活性污泥包埋颗粒的制备及其氨氮处理性能

Preparation of activated sludge embedded particles and the treatment performance of ammonia nitrogen

脱氮是污水治理的重要目标之一。在实际污水处理中,由于起主要脱氮作用的硝化菌生殖代谢速率慢,易受冲击,且易流失,以致活性污泥的脱氮能力在运行过程中易受影响,因此,利用微生物固定化技术将硝化菌截留在生化池中具有重要意义。经聚氧化丙烯三醇(polyoxypropylene triol, PPT)改性后的聚乙烯醇(polyvinyl alcohol, PVA)凝胶颗粒可以有效将活性污泥进行固定化并用于污水处理中。结果表明:改性后的凝胶球具有热稳定性好、孔隙分布均匀、比表面积较大、总孔容较大等优点,用改性聚乙烯醇凝胶颗粒包埋驯化后的活性污泥,经过活性恢复处理后,与初始污泥相比,氨氧化速率提升18.28%,呼吸速率降低2.01%,且由于形成较好的厌氧、缺氧、好氧环境,微生物种群多样性、物种丰富度及群落均匀性均升高,并有较好的氨氮去除性能,在低浓度废水治理中,氨氮去除率达到70%。上述研究中分析了改性凝胶颗粒的性能以及包埋活性污泥中微生物菌群和活性的变化,可为凝胶包埋活性污泥技术在氨氮废水治理的研究提供参考。

Nitrogen removol is one of the most important objectives in sewage treatment. In actual sewage treatment, the nitorgen removal capacity of activated sludge can be easily influenced due to the slow reproduction and metabolism rates, susceptible to shock and easy-loss of nitrifying bacteria, which play the key role in nitrogen removal. So it is of great significance to use immobilized microorganism technology to maintain nitrifying bacteria in biochemical tank. The polyvinyl alcohol(PVA) gel particles modified by polyoxypropylene triol(PPT) can effectively immobilize activated sludge and be used in sewage treatment. This study showed that the modified gel ball had the advantages of good thermal stability, uniform pore distribution,large specific surface area, and large total pore volume. After activity recovery, the embedded and domesticated activated sludge by modified polyvinyl alcohol gel particles showed 18.28% increase in its ammonia oxidizing rate and 2.01% decrease in its respiration rate when compared with the original sludge. Due to the formation of the anaerobic-anoxic-aerobic environment in gel particle, the microbial community diversity indexes, i.e.shannon diversity, species richness, and community evenness, increased, and good ammonia nitrogen removal occurred for immobilized activated sludge. The removal rate of ammonia nitrogen could reach 70% for low strength wastewater treatment. In this research, the properties of modified gel materials and the changes of microbial community and activity in embedded activated sludge were studied and analyzed, which provides reference for the research of gel-embedding activated sludge technology in ammonia nitrogen wastewater treatment.