Enhancing integrated denitrifying anaerobic methane oxidation and Anammox processes for nitrogen and methane removal: A review

The integration of denitrifying anaerobic methane oxidation (DAMO) and anaerobic ammonium oxidation (Anammox) simultaneously converts ammonium, methane, and oxidized nitrogen species (nitrite and nitrate) to harmless N2 and CO2. This integrated and complementary process achieves the nitrogen and carbon cycles in wastewater with the potential to be applied widely at full scale to realize energy-positive wastewater treatment plants (WWTPs). In this review, we summarize the collaborative and competitive interactions of DAMO–Anammox microorganisms and systematically evaluate the challenges for the full-scale application of integrated DAMO–Anammox for wastewater treatment, including their extremely slow growth rate, low metabolic activity, and limited nitrogen and methene removal rate. We examine comprehensively the critical role of bioreactor design (attached, suspended, and granular sludge systems) for biomass retention and substrate transfer. The paper also discussed strategies involving trace elements (Cu(II) and Fe(II)), Zero Valent Iron (ZVI), and External Electrostatic Fields (EEFs) to enhance the DAMO–Anammox microbial activities. Further review is provided on the addition of Humics, quinone-compound anthraquinone-2,6-disulfonate (AQDs), Fe(III), Mn(IV) as electron acceptors through extracellular electron transfer (EET) and couple with autotrophic denitrification (AuDen) (H2S and Fe(II)) to accelerate nitrogen and methane removal. Finally, a conceptual design of innovative WWTPs based on the integrated DAMO–Anammox was proposed.

反硝化厌氧甲烷氧化（denitrifying anaerobic methane oxidation, DAMO）与厌氧氨氧化（anaerobic ammonium oxidation, Anammox）的耦合工艺，可同时将铵盐、甲烷与氧化态氮物种（亚硝酸盐与硝酸盐）转化为无害的氮气（N₂）与二氧化碳（CO₂）。该耦合互补工艺可实现污水中的氮、碳循环，具备大规模全流程应用的潜力，助力实现能量自给型污水处理厂（wastewater treatment plants, WWTPs）。本综述总结了DAMO与Anammox微生物的协同与竞争相互作用，并系统评估了耦合DAMO-Anammox工艺用于污水处理的全规模应用挑战，包括微生物生长速率极慢、代谢活性低下，以及氮与甲烷去除速率有限等问题。本综述全面探讨了生物反应器设计（附着型、悬浮型及颗粒污泥系统）在生物质保留与底物传递中的关键作用。本文还讨论了通过微量元素（Cu(II)与Fe(II)）、零价铁（Zero Valent Iron, ZVI）及外部静电场（External Electrostatic Fields, EEFs）强化DAMO与Anammox微生物活性的相关策略。本文进一步综述了通过添加腐殖质、醌类化合物蒽醌-2,6-二磺酸盐（AQDs）、Fe(III)与Mn(IV)作为电子受体，借助胞外电子传递（extracellular electron transfer, EET）并与自养反硝化（autotrophic denitrification, AuDen，涵盖H₂S与Fe(II)途径）耦合，以加速氮与甲烷去除的相关研究进展。最后，本文提出了基于耦合DAMO-Anammox工艺的创新型污水处理厂概念设计方案。