三個垃圾滲出水處理廠的微生物氮循環交互作用

Abstract

厭氧氨氧化反應是一種低成本、無需碳源和氧氣供應的脫氮技術，在垃圾滲濾液處理中已有應用。本研究所探討之 TWT、BL 以及 XF 三個廠區在過去皆有成果培養出或是植種了厭氧氨氧化菌。然而，經過多年的水質操作變化，本研究藉由數位化核酸定量儀 (Digital Polymerase Chain Reaction, dPCR) 以及次世代定序 (Next Generation Sequencing, NGS)，定量氮相關基因並探討微生物組成的關係，以瞭解過去和現在水質以及微生物組成之間的差異。 根據水質參數分析、功能性基因定量以及菌種分析結果得知三個廠區反應槽性質差異大，TWT、BL 以及 XF 分別以硝化脫硝、部分硝化以及脫硝作用為各廠區反應槽主要之氮循環途徑。在過去三個廠區中皆有檢測到 Ca. Brocadia、Ca. Kuenenia 和 Ca. Anammoxoglobus 三種厭氧氨氧化菌屬，但目前 TWT 廠區僅剩下 Ca. Brocadia 以及 Ca. Anammoxoglobus 兩種菌屬；BL廠區在相對占比上則佔有一定比例的 Ca. Kuenenia 屬；而 XF 廠區則無檢測至厭氧氨氧化菌之存在，與過去相比，各廠區的厭氧氨氧化基因多樣性以及豐富度皆下降。 在水質條件上，以碳氮比和額外添加碳源對於廠區厭氧氨氧化菌的存在最具影響性。在碳氮比條件上，由於 BL 廠區具有較佳的碳氮比1.4，符合厭氧氨氧化菌生長所需；而現階段由於 BL 廠區的額外添加碳源－甲醇濃度的提高，以及 XF 跟 TWT 廠區的水肥處理量提升，增加了廠內 COD 之含量，一方面改變廠區優勢基因的組成，另一方面更不利於厭氧氨氧化菌的生存，導致厭氧氨氧化基因豐富度降低。

Anaerobic ammonia oxidation (Anammox) is a cost-effective nitrogen removal technology that does not require carbon sources or oxygen supply. It has been utilized in the treatment of landfill leachate. This study focuses on three treatment plants: TWT, BL and XF, which had achieved successful cultivation or inoculation of anaerobic ammonia-oxidizing bacteria. However, due to long-term changes in water quality, this research employs digital polymerase chain reaction (dPCR) and next-generation sequencing (NGS) techniques to quantify nitrogen-related genes and investigate the relationship with microbial composition. The aim is to understand the differences in water quality and microbial composition between the past and current. Analysis of water quality parameters, quantification of functional genes, and microbial analysis revealed significant differences among the three plants: TWT, BL, and XF. TWT primarily operates with nitrification-denitrification, BL exhibits partial nitrification, and XF relies on denitrification as the main nitrogen cycling pathway. In the past, all three plants harbored three types of Anammox bacteria, namely Ca. Brocadia, Ca. Kuenenia, and Ca. Anammoxoglobus. However, presently, only Ca. Brocadia and Ca. Anammoxoglobus are found in the TWT plant, with BL showing a certain proportion of Ca. Kuenenia. Also, no Anammox bacteria were detected in the XF plant. The diversity and abundance of Anammox genes have decreased in three plants compared to the past. According to water quality conditions, carbon-to-nitrogen ratio and the addition of supplemental carbon sources, greatly influence the presence of Anammox bacteria in the plants. BL plant demonstrates a favorable carbon-to-nitrogen ratio of 1.4, which is conducive to the growth of Anammox bacteria. However, the increase in concentration of additional carbon source-methanol in the BL plant and the elevated septic tank effluent concentration in XF and TWT plants, leading to higher COD levels, have altered the composition of dominant genes in each plant and created an unfavorable environment for Anammox bacteria, resulting in decreased abundance of Anammox genes.