基于复合微生物菌剂对化粪池水原位生化降解机理及效能优化的研究

Research on the Mechanism and Efficiency Optimization of in Situ Bio-Chemical Degradation of Septic Tank Wastewater Based on Compound Microbial Agents

摘要: 针对传统化粪池系统处理效率低、环境适应性差的问题，本研究系统探究了由短小芽孢杆菌(Bacillus pumilus)、短杆菌(Brevibacterium sp.)和铜绿假单胞菌(Pseudomonas aeruginosa)组成的复合微生物菌剂对化粪池废水的原位生化降解作用。通过单因素实验，优化确定了菌剂最佳投加比例(生物质湿重:废水体积 = 1:2)及关键参数(温度35℃、搅拌速率180~220 rpm)。在最优的菌种投加比例下，复合菌剂对化学需氧量(COD)、五日生化需氧量(BOD₅)、总氮(TN)和总磷(TP)的去除率分别达到85.3% ± 1.2%、83.7% ± 1.5%、82.6% ± 1.8%和81.9% ± 1.3%，同时温度和搅拌速率对降解效果有较大影响。同时开展了系统长期运行的效果分析，长期运行实验的平均去除率表明系统处理效能稳定。机理分析揭示，功能菌群通过协同代谢(包括水解、硝化及氧化还原等作用)高效降解有机物与营养盐，16S rRNA基因高通量测序证实了核心功能菌属的稳定存在与高活性。本研究为提升分散式污水处理系统的效能与稳定性提供了理论依据与技术方案，具有显著的生态环境效益与应用潜力。

Abstract: To address the issues of low treatment efficiency and poor environmental adaptability in tradi tional septic tank systems, this study systematically investigated the in situ biochemical degradation of septic tank wastewater by a compound microbial agent consisting of Bacillus pumilus, Brevibacterium sp., and Pseudomonas aeruginosa. Through single-factor experiment, the optimal dosage ratio of the agent (biomass wet weight: wastewater volume = 1:2) and key environmental parameters (temperature 35˚C, stirring rate 180~220 rpm) were determined. Under the optimal inoculation ratio of the composite microbial agent, the removal rates of chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD₅), total nitrogen (TN), and total phosphorus (TP) reached 85.3% ± 1.2%, 83.7% ± 1.5%, 82.6% ± 1.8%, and 81.9% ± 1.3%, respectively. Meanwhile, temperature and stirring rate had significant effects on the degradation performance. A 21-day long-term operation experiment demonstrated stable system performance. Mechanistic analysis revealed that the functional microbial community achieved efficient degradation of organic matter and nutrients through synergistic metabolism (including hydrolysis, nitrification, and redox reactions). Metagenomic sequencing confirmed the stable presence and high activity of the core functional genera. This study provides a theoretical basis and a technical solution for enhancing the efficiency and stability of decentralized wastewater treatment systems, demonstrating significant ecological and environmental benefits as well as application potential.