State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China..
J Environ Sci (China). 2019 Oct;84:144-154. doi: 10.1016/j.jes.2019.04.006. Epub 2019 Apr 13.
A systemic strategy was proposed to improve aerobic granular sludge (AGS) stability and nitrogen (N) removal efficiency by optimizing feeding mode and substrate aiming at complicated wastewater characteristics. Key functional groups at the genus level identified by high-throughput sequencing were evaluated as well. The results showed that anaerobic feeding mode and acetate promoted the compact AGS formation with excellent total nitrogen (TN) removal efficiency (averaging 91.7% ± 4.1%) at various dissolved oxygen conditions. While the aerobic feeding mode led to a loose AGS structure with a vulnerable anaerobic core and poor TN removal efficiency (averaging 58.8% ± 7.4%). Simultaneous nitrification and denitrification process played the dominant role in N removal in compact AGS over the alternating nitrification and denitrification process. High-concentration glucose undermined feast-famine condition with filamentous bacteria growth out of granule and decreased TN removal efficiency to 67.3% ± 15.2%. Lower food to microorganism ratio may result in a lower N removal rate attributed to the sharply increased biomass concentration fed by glucose. Ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying bacteria, and denitrifying phosphorus accumulation organisms enriched during AGS granulation also contributed to the efficient N removal. The proposed strategy provided insights into the relationship between various factors and stable AGS formation, and systemic operation methods for various complicated wastewater treatment.
提出了一种系统的策略，通过优化进料方式和基质，针对复杂废水的特点，提高好氧颗粒污泥（AGS）的稳定性和脱氮效率。还评估了高通量测序确定的关键功能组在属水平上的作用。结果表明，在不同溶解氧条件下，采用厌氧进料方式和乙酸盐促进了紧凑 AGS 的形成，具有优异的总氮（TN）去除效率（平均 91.7%±4.1%）。而好氧进料方式导致AGS 结构松散，厌氧核心脆弱，TN 去除效率差（平均 58.8%±7.4%）。在紧凑的AGS 中，同步硝化反硝化过程在脱氮中起主导作用，而交替硝化反硝化过程则起次要作用。高浓度葡萄糖破坏了饥饿-饱食条件，丝状菌从颗粒中生长出来，降低了 TN 去除效率至 67.3%±15.2%。由于葡萄糖进料引起的生物量浓度急剧增加，较低的食物与微生物比可能导致较低的氮去除率。AGS 成粒过程中富集的氨氧化菌、亚硝酸盐氧化菌、反硝化菌和反硝化除磷菌也有助于高效脱氮。所提出的策略为各种因素与稳定 AGS 形成之间的关系以及各种复杂废水处理的系统操作方法提供了新的思路。
