Organic Wastewater Treatment Research Articles

Efficient utilization of photoelectron-hole at semiconductor-microbe interface for pyridine degradation with assistance of external electric field

In this study, enhanced pyridine bio-photodegradation with assistance of electricity was achieved. Meanwhile, photoelectron-hole played a vital role in accelerating pyridine biomineralization. The significant separation of photoelectron-hole was achieved with an external electric field, which provided sufficient electron donors and acceptors for pyridine biodegradation. The enhanced electron transport system activity also revealed the full utilization of photoelectron-hole by microbes at semiconductor-microbe interface with assistance of electricity. Microbial community analysis confirmed the enrichment of functional species related to pyridine biodegradation and electron transfer. Microbial function analysis and microbial co-occurrence networks analysis indicated that upregulated functional genes and positive interactions of different species were the important reasons for enhanced pyridine bio-photodegradation with external electric field. A possible mechanism of enhanced pyridine biodegradation was proposed, i.e., more photoelectrons and holes of semiconductors were utilized by microbes to accelerate reduction and oxidation of pyridine with the assistance of electrical stimulation. The excellent performance of the photoelectrical biodegradation system showed a potential alternative for recalcitrant organic wastewater treatment.

Recent developments in synthesis of attapulgite composite materials for refractory organic wastewater treatment: a review.

Attapulgite clay, due to its unique crystalline hydrated magnesium-aluminium silicate composition and layer-chain structure, possesses exceptional adsorption and catalytic properties, which enable it or its composites to be utilized as adsorbents and catalysts for wastewater treatment. But the drawbacks of attapulgite are also very obvious, such as relatively low specific surface area (compared to traditional adsorbents such as activated carbon and activated alumina), easy aggregation, and difficulty in dispersion. In order to fully utilize and improve the performance of attapulgite, researchers have conducted extensive research on its modification, but few specialized works have comprehensively evaluated the synthesis, applications and challenges for attapulgite-based composite materials in refractory organic wastewater treatments. This paper provides a comprehensive review of controllable preparation strategies, characterization methods and mechanisms of attapulgite-based composite materials, as well as the research progress of these materials in refractory organic wastewater treatment. Based on this review, constructive recommendations, such as deep mechanism analysis from molecular level multi-functional attapulgite-based material developments, and using biodegradable materials in attapulgite-based composites, were proposed.

Anaerobic MBR for High Organic Wastewater Treatment

Anaerobic MBR for High Organic Wastewater Treatment

Enhanced detection of acrylamide using a versatile solid-state upconversion sensor through spectral and visual analysis

Acrylamide (AM) generally forms in high-temperature processes and has been classified as a potential carcinogen. In this study, we put forward a maneuverable solid-state luminescence sensor using polydimethylsiloxane (PDMS) as the matrix coupled with upconversion nanoparticles as the indicator. The core-shell upconversion nanoparticles emitting cyan light were uniformly encapsulated in PDMS. Then it was further modified with complementary DNA of AM aptamer. The nanocrystalline fluorescein isothiocyanate isomer (FITC), coupled with AM aptamer, was attached to the surface of PDMS. FITC effectively quenched the upconversion luminescence through fluorescence resonance energy transfer (FRET). The introduction of AM resulted in preferentially bound to aptamer caused the separation of the quencher and the donor, and led to luminescence recovery. The developed sensor was applied for both spectral and visual monitoring, demonstrating a detection limit (LOD) of 1.00 nM and 1.07 nM, respectively. Importantly, in the actual foodstuffs detection, there is no obvious difference between the results of this study and the standard method, which indicates the developed method has good accuracy. Therefore, this solid-state sensor has the potential for on-site detection using a smartphone device and an Android application.

Novel process for organic wastewater treatment using aerobic composting technology: Shifting from pollutant removal towards resource recovery

In this study, an organic wastewater treatment process based on aerobic composting technology was developed in order to explore the transition of wastewater treatment from pollutants removal to resource recovery. The novelty of the process focuses towards the microbial metabolic heat that is often ignored during the composting, and taking advantage of this heat for wastewater evaporation to achieve zero-discharge treatment. Meanwhile, this process can retain the wastewater's nutrients in the composting substrate to realize the recovery of resources. This study determined the optimum condition for the process (initial water content of 50 %, C/N ratio of 25:1, ventilation rate of 3 m3/h), and 69.9 % of the total heat generated by composting was used for wastewater treatment under the condition. The HA/FA ratio of composting substrate increased from 0.07 to 0.53 after wastewater treatment, and the retention ratio of TOC and TN was 52.3 % and 61.7 %, respectively, which proved the high recycling value of the composting products. Thermoduric and thermophilic bacteria accounted for 44.3 % of the community structure at the maturation stage, which played a pivotal role in both pollutant removal and resource recovery.

Silver‐anchored dendrimer efficiently Light‐drive conversion of p‐nitrophenol

AbstractEfficient use of solar energy for photocatalytic organic synthesis and degradation of organic matter is one of the most promising ways to solve energy shortage and environmental pollution. Silver/sulfur‐doped polyimide (Ag/SPI) was successfully prepared by anchoring silver nanoparticles on sulfur doped polyimide with dendriform structure by an open‐loop and closed‐loop method. Through the analysis of the structure, morphology and photoelectric properties by different characteristics, it is found that the anchoring of silver nanoparticles greatly reduces the electron‐hole recombination rate of SPI, and the cyclic stability is relatively good, and the electrons generated by photoexcitation can participate in the reduction of p‐nitrophenol more. Therefore, the activity of degradation of organic pollutants was greatly improved under the irradiation of visible light. At 5 minutes, the degradation rate of p‐nitrophenol reached 100 %, and the only product p‐nitrophenol was generated. The reaction time was 12 times that of SPI without anchored metal particles. The Ag/SPI dual‐function catalyst provides a new idea for the application of p‐nitrophenol wastewater treatment and the conversion of p‐aminophenol and provides a new reference direction for the field of organic wastewater treatment and organic synthesis.

Synergistic removal of organics from semi-coke wastewater by persulfate and cyanide tailings

In this study, the persulfate and cyanide tailings (PS-CTs) were used for the synergistic treatment of semi-coke wastewater to achieve advanced oxidation and in-situ coagulation removal of organics in semi-coke wastewater. The effects of persulfate concentration, reaction temperature, cyanide tailing concentration and initial pH on chemical oxygen demand (COD) removal efficiency were investigated, and the synergistic mechanism in the treatment process was further explored. The results showed that the removal efficiency of COD in semi-coke wastewater was 94.49 % under the conditions of persulfate concentration 0.025 mol/L, reaction temperature 60 °C, cyanide tailings concentration 5 g/L, the initial pH value of 3. The results of the mechanistic analysis showed that in PS-CTs system, pyrite was oxidized by persulfate. The dissolved Fe2+ activated the persulfate to produce SO4− and OH and generated Fe3+ in situ. The hydrolysis of Fe3+ produced a series of complex ions and amorphous iron hydroxides, which could remove some organics by adsorption and sweeping netting. The organics in semi-coke wastewater were effectively removed by the combined effect of oxidation and coagulation. In addition, the PS-CTs system also achieved the oxidative de-cyanidation of cyanide tailings simultaneously, and the total cyanide concentration of treated cyanide tailings was 8.21 mg/kg, and the leaching cyanide concentration was 0.12 mg/L, which was in line with the emission standards. This process implemented the concept of “treating waste with waste”, and provided theoretical support for the treatment of semi-coke wastewater and other organic wastewater.

Process-specific volatile organic compounds emission characteristics, environmental impact and health risk assessments of the petrochemical industry in the Beijing-Tianjin-Hebei region.

Volatile organic compounds (VOCs) concentration, source profiles, O3 and SOA formation, and health risks were investigated in the petrochemical industry in Beijing-Tianjin-Hebei. The results showed that total VOCs concentrations were 547.1-1956.5μg·m-3, and alkanes were the most abundant group in all processes (31.4%-54.6%), followed by alkenes (20.6%-29.2%) and aromatics (10.1%-25.1%). Moreover, ethylene (11.3%), iso-pentane (7.1%), n-hexane (5.1%), benzene (4.9%) and 2,2-dimethylbutae (4.8%) were identified as the top five species released for the whole petrochemical industry. The coefficient of divergence between the source profiles from different processes was 0.49-0.73, indicating that most source profiles must not be similar. Moreover, because of the different raw materials and technologies used, the source profiles in this study are significantly different from those of other regions. The ozone and secondary organic aerosol formation potentials (OFPs and SOAPs) were evaluated, suggesting that ethylene, propylene, 1-butene, m,p-xylene, and 1,3-butadiene should be preferentially controlled to reduce OFPs. That benzene, toluene, ethylbenzene, m,p-xylene, isopropylbenzene, o-ethyltoluene, and 1,3,5-trimethylbenzene should be priority control compounds for SOAPs. Additionally, the total hazard ratio for non-cancer risk ranged from 0.9 to 7.7, and only living area was unlikely to be related to adverse health effects. Cancer risks associated with organic chemicals, rubber synthesis, oil refining, and wastewater collection and treatment have definite risks, whereas other processes have probable risks. This study provides a scientific basis for VOCs emission control and management and guides human health in the petrochemical industry.

Mutualistic symbiosis of fungi and nitrogen-fixing bacteria in halophilic aerobic granular sludge treating nitrogen-deficient hypersaline organic wastewater

Hypersaline organic wastewater is characterized as being nitrogen-deficient, and is easily prone to sludge bulking. In this study, the stability of halophilic aerobic granular sludge (HAGS) for the treatment of hypersaline organic wastewater is explored. Along with the decrease of influent ammonium, the bacterial population substantially reduced, whereas the fungal population continuously increased in HAGS. Saccharomycetales in fungi become the dominant sequence (99.78%) in HAGS bulking. Additionally, Halanaerobium (77.47%) remained prevalent in HAGS despite bacterial washout. Halanaerobium, a nitrogen-fixing genus of bacteria, provided nitrogen for ammonium-assimilating fungi. Saccharomycetales encapsulating HAGS reduced the transfer efficiency of dissolved oxygen, thereby creating favorable growth conditions for Halanaerobium. This paper for the first time highlights the mutualistic symbiosis of fungi and bacteria in HAGS treating the hypersaline organic wastewater. The study lays the foundation for the control and recovery of HAGS bulking.

Enhanced oxidative capacity of red mud-lignin composite/peroxydisulfate to degrade sulfamethazine through electron transfer mechanism

Advanced oxidation processes based on peroxydisulfate (PDS-AOPs) have been used for the remediation of organic wastewater. However, the mechanism for the generation of electron transfer sub-stable complexes in the metal–carbon/PDS system has not been fully elucidated. Herein, two environmental solid wastes were selected to synthesize a novel Fe-carbon catalyst (RM@KC1:2–800) using alkali lignin as the carrier and red mud (RM) as the iron source, and applied for peroxydisulfate (PDS) activation in sulfamethazine (SMZ) removal. The complexation of alkali lignin with RM favored the exposure of Fe active sites and adsorption of PDS. 97% of SMZ could be removed efficiently in the RM@KC1:2–800/PDS system, and the degradation efficiency remained at 80.81% after 5 cycles without metal leaching, which was suitable for a variety of natural water bodies. Combined with density functional theory (DFT) and other analyses confirmed that the electron transfer pathway is the main pathway for PDS activation and SMZ degradation. And the reactive Fe species were the active sites that contributed to the adsorption of PDS on the RM@KC1:2–800 surface to form sub-stable complexes (RM@KC-PDS*), whereby the electron transfer occurred. Surprisingly, the prediction of environmental toxicity of the degradation intermediates based on T.E.S.T software and biological experiments proved their environmental friendliness. Overall, this study follows the concept of “waste-to-waste” and proposes a strategy for a suitable and cost-effective Fe-carbon catalyst for large-scale production, while demonstrating its potential application in the treatment of organic wastewater.

Research Progress in the Development and Application of Photocatalysis Technology and Materials

In recent years, photocatalytic technology has become a research hotspot for the treatment of organic wastewater, uranium containing wastewater, and Cr (VI) containing wastewater due to its advantages of environmental friendliness, simple reaction process, and high degradation efficiency. Uranium, as the main component of nuclear fuel, is an important strategic resource. The separation and enrichment technology of uranium is of great significance for the sustainable development of nuclear energy. Previously, a series of solid adsorption materials for uranium extraction have been developed, such as inorganic minerals, mesoporous silica, magnetic nanomaterials, carbon based materials, and advanced porous materials. However, due to the comprehensive performance of stability, removal kinetics, adsorption capacity, selectivity, and reusability, the practical application of these materials is still inevitably limited. And photocatalytic technology can reduce easily soluble and easily flowing U (VI) to more difficult to dissolve and relatively non flowing U (IV), thus overcoming the above problems and achieving the reduction and fixation of uranium. Moreover, this technology only relies on inexhaustible solar energy as energy source, and has the advantage of green and clean. Therefore, the use of photocatalytic technology to separate and enrich uranium is of great significance for the sustainable development of nuclear energy. However, most semiconductor photocatalysts have shortcomings in terms of light absorption capacity and charge separation ability, which limits their practical application in wastewater treatment. In addition, there are many difficulties in photocatalytic treatment of wastewater, such as the fast recombination speed of photo generated electron hole pairs generated by the catalyst, the weak visible light response of most single semiconductor materials, the need to introduce additional sacrificial agents to capture holes in the reaction, and the introduction of inert gases to eliminate the interference of oxygen. This article provides a certain scientific basis for expanding the application of various photocatalytic technologies in wastewater treatment.

Performance and mechanism of enhanced phenolic compounds treatment via mycelial pellets

AbstractBACKGROUNDBiological enhancement in organic wastewater treatment is currently considered an effective and economical method. As a biomass carrier, mycelial pellets are attracting increasing attention, with substantial progress recently being made. To investigate their bioaugmentation effect as a biomass carrier, mycelial pellets with immobilized phenol‐degrading bacteria were applied in a sequencing batch reactor. The phenolic compound removal efficiency of the mycelial pellet‐enhanced system was then studied and compared to the control aerobic activated sludge‐enhanced system. Finally, the settling velocity, internal structure, and surface properties were studied to explore the main bioaugmentation mechanisms of the mycelial pellets.RESULTSThe stable degradation effects of phenolic compounds and total organic carbon (TOC) were observed in both systems. In the mycelial pellet system, the biological removal efficiency was approximately 0.5 mg phenolic compounds L−1 d−1MLSS−1 and 0.4 mg TOC L−1 d−1MLSS−1, which was higher than the aerobic activated sludge system. Bioaugmentation by the pellets was mainly attributed to the structure of the connected macropores, the electrostatic attraction of positive charges, the adsorption of functional groups on the hypha surface, and flocculation due to the extracellular polymeric substances secreted on the pellet.CONCLUSIONThe excellent phenolic compound removal efficiency and bioaugmentation effect of the mycelial pellets suggest their potential to enhance organic wastewater treatment as a biomass carrier. © 2023 Society of Chemical Industry.

A novel bimetallic Fe-Cu-CNT catalyst for effective catalytic wet peroxide oxidation: reaction optimization and mechanism investigation

Treatment of organic wastewater is of great importance and can be carried out by catalysis technologies such as catalytic wet peroxide oxidation (CWPO). A novel bimetallic Fe-Cu-CNT catalyst was first developed by a facile hydrothermal method; Fe species (Fe (Ⅱ) and Fe (Ⅲ)) and Cu species (Cu (Ⅰ) and Cu (Ⅱ)) were used to fabricate the catalyst with the CNTs, which was stable during testing. Methylene blue (MB) was chosen as model compound for the study; the optimization for treatment by the Box-Behnken design indicated that a combination of low pH, high MB concentration and intermediate temperature led to better treatment performance. The CWPO reaction obeyed the 2nd-order kinetic equation and the catalyst activity increased with an increase in the Cu content. The reaction induction period was shortened with decreasing Fe:Cu ratio. The cycling reaction between Fe3+/Fe2+ and Cu2+/Cu+ pairs generated a large number of oxidative radicals and improved the pollutant degradation efficiency. Finally, the reaction rate equation of CWPO over Fe-Cu-CNT was derived, and it was experimentally illustrated that hydroxyl radicals played a crucial role in the treatment. This study demonstrates that the optimized Fe-Cu-CNT has great potentials for treatment of organic wastewater with higher efficiency and lower cost.

Thermally activated natural chalcopyrite for Fenton-like degradation of Rhodamine B: Catalyst characterization, performance evaluation, and catalytic mechanism

In this work, catalytic activity of natural chalcopyrite (CuFeS2) was improved by thermal activation. The modified chalcopyrite was used as efficient catalyst for degradation of organic dye Rhodamine B (RhB) through advanced oxidation process (AOP). Effects of catalyst dosage, H2O2 concentration, reaction temperature, solution pH, anions, and natural organic matter on the degradation efficiency of RhB were investigated. This study revealed that thermal activation at 300 °C changed the chemical valency of surface elements rather than transforming the major chemical phase of natural chalcopyrite. The Fenton-like degradation of RhB was significantly improved by thermally activated chalcopyrite. RhB degradation could be obtained under broad pH and showed high resistance to natural organic matter and anions. Under optimal conditions of H2O2 43.0 mM, catalyst 0.75 g/L, initial pH 5.1, and reaction temperature 25 °C, the degradation of RhB reached 96.7% at 50 min. Based on the rate constant of reaction kinetics, the activation energy for RhB degradation was calculated to be 9 kJ/mol. Radical scavenging experiments and electron paramagnetic resonance (EPR) technique demonstrated that RhB degradation was dominated by the generated hydroxyl radicals in activated chalcopyrite/H2O2 system. The formation of surface sulfates resulted from thermal activation induced the dissolved copper or iron ions, and promoted H2O2 activation and facilitated RhB degradation by reactive hydroxyl radicals. This work provides an in-depth understanding of the mechanism behind thermal activation to enhance the activity of natural chalcopyrite, offering a theoretical basis for utilizing natural minerals for Fenton-like treatment of organic wastewater towards cleaner production.

Performance and Energy Utilization Efficiency of an Expanded Granular Sludge Bed Reactor in the Treatment of Cassava Alcohol Wastewater

In recent years, expanded granular sludge blanket (EGSB) reactor has been widely used in the treatment of high-concentration organic wastewater, but its research mainly focused on treatment efficiency and microbial community composition. There were few studies on the relationship of operation conditions and energy utilization efficiency. Therefore, the methanogenic characteristics and energy utilization efficiency of EGSB reactor were studied by using cassava alcohol wastewater (CAW) as a raw material at (36 ± 1) °C. The results show that the degradation of volatile fatty acids (VFAs) is an important step affecting methane generation compared to the hydrolysis stage. When organic load rate (OLR) was 12.73 gCOD/L·d, the chemical oxygen demand (COD) removal rate was above 95%, the methane production efficiency of raw material was 202.73 mLCH4/ gCOD·d, the four-stage conversion efficiency was the highest, and the energy utilization efficiency was 62.26%, which was the optimal stage for EGSB reactor to treat CAW. These findings support high-efficiency bioenergy recovery from CAW in practice and highlight the potential wide application of high-performance anaerobic reactors for CAW.

Synthesis and immobilization of HC/BiVO4 catalyst particles with PTFE for photocatalytic tetracycline degradation: Preparation, performance and mechanism

The hydrothermal carbon/bismuth vanadate (HC/BiVO4) composite catalyst particles were prepared by one-step hydrothermal process. For effective and convenient photocatalytic organics degradation, the sandwich-like immobilization of HC/BiVO4 particles was performed utilizing polytetrafluoroethylene (PTFE) as an adhesive agent, NaCl as a pore-creating agent and PTFE/graphite composite as the interlayer. The obtained results indicated that HC/BiVO4 exhibited the higher performance than the pure BiVO4 towards photocatalytic tetracycline degradation owing to its enhanced separation of electron-hole (e−-h+) pairs as well as relatively higher electron transfer ability. Four active species including superoxide anion radical (O2−), h+, hydroxyl radical (OH) and singlet oxygen (1O2) could be identified from the developed photocatalytic system, whereas O2− played the predominant role in tetracycline degradation. It was found that the immobilized photocatalyst owned a certain photocatalytic degradation activity, fine renew-ability and high mechanical strength. The pore-creating function of NaCl particles enhanced the immobilized photocatalyst's photocatalytic performance evidently. The photocatalytic treatment of tetracycline solution by the immobilized catalyst presented the removal efficiency of over 90 % in 120 min. In addition, after the degradation, the biodegradability of the solution was enhanced evidently due to the generation of readily biodegradable organic intermediates. This study mainly presents a new method to prepare the immobilized HC/BiVO4 photocatalyst promoting the application of photocatalytic technology in organic wastewater treatment.

Study and Application Status of Ultrasound in Organic Wastewater Treatment

Ultrasound waves have been widely used in the field of organic wastewater treatment due to their mechanical, thermal, and chemical effects derived from their cavitation effect. Many researchers have combined ultrasound waves with other organic wastewater treatment methods because they have the potential to offset the disadvantages of other methods. In recent years, many authors within the literature have reviewed the application of ultrasound combined with a certain wastewater treatment method. In this review, we introduce the working mechanism of ultrasound in the treatment of organic wastewater and then examine the synergistic effects of ultrasound with other organic wastewater treatment methods based on various applications, indicating a strong synergistic effect between ultrasound and other wastewater treatment methods. Subsequently, we introduce typical ultrasound-enhanced organic wastewater treatment equipment and propose some possible developmental directions for ultrasound in the treatment of organic wastewater.

Efficient removal of aromatic pollutants via catalytic wet peroxide oxidation over synthetic anisotropic ilmenite/carbon nanocomposites

As one of the most common ferrous (Fe2+)-containing oxide minerals in the Earth’s crust, ilmenite (FeTiO3) is a potential low-cost heterogeneous Fenton-like catalyst for organic wastewater treatment via catalytic wet peroxide oxidation (CWPO). However, it suffers from low activity and long induction time. Herein anisotropic FeTiO3/C nanocomposite with rich Fe2+ ions on large surface area of 159.0 m2 g−1 (surface Fe/Ti and Fe2+/Fe3+ ratios were respectively 2.1 and 2.0) was prepared via cetyltrimethylammonium (CTA+)-assisted sol-gel synthesis. CTA+ modulated the growth of FeTiO3 nanoparticles with more exposed metallic sites by preferential adsorption on its (104) plane via electrostatic attraction, provided the carbon source and facilitated the generation of more Fe2+ ions at the interface of FeTiO3/C via carbothermal reduction of FeTiO3. FeTiO3/C efficiently catalyzed CWPO removal of six aromatic pollutants with different charges (25 mg L−1 each) at 25 oC and pH 3.0 without an induction period owing to rich Fe2+ content on neutral surface (pHpzc ~3.3)—three dye solutions completely decolorized in 1 h and three antibiotics degraded by >90% in 3 h. Reusability of FeTiO3/C was demonstrated with cationic rhodamine B and anionic orange G dyes in five consecutive runs. Scavenging tests and spin-trapping EPR spectra confirmed the generation of dominant ·OH and minor O2•− species for organic degradation via catalytic decomposition of H2O2 on FeTiO3/C as a heterogeneous Fenton-like catalyst.

Effects of salinity and betaine addition on anaerobic granular sludge properties and microbial community succession patterns in organic saline wastewater

In this study, the effects of different salinity gradients and addition of compatible solutes on anaerobic treated effluent water qualities, sludge characteristics and microbial communities were investigated. The increase in salinity resulted in a decrease in particle size of the granular sludge, which was concentrated in the range of 0.5-1.0 mm. The content of EPS (extracellular polymeric substances) in the granular sludge gradually increased with increasing salinity and the addition of betaine (a typical compatible solute). Meanwhile, the microbial community structure was significantly affected by salinity, with high salinity reducing the diversity of bacteria. At higher salinity, Patescibacteria and Proteobacteria gradually became the dominant phylum, with relative abundance increasing to 13.53% and 12.16% at 20 g/L salinity. Desulfobacterota and its subordinate Desulfovibrio, which secrete EPS in large quantities, dominated significantly after betaine addition.Their relative abundance reached 13.65% and 7.86% at phylum level and genus level. The effect of these changes on the treated effluent was shown as the average chemical oxygen demand (COD) removal rate decreased from 82.10% to 79.71%, 78.01%, 68.51% and 64.55% when the salinity gradually increased from 2 g/L to 6, 10, 16 and 20 g/L. At the salinity of 20 g/L, average COD removal increased to 71.65% by the addition of 2 mmol/L betaine. The gradient elevated salinity and the exogenous addition of betaine played an important role in achieving stability of the anaerobic system in a highly saline environment, which provided a feasible strategy for anaerobic treatment of organic saline wastewater.

Performance and mechanism of glycerol-driven denitrifying phosphorus removal from low organic matter sewage

The performance and mechanism of the glycerol-driven denitrifying phosphorus removal (DPR) process were investigated in low organic matter wastewater treatment using the modified anaerobic-anoxic–oxic (MAAO) system. The results revealed that denitrifying bacteria preferentially utilized glycerol, reducing nitrate interference on anaerobic phosphate release. Fermentation bacteria converted excess glycerol into available carbon sources, which were utilized by denitrifying phosphorus-accumulating organisms (DPAOs). Optimize glycerol dosage (calculated in chemical oxygen demand) could be estimated based on 6 times the effluent NO3−-N of the anoxic zone. As glycerol dosage increased, the relative abundance of fermentation bacteria surged from 8.2% to 17.7%, subsequently boosting the DPR rate from 34.6% to 77.2%. Notably, denitrifying glycogen-accumulating organisms (DGAOs) decreased from 0.5% to 0.2% but remained instrumental in nitrogen removal. The collaborative actions of fermentation bacteria, DPAOs, and DGAOs were vital in upholding the stability of nutrient removal in the glycerol-driven DPR process.