School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China.
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China.
J Environ Sci (China). 2020 Dec;98:179-185. doi: 10.1016/j.jes.2020.06.007. Epub 2020 Jun 21.
Bioaugmentation of denitrifying bacteria can serve as a promising technique to improve nutrient removal during wastewater treatment. While denitrification inhibition by bacterial quorum sensing (QS) in Pseudomonas aeruginosa has been indicated, the application of bacterial QS disruption to improve nitrate removal from wastewater has not been investigated. In this study, the effect of bioaugmentation of P. aeruginosa SD-1 on nitrate removal in sequencing batch reactors that treat nitrate rich wastewater was assessed. Additionally, the potential of a quorum sensing inhibitor (QSI) to improve denitrification following bacterial bioaugmentation was evaluated. Curcumin, a natural plant extract, was used as a QSI. The chemical oxygen demand (COD) and initial nitrate concentration of the influent were 700±20 mg/L and 200±10 mg/L respectively, and their respective concentrations in the effluent were 56.9±3.2 mg/L and 9.0±3.2 mg/L. Thus, the results revealed that bioaugmentation of P. aeruginosa SD-1 resulted in an increased nitrate removal to 82%±1%. Further, nitrate was almost completely removed following the addition of the QSI, and activities of nitrate reductase and nitrite reductase increased by 88%±2% and 74%±2% respectively. The nitrogen mass balance indicated that aerobic denitrification was employed as the main pathway for nitrogen removal in the reactors. The results imply that bioaugmentation and modulation of QS in denitrifying bacteria, through the use of a QSI, can enhance nitrate removal during wastewater treatment.
生物强化反硝化细菌可以作为一种提高废水处理中养分去除的有前途的技术。虽然已经表明铜绿假单胞菌的细菌群体感应（QS）对反硝化有抑制作用，但尚未研究利用细菌 QS 破坏来提高废水中硝酸盐的去除率。在这项研究中，评估了在处理富硝酸盐废水的序批式反应器中添加铜绿假单胞菌 SD-1 对硝酸盐去除的影响。此外，还评估了使用群体感应抑制剂（QSI）来改善细菌生物强化后的反硝化作用的潜力。姜黄素是一种天然植物提取物，用作 QSI。进水的化学需氧量（COD）和初始硝酸盐浓度分别为 700±20mg/L 和 200±10mg/L，出水的相应浓度分别为 56.9±3.2mg/L 和 9.0±3.2mg/L。因此，结果表明，添加铜绿假单胞菌 SD-1 可将硝酸盐去除率提高到 82%±1%。此外，添加 QSI 后几乎完全去除了硝酸盐，硝酸盐还原酶和亚硝酸盐还原酶的活性分别提高了 88%±2%和 74%±2%。氮质量平衡表明，好氧反硝化是反应器中脱氮的主要途径。结果表明，通过使用 QSI 对反硝化细菌进行生物强化和 QS 调节，可以增强废水处理中的硝酸盐去除。
