MBR Process Research Articles

Exploring the impact of hyper-treated-quantity on the performance to access GHG emission in a full-scale A2O + MBR process: from predictions to implementation

Exploring the impact of hyper-treated-quantity on the performance to access GHG emission in a full-scale A2O + MBR process: from predictions to implementation

Treatment of printing and dyeing wastewater using Fenton combined with ceramic microfiltration membrane bioreactor

The release of printing and dyeing wastewater (PDW) into the environment is a concern attributed to its acute, chronic and cytotoxic effects to aquatic life. Two anaerobic/aerobic-membrane bioreactors (A/O–MBRs) were operated continuously to treat raw (untreated) and Fenton oxidized PDW. After about 70 days acclimatization, 67% of the chemical oxygen demand (COD) and 35% of adsorbable organic halogens (AOX) were removed by direct biodegradation in A/O–MBR without Fenton pre-treatment, while 90% of the COD and 79% of AOX were removed in Fenton + A/O–MBR system. Fenton oxidation play a dominate role on the COD and AOX removal of PDW in the combination system. The Fenton pre–treatment of PDW could remarkably reduce membrane fouling. The Shannon indices showed that the microbial diversity in anaerobic flocs were significantly higher than the microbial diversity in aerobic flocs in both two A/O–MBR systems. The metagenomics analysis found that the key functional genes responsible for the AOX biodegradation were EC3.1.1.45, pcaI, and pcpD. The transcript per million (TPM) abundance of EC3.1.1.45 and pcaI significantly up-regulated in both anaerobic and aerobic flocs after 70 days acclimatization. Based on the pilot applications study, the total operation cost of Fenton + A/O–MBR processes for PDW remediation was approximately 1.263–1.384 USD/t. This study provides a promising technique for removing AOX and other organic contaminants from PDW.

Effect of packing media type of moving and fixed on performance and membrane fouling in biofilm-based MBR processes

Effect of packing media type of moving and fixed on performance and membrane fouling in biofilm-based MBR processes

Variations in the morphological phosphorus in a full‐scale A2O + MBR process with heavy chemical P removal addition dosing

AbstractThe removal of biological phosphorus (P) removal along with chemical P removal additions is significantly important role in removing P at full‐scale wastewater treatment plants (WWTPs). Few research groups have recently reported the use of P forms in these WWTPs. The current study mainly presents the varied forms of morphological phosphorus and the fate of chemical P removal agents in a full‐scale WWTP that has adopted the A2O + MBR process. With time, the TP concentration in the liquid phase and the solid phase reaches the minimum (0.27 mg/L) and maximum values (1.75 mg/g), respectively. At this point, the TP concentration at the end of the aerobic and membrane pool becomes nearly constant. This indicates the complete removal of effluent TP from in the system. The heavy chemical P removal and addition dosing result in Al–P being the predominant P form in the solid phase. The fate of the chemical P removal and agents was determined by investigating the valences of the surface elements in freeze‐dried MLSS at the membrane pool.

Mitigation of Antimicrobial Resistance during Wastewater Treatment by Membrane Technologies

The threat of antimicrobial resistance (AMR) to human health is predicted to become a significant infectious disease. Domestic sewage and wastewater treatment plants (WWTPs) are critical hotspots for controlling the spread of antibiotic resistant bacteria (ARB) and antimicrobial resistance genes (ARGs) in the environment. A wastewater treatment system is not necessarily designed to mitigate AMR problems in wastewater. Furthermore, the presence of ARB and ARGs for a long time in WWTPs is reported as a reservoir of intracellular and extracellular ARG through horizontal gene transfer. Based on the studies, the additional membrane filtration with either microfiltration (MF) or ultrafiltration (UF) can reduce ARB and ARGs effectively through the separation mechanism. However, there are still inconclusive results when comparing ARG removal efficiencies between MBR and conventional processes. Further studies are required to clarify the effect of water qualities and membrane fouling conditions on ARG removal.

The potential of microalgae Dunaliella salina to treat shrimp pond wastewater in a PAN/GO membrane bioreactor

Graphene has attracted a significant amount of attention because to its excellent mechanical, electrical, thermal, and optical characteristics. In this work, a membrane bioreactor with hollow fibre PAN/GO nanocomposite was studied for the treatment of Persian Gulf shrimp pond wastewater. Dunaliella salina microalgae have been used for better treatment and the formation of sludge mass in a shorter period of treatment in the MBR system. Additionally, GO nanoparticles were used in order to improve the hydrophilicity of the membranes. Various tests, such as Pure water permeate (PWP), X-ray diffraction spectroscopy (XRD), Atomic force microscopy (AFM), Dynamic light scattering (DLS), Contact angle (CA), Scanning electronic microscopy (SEM), Fourier transform infrared substances (FTIR) were used to characterize the synthesized membranes. To evaluate the treated wastewater, several factors were evaluated, including: TP, TN, TSS, NTU, BOD, COD, EC. The contact angle was reduced by the inclusion of GO nanoparticles from 53.8° for PAN-0 to 45.4° for PAN-3. The results of FTIR analysis confirmed the synthesis of GO and showed the formation of different deposits as fouling on the surface of the prepared membranes after MBR process. Also, the removal percentage of COD and BOD5 was over 90% for membranes with graphene oxide nanoparticles. The turbidity for all fabricated membranes were removed ∼98%. Also, very little fouling occurred in the membranes constructed with GO membranes and the maximum concentration of GO let to maximum performance regarding to the high potential of fouling control. In addition, the growth of Microalgae Dunaliella salina with shrimp wastewater was observed successfully. In conclusion, the finding of this work not only proposed a promising solution for controlling fouling in an MBR but also resulted in a benefit product, i.e. microalgae Dunaliella salina.

Advanced nitrogen and phosphorus removal by the symbiosis of PAOs, DPAOs and DGAOs in a pilot-scale A2O/A+MBR process with a low C/N ratio of influent

Cooperating in harmony to avoid competition with dominant functional microbial symbiosis is an efficient way in advanced nitrogen and phosphorus removal in wastewater treatment processes. In this study, a niche-based coordinating strategy was implemented to cooperate in harmony with phosphorus-accumulating organisms (PAOs), denitrifying phosphorus-accumulating organisms (DPAOs) and denitrifying glycogen-accumulating organisms (DGAOs) to advance nitrogen and phosphorus removal based on an anaerobic-anoxic-oxic-anoxic-membrane bioreactor (A2O/A+MBR) under low C/N in municipal wastewater influent. The niche-based strategy was conducted based on the ORP change during the process as an indicator combined with the adjustment of recirculation and anoxic zone shifting. The results indicated that the strategy of the post-anoxic unit could enable significant enhancement of biological nitrogen and phosphorus removal (BNPR) by 9.9% and 16.3%, respectively, with low effluent concentrations of 7.0 ± 2.2 mg N/L and 0.36±0.32 mg P/L. The satisfactory performance was dominated along with the shift in the microbial community: the relative abundance of Tetrasphaera (PAO genus) increased from 0.14±0.08% to 0.32±0.12%, while the relative abundance of Decchloromonas (DGAO genus) and Candidatus Competibacter (DGAO genus) also increased. The advanced combination of anaerobic phosphorus release, anoxic denitrification, denitrifying phosphorus removal and endogenous denitrification was qualified by the modeling simulation of the biochemical kinetics mechanism of activated sludge in the A2O+MBR and A2O/A+MBR processes, which means that cooperation in the harmony of PAOs, DPAOs and DGAOs could be efficiently realized by a promising control strategy to enhance BNPR in an A2O+MBR with a post-anoxic unit. This study provides an efficient and simple novel control strategy to overcome the limitation of traditional nitrogen and phosphorus removal under an insufficient carbon source.

Efficiencies of O-MBR and A/O-MBR for Organic Matter Removal from and Trihalomethane Formation Potential Reduction in Domestic Wastewater.

Lab-scale anoxic/oxic membrane bioreactor (A/O-MBR) and oxic membrane bioreactor (O-MBR) systems using a submerged polysulfone hollow-fiber membrane module with a pore size of 0.01 μm and a total surface area of 1.50 m2 were used to treat domestic wastewater. The sludge retention time (SRT) of each system was examined by setting the SRT to 10, 20, and infinity (no sludge withdrawal). The results showed that the total nitrogen removal efficiency of the A/O-MBR was more significant than that of the O-MBR at a SRT of infinity, with figures of 72.3% and 33.1% being found, respectively. The COD removal efficiencies of the A/O-MBR system with a SRT of 10 days, 20 days, and infinity were 82.4%, 84.3%, and 91.5%, respectively. The COD removal efficiencies of the O-MBR system with a SRT of 10 days, 20 days, and infinity were 79.3%, 81.5%, and 89.8%, respectively. An increase in the SRT resulted in an increase in the COD removal efficiency. The FEEM peak of the influent tended to decrease after an increase in the SRT for both systems (A/O-MBR and O-MBR). For the A/O-MBR system, the trihalomethane formation potential (THMFP) was significantly reduced by 88.91% (at a SRT of infinity). The THMFP declined significantly by 85.39% for the O-MBR system at a SRT of infinity. The A/O-MBR system showed a slightly higher efficiency than the O-MBR system in terms of the COD removal and the THMFP reduction. These results indicated that the MBR process, and the A/O-MBR system, in particular, could be used as an effective wastewater treatment process for many developing countries that are troubled by the emerging contamination of water and wastewater.

Pilot Scale Application of a Ceramic Membrane Bioreactor for Treating High-Salinity Oil Production Wastewater.

The offshore oil extraction process generates copious amounts of high-salinity oil-bearing wastewater; at present, treating such wastewater in an efficient and low-consumption manner is a major challenge. In this study, a flat ceramic membrane bioreactor (C−MBR) process combining aerobic microbial treatment technology and ceramic membrane filtration technology was used to treat oil-bearing wastewater. The pilot test results demonstrated the remarkable performance of the combined sequential batch reactor (SBR) and C-MBR process, wherein the chemical oxygen demand (COD) and ammonia nitrogen (NH4+−N) removal rates reached 93% and 98.9%, respectively. Microbial analysis indicated that the symbiosis between Marinobacterium, Marinobacter, and Nitrosomonas might have contributed to simultaneously removing NH4+−N and reducing COD, and the increased enrichment of Nitrosomonas significantly improved the nitrogen removal efficiency. Cleaning ceramic membranes with NaClO solution reduces membrane contamination and membrane cleaning frequency. The combined SBR and C−MBR process is an economical and feasible solution for treating high-salinity oil-bearing wastewater. Based on the pilot application study, the capital expenditure for operating the full-scale combined SBR and C−MBR process was estimated to be 251,717 USD/year, and the unit wastewater treatment cost was 0.21 USD/m3, which saved 62.5% of the energy cost compared to the conventional MBR process.

Designing Multi-Stage 2 A/O-MBR Processes for a Higher Removal Rate of Pollution in Wastewater.

Multi-stage A/O-MBR processes were designed to improve wastewater treatment efficiency; three different designs were carried out and compared in this study. The 2(A/O)-MBR process, i.e., with two sets of anoxic/oxic tanks in series, showed better effluent quality than A/O-MBR and 3(A/O)-MBR processes. The removal rates of COD, NH-N, TP and TN were 95.29%, 89.47%, 83.55% and 78.58%, respectively, complying satisfactorily with China’s urban sewage treatment plant pollutant discharge standards. In terms of membrane fouling, the 3(A/O)-MBR process demonstrated the lowest fouling propensity. The microbial community structure in each bioreaction tank was analyzed, the results from which matched with the process efficiency and fouling behavior.

A Study on the Validity of the Metal Filter Application in MBR Process

A Study on the Validity of the Metal Filter Application in MBR Process

Fates of antibiotic resistance genes during upgrading process of a municipal wastewater treatment plant in southwest China

This study comprehensively analyzed the fates of antibiotics, antibiotic resistance genes (ARGs) and microbial community during upgrading process of municipal wastewater treatment plant (MWTP) of Anaerobic/Anoxic/Oxic-membrane bioreactor (A2/O-MBR) from regulation to stable operation phase. The factors most affecting ARGs profile were investigated, and the potential hosts for ARGs were further determined. Results showed that the removal rate of total antibiotics and the reduction of ARGs increased by 10.49% and 1.37 logs in A2/O-MBR during upgrading process, respectively. The most prevalent ARG was sul1 in both water and sludge phase. Mobile genetic elements (MGEs) and microbial community were the most significant factors affecting ARGs distribution in water phase and sludge, respectively. Notably, the abundance of potential antibiotic resistance bacteria (ARB) was significantly decreased during upgrading process. Therefore, sul1and intI1 proliferation as well as microbial community succession should be emphasized in ARGs pollution management and control. This study expected to provide a theoretical basis for the application of MBR process to remove antibiotics and ARGs in upgrading of MWTPs.

Purification and recycling of municipal wastewater based on MBR process

Purification and recycling of municipal wastewater based on MBR process

Purification and recycling of municipal wastewater based on MBR process

Purification and recycling of municipal wastewater based on MBR process

Multi-Parameter Control-Based Operation Strategy for Mainstream Deammonification of Municipal Wastewater in an Integrated Anaerobic Biofilm Reactor-Step Feed Mbr Process

Multi-Parameter Control-Based Operation Strategy for Mainstream Deammonification of Municipal Wastewater in an Integrated Anaerobic Biofilm Reactor-Step Feed Mbr Process

Electro-Fenton Treatment of Landfill Leachate after Mbr Process Diluted by Electro-Fenton Effluent Through Analysis of Cod, Uv-Vis and 3d-Eem

Electro-Fenton Treatment of Landfill Leachate after Mbr Process Diluted by Electro-Fenton Effluent Through Analysis of Cod, Uv-Vis and 3d-Eem

High Concentration Organic Wastewater with High Phosphorus Treatment by Facultative MBR

Phosphorus is one of the main factors causing water eutrophication, and the traditional phosphorus removal process causes phosphorus-rich sludge pollution. The facultative MBR process uses phosphate-reducing bacteria to convert phosphate into directly recyclable gaseous phosphine to solve this malpractice and make sewage become a new phosphorus resource. In order to investigate the phosphorus removal efficiency and the mechanism under facultative conditions, run the facultative MBR reactor for 30 days. The COD value, phosphate concentration, and phosphine yield were measured, and the changes of sludge metabolic pathway abundance and community composition in different periods were detected. According to the measurement, the maximum phosphorus removal efficiency is 43.11% and the maximum yield of phosphine is 320 μg/m3 (measured by the volume of sewage). Combined with thermodynamic analysis, the microbial mechanism of the reactor was proposed, and the possible transformation pathway of phosphorus was analyzed. At last, changes the phosphorus removal process from the ‘removal type’ to the ‘recycling type’.

Green Environmental Protection Technology Applied in Sewage Treatment System Upgrading Modern Management

The sewage treatment system is upgraded from the original UNITANK process to A2O+MBR process and pharmaceutical sewage treatment process. The automatic control system involves the problem of combining with the original automatic control system. The design is based on advanced nature, flexibility, reliability, and ease of use. The principle of scalability, the control project covers all technological processes, can realize the centralized monitoring of the central control room of the whole plant equipment, and effectively improve the automation of sewage treatment. Through the project budget, the total cost of different processes and different scales of treatment schemes is obtained, and the functional relationship between the cost and scale of different processes is obtained through curve fitting. According to the principles of technical economics, the cost of the sewage treatment project is related to the quantity of reduced pollutants, and the cost flow of the project and the reduced pollutant load flow are discounted.

Study on the Application of MBR Process in Reclaimed Water Reuse

Study on the Application of MBR Process in Reclaimed Water Reuse

An enhanced denitrifinal membrane bioreactor -A case study for Taihu Lake of Changzhou

In recent years, with the rapid development of the economy of villages and towns and the improvement of the living standards of residents, the rural sewage discharge tends to be concentrated and the discharge increases. People begin to pay attention to the treatment and reuse of rural sewage gradually. However, due to the backward rural economy and the low level of technical management, the progress of sewage treatment is slow. In this paper, a new wastewater treatment and recovery process, which is mainly denitrification, is developed for the area with small water environment capacity, which is enhanced denitrification MBR process. The system not only has the advantages of the original membrane bioreactor, but also is convenient to use, and can carry out the sewage evolution treatment for the domestic sewage of the individual households, which improves the flexibility of the sewage treatment. The results of effluent test show that MBR process effluent meets the first level B standard in GB18918-2002, and has high efficiency in removing ammonia nitrogen, COD, BOD and other pollutants, which plays a significant role in improving the water quality of the drainage basin and region, and has important value for the improvement of the water quality in rural areas.