynamics and kinetics between microbial species in anaerobic digestion and bioelectrochemical system was studied. Under the different ecological conditions including electron donor, electron acceptor, temperature and pH value, the electron flow direction of substrate and the dynamic change of microbial community structure were analyzed. [Methods] A multi-agent-based simulation (MAS) model was established for the microbial electrolysis cell (MEC) fed with waste sludge to evaluate the energy efficiency, mass transfer efficiency, and electron transfer from substrate oxidation of MEC, and to simulate the real-time change of microbial community structure coupled with dynamic and thermodynamic analysis. It revealed the decisive factors affecting the electronic flow direction of MEC and the corresponding microbial community, and provided the basis research on interspecies interaction and dynamics in the biological treatment system in complex pollutants. [Results] The optimal energy transfer efficiency (0.2) and mass transfer efficiency (0.5) of the MEC using waste sludge were determined through MAS simulation. The predicted microbial community dynamics under MAS with thermodynamic and kinetic parameters agreed with the high-throughput sequencing of 16S rRNA gene. Propionic acid was not accumulated in MEC during long-term operation. [Conclusion] It confirms that MAS combined thermodynamic and kinetic parameters can real-time predict the microbial community dynamics. The research shows that multi-agent simulation provides a new method to monitor the change of microbial community structure, which is flexible to combine with high-throughput nucleic acid sequencing technology, and will become a new approach for the prediction and estimation of microbial community in the engineered and natural ecosystems.