An Innovative Process for Mature Landfill Leachate and Waste Activated Sludge Simultaneous Treatment Based on Partial Nitrification, In Situ Fermentation, and Anammox (PNFA)

Abstract

An innovative partial nitrification, in situ fermentation, and Anammox (PNFA) system was developed to achieve mature landfill leachate and waste activated sludge simultaneous treatment. Three separate sequencing batch reactors (SBRs) were used for partial nitrification (PN-SBR), integrated fermentation–denitrification (IFD-SBR), and partial nitrification–Anammox (PNA-SBR). After 200 days of continuous operation, a satisfactory nitrogen removal efficiency (NRE) of 99.2 ± 0.1% was obtained, with an effluent total nitrogen (TN) of 15.2 ± 3.2 mg/L. In IFD-SBR, the volatile fatty acids generated from fermentation drove efficient denitrification, obtaining sludge and nitrogen reduction rates of 4.2 ± 0.7 and 0.61 ± 0.04 kg/m3·day, respectively. Furthermore, unwanted fermentation metabolites (134.1 mg/L NH4 +-N) were further treated by PNA-SBR using a combination of step-feed and intermittent aeration strategies. In PNA-SBR, Anammox significantly contributed to 82.1% nitrogen removal, and Anammox bacteria (Candidatus Brocadia, 2.3%) mutually benefited with partially denitrifying microorganisms (Thauera, 4.2%), with 66.3% of generated nitrate reduced to nitrite and then reutilized in situ by Anammox. Compared with the conventional nitrification–denitrification process, PNFA reduced oxygen energy consumption, external carbon source dosage, and CO2 emission by 21.3, 100, and 38.9%, respectively, and obtained 50.1% external WAS reduction efficiency.

Achieving stable anammox process and revealing shift of bacteria during the start‐up in landfill leachate treatment

“…It took more than 200 days to obtain a relative abundance of Nitrosomonas up to 0.95% and 5.2%, respectively, when treating domestic wastewater and landfill leachate with reduced dissolved oxygen (DO < 1.5 mg·L −1 ). (Deng et al, 2021; Zhang et al, 2022). In conclusion, AOB and AnAOB coexist in a low‐oxygen reactor and would endure the presence of COD as a novel sewage treatment method.…”

“…Prior research has enriched Ca . Kuenenia with percentages of 1.39% and 2.3% in a separate reactor under landfill leachate treatment (Wu et al, 2019; Zhang et al, 2022) inoculating enriched AnAOB sludge. Compared to the stable stage, a small increase was detected in the crash stage.…”

Revisiting the Engineering Roadmap of Nitrate/Nitrite-Dependent Anaerobic Methane Oxidation

“…The treatment of leachate is of great importance to prevent the contamination of soil, surface water, and groundwater. 105 Since mature landfill leachate contains high-strength ammonia but low-strength biodegradable organic matter, traditional biological nitrogen removal based nitrification-denitrification faces great challenges due to the shortage of carbon sources. 106 In the leachate treatment scenario (Figure 10c), the ammonia-rich leachate is subjected to generate steam containing nitrite and ammonium via a PN unit.…”

Feasibility of Partial Nitrification Combined with Nitrite-Denitrification Phosphorus Removal and Simultaneous Nitrification–Endogenous Denitrification for Synchronous Chemical Oxygen Demand, Nitrogen, and Phosphorus Removal

“…The nitrite needed for the nDNPR process could be provided through the PN of ammonia-rich wastewater. 13 Therefore, the novelty of this study is underlying the detailed mechanism of the integrated PN and nDNPR-SNED system for synchronous COD, N, and P removal from municipal wastewater. The metabolic pathways and nutrient mass balance were investigated.…”

“…Therefore, the nDNPR-SNED process would be more attractive than traditional biological wastewater treatment in saving carbon and reducing aeration. The nitrite needed for the nDNPR process could be provided through the PN of ammonia-rich wastewater …”