Traditional Activated Sludge Process Research Articles

Efficient nitrogen removal by multi-stage A/O mud membrane composite process with segmented influent: Performance and microbial community structure

In this paper, a multi-stage A/O mud membrane composite process with segmented influent was constructed for the first time and compared with the traditional activated sludge process and the multi-stage A/O pure membrane process with segmented influent. The nitrogen removal efficiency of the process under different influencing factors was studied. Under the optimum conditions, the highest removal rate of ammonia nitrogen can reach 99%, and the average removal rate of total nitrogen was 80%. The removal rate of COD in effluent reached 93%. The relative abundance of Proteobacteria was the highest in the multi-stage A/O mud membrane composite reactor with segmented influent. The community diversity and richness of activated sludge and biofilm in aerobic pool were the highest. Dechloromonas, Flavobacterium and Rhodobacter were dominant bacteria, and they were aerobic denitrifying bacteria that significantly contributed to the removal rate of ammonia nitrogen.

Investigation of lysing excess sludge slurry using hydrolase secreting thermophilic bacterial communities

Sludge reduction is a critical challenge in biological wastewater treatment. Combining excess sludge slurry lysis technology with traditional activated sludge processes is a promising approach for in-situ sludge reduction. Here, a strategy for excess sludge slurry lysis based on thermophilic bacterial communities (LTBC) was proposed. This investigation focused on the process of excess sludge slurry lysis dominated by thermophilic bacterial communities domesticated at different temperatures (55–75 °C). The evolution of sludge lysate was analyzed, and the mechanism of excess sludge slurry lysis under the action of thermophilic bacterial communities was elucidated through amplicon sequencing analysis. The results demonstrated that the aerobic thermophilic bacterial communities adapted to 75 °C exhibit the highest efficiency in sludge slurry lysis. During LTBC process, the removal efficiency of volatile suspended solids reached 53.9 ± 1.8% within 2 h, and 97.0 ± 1.0% of the protein and 96.0 ± 1.0% of the polysaccharide in the extracellular polymers was solubilized, and bacterial cell walls in sludge were disrupted. Fourier transform infrared spectroscopy and excitation-emission matrix spectroscopy of the sludge lysate demonstrated that the LTBC process was accompanied by humification process. The accumulation of humic acid primarily occurred at 55 °C and 65 °C, while fulvic acid occurred at 75 °C. The thermophilic bacterial communities adapted to 75 °C were dominated by Thermus and Thermaerobacter. Phylogenetic studies showed that the LTBC hydrolase system comprises enzymes related to protein hydrolysis, carbohydrate hydrolysis, and peptidoglycan hydrolysis, including metalopeptidase MepB, neutral α-glucosidase C, N-acetyl Muramyl-L-alanine amidase, and others enzymes. These results provide a theoretical basis for the application of LTBC technology in the reduction of sludge which generated in traditional waste water activated sludge processes.

Simultaneously enhancement in the assimilation of microalgal nitrogen and the accumulation of carbohydrate by Debaryomyces hansenii

Microalgae-based techniques are considered an alternative to traditional activated sludge processes for removing nitrogen from wastewater. Bacteria consortia have been broadly conducted as one of the most important partners. However, fungal effects on the removal of nutrients and changes in physiological properties of microalgae, and their impact mechanisms remain unclear. The current work demonstrates that, adding fungi increased the nitrogen assimilation of microalgae and the generation of carbohydrates compared to pure microalgal cultivation. The NH4+-N removal efficiency was 95.0% within 48 h using the microalgae-fungi system. At 48 h, total sugars (glucose, xylose, and arabinose) accounted for 24.2 ± 4.2% per dry weight in the microalgae-fungi group. Gene ontology (GO) enrichment analysis revealed that, among various processes, phosphorylation and carbohydrate metabolic processes were more prominent. Gene encoding the key enzymes of glycolysis, pyruvate kinase, and phosphofructokinase were significantly up-regulated. Overall, for the first time, this study provides new insights into the art of microalgae-fungi consortia for producing value-added metabolites.

Study on the removal characteristics and degradation pathways of highly toxic and refractory organic pollutants in real pharmaceutical factory wastewater treated by a pilot-scale integrated process.

Pharmaceutical wastewater frequently contains high levels of toxic pollutants. If they are discharged untreated, they pose a threat to the environment. The traditional activated sludge process and the advanced oxidation process do not sufficiently remove toxic and conventional pollutants from pharmaceutical wastewater treatment plants (PWWTPs). We designed a pilot-scale reaction system to reduce toxic organic pollutants and conventional pollutants from pharmaceutical wastewater during the biochemical reaction stage. This system included a continuous stirred tank reactor (CSTR), microbial electrolysis cells (MECs), an expanded sludge bed reactor (EGSB), and a moving bed biofilm reactor (MBBR). We used this system to further investigate the benzothiazole degradation pathway. The system effectively degraded the toxic pollutants (benzothiazole, pyridine, indole, and quinoline) and the conventional chemicals (COD, NH4 +-N, TN). During the stable operation of the pilot-scale plant, the total removal rates of benzothiazole, indole, pyridine, and quinoline were 97.66, 94.13, 79.69, and 81.34%, respectively. The CSTR and MECs contributed the most to the removal of toxic pollutants, while the EGSB and MBBR contributed less to the removal of the four toxic pollutants. Benzothiazoles can be degraded via two pathways: the benzene ring-opening reaction and the heterocyclic ring-opening reaction. The heterocyclic ring-opening reaction was more important in degrading the benzothiazoles in this study. This study provides feasible design alternatives for PWWTPs to remove both toxic and conventional pollutants at the same time.

Activated carbon enhanced traditional activated sludge process for chemical explosion accident wastewater treatment

With the development of industries, explosion accidents occur frequently during production, transportation, usage and storage of hazard chemicals. It remained challenging to efficiently treat the resultant wastewater. As an enhancement of traditional process, the activated carbon-activated sludge (AC-AS) process has a promising potential in treating wastewater with high concentrations of toxic compounds, chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N), etc. In this paper, activated carbon (AC), activated sludge (AS) and AC-AS were used to treat the wastewater produced from an explosion accident in the Xiangshui Chemical Industrial Park. The removal efficiency was assessed by the removal performances of COD, dissolved organic carbon (DOC), NH4+-N, aniline and nitrobenzene. Increased removal efficiency and shortened treatment time were achieved in the AC-AS system. To achieve the same COD, DOC and aniline removal (90%), the AC-AS system saved 30, 38 and 58 h compared with the AS system, respectively. The enhancement mechanism of AC on the AS was explored by metagenomic analysis and three-dimensional excitation-emission-matrix spectra (3DEEMs). More organics, especially aromatic substances were removed in the AC-AS system. These results showed that the addition of AC promoted the microbial activity in pollutant degradation. Bacteria, such as Pyrinomonas, Acidobacteria and Nitrospira and genes, such as hao, pmoA-amoA, pmoB-amoB and pmoC-amoC, were found in the AC-AS reactor, which might have played important roles in the degradation of pollutants. To sum up, AC might have enhanced the growth of aerobic bacteria which further improved the removal efficiency via the combined effects of adsorption and biodegradation. The successful treatment of Xiangshui accident wastewater using the AC-AS demonstrated the potential universal characteristics of the process for the treatment of wastewater with high concentration of organic matter and toxicity. This study is expected to provide reference and guidance for the treatment of similar accident wastewaters.

The Advancement in Membrane Bioreactor (MBR) Technology toward Sustainable Industrial Wastewater Management.

The advancement in water treatment technology has revolutionized the progress of membrane bioreactor (MBR) technology in the modern era. The large space requirement, low efficiency, and high cost of the traditional activated sludge process have given the necessary space for the MBR system to come into action. The conventional activated sludge (CAS) process and tertiary filtration can be replaced by immersed and side-stream MBR. This article outlines the historical advancement of the MBR process in the treatment of industrial and municipal wastewaters. The structural features and design parameters of MBR, e.g., membrane surface properties, permeate flux, retention time, pH, alkalinity, temperature, cleaning frequency, etc., highly influence the efficiency of the MBR process. The submerged MBR can handle lower permeate flux (requires less power), whereas the side-stream MBR can handle higher permeate flux (requires more power). However, MBR has some operational issues with conventional water treatment technologies. The quality of sludge, equipment requirements, and fouling are major drawbacks of the MBR process. This review paper also deals with the approach to address these constraints. However, given the energy limitations, climatic changes, and resource depletion, conventional wastewater treatment systems face significant obstacles. When compared with CAS, MBR has better permeate quality, simpler operational management, and a reduced footprint requirement. Thus, for sustainable water treatment, MBR can be an efficient tool.

Development and Application of Membrane Aerated Biofilm Reactor (MABR)—A Review

As a new type of biological treatment process, membrane aerated biofilm reactors (MABRs), which have received extensive attention and research in recent years, could reduce energy consumption by 70% compared to the traditional activated sludge process. The MABR system uses bubble-free aeration membrane material as the carrier, the counter-diffusion mechanism of oxygen and pollutants enables ammonium oxidizing bacteria (AOB) and nitrate oxidizing bacteria (NOB) to adhere to the membrane surface so that simultaneous nitrification and denitrification (SND) can occur to achieve simultaneous nitrogen and carbon removal. Currently, MABR technology has been successfully applied to the treatment of municipal sewage, various industrial wastewater, pharmaceutical, high salinity, high ammonia, aquaculture wastewater, landfill leachate and black and odorous water bodies in rivers. Many laboratory experiments and pilot-scale MABR reactors have been used to study the performance of membrane materials, the mechanism of pollutant removal and the effects of different factors on the system. However, the performance of MABR is affected by factors such as dissolved oxygen (DO), pH, C/N, biofilm thickness, hydraulic retention time (HRT), temperature, etc., which limits large-scale promotion. Therefore, membrane materials, membrane modules, biofilm, application of MABR technology, influencing factors of MABR system performance, and limitations and perspectives of MABR are reviewed in this paper, and we expect to provide valuable information.

Enhancement of nitrogen removal and energy recovery from low C/N ratio sewage by multi-electrode electrochemical technology and tidal flow via siphon aeration

In view of the difficulty in denitrification of low C/N ratio wastewater, electrochemical technology with multiple electrodes and tidal flow method via siphon aeration were used to enhance the denitrification process. At the same time, because of the low phosphorus removal efficiency in traditional activated sludge process, the constructed wetland and microbial fuel cell (CW-MFC) reactor with dewatered alum sludge (DAS) as substrate were constructed. In addition, the REDOX conditions of the reactor were changed by siphon, which significantly improved the removal efficiency of N and P and the energy recovery capacity of the reactor. In the 172 d, the Tidal Flow Constructed Wetland-Microbial Fuel Cell (TF CW-MFC) had the highest removal efficiency of COD and total nitrogen (TN), which were 97.4% and 83.4%, respectively. Although the removal rate of total phosphorus (TP) by TF CW-MFC was lower than artificial aeration, it can still reached 89.0%. The removal effect of aromatic protein substances in water was also significant. The amount of electrons generated by the artificial aeration anode and the amount of oxygen generated by the cathode were not enough to match. The voltage of TF CW-MFC was significantly higher than artificial aeration, around 350 mV, and the maximum power density was 98.16 mW m−3. In addition, MFC had an inhibitory effect on CW methane emissions. The analysis of the microbial community structure showed that most of the dominant bacteria of TF CW-MFC belonged to the Proteobacteria, Actinobacteria and Chloroflexi. These results showed that the TF CW-MFC technology as a zero-energy oxygen supply mode had high efficiency in the treatment of low C/N ratio wastewater and also had the environmental effect of reducing methane emissions. This study suggests that this green wastewater treatment technology has potential application value.

Algae-bacterial aquaculture can enhance heavy metals (Pb2+ and Cd2+) remediation and water re-use efficiency of synthetic streams

The synergistic interaction between algae and bacteria can be exploited to develop the next-generation wastewater treatment systems as the traditional activated sludge process are expensive, time-consuming, and release several greenhouse gasses. Thus, the protocooperation of algae bacterial consortia was studied during bioremediation of Pb2++Cd2+, followed by a bioassay study with bioremediated stream using Sorghum bicolor. Bacterial [Bacillus sp., (NCBI Acc. No. MK999907), Bacillus sp. (NCBI Acc. No. MN005950) and Micrococcus sp. (NCBI Acc. No. MN005949)]-algal [Scenedesmus acutus (NCIM 5584) and Chlorella pyrenoidosa (NCIM 2738)] consortium was constructed in such as way, which can tolerate and efficiently remove 200 ppm Pb2+ +1.5 ppm Cd2+. The individual consortia showed higher bioremediation attributes when they were mixed in equal quantities. However, the algae-bacterial consortia in the protocooperation study showed ∼30–33% higher bioremediation than individual consortia of algae/bacteria. Due to positive protocooperation 30% higher algal AFDW, 13% higher bacterial CFU mL−1, 82% lower dissolved oxygen, and 62% higher bicarbonates were reported as compared to individual consortia systems. For reuse of water, Sorghum plants were treated with bioremediated mixed metal stream (amino acid rich) reported higher total chlorophyll, Fv/Fm, and dry weight. The FTIR signal patterns and SEM-EDX images of Sorghum roots treated with bioremediated mixed metal stream were found negative for presence of any metals, whereas the seedlings treated with mixed metal showed deposition of Pb2+and Cd2+. Therefore, algal bacterial consortia-based bioremoval approaches can be adopted as an efficient tool for metal bioremediation and reuse of wastewater.

Sustained and enhanced anaerobic removal of COD and nitrogen in a zeolite amended glycogen accumulating organism dominated biofilm process

Activated sludge, the most widely used biological wastewater treatment process is known to be expensive to operate, largely due to energy expense for oxygen transfer into the bulk wastewater solution. The alternative of using passive aeration facilitates oxygen supply directly from the air resulting in aeration energy savings. The current study demonstrated sustained and improved removal of chemical oxygen demand (COD) and nitrogen in a zeolite modified glycogen accumulating organisms (GAOs) dominated biofilm reactor, which achieved anaerobic removal of COD and ammonium by the activity of GAOs and zeolite, respectively. Draining of the batch-operated reactor enabled the biofilm to directly uptake oxygen from air (passive aeration) to carry out simultaneous nitrification and denitrification due to the activity of GAO (Candidatus competibacter) and nitrifying bacteria (Nitrosomonas and Nitrospira). Under stable long-term (4-months) operation, the process achieved COD and nitrogen removal at rates of 1354 and 79.1 g m−3 d−1, respectively. The biofilm process demonstrated >90% nitrogen removal efficiency in multi-cycle (4/8 cycles) strategy with a short treatment time of 8 h. Due to the passive aeration scheme, the energy consumption of the proposed wastewater treatment process is calculated to be about 13-times less than that of traditional activated sludge process. Therefore, the Passive Aeration Simultaneous Nitrification and Denitrification (PASND) biofilm process is a promising low-energy treatment step for efficient removal of COD and nitrogen from wastewater.

Enhancing the treatment of petrochemical wastewater using redox mediator suspended biofilm carriers

The treatment efficiency of petrochemical wastewater via the traditional activated sludge process is generally unsatisfactory due to the complex and toxic features of petroleum compounds. Redox mediator (RM) can improve the biodegradation of organic contaminants by participating in the microbial extracellular electron transfer process. However, the continuous dosing of the soluble redox mediator would lead to secondary pollution and rise operation cost. In this study, an insoluble and economical redox mediator material (biochar) was introduced into high-density polyethylene (HDPE) to prepare suspended biofilm carriers (RM-modified carriers), and applied in anaerobic/oxic (A/O) reactors. The reactor filled with RM-modified carriers (R3) showed the removal efficiency of chemical oxygen demand (COD) and phenol in the anaerobic zone were 34.6 % and 43.0 % respectively at organic loading rates (OLRs) of 22.2 kg COD/(m3·d), which increased by 6.8 % and 8.3 % respectively compared with that of the reactor filled with conventional HDPE carriers (R2), and increased by 12.4 % and 17.7 % respectively compared with that of the reactor without filled with carriers (R1). Microbial analysis proved that the relative abundance of Bacteroides that participated in electron transfer of R3 improved by approximately 6.3 % compared with that of R2. These findings demonstrated that RM-modified carriers improved the abundance of relevant functional bacteria and enhanced the degradation efficiency of the contaminants in petrochemical wastewater.

Recent Advances in the Prediction of Fouling in Membrane Bioreactors.

Compared to the traditional activated sludge process, the membrane bioreactor (MBR) has several advantages such as the production of high-quality effluent, generation of low excess sludge, smaller footprint requirements, and ease of automatic control of processes. The MBR has a broader prospect of its applications in wastewater treatment and reuse. However, membrane fouling is the biggest obstacle for its wider application. This paper reviews the techniques available to predict fouling in MBR, discusses the problems associated with predicting fouling status using artificial neural networks and mathematical models, summarizes the current state of fouling prediction techniques, and looks into the trends in their development.

Application of MBR Technology in Schoolyard Domestic Sewage Treatment

This paper discusses the special features of campus sewage, and chooses more suitable sewage treatment for campus sewage. At the same time, it expounds the advantages and disadvantages of it. Compared with city sewage from industry and agriculture, campus sewage has much more characteristic content of pollutants with higher COD, SS and tiny toxic pollutants[5]. Therefore rather than using the traditional activated sludge process, MBR is more appropriate for schoolyard domestic sewage treatment for small area, stable effluent quality, good removal efficiency and little residual sludge production. Additionally, new campuses of universities are always built far away from the city centre, and the water transportation cost can be saved with a sewage treatment system in the campus. The treated water has the quality to be used as gray water for campus watering, cleaning and so on, which can also help the universities to save money. Undeniably, it also has the disadvantages of high energy consumption and cost, for it needs to update the active membrane regularly. If it is used in cities, it will be a huge financial burden for governments. But when it is used in campuses, less sewage will need less membranes, and the polluted membranes can also be used for students’ research.

Comparative Preliminary Evaluation of 2 In-stream Water Treatment Technologies for the Agricultural Reuse of Drainage Water in the Nile Delta.

In the Nile Delta, a complex network of canals collects drainage water from surface-irrigated fields but also from municipal wastewater. The goal of this work was to assess the technical, environmental, and financial feasibility of the upgrade of a drainage canal (DC) into either an in-stream constructed wetland (ICW) or a canalized facultative lagoon (CFL), in order to produce a water reusable in agriculture according to Egyptian law. The model-based design of the proposed technologies was derived from field experimental data for the ICW and laboratory data for the CFL. Both technologies, integrated by a sedimentation pond and a disinfection canal, led to the attainment of the water quality standards imposed by Egyptian Law 92/2013 for the reuse of drainage water. The life cycle assessment indicated that the upgrade of an existing DC to either an ICW or a CFL results in an extremely small environmental burden, ≤0.3% of that of a traditional activated sludge process. The cost-benefit analysis (CBA) was based on the assumptions that 1) farmers currently irrigate a nonfood crop (cotton) with the low-quality drainage water present in the DC, and 2) thanks to the upgrade to a ICW or CFL, farmers will irrigate a food crop characterized by a higher market price (rice). The CBA indicated that the DC upgrade to an ICW represents an attractive investment because it leads to a financial rate of return >10% over a wide range of cotton market prices. Conversely, the upgrade to a CFL is less attractive due to high investment costs. In conclusion, the upgrade of DCs to ICWs appears a promising option for the treatment of drainage canal water in the Nile Delta, thanks to the high pollutant removal performances, low cost, and negligible environmental burden. Integr Environ Assess Manag 2020;16:920-933. © 2020 SETAC.

Economic evaluation of ion-exchange processes for nutrient removal and recovery from municipal wastewater

Ion exchange (IEX) processes are a promising alternative to remove and recover nutrients from municipal wastewater. To assess the feasibility and viability of IEX processes for full-scale application, this study aimed at providing an evaluation of performance and economics on upscaling these processes for two different configurations in a 10,000 population equivalent wastewater treatment plant (WWTP) and compared them with a traditional biological nutrient removal (BNR) plant. The IEX processes were designed based on existing pilot-scale data, and after aerobic or anaerobic carbon removal stages. The nutrients were recovered from spent regenerants in the form of (NH4)2SO4 and hydroxyapatite Ca5(PO4)3(OH), allowing regenerant reuse. The 40-year whole life cost (WLC) of IEX coupled with traditional activated sludge processes was estimated to be ~£7.4 M, and WLC of IEX coupled with anaerobic membrane process was estimated to be £6.1 M, which was, respectively, 17% and 27% less than the traditional BNR based WWTP. Furthermore, ~98 tonnes of (NH4)2SO4 and 3.4 tonnes of Ca3(PO4)2 could be recovered annually. The benefits of lower costs, reduction in greenhouse gas emissions and nutrient recovery aligned with circular economy, illustrated that IEX processes are attractive for nutrient removal and recovery from municipal wastewater.

A Review on the Mechanism, Impacts and Control Methods of Membrane Fouling in MBR System.

Compared with the traditional activated sludge process, a membrane bioreactor (MBR) has many advantages, such as good effluent quality, small floor space, low residual sludge yield and easy automatic control. It has a promising prospect in wastewater treatment and reuse. However, membrane fouling is the biggest obstacle to the wide application of MBR. This paper aims at summarizing the new research progress of membrane fouling mechanism, control, prediction and detection in the MBR systems. Classification, mechanism, influencing factors and control of membrane fouling, membrane life prediction and online monitoring of membrane fouling are discussed. The research trends of relevant research areas in MBR membrane fouling are prospected.

Proof of concept of wastewater treatment via passive aeration SND using a novel zeolite amended biofilm reactor

The current paper describes a novel passive aeration simultaneous nitrification and denitrification (PASND) zeolite amended biofilm reactor that removes organic carbon and nitrogen from wastewater with low-energy consumption. Next to the ammonium oxidizing bacteria (AOB), this reactor contained naturally enriched glycogen accumulating organisms (GAOs) and zeolite powder to initially adsorb BOD (acetate) and ammonium (NH4 +-N) from synthetic wastewater under anaerobic conditions. Draining of the treated wastewater exposed the biofilm directly to air enabling low-energy oxygen supply by passive aeration. This allowed the adsorbed ammonium to be oxidized by the AOB and the produced nitrite and nitrate to be reduced simultaneously by the GAOs using the adsorbed BOD (stored as PHAs) as carbon source. Overall, with an operation mode of 1 h anaerobic and 4 h aerobic phase, the nutrient removal efficiency after single treatment was about 94.3% for BOD and 72.2% for nitrogen (NH4 +-N). As high-energy aeration of the bulk solution for oxygen supply is completely avoided, the energy requirement of the proposed PASND biofilm reactor can be theoretically cut down to more than 50% compared to the traditional activated sludge process.

Study on Sludge Reduction of Printing and Dyeing Wastewater Treatment by Biofilm Process

Aiming at the problem of large output of sludge in the traditional activated sludge process, the sludge reduction efficiency of the biofilm process was investigated on treating the printing and dyeing wastewater. The coefficient of producing sludge of three kinds of biofilm reactors for basalt fiber filler, combined filler and elastic filler were calculated and analyzed. The results indicated that, the coefficient of producing sludge of basalt fiber filler, combined filler and elastic filler reactors were 0.36gSS/g COD, 0.46gSS/gCOD and 0.60gSS/gCOD respectively. The sludge reduction ratios were 52.6%, 39.5% and 21.1% comparing with the traditional activated sludge method respectively and sludge reduction has the best effect on the basalt fiber biofilm reactor. The microscopic examination showed that there were abundant protozoa and metazo an in the biofilm and the reduction of sludge was realized by the predation relationship in the microbial ecosystem.

Adsorption characteristics of organics in the effluent of ultra-short SRT wastewater treatment by single-walled, multi-walled, and graphitized multi-walled carbon nanotubes

With a conceptual shift in sewage treatment from ‘waste pollution’ to ‘vehicle of resource and energy recovery’ and the further intensification of the energy crisis, the separation and recovery of carbon resources from discharged sewage has gained increasing recent attention in the field of water treatment. The ultra-short Solids Retention Time (SRT) activated sludge process (SRT ≤ 4 d) is highly efficient for separating organic matter and improving the energy recovery rate in wastewater treatment plants, but the effluent quality is relatively poor. If organics in the ultra-short SRT effluent can be reduced further to separate and recover carbon resources, the process may soon replace the traditional activated sludge process. We conducted physical adsorption carbon recovery experiments in an ultra-short SRT (SRT = 2 d) activated sludge system using three carbon nanotubes. Considering that Chemical Oxygen Demand (COD) arises from a mixture of organic compounds, and because humic acid (HA) makes up a large fraction of the effluent and can cause great environmental harm, further experiments were conducted on the adsorption of HA in the effluent COD to three nanotubes. This study proposes a novel method to completely remove organics from the effluent from ultra-short SRT activated sludge processes and reveals nanotube adsorption properties and mechanisms.

Application of Ozone MBBR Process in Refinery Wastewater Treatment

Moving Bed Biofilm Reactor (MBBR) is a kind of sewage treatment technology based on fluidized bed. At the same time, it can also be regarded as an efficient new reactor between active sludge method and the biological membrane method. The application of ozone MBBR process in refinery wastewater treatment is mainly studied. The key point is to design the ozone +MBBR combined process based on MBBR process. The ozone +MBBR process is used to analyze the treatment of concentrated water COD discharged from the refinery wastewater treatment plant. The experimental results show that the average removal rate of COD is 46.0%~67.3% in the treatment of reverse osmosis concentrated water by ozone MBBR process, and the effluent can meet the relevant standard requirements. Compared with the traditional process, the ozone MBBR process is more flexible. The investment of this process is mainly ozone generator, blower and so on. The prices of these items are relatively inexpensive, and these costs can be offset by the excess investment in traditional activated sludge processes. At the same time, ozone MBBR process has obvious advantages in water quality, stability and other aspects.