Oxidation Ditch Research Articles

Performance Evaluation of Al-Muamirah Wastewater Treatment Plant

Wastewater treatment is a process, which is being done on the wastewater to change its quality to be within the required specifications of water discharged to the surface waterway or water used for different purposes. In the present study, the performance of the oxidation ditch system related to Al-Muamirah wastewater treatment plant in Hilla city, province of Babylon, Iraq, in removing the pollutant of municipal were evaluated. The samples were taken from input wastewater and output treated water of the plant to measure the pollutant parameters. These parameters are the Biochemical Oxygen Demand (BOD5 ), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Ammonia (NH3 ), Phosphorus (P04 ), and the quantitative measure of the acidity or basicity (pH). Data were analyzed by using Excel software. The results show that the efficiency of removal of BOD 5, COD, TSS, NH3 and P04 was 91%, 78%, 93%, 69% and 68%, respectively on a monthly basis. Accordingly, it can be recommended that the Al-Muamirah wastewater treatment plant has an acceptable efficiency of wastewater treatment and producing water in accordance with Iraqi environmental standards of water discharged to the surface water or water of other uses.

Microplastics in Wastewater and Drinking Water Treatment Plants: Occurrence and Removal of Microfibres

Microplastics (MPs), and specifically microfibres (MPFs), are ubiquitous in water bodies, including wastewater and drinking water. In this work, a thorough literature review on the occurrence and removal of MPs, and specifically MPFs in WWTPs and DWTPs, has been carried out. When the water is treated, an average microfiber removal efficiency over 70% is achieved in WWTPs and DWTPs. These high percentages are still inefficient for avoiding the presence of a large number of microfibres in treated wastewater and also in tap water. RSF, DAF, oxidation ditch and CAS processes have been described as the most efficient treatments for eliminating MPFs from wastewater treatment. It is remarkable the wide range of the data reported on this topic; for example, treated wastewater contains between not detected and 347 MPFs/L, whereas tap water contains between not detected and 168 MPFs/L. Microfibres constitute more than half of the MPs found in treated wastewater and sewage sludge, whereas in DWTP effluents the percentage of MPFs is around 32%. Nevertheless, the relative amount of MPFs reported in tap water is notably higher (71%). Microfibres from WWTPs are discharged to the environment, being a source of MP pollution. Additionally, MPs released by DWTPs directly enter the drinking water lines, which constitute a direct route for MP human consumption, so that it has been estimated that an adult may ingest an average value of 7500 MPFs per year only via tap water. Thus, this review provides an update on the performance of WWTPs and DWTPs in removing MPs from water, which is an issue of great interest.

Study on Sludge and Dissolved Oxygen Distribution in a Full-Scale A2/O Oxidation Ditch

The distribution of velocity, sludge, and dissolved oxygen in a full-scale anaerobic-anoxic-oxic (A2/O) oxidation ditch was numerically simulated under three rotation speed scenarios. The viscosity and settling rate of activated sludge were defined through a user-defined function (UDF), and the sludge phase was calculated using the mixture multiphase flow model. Dissolved oxygen (DO) was set as a user-defined source (UDS) and its generation and consumption rates were defined with UDFs. The relationship between velocity and sludge concentration was found to be contradictory, with dead zones leading to large sludge concentrations at the bottom of the oxidation ditch (OD), but not at the middle-curved wall of the anoxic pool. The flow rate of the reflux slot and aerator oxygenation rate were checked and correlated with DO concentrations in the anaerobic pool. The majority of the large sludge concentrations were concentrated in the biological selection pool and these remained constant with bed height. With reduced propeller and agitator rotation speed, the sludge concentrations reduced in the biological selection pool, but increased in the anaerobic and anoxic pools.

Energy efficiency assessment of China wastewater treatment plants by unit energy consumption per kg COD removed

ABSTRACT Unit energy consumption per kg pollutant removed (kWh/kgCODremoved) is used for the first time in assessing and ranking the sustainability of main treatment technologies of 1215 wastewater treatment plants (WWTPs) in China. The metric better measures the sustainability of main treatment technologies in WWTPs than unit energy consumption per cubic meter treated (kWh/m3). The energy consumption data of these WWTPs were selected from the database of 1399 WWTPs to evaluate the energy efficiency of different treatment technologies. 80.3% of the WWTPs applied anaerobic-oxic plus anaerobic–anoxic–oxic, oxidation ditch, and sequencing batch reactor as main technologies. Statistical analysis shows that the unit energy consumption of WWTPs decreases with increasing design flow rate, operation loading rate, and influent COD concentration. For example, the average unit energy consumption of SBR decreases from 2.76 kWh/kgCODremoved to 0.83 kWh/kgCODremoved when the design flow rate increases from less than 10,000 m3/d to 100,000–200,000 m3/d. The mean unit energy consumption of SBR decreases from 1.71 kWh/kgCODremoved to 1.32 kWh/ kgCODremoved and 2.85 kWh/ kgCODremoved to 0.63 kWh/kgCODremoved as the operation loading rate and COD removal increase from 40% to 100% and from less than 150 mg/L to over 450 mg/L, respectively. SBR has the lowest unit energy consumption among all the technologies. Therefore, SBR might be the most appropriate technology in small and medium-scale WWTPs in China. Regression equations were developed to predict the unit energy consumption for sustainable design treatment trains by input variables such as design flow rate, operation loading rate, and influent COD concentration.

Virus reduction at wastewater treatment plants in Nepal

Continuous discharge of enteric viruses through treated wastewater is a potential threat to the environment and humans. This study aimed to investigate the occurrence and reduction of enteric viruses at two wastewater treatment plants (WWTPs) in the Kathmandu Valley, Nepal. Twenty-two samples (from the influent samples and effluent samples, n = 11 each) were collected at two WWTPs (WWTP A and WWTP B, installing oxidation ditch and non-aerated lagoon systems, respectively) between April and August 2018. Human adenoviruses, JC and BK polyomaviruses, Aichi virus 1, enteroviruses, noroviruses of genogroup I (NoVs-GI), group A rotaviruses, and human cosavirus, along with plant viruses (pepper mild mottle and tobacco mosaic viruses), were detected using quantitative PCR. The most prevalent enteric virus was NoVs-GI (100%), followed by human adenoviruses (95%), and enteroviruses and JC polyomaviruses (91%). Log10 reduction values of all tested viruses were found to be lower than those of fecal indicator bacteria. Both WWTPs were less efficient for the reduction of pathogens (p < 0.05). A significant positive correlation was found in the concentrations between indicator viruses (JC and BK polyomaviruses) and total enteric viruses in the effluents (p < 0.05). Both WWTPs were not adequately effective to reduce enteric viruses and indicator viruses. Our findings suggested that advanced treatment processes are needed for both WWTPs to achieve better reduction efficiency in the future.

Application of Flow Field Analysis in the Process Design of Modified Microporous Aeration Oxidation Ditch

According to the environment and water quality factors of the project location, an improved microporous aeration oxidation ditch process is designed, which has the characteristics of biochemical reaction of space division, microporous aeration, infinite water circulation in the ditch, and multiple water inlets; under simplified boundary conditions, based on the CFD method, the SSTK-W model is used to close the RANS equation to simulate the flow field in the hypoxic and aerobic areas. With the optimal equipment configuration and the lowest energy consumption, the flow velocity in the trench is more than 0.3m/s, to ensure high buffering capacity of the process; study the flow field state and the unfavorable flow velocity under the optimized operation state of the flow thruster; the rationality of the design is verified through the commissioning and operation of the sewage treatment plant.

Comparison of various turbulence model performance in computational fluid dynamics analyses of the oxidation ditches with experimental validation

Experimental and numerical studies were carried out to determine the full-scale Oxidation Ditch (OD) hydrodynamics considering various turbulence models. Firstly, the experimental work was carried out in a full-scale plant by Acoustic Doppler Velocimeter (ADV) for field-measurements. Secondly, the experimental data was used to validate numerical models by using Computational Fluid Dynamics (CFD) software Ansys Fluent. Eight different turbulence models were compared in the numerical study to predict full-scale hydrodynamics. Results showed that standard k-ε, renormalization group k-ε, realizable k-ε turbulence models gave more accurate prediction results with relative errors of 13 %, 17 %, and 18 % respectively, whereas the standard k-ω turbulence model gave the worst prediction results with 39 % relative error. This study also shows that the velocities in the ODs are very low without external force such as air diffusers, rotors, and mixer and there is no homogeneous flow field distribution in the ODs. Moreover, the maximum wastewater velocities occurred at the inlet and outlet.

Mitigating NO and N2O emissions from a pilot-scale oxidation ditch using bioaugmentation of immobilized aerobic denitrifying bacteria

Nitrous oxide (N2O) emission from wastewater treatment plants (WWTPs) requires urgent mitigation because of its significant contribution to the greenhouse effect. In this study, bioaugmentation was applied in a pilot-scale oxidation ditch with the aerobic denitrifying bacteria strain PCN-1 immobilized on polyurethane biocarriers, which demonstrated effective N2O mitigation. Microbial community analysis suggested that the bioaugmentation facilitated a symbiotic relationship of the bacterial populations between the activated sludge and the biocarriers. The denitrifying bacteria with well-known N2O reducing capabilities predominated on the biocarriers. Correspondingly, the increases of denitrifying genes and NO and N2O reductase provided evidence for the enhanced genetic potential for NO and N2O reduction. Besides, the enriched comammox Nitrospira on the biocarriers is proposed as another significant driver for N2O mitigation by avoiding nitrite accumulation. In addition, the bioaugmentation enhanced the stability and recovery capability of the system in the ammonia overload and aeration failure shock tests.

The evaluation of GHG emissions from Shanghai municipal wastewater treatment plants based on IPCC and operational data integrated methods (ODIM)

Due to the rapid wastewater treatment plants (WWTPs) development and the China's 2060 goal of carbon neutrality, the contribution of greenhouse gas (GHG) emissions from WWTPs should not be overlooked. Thus, the GHG accounting method, featured with site-specific and real operation data targeting city-level WWTPs, is scientifically and pragmatically called for. In this paper, we compared IPCC (IPCC 2006 and IPCC 2019), optimized IPCC and operational data integrated methods (ODIM) for the direct N2O and CH4 emissions for total 50 WWTPs in Shanghai. Data for all WWTPs were collected for ODIM and indirect GHG emissions evaluation, covering frequently used wastewater treatment processes in China such as anaerobic anoxic oxic, oxidation ditch, sequencing batch reactor, anoxic oxic, biofilm and membrane bio-reactor. The factors affecting the total GHG emissions intensity were also analyzed. The results showed that, in comparison with IPCC 2019, IPCC 2006 underestimated both direct N2O and CH4 emissions for a total percentage of 87%. What's more, IPCC 2019 overestimated by a percentage of 355% compared to ODIM due to the general default values. ODIM considered the significant differences in emission factor values of specific treatment process, making use of the local operational data to achieve more accurate city-level estimation with direct GHG emissions of 243,320 tCO2-eq in 2016. While indirect emissions were 511,851 tCO2-eq, accounting for 68% of total direct and indirect emissions. Average GHGs emission intensity for Shanghai WWTPs was evaluated as 0.290 kgCO2-eq/m3 while the specific WWTP intensity varied between 0.268 and 0.738 kgCO2-eq/m3. In detail, WWTPs with AAO process, large-scale (>100 k m3/day), high load rate (80%–100%), low theoretical oxygen consumption (0.2– 0.4 kgO2/t), influent COD of 150– 250 mg/L, NH3-N of 15– 25 mg/L and discharge limits B demonstrated lower amounts of total GHG emissions than other WWTPs. Shanghai cases in this study provided a reference for future city-level WWTPs GHG management in China.

Biodegradation of Paracetamol by Some Gram-Positive Bacterial Isolates.

Bacterial isolates with the capacity to remove paracetamol were selected from an activated sludge sample collected in an oxidation ditch of a wastewater treatment plant. Among these, twelve bacterial isolates were selected according to their capacity to grow in the presence of paracetamol. They were identified using the colony morphotype procedure and by 16S rRNA gene sequencing analysis, but only four of them showed the ability to utilise paracetamol as the sole carbon source in the presence of a nitrogen supply. Those four bacterial isolates were assigned to species of the genera Bacillus, [Brevibacterium], Corynebacterium and Enterococcus. Bacterial isolates were cultured in liquid mineral salt medium (MSM) spiked with 200mg/L of paracetamol at 28°C in the dark. In cultures inoculated with [Brevibacterium] frigoritolerans, Corynebacterium nuruki and Enterococcus faecium, removal of 97 ± 4%, 97 ± 6% and 86.9 ± 0.8% of paracetamol at 200mg/L were obtained, respectively, while in the presence of a species belonging to Bacillus cereus group removal of the drug below the limits of detection was attained with evidence of mineralisation, after 144h of incubation. During the degradation process, the metabolites 4-aminophenol, hydroquinone and 2-hexenoic acid were detected. As far as we know, these species are herein first-time described as paracetamol degraders.

Assessment of Microplastics in a Municipal Wastewater Treatment Plant with Tertiary Treatment: Removal Efficiencies and Loading per Day into the Environment

This study investigates the removal of microplastics from wastewater in an urban wastewater treatment plant located in Southeast Spain, including an oxidation ditch, rapid sand filtration, and ultraviolet disinfection. A total of 146.73 L of wastewater samples from influent and effluent were processed, following a density separation methodology, visual classification under a stereomicroscope, and FTIR analysis for polymer identification. Microplastics proved to be 72.41% of total microparticles collected, with a global removal rate of 64.26% after the tertiary treatment and within the average retention for European WWTPs. Three different shapes were identified: i.e., microfiber (79.65%), film (11.26%), and fragment (9.09%), without the identification of microbeads despite the proximity to a plastic compounding factory. Fibers were less efficiently removed (56.16%) than particulate microplastics (90.03%), suggesting that tertiary treatments clearly discriminate between forms, and reporting a daily emission of 1.6 × 107 microplastics to the environment. Year variability in microplastic burden was cushioned at the effluent, reporting a stable performance of the sewage plant. Eight different polymer families were identified, LDPE film being the most abundant form, with 10 different colors and sizes mainly between 1–2 mm. Future efforts should be dedicated to source control, plastic waste management, improvement of legislation, and specific microplastic-targeted treatment units, especially for microfiber removal.

Parameters to characterize the internal recirculation of an oxidation ditch

Mixed liquor circulates ceaselessly in the closed-loop corridor in an oxidation ditch (OD), which is significantly different from other wastewater treatment processes. The internal recirculation ratio (IRR), i.e., the ratio between circulation flow rate (QCC) and influent flow rate (QIn), and the circulatory period (T), i.e. the time consumed for the mixed liquor to complete one lap in the circular corridor, was used to quantify the internal recirculation characteristics of the OD system. In order to elucidate the characteristics and applicability of IRR and T, this study obtained the numerical relationship between IRR and T by formula derivation. It also discusses the factors influencing IRR and analyses the applications of IRR and T. The results showed that IRR = QCC/QIn = HRT/T = HRT ž IRF (HRT = hydraulic retention time of the mixed liquor in the circular corridor; IRF = internal recirculation frequency). Moreover, three kinds of parameters had an effect on IRR: QIn; reactor dimensions, i.e., length (Lmid), width (B), and height (H) of the circular corridor; and horizontal velocity of the mixed liquor in the circular corridor (v). QIn changed IRR by altering HRT. However, B, H, Lmid, and v changed IRR by altering IRF and T. Furthermore, the same IRR corresponded to many different HRT and IRF. Therefore, when QIn and QCC varied in the OD system, using HRT and IRF to evaluate the variation of QIn and QCC, respectively, was better than using IRR to evaluate their synthetical variation. IRF and T were useful for directly and precisely characterizing the circulation speed and circulation flow rate in the circular corridor, while IRR was more useful for evaluating the dilution effect of reflux on influent.

Comparison of bacterial communities and antibiotic resistance genes in oxidation ditches and membrane bioreactors

Oxidation ditches (ODs) and membrane bioreactors (MBRs) are widely used in wastewater treatment plants (WWTPs) with bacteria and antibiotic resistance genes (ARGs) running through the whole system. In this study, metagenomic sequencing was used to compare the bacterial communities and ARGs in the OD and MBR systems, which received the same influent in a WWTP located in Xinjiang, China. The results showed that the removal efficiency of pollutants by the MBR process was better than that by the OD process. The composition and the relative abundance of bacteria in activated sludge were similar at the phylum and genus levels and were not affected by process type. Multidrug, fluoroquinolones and peptides were the main ARG types for the two processes, with macB being the main ARG subtype, and the relative abundance of ARG subtypes in MBR effluent was much higher than that in the OD effluent. The mobile genetic elements (MGEs) in the activated sludge were mainly transposons (tnpA) and insertion sequences (ISs; IS91). These results provide a theoretical basis for process selection and controlling the spread of ARGs.

A coupled hydrodynamic‐biokinetic simulation of three‐phase flow in an oxidation ditch using CFD

AbstractCoupling the hydrodynamic and biokinetic models, was done on a lab‐scale oxidation ditch as the bioreactor of the activated sludge process and validated against the available experimental data. The simulation was carried out in three‐phase, three‐dimensional conditions with k‐є and Eulerian–Eulerian methods. A simplified activated sludge model No.1 (ASM1) has been added to transport terms to account for the biokinetic model. Rotatory speed for surface aerator was initially increased and its corresponding effects on solid volume fraction, dissolved oxygen, and velocity profile and values were observed. A 150 rpm increase in the rotational velocity resulted in 36% higher average liquid phase velocity for the one‐aerator arrangement, which was 3% more than that of the two‐aerator oxidation ditch. The 150% increase in the solid volume fraction led to a 10% reduction in the maximum liquid phase velocity. The effect of aerators number has been considered explicitly on baffle performance and liquid phase velocity profile. Finally, a new design for the aerator has been offered that provides an ordered flow field and optimal conditions for the performance of the baffle and oxidation process.

Distribution and transformation of phosphorus-containing substances in a combined oxidation ditch-membrane bioreactor

This work aimed at revealing the distribution and transformation of phosphorus (P) -containing substances in a combined oxidation ditch (OD)-membrane bioreactor (MBR). During the operation, it was found that P mainly occurred in microbial cells, followed by extracellular phase and the least in aqueous phase. The primary P fraction in the bioreactor was inorganic phosphorus (IP), in which non-apatite inorganic P (NAIP) accounted for the major ratio, comprising 57–73% of IP. The values of P uptake and release rate attained a low value after operating for 40 days with no sludge discharged. The relative proportion of Poly-P identified by 31P NMR declined obviously after long-term operation without discharging sludge, revealing lower bioactivity of PAOs in the OD-MBR. In terms of maintaining a stable P-removal efficiency, an MBR should discharge excess sludge at a suitable time point by comprehensively considering the relative values of PUR&PRR, and the proportion of Poly-P.

Optimizing nitrogen removal in a hybrid oxidation ditch

Wastewater treatment plants are now facing the challenges of high cost, high energy consumption, while effluent quality is relatively poor with total nitrogen concentration exceeding the requirement of reuse. This study investigated the performance of contaminants removal, especially nitrogen by a hybrid oxidation ditch (H-OD) which is based on the theory of integrated fixed-film activated sludge under different control factors. The aeration rate, return ratio and hydraulic loading were controlled at 0.4 m3/h, 100% and 0.55 m3/m3 h, respectively as the optimized control parameter values. Under the optimized conditions, the effluent concentrations of chemical oxygen demand and ammonium were 35.8 mg/L, 1.04 mg/L, respectively, while the suspended solid was below 10 mg/L. The average removal rate of total nitrogen was 72.8%, and simultaneous nitrification and denitrification (SND) was achieved at 42.7%. Besides, when the carbon/nitogen ratio was maintained from 2.12 to 5.56, the complete nitrification and denitrification was obtained. The results showed that the H-OD was suitable for nitrogen removal and SND was very attractive for practical engineering applications.

Comparison of Aerobic Digestion and Oxidation Ditch Wastewater Treatment Systems

Wastewater treatment is the process of converting wastewater into water that is suitable to be discharged back into the environment. Proper wastewater treatment is essential in order to ensure the health of the population and the environment. According to a June 2012 USEPA case study in Fairfax County, Virginia, poorly designed/managed wastewater treatment systems lead to the pollution of nearly 900 miles of streams, lakes, and ponds. Due to environmental consequences resulting from poor management, two distinct treatment systems will be explored to observe their efficacy. They are aerobic digestion at Bland Correctional Center and oxidation ditch at Appalachian Detention Center. Both systems are common as they are simple and cost effective.My hypothesis is that aerobic digestion will be the more effective over oxidation ditch, and objective is to determine which is the more effective system. The tests to be performed include carbonaceous biochemical oxygen demand, total suspended solids, and E. coli. Once all data from both institutions are collected, it will all be analyzed and compared against current USEPA standards.It is anticipated that the Bland Correctional Center’s aerobic digestion system will have much lower E. coli, TSS, and CBOD readings in their samples because the institution sends samples to Blue Ridge Analytical Environmental Laboratory thrice weekly to ensure compliance to EPA standards, while Appalachian Detention Center only sends samples once monthly. Given the data observed so far, all tests conducted at Bland Correctional Center have proved that the facility is well within compliance of USPEA standards.

MICROBIAL AND PHYSICO-CHEMICAL ASSESSMENT OF WASTEWATER PLANTS BEFORE DISCHARGE IN QARUN LAKE, EL-FAYOUM GOVERNORATE, EGYPT.

This study is performed on six wastewater stations that discharging wastewater into Qarun lake, El-Fayoum Govenorate, Egypt, to assessment wastewater treatment on the period from April 2017 to February 2019. Sewage treatment plants use different biological treatment technologies (conventional activated sludge, oxidation ditch, aeration). In this investigation, wastewater samples were collected from the influent and effluent of each plant and transferred directly to central laboratory of Fayoum Wastewater Company for complete analysis. The obtained data reflects a large amount of drainage on the wastewater treatment stations which means high percentages of total coliform and fecal coliform. Also, the high algal content is detected at Tamiya station with total cell count 282-1210/L. Nutrients as nitrate, nitrite, ammonia and phosphate are assessed and exhibit in ranges 4.4-104.5, 0.0-8.0, 1.1-43.0 and 1.0-42.1 mg/L, respectively. On other hand, the increase of TDS and TSS were achieved during summer season. Furthermore, higher values of DO, BOD and COD considered as a strong indicator for higher microbial activity.

Sustainability assessment of wastewater treatment techniques in urban areas of Iraq using multi-criteria decision analysis (MCDA)

AbstractSustainable development is based on environmental, social, economic, and technical dimensions. In this study, the sustainability of wastewater treatment techniques in urban areas of Iraq was assessed using a multi-criteria decision analysis (MCDA)/the weighted sum model (WSM). The analysis was performed on 13 operating wastewater treatment plants in 10 provinces, Iraq, using a questionnaire sheet with the assistance of 52 specialists in the Ministry of Municipalities and Public Works, Iraq. Four types of wastewater treatment techniques (Conventional Treatment, Oxidation Ditches, Aeration Lagoons, and membrane bio-reactor (MBR)) were assessed. The environmental, social, economic, and technical dimensions were represented by 11, 5, 7, and 4 indicators, respectively. The main results of this study indicate that the sustainability of MBR recorded the highest total importance; the order of the total importance from the highest to the lowest was: MBR &amp;gt; Oxidation Ditches &amp;gt; Aeration Lagoons &amp;gt; Conventional Treatment. The environmental dimension proved its dominance in the four studied treatment techniques' sustainability as it recorded the maximum contribution to sustainability. While the technical dimension recorded the least contribution to sustainability, the order from the highest to the lowest was: Environmental Dimension &amp;gt; Economic Dimension &amp;gt; Social Dimension &amp;gt; Technical Dimension.

An efficient hydrodynamic-biokinetic model for the optimization of operational strategy applied in a full-scale oxidation ditch by CFD integrated with ASM2

Oxidation ditches (ODs) are often used for wastewater treatment. However, limitations of ODs like high energy expenditure and increased sludge sedimentation hinder its wide application. In this study, the computational fluid dynamics (CFD) model integrated with Activated Sludge Model No. 2 (ASM2) was proposed and applied in a full-scale OD. The integrated model provided heterogeneous information on the characteristics of hydrodynamics and biokinetics of OD, especially with respect to the simulation of total phosphorus removal by CFD-ASM2 integration model for the first time. The simulated values of flow velocities, suspended solids (SS), dissolved oxygen, chemical oxygen demand, total nitrogen, ammonium nitrogen, and total phosphorus concentrations were well validated with the measured results, with the standard deviation errors of less than 5.56%, 0.28%, 0.74%, 7.39%, 3.17%, 5.27%, and 7.40%, respectively. Based on the integrated model, four different operational strategies were simulated. The proposed operational strategy of operating 7 surface aerators and 10 submerged impellers not only met the standard discharge requirements (GB 18918–2002) but also consumed less energy by 22.3%, compared with the original strategy of operating 9 surface aerators and 13 submerged impellers. Meanwhile, this proposed operational strategy also reduced the SS concentrations in the second and fourth channels, which was beneficial to elimination of sludge sedimentation. Moreover, the proposed operational strategy was successfully applied and validated in full-scale OD. The foregoing results collectively suggest that the CFD-AMS2 integration model is numerically capable to optimize the operational strategy of ODs.