Civil Engineering Department, Sharif University of Technology, Azadi Ave., P.O. Box. 11365-11155, Tehran, Iran.
Chemical and Petroleum Engineering Department, Sharif University of Technology, Azadi Ave., P.O. Box. 11365-11155, Tehran, Iran.
J Environ Manage. 2022 Jan 15;302(Pt A):113976. doi: 10.1016/j.jenvman.2021.113976. Epub 2021 Nov 8.
This research aims to improve simultaneous nitrification-denitrification and phosphorus removal (SNDPR) using novel carriers and to demonstrate the effect of carrier characteristics on nutrient removal in a biofilm reactor. For this purpose, biofilms enriched with both polyphosphate-accumulating organisms (PAOs) and nitrifiers were cultivated in two parallel sequencing batch reactors containing conventional moving bed bioreactor carriers (MBBR) and a novel type of carriers (carbon-based moving carriers (CBMC)). The new carriers were produced based on recycled waste materials via a chemical-thermal process and their specific surface area were 10.4 times higher than typical MBBR carriers of similar dimensions. The results showed that the use of CBMC carriers increased bacterial adhesion by about 18.5% and also affected the microbial population inside the biofilms, leading to an increase in PAOs abundancy and thus an increase in biological phosphorus removal up to 12.5%. Additionally, it was corroborated that the volume of the anoxic zones with dynamic behavior is strictly influenced by the carrier structure and biofilm thickness due to a limitation in oxygen penetration. Accordingly, the formation of broader anoxic zones and shrinkage of these zones to a lesser extent resulted in the continuation of anoxic reactions for longer periods using the novel carriers. Thereby, an increase in nitrogen removal by about 15% was obtained mainly by denitrifying PAOs. The results also exhibited that a higher simultaneous nitrification-denitrification (SND) efficiency can be achieved by selecting an appropriate aeration program influencing the dynamic changes of anoxic zones. Overall, a biofilm system using the new carriers, with phosphorus and nitrogen removal efficiencies of 97.5% and 92.3%, was presented as an efficient, compact, and simple operation SNDPR process.
本研究旨在利用新型载体提高同步硝化反硝化除磷（SNDPR）效率，并展示载体特性对生物膜反应器中营养物质去除的影响。为此，在两个平行的序批式反应器中培养了同时富含聚磷菌（PAOs）和硝化菌的生物膜，这两个反应器中分别填充了传统的移动床生物膜反应器载体（MBBR）和新型载体（基于回收废料的碳基移动载体（CBMC））。新型载体是通过化学-热过程由废弃材料制成的，其比表面积比典型的类似尺寸的 MBBR 载体高 10.4 倍。结果表明，使用 CBMC 载体可使细菌附着增加约 18.5%，并影响生物膜内的微生物种群，从而使 PAOs 的丰度增加，进而使生物除磷提高 12.5%。此外，还证实了具有动态行为的缺氧区的体积严格受到载体结构和生物膜厚度的影响，因为氧的穿透受到限制。因此，新型载体的使用会形成更宽的缺氧区，且这些区的缩小程度较小，从而使缺氧反应持续更长时间。因此，主要通过反硝化 PAOs 获得了约 15%的氮去除率的提高。结果还表明，通过选择影响缺氧区动态变化的适当曝气方案，可以实现更高的同步硝化反硝化（SND）效率。总体而言，使用新型载体的生物膜系统具有 97.5%的磷去除效率和 92.3%的氮去除效率，是一种高效、紧凑且简单操作的 SNDPR 工艺。
