Sequencing Batch Moving Bed Biofilm Research Articles

Correction: Zajac et al. Changes in Nitrification Kinetics and Diversity of Canonical Nitrifiers and Comammox Bacteria in a Moving Bed Sequencing Batch Biofilm Reactor—A Long-Term Study. Water 2024, 16, 534

There was an error in the original publication [...]

Dynamic pH regulation drives Nitrosomonas for high-rate stable acidic partial nitritation

How to intensify the ammonia oxidation rate (AOR) is still a bottleneck impeding the technology development for the innovative acidic partial nitritation because the eosinophilic ammonia-oxidizing bacteria (AOB), such as Nitrosoglobus or Nitrosospira, were inhibited by the high-level free nitrous acid (FNA) accumulation in acidic environments. In this study, an innovative approach of dynamic acidic pH regulation control strategy was proposed to realize high-rate acidic partial nitritation driven by common AOB genus Nitrosomonas. The acidic partial nitrification process was carried out in a laboratory-scale sequencing batch moving bed biofilm reactor (SBMBBR) for long-term (700 days) to track the effect of dynamic acidic pH on nitrifying bacterial activity. The results indicated that the influent NH4+-N concentration was about 100 mg/L, the nitrite accumulation ratio was exceeding 90%, and the maximum AOR can reach 14.5 ± 2.6 mg N L−1h−1. Although the half-saturation inhibition constant of NOB (KI_FNA(AOB)) reached 0.37 ± 0.10 mg HNO2N/L and showed extreme adaptability in FNA, the inactivation effect of FNA (6.1 mg HNO2N/L) for NOB was much greater than that of AOB, with inactivation rates of 0.61 ± 0.08 h−1 and 0.06 ± 0.01 h−1, respectively. The effluent pH was gradually reduced to 4.5 by ammonia oxidation process and the periodic FNA concentration reached 6.5 mg HNO2N/L to inactivate nitrite-oxidizing bacteria (NOB) without negatively affecting Nitrosomonas during long-term operation. This result provides new insights for the future implementation of high-rate stabilized acidic partial nitritation by Nitrosomonas.

Exposure to zinc and dialkyldimethyl ammonium compound alters bacterial community structure and resistance gene levels in partial sulfur autotrophic denitrification coupled with the Anammox process

Dialkyldimethyl ammonium compound (DADMAC) is widely used in daily life as a typical disinfectant and often co-exists with the heavy metal zinc in sewage environments. This study investigated the effects of co-exposure to zinc (1 mg/L) and DADMAC (0.2–5 mg/L) on the performance, bacterial community, and resistance genes (RGs) in a partial sulfur autotrophic denitrification coupled with anaerobic ammonium oxidation (PSAD-Anammox) system in a sequencing batch moving bed biofilm reactor for 150 days. Co-exposure to zinc and low concentration (0.2 mg/L) DADMAC did not affect the nitrogen removal ability of the PASD-Anammox system, but increased the abundance and transmission risk of free RGs in water. Co-exposure to zinc and medium-to-high (2–5 mg/L) DADMAC led to fluctuations in and inhibition of nitrogen removal, which might be related to the enrichment of heterotrophic denitrifying bacteria dominated by Denitratisoma. Co-exposure to zinc and high concentration DADMAC (5 mg/L) stimulated the secretion of extracellular polymeric substances and increased the proliferation risk of intracellular RGs in sludge. This study provided insights into the application of PSAD-Anammox system and the ecological risks of wastewater containing zinc and DADMAC.

Experimental investigation of simultaneous nitrification-denitrification and phosphorus removal in pilot-scale sequencing batch moving bed biofilm reactors (SB-MBBRs)

Sequencing batch moving bed biofilm reactors have been widely used in commercial wastewater treatment facilities for organic carbon and nitrogen removal. However, these reactors can remove low phosphorus (P) levels. Therefore, this study investigated the potential of SB-MBBRs for maximizing simultaneous nitrification-denitrification and P removal (SNDPR) potential from P-rich municipal wastewater impacted by industrial discharges. A series of experiments were carried out to investigate the effect of external volatile fatty acid (VFA) dosing, airflow rate, and temperature on SNDPR using pilot-scale SBMBBRs. Stable and robust SNDPR was achieved with an optimum acetic acid supply of 150 mg SCOD/L, at 20 oC and 2.5 L air/min. A low airflow rate (AFR) and high-temperature conditions affected P release and uptake kinetics. Efficient PHA storage, dissolved oxygen (DO) transfer (outer layer), DO diffusion limitation (inner layer) of biofilm, and conversion of NH4-N to NO2-N/NO3-N enhanced SNDPR in the two pilot SB-MBBRs.

Changes in Nitrification Kinetics and Diversity of Canonical Nitrifiers and Comammox Bacteria in a Moving Bed Sequencing Batch Biofilm Reactor—A Long-Term Study

A lab-scale pure moving bed sequencing batch biofilm reactor (MBSBBR) was employed to investigate changes in nitrification kinetics and microbial diversity. The MBSBBR operated under different aeration strategies (defined by the ratio of the duration of the subphases with (t1) and without (t2) aeration (R = t2/t1)) − continuous (R = 0) and intermittent (with constant time of non-aerated subphases (t2 = 10 min) and variable duration of subphases with aeration (t1 = 40 min–R = 1/4, t1 = 30 min–R = 1/3, t1 = 20 min–R = 1/2) and dissolved oxygen (DO) concentrations (6 mg/L; 3.5 mg/L). Moreover, the reactor’s organic (OLR) and nitrogen (NLR) loading rates were changed in the following ranges: OLR—537–402 gCOD/m3·d, NLR—64–48 gN/m3·d. The obtained results showed that, irrespective of changes introduced in particular series, a highly effective nitrification process (93.36 ± 2.13%) was achieved. The activity of bacteria capable of oxidizing ammonia nitrogen changed differently from that of bacteria capable of oxidizing nitrites (NOB). An increase in R was the primary factor changing the activity of ammonia-oxidizing microorganisms. NOB activity was affected only by the reduction of OLR and NLR. NOB were the predominant bacterial group, consistent with the kinetics studies. A DO decrease caused an increase in the abundance of AOB, NOB, and Comammox bacteria. Comammox bacteria were the most abundant at R = 1/2 and DO = 3.5 mg/L.

Decrease in Oxygen Concentration for the Fast Start-Up of Partial Nitritation/Anammox without Inoculum Addition

Initiating the partial nitritation and anammox (PN/A) process without inoculation poses a significant challenge. Thus, there is a notable amount of interest in devising a straightforward strategy for the start-up of PN/A. This study demonstrates the feasibility of achieving the rapid start-up of a one-stage PN/A process within a moving-bed sequencing batch biofilm reactor (MBSBBR) by reducing the oxygen concentrations: 3.0 mg O2/L (Stage I), 2.0 mg O2/L (Stage II), and 1.0 mg O2/L (Stage III). The anammox activity was observed 15 days after a gradual decrease in the oxygen concentration and confirmed using a specific anammox activity test (5.9 mg N/gVSS∙h). During Stage III, the average total inorganic nitrogen (TIN) removal efficiency was 60.6%. The relative abundance of planctomycetes, a typical phylum representing anammox microorganisms, increased almost three times from Stage I (2.8%) to Stage III (7.1%). These results demonstrate the potential of a decrease in oxygen concentration for the fast start-up of the one-stage partial nitritation and anammox process without inoculation. The implementation of the studied DO strategy has practical implications for wastewater treatment plant operators, particularly in the start-up of the PN/A processes. Additionally, batch assays allow for the rapid assessment of treatment plant performance, providing real-time insights into its functionality and, thereby, optimizing wastewater treatment practices.

The microbiome of two strategies for ammonia removal with the sequencing batch moving bed biofilm reactor treating cheese production wastewater.

Cheese production facilities must abide by sewage discharge bylaws that prevent overloading municipal water resource recovery facilities, eutrophication, and toxicity to aquatic life. Compact treatment systems can permit on-site treatment of cheese production wastewater; however, competition between heterotrophs and nitrifiers impedes the implementation of the sequencing batch moving bed biofilm reactor (SB-MBBR) for nitrification from high-carbon wastewaters. This study demonstrates that a single SB-MBBR is not feasible for nitrification when operated with anerobic and aerobic cycling for carbon and phosphorous removal from cheese production wastewater, as nitrification does not occur in a single reactor. Thus, two reactors in series are recommended to achieve nitrification from cheese production wastewater in SB-MBBRs. These findings can be applied to pilot and full-scale SB-MBBR operations. By demonstrating the potential to implement partial nitrification in the SB-MBBR system, this study presents the possibility of implementing partial nitrification in the SB-MBBR, resulting in the potential for more sustainable treatment of nitrogen from cheese production wastewater.

Study on the Efficacy of Polyethylene Filled SBMBBR Process for Treating Low Temperature Municipal Wastewater

To tackle the hassle of low efficiency of low temperature denitrification in wintry weather in northern region,Sequencing Batch Moving Bed Biofilm Reactor (SBMBBR) used to be used for deep treatment of low temperature municipal wastewater and polyethylene fillers have been compared. The outcomes confirmed that the Sequencing Batch Activated Sludge Reactor (SBR) used to be started correctly at 64 d beneath the prerequisites of water temperature 9-12 °C,pH 7-8 and HRT of 48 h,and two polyethylene fillers had vast biofilm after 7 d operation,and the elimination rates of COD,Ammonia Nitrogen and TP in polyethylene K3 fillers have been stabilized at 83.6%,74.4% and 60.8% respectively as the quality fillers after 24 d operation. After optimizing the process parameters,the steady effluent evaluation effect used to be determined for 27 d operation beneath the most advantageous anoxic (3 h) and aerobic time (7 h) modes of the reactor,and the corresponding elimination quotes of COD and Ammonia Nitrogen were 87.7% and 93.5%,respectively,and the corresponding average effluent concentrations had been 44.4 mg/L and 1.9 mg/L,which reached the Pollutant Discharge Standard for Urban Sewage Treatment Plants (GB 18918-2002). Two vital factors,Dissolved Oxygen (DO) concentration and Hydraulic retention time (HRT) in the aerobic part were studied,and the great HRT of 82 h was once performed in the biointensive domestication SBR machine under the stipulations of the foremost vary of DO attention of 6.0-7.5 mg/L in the aerobic part at low water temperature.

Deciphering community assembly and succession in sequencing batch moving bed biofilm reactor: Differentiation between attached and suspended communities

Elucidating community assembly and succession is crucial to understanding the ecosystem functioning. Herein, the ecological processes underpinning community assembly and succession were studied to uncover the respective ecological functions of attached biofilms and suspended biomass in a sequencing batch moving bed biofilm reactor. Compared with suspended biomass, attached biofilms presented higher relative abundances of Nitrospira (2.94 %) and Nitrosomonas (1.25 %), and contributed to 66.89 ± 11.37 % and 68.11 ± 12.72 % of nitrification and denitrification activities, respectively. The microbial source tracking result demonstrated that early formation of suspended biomass was dominated by the seeding effect of detached biofilms in the start-up period (days 0–30), while self-growth of previous suspended biomass was eventually outcompeted the seeding effect when the reactor stabilized (days 31–120). Null model and ecological network analysis further suggested distinctive ecological processes underpinning the differentiation between attached and suspended communities in the same reactor. Specifically, in the start-up period, positive interactions facilitated early formation of attached (73.84 %) and suspended communities (59.41 %), while homogenous selection (88.89 %) and homogenizing dispersal (65.71 %) governed assembly of attached and suspended communities, respectively. When the reactor stabilized, attached and suspended communities showed low composition turnover as reflected by dominant homogenizing dispersal, while they presented distinctive trends of interspecies interactions. This study sheds light on discrepant ecological processes governing community differentiation of attached biofilms and suspended biomass, which would provide ecological insights into the regulation of hybrid ecosystems.

Improving the performance of coupled solid carbon source biofilm carriers through pore-forming methods

Coupled solid carbon source biofilm carriers (CCBs) was usually utilized to enhance the treatment efficiency of low carbon/nitrogen (C/N) wastewater. However, current CCBs have low carbon release capacity because of its small inner mass transfer coefficient. Therefore, this study innovatively applied pore-forming methods to modify CCBs. After orthogonal selections, two porous CCBs, which were respectively prepared through circulating freezing pore-forming method (CCB2) and ammonium bicarbonate pore-forming method (CCB3), were proposed and further applied in sequencing batch moving bed biofilm reactors (SBMBBRs). The results indicated that circulating freezing pore-forming method could improve the mechanical strength and carbon source release rate of CCBs. In addition, CCB2 could significantly enhance the total nitrogen (TN) removal efficiency of SBMBBRs, when compared with the non-porous CCBs (i.e., CCB1). Further biofilm and simultaneous nitrification and denitrification (SND) rate calculation attributed this enhancement to the higher biofilm amount (i.e., 0.06 g g−1 CCB) and the higher SND rate (i.e., 33.60%). Microbial community analysis reiterated these observations that CCB2 and CCB3 could accumulate Proteobacteria, Actinobacteriota and Nitrospirota, and also stimulate nitrification and denitrification associated pathways. More importantly, the cost calculation indicated CCB2 cost only 47.37% of CCB1 and 31.34% of CCB3, showing highly economic applicability. Overall, our results collectively proved that CCBs manufactured by circulating freezing pore-forming method could provide more carbon releasing points and microorganisms attaching positions, exhibiting effectively nitrogen removal when treating low C/N wastewater.

A Comparison of Biosolids Production and System Efficiency between Activated Sludge, Moving Bed Biofilm Reactor, and Sequencing Batch Moving Bed Biofilm Reactor in the Dairy Wastewater Treatment

Dairy industry wastewater is rich in organic content, presenting a high biodegradability, and therefore biological treatments are widely employed. This study aimed to evaluate biosolids production in three systems: activated sludge (AS), movingbed biofilm reactor (MBBR), and sequencingbatch movingbed biofilm reactor (SBMBBR). Simulated dairy wastewater was used at different organic load rates (OLRs): 1.22, 2.87, and 5.44 gCOD L−1d−1. Besides biosolids production, COD, total carbon (TC), and total nitrogen (TN) removal efficiency was evaluated. Biosolids production was measured in the mixed liquor, carrier-adhered biomass, treated wastewater, and surplus sludge. The operational conditions were kept similar for the three systems, with a carrier filling ratio of 50% for MBBR and SBMBBR. The SBMBBR proved to have better performance in the removal efficiencies of COD, TC, and TN for all OLRs studied. The MBBR presented a similar COD and TC removal efficiency as the SBBR for the two highest OLRs (2.87 and 5.44 gCOD L−1d−1). Concerning biosolids production, the MBBR system produced less biomass and delivered the lowest amount of adhered biomass inside the carriers. The AS treatment generated the highest amount of sludge and offered the worst treatment capability for all OLRs evaluated.

Biofilm morphology and microbiome of sequencing batch moving bed biofilm reactors treating cheese production wastewater

Compact, on-site treatment of cheese production wastewater is required to meet increasing regulations. This study investigates the treatment of cheese production wastewater of a sequencing batch moving bed biofilm reactor (SB-MBBR); the effects of anaerobic staging times and aeration rates on biofilm morphology, dry-mass, thickness, mean dry-density, biomass viability, and microbiome. Increasing anaerobic staging time from 72 to 168 min improved carbon removal rates from 24.8 ± 0.5 to 41.6 ± 1.3 g·m−2 d−1, likely due to a rougher biofilm morphology, lower mean dry-density and therefore enhanced biofilm mass transport. The microbiome community shifts from a population dominated by denitrifiers and possibly putative polyphosphate accumulating organisms, Brachymonas, Dechloromonas, and Rhodoferax, to a lower abundance of fermenting bacteria with increasing anaerobic staging time and lower aeration. This study provides new evidence of polyphosphate accumulating organisms in SB-MBBRs treating cheese production wastewater, supporting the feasibility of the SB-MBBR for on-site treatment of carbon, nitrogen and phosphorous.

Selection and synthesization of multi–carbon source composites to enhance simultaneous nitrification–denitrification in treating low C/N wastewater

Low carbon/nitrogen ratio (C/N) wastewater is widespread and difficult to treat. To find a resolution to this issue, this study systematically evaluated the constituents of composite solid carbon (i.e., skeletons, carbon sources and crosslinking agents), and proposed a new multi-carbon source composite S1 (MCSC.S1). The effects on nitrogen removal were further determined through a sequencing batch moving bed biofilm reactor (SBMBBR). The results showed that MCSC.S1, which was composed of polyvinyl alcohol-sodium alginate (PVA-SA), corncob + poly (R-β-hydroxybutyrate) (CC + PHB), and H3BO3-4% CaCl2+Na2SO4 had high stability and absorption. With MCSC.S1, total nitrification removal was enhanced by more than 48.56% through releasing carbon and absorbing the attached denitrifying bacteria. In addition, it was found that MCSC.S1 can simulate the simultaneous nitrification and denitrification (SND) process and contribute to 29.85% of the total nitrogen removal. 16S gene-based analysis attributed this supplementary nitrogen removal to the enrichment of nitrification (i.e., Proteobacteria, Actinobacteria and Chloroflexi), denitrification of associated bacteria (i.e., Nitrospirota) in MCSC.S1 added reactor, and the increase in nitrogen recycling associated genes. These findings collectively demonstrate that the new MCSC.S1 could effectively enhance nitrogen removal efficiency in low C/N ratio wastewater.

Two moving bed biofilm reactors in series for carbon, nitrogen, and phosphorous removal from high organic wastewaters

Government regulations require on-site treatment of industrial wastewater prior to sewage discharge to prevent environmental degradation of receiving waterbodies. The sequencing batch moving bed biofilm reactor (SB-MBBR) can permit on-site treatment of high organic and nutrient content of cheese production wastewater. However, the critical challenge exists of maintaining both an active heterotrophic and an autotrophic population in a single biofilm system treating carbon and ammonia to low discharge levels from cheese production wastewater. Two SB-MBBRs in series separate the heterotrophic and autotrophic communities, circumventing the competition between the heterotrophic and autotrophic populations in a single biofilm system treating wastewater with high carbon to nitrogen ratios. The first reactor (AN/AE) was operated by cycling between anaerobic and aerobic stages to select for polyphosphate accumulating organisms, and the AN/AE reactor degraded carbon and phosphorous. The second reactor (NIT) was operated with aerobic conditions to promote nitrifying bacteria and treat total ammonia nitrogen. The performance of this system for carbonaceous constituents and ammonia was evaluated by quantifying the kinetics, biofilm morphology, thickness, dry-mass, and dry-density of the two SB-MBBR in series technology. The AN/AE reactor achieved 97.5 ± 1.7%, 58.8 ± 5%, and 49 ± 1% soluble chemical oxygen demand, total nitrogen, and total phosphorous removal efficiencies respectively. The NIT reactor achieved 98.7 ± 2.4 % total ammonia nitrogen removal, though partial nitritation at rates of 1.09 ± 0.03 g-N·m-2d-1, indicating this system can be incorporated in an anammox system. The study demonstrates that enhanced biological phosphorous removal, and potentially anaerobic removal of ammonia can be achieved for on-site treatment of cheese production wastewater.

Phosphorus removal from industrial discharge impacted municipal wastewater using sequencing batch moving bed biofilm reactor

This study aimed to investigate the performance of a sequencing batch moving bed biofilm reactor (SB-MBBR) for biological P removal (Bio-P) treating diluted municipal wastewater at 10 °C and 20 °C, with volatile fatty acid (VFA) dosing during weekdays and without VFA dosing during weekends to simulate an industrial influenced wastewater. The overall results revealed that phosphorus removal efficiency for weekdays reached 53 % and 81 % at cold and moderated temperatures respectively. However, phosphorus removal efficiency for the weekend was 49 % for cold temperature and 52 % for moderate temperature. It was concluded that low temperature and low VFA might have suppressed the phosphate accumulating organisms (PAOs) performance. Besides, high extracellular polymeric substance (EPS) production might have hampered the PAOs activity, which could be linked to the observed high consumption of soluble chemical oxygen demand (SCOD) to P release ratio and thick biomass growth in the cold system.

Anaerobic-aerobic processes for the treatment of textile dyeing wastewater containing three commercial reactive azo dyes: Effect of number of stages and bioreactor type

In this study, the effect of number of stages and bioreactor type on the removal performance of a sequential anaerobic–aerobic process employing activated sludge for the treatment of a simulated textile dyeing wastewater containing three commercial reactive azo dyes was considered. Two stage processes performed better than one stage ones, both in terms of overall organic and color removal, as well as the higher contribution of anaerobic stage to the overall removal performance, thereby making them a more energy efficient option. The employment of a moving bed sequencing batch biofilm reactor, which uses both suspended and attached biomass, for the implementation of the anaerobic stage of the process, was compared with a sequencing batch reactor that only employs suspended biomass. The results showed that, although there was no meaningful difference in biomass concentration between the two bioreactors, the latter reactor had better performance in terms of chemical oxygen demand (COD) removal efficiency and rate and color removal rate. Further exploratory tests revealed a difference between the roles of suspended and attached bacterial populations, with the former yielding better color removal whilst the latter had better COD removal performance. The sequential anaerobic–aerobic process, employing an aerobic membrane bioreactor in the aerobic stage resulted in COD and color removal of 77.1 ± 7.9% and 79.9 ± 1.5%, respectively. The incomplete COD and color removal was attributed to the presence of soluble microbial products in the effluent and the autoxidation of dye reduction metabolites, respectively. Also, aerobic partial mineralization of the dye reduction metabolites, was experimentally observed.

Degradation of p-nitroaniline from aqueous solutions using ozonation/Mg-Al layered double hydroxides integrated with the sequencing batch moving bed biofilm reactor

In this study, two treatment steps were performed to completely remove p-nitroaniline (PNA). In the first stage, the catalytic ozonation process (COP) using the synthesized nanoparticles of magnesium–aluminum layered double hydroxide (MgAl-LDH) was applied for pre-treatment. Effective parameters in the COP, including initial pH, initial PNA concentration, catalyst dose, and contact time has been investigated. Response Surface Method)RSM(was applied to optimize process conditions in the COP. The effluent from the COP entered the sequencing batch moving bed biofilm reactor (SBMBBR). The optimum conditions for the COP process were initial PNA concentration: 120 mg/L, pH: 8.25, LDH dose: 750 mg/L, and reaction time: 70 min. Under these conditions, the maximum removal efficiency of PNA, COD, and TOC was about 91.5, 83, and 70%, respectively. The biological reactor was operated under conditions of hydraulic retention time (HRT) of 24 h, pH of 6.5–7, mixed liquor suspended solids attached to bio-carriers (MLSSatt.) of 4700 mg/L, mixed liquor volatile suspended solids attached to bio-carriers (MLVSSatt.) of 3200 mg/L, MLSS of 1000 mg/L, and MLVSS of 880 mg/L. In this study, using the COP/SBMBBR system, the complete PNA analysis and maximum removal efficiency of COD and TOC were about 99 and 97%, respectively.

Effect of anaerobic phases length on denitrifying dephosphatation biocenosis \u2013 a case study of IFAS-MBSBBR

BackgroundThe study aimed to evaluate the influence of the duration times of anaerobic phases on the bacterial biocenosis characterisation while denitrifying dephosphatation in the Integrated Fixed-Film Activated Sludge – Moving-Bed Sequencing Batch Biofilm Reactor (IFAS-MBSBBR). The experiment was conducted in a laboratory model. The study consisted of four series, which differed in terms of the ratio of the anaerobic phases.duration concerning the overall reaction time in the cycle. The anaerobic phases covered from 18 to 30% of the whole cycle duration. During the reactor performance that took 9 months, the influent and effluent were monitored by analysis of COD, TKN, NH4-N, NO2-N, NO3-N, TP, PO4-P, pH, alkalinity and the phosphorus uptake batch tests. Characterisation of the activated sludge and the biofilm biocenosis was based on fluorescent in situ hybridisation (identification of PAO and GAO) and the denaturing gradient gel electrophoresis patterns.ResultsThe organic compounds removal was high (more than 95.7%) independently of cycle configuration. The best efficiency for nitrogen (91.1%) and phosphorus (98.8%) removal was achieved for the 30% share of the anaerobic phases in the reaction time. Denitrifying PAO (DPAO) covered more than 90% of PAO in the biofilm and usually around 70% of PAO in the activated sludge. A substantial part of the polyphosphate accumulating organisms (PAO) community were Actinobacteria. The denitrifying dephosphatation activity was performed mainly by Accumulibacter phosphatis.ConclusionsHigh nutrient removal efficiencies may be obtained in IFAS-MBSBBR using the denitrifying dephosphatation process. It was found that the length of anaerobic phases influenced denitrification and the biological phosphorus removal. The extension of the anaerobic phases duration time in the reaction time caused an increase in the percentage share of denitrifying PAO (DPAO) in PAO. The biocenosis of the biofilm and the activated sludge reveal different species patterns and domination of the EBPR community.

Biodegradation of mono azo dye-Reactive Orange 16 by acclimatizing biomass systems under an integrated anoxic-aerobic REACT sequencing batch moving bed biofilm reactor

This study dealt with the biodegradation of Reactive Orange 16 (RO16) containing wastewater via a novel integrated anoxic-aerobic REACT sequencing batch moving bed biofilm reactor (SBMBBR). The chemical oxygen demand (COD) removal and biodecolorization from three design schemes pertinent to the effects of (i) dye concentration under stepwise approach, Scheme 1; (ii) dye concentration under shock load approach, Scheme 2 and (iii) hydraulic retention time (HRT) coupled with the increase of biocarrier filling ratio, Scheme 3 were evaluated orderly along the evaluation. A complete biodecolorization and over 97 % of COD removal were attained in Scheme 1. Although both COD removal and biodecolorization in Scheme 2 was deteriorated to approximate 40 % by successive RO16 shocks, the microbial strength in removing RO16 molecules (mg RO16/mg biomass) reflected a two-fold amelioration from 0.015 to 0.0304 as the result of actively metabolic system. The maximum co-substrate uptake also reduced from 100 % to 69 %. At higher biocarrier filling ratio (10 % (v/v)) in Scheme 3, the difference in COD removal and biodecolorization rates reflected an improvement of 0.16 and 0.30 % hour-1, respectively, throughout the anoxic-REACT period. However, the performance changed insignificantly due to the reduction of HRT. The presence of the attached-growth biomass system was of great importance, although the suspended-growth biomass dominated more than 76 % of the biomass system in SBMBBR.

Kinetic effects of anaerobic staging and aeration rates on sequencing batch moving bed biofilm reactors: Carbon, nitrogen, and phosphorus treatment of cheese production wastewater

The food and beverage industry produces wastewaters containing high concentrations of organic carbon and nutrients, which when discharged leads to eutrophication and algal blooms. Given recent stringencies in effluent regulations, industries are required to treat their wastewater on-site. There is a critical need for compact, high-rate, cost-effective wastewater technologies to treat industrial wastewaters, such as the sequencing batch moving bed biofilm reactor. The aim of this study is to investigate the potential and evaluate the performance of the sequencing batch moving bed biofilm reactor cycling between anaerobic and aerobic stages to treat high-strength food and beverage wastewaters. Specifically, this study focuses on the effects of anaerobic staging times and enhanced aeration on the removal of carbon, nitrogen, and phosphorous from cheese production wastewaters. Increasing anaerobic staging times was found to improve the removal rates of carbon beyond previously reported moving bed biofilm reactor results. Increasing the anaerobic stage however decreased the total nitrogen removal, with organic nitrogen undergoing ammonification during the anaerobic stage. This study demonstrates an optimum anaerobic staging time of 138 min; with a carbon removal rate of 31.1 g-sCOD·m−2d−1 and a nitrogen removal rate of 1.3 g-N·m−2d−1. Enhanced aeration was found to be detrimental to phosphorous removal, where a moderate aeration rate demonstrated a net total phosphorous removal of approximately 22 mg-P·l−1 with the phosphorous-content of the suspended solids being approximately 4%. Finally, the sequencing batch moving bed biofilm reactor shows potential for on-site treatment of carbon, nitrogen, and phosphorous from cheese production wastewater.