Moving Bed Biofilm Reactor-membrane Bioreactor Research Articles

Responses of biofilm communities in a hybrid moving bed biofilm reactor-membrane bioreactor system to sulfadiazine antibiotic exposure

Antibiotics in wastewater can affect the structures and functions of bacterial communities, subsequently influencing how well a biological process performs. Therefore, the characteristics of bacterial community were investigated in a hybrid moving bed biofilm reactor-membrane bioreactor system when treating domestic wastewater containing sulfadiazine (SDZ). Results indicated total nitrogen removal reduced by 10.2%, 9.1%, 2.7% and 2.9%, respectively, with increasing carbon to nitrogen (C/N) ratios (2.5, 4, 6 and 9) when SDZ was present (0.5 mg/L). The microbial communities' analysis revealed that the abundance of nitrogen removal-related bacteria increased with C/N. Specifically, the abundance of ammonia-oxidizing bacteria (0.46%-0.90%) was low, and the nitrite-oxidizing bacteria (2.16%-7.13%) and denitrifying bacteria showed a significant increase (Hyphomicrobium: 0.57%-3.54%) when C/N ratio increased. The abundance of denitrifying bacterial declined by 4.82–8.56% at different C/N ratios, while nitrifying bacterial rose by 0.70–5.67%. Interestingly, the denitrifying bacteria Enterobacter, Sphingomonas and Gemmatimonas acted as mutualistic bacteria that stabilized denitrification.

Rapid granulation of aerobic granular sludge in an integrated moving bed biofilm reactor-membrane bioreactor: Effects and mechanism of Streptomyces cellulosus microspheres

This work focuses on revealing the effects of functional microorganism on rapid granulation process of aerobic granular sludge (AGS) in an integrated moving bed biofilm reactor-membrane bioreactor (MBR), and tries to illustrate the related mechanism. The result verified that the functional microorganism, Streptomyces cellulosus microspheres (Scms), could promote the rapid granulation of AGS within only 4 days, and the average size of AGS kept at around 1850 μm on day 80 and showed no obvious reduction in the size even for operating over 3 months. Scms first reduced the negative surface charge on sludge particles, which was beneficial to the aggregation of floc sludge, and then caused the changes in the structure of AGS and the composition of microbial community within the system. Under these effects, the formed large and stable AGS promoted a higher and more stable efficiency in the removal of COD (> 93 %).

Effect of a Functional Microorganism on the Rapid Granulation of Aerobic Granular Sludge in an Integrated Moving Bed Biofilm Reactor-Membrane Bioreactor And its Joint Mechanism

Effect of a Functional Microorganism on the Rapid Granulation of Aerobic Granular Sludge in an Integrated Moving Bed Biofilm Reactor-Membrane Bioreactor And its Joint Mechanism

Effects of a Functional Microorganism on Rapid Granulation of Aerobic Granular Sludge in an Integrated Moving Bed Biofilm Reactor-Membrane Bioreactor and its Joint Mechanism

Effects of a Functional Microorganism on Rapid Granulation of Aerobic Granular Sludge in an Integrated Moving Bed Biofilm Reactor-Membrane Bioreactor and its Joint Mechanism

Reduction of Cost and Environmental Impact in the Treatment of Textile Wastewater Using a Combined MBBR-MBR System.

A hybrid Moving Bed Biofilm Reactor—Membrane Bioreactor (MBBR-MBR) was developed for the treatment of wastewater from a Spanish textile company. Compared with conventional activated sludge (CAS) treatment, the feasibility of this hybrid system to reduce economic and environmental impact on an industrial scale was conducted. The results showed that, technically, the removal efficiency of COD, TSS and color reached 93%, 99% and 85%, respectively. The newly dyed fabrics performed with the treated wastewater were qualified under the standards of the textile industry. Economically, the values of Capital Expenditure (CAPEX) calculated for the hybrid MBBR-MBR system are profitable because of the reduction in Operational Expenditure (OPEX) when compared with CAS treatment, due to the lower effluent discharge tax thanks to the higher quality of the effluent and the decolorizing agent saved. The result of Net Present Value (NPV) and the Internal Rate of Return (IRR) of 18% suggested that MBBR-MBR is financially applicable for implantation into the industrial scale. The MBBR-MBR treatment also showed lower environmental impacts than the CAS process in the life cycle assessment (LCA) study, especially in the category of climate change, thanks to the avoidance of using extra decolorizing agent, a synthetic product based on a triamine.

Performance of a membrane bioreactor and a moving bed biofilm reactor–membrane bioreactor treating table olive processing wastewater: a comparative study

AbstractBACKGROUNDTwo laboratory‐scale experimental systems – a membrane bioreactor (MBR) and a moving bed biofilm reactor–membrane bioreactor (MBBR‐MBR), both treating real high‐strength, saline wastewater from a table olive processing plant – were operated under identical conditions to comparatively evaluate their performance for three different hydraulic retention times (HRTs) of 88, 96 and 104 h.RESULTSThe biological process of both systems, after appropriate biomass acclimatization, was stable and the removal efficiencies were rather high; i.e., regarding total organic carbon (TOC) ≥86.4% and ≥85.6% for the MBR and MBBR‐MBR, respectively, and ≥89.1% regarding total polyphenols (TPh) for both systems. Concerning TOC and TPh removal, no statistically significant difference (p < 0.05) was observed between the two systems. Reduction of HRT resulted in a slight decrease in mean TOC removal efficiency, but the mean TPh removal was practically unchanged. No membrane chemical cleaning was applied to either system during the 85‐day long continuous operation.CONCLUSIONThe comparative assessment showed that both systems (i.e., MBR and MBBR‐MBR) are effective for the advanced biological treatment of table olive processing wastewater and can achieve quite high removal efficiencies of organic matter and TPh. However, direct effluent reuse for irrigation purposes seems to be hindered by its high salinity. No significant differences were observed in the performance of these systems, apart from the increased aeration (and related energy costs), which is necessary to keep the biofilm carriers floating in the case of the MBBR‐MBR. © 2020 Society of Chemical Industry

Analysis of the biodegradation performance and biofouling in a halophilic MBBR-MBR to improve the treatment of disinfected saline wastewater

Disinfectant-containing wastewaters have been generated from many places, including marine industries. The synthetic NaClO-containing wastewaters have been effectively treated in a saline MBBR-MBR (moving bed biofilm reactor & membrane bioreactor) system containing marine microorganisms. A low concentration of NaCl (below 100 mg/L) is not enough to kill the microorganisms, but can affect their bioactivity and induce membrane biofouling. A linear relationship has been obtained for the half-life of membrane biofouling as a function of the NaClO concentration (10–100 mg/L): [half-life] = 25–0.12 × [NaClO concentration]. The COD and NH3–N removals are the highest at a salinity of 30 g/L for the marine bioreactors. The behaviour of the typical biofoulants, measured real-timely by fluorescence spectroscopy, can indicate the levels of membrane biofouling and microbial activity, responding to the NaClO and NaCl influences. Based on the behaviour of biofoulants, this work has also proposed a novel strategy of biofoulants monitoring for membrane antifouling, where antifouling responses can be carried out when the concentration of biofoulants significantly increases.

Impacts of sulfadiazine on the performance and membrane fouling of a hybrid moving bed biofilm reactor-membrane bioreactor system at different C/N ratios

The performance and membrane fouling of a hybrid moving bed biofilm reactor-membrane bioreactor (MBBR-MBR) system was evaluated when exposed to 0.5 mg/L of antibiotic sulfadiazine (SDZ). Results indicated that although SDZ reduced the removal efficiency of NH4+-N and TN (up to 12%) and TOC (up to 6%) at low C/N (2.5 and 4), it had no significant effect at high C/N (6 and 9). It was found that SDZ was removed 75% and 58% at high C/N of 9 and low C/N of 2.5, respectively. SDZ decreased the ratio of volatile biomass/total biomass and sludge particle size and increased the concentrations of extracellular polymeric substance (EPS) and soluble microbial product (SMP) in MBR. Consequently, this accelerated the membrane fouling rates, with an average increase of 6.85 kPa/d at low C/N (2.5) and 0.513–0.701 kPa/d at medium and high C/N (4, 6 and 9).

Real-time monitoring of the membrane biofouling based on spectroscopic analysis in a marine MBBR-MBR (moving bed biofilm reactor-membrane bioreactor) for saline wastewater treatment

A MBBR-MBR system has been developed with marine microorganisms enriched for saline wastewater treatment in this work, showing high COD and NH3–N removals. The behaviour of fouling-related components (EPS and SMP) has been studied as functions of operating time (40–90 days), salinity (0–30 g/L NaCl) and backflow ratio (0–300%, from MBR to MBBR). High biodegradability of the MBBR-MBR at optimal conditions can induce more biodegradation of humic acid-like (λex/λem: 350nm/430 nm) and fulvic acid-like (260nm/445 nm) molecules to soluble microbial by-product-like molecules (275nm/325 nm), reducing the membrane biofouling rate. The biodegradation process is suggested by the excitation-emission matrix (EEM) images. In the study of sudden salinity shock, results show that real-time monitoring the concentration of biofoulants is more effective (operative time extended by 60%) than monitoring the transmembrane pressure (operative time extended by 33%) to prevent membrane fouling. Due to an early warning from the real-time monitoring, the coming membrane-fouling is predictable and the operating conditions, such as backflow ratio, can be changed to minimize the biofouling rate.

Effect of salinity variation on the autotrophic kinetics of the start-up of a membrane bioreactor and hybrid moving bed biofilm reactor-membrane bioreactor at low hydraulic retention time

A membrane bioreactor (MBR) and a hybrid moving bed biofilm reactor-membrane bioreactor (hybrid MBBR-MBR) for municipal wastewater treatment were studied to determine the effect of salinity on nitrogen removal and autotrophic kinetics. The biological systems were analyzed during the start-up phase with a hydraulic retention time (HRT) of 6 h, total biomass concentration of 2,500 mg L-1 in the steady state, and electric conductivities of 1.05 mS cm-1 for MBR and hybrid MBBR-MBR working under regular salinity and conductivity variations of 1.2-6.5 mS cm-1 for MBR and hybrid MBBR-MBR operating at variable salinity. The variable salinity affected the autotrophic biomass, which caused a reduction of the nitrogen degradation rate, an increase of time to remove ammonium from municipal wastewater and longer duration of the start-up phase for the MBR and hybrid MBBR-MBR.

Membrane bioreactor and hybrid moving bed biofilm reactor-membrane bioreactor for the treatment of variable salinity wastewater: Influence of biomass concentration and hydraulic retention time

A membrane bioreactor and two hybrid moving bed biofilm reactor-membrane bioreactor systems were operated for the treatment of wastewater with tidal salinity fluctuations under hydraulic retention times of 6, 9.5 and 12 h, and operational solids concentrations of around 2500 and 3500 mg L−1. The three configurations were studied in terms of carbon and nitrogen removal, heterotrophic and autotrophic kinetics, and bacterial community structure. The performance of the systems was good in terms of organic matter removal – between 85–100% and 95–100% for COD and BOD5, respectively, showing higher efficiencies at higher solids concentration and hydraulic retention times. Nitrogen removal obtained was in the range of 30–50%. The bacterial community structure of the suspended and attached biomass in the systems was more influenced by the operational solids (80% clustering cutoff) and hydraulic retention time (60% clustering cutoff) than by technological configuration (40% clustering cutoff), as determined by ordination analyses. Massive parallel sequencing showed the presence of Nitrobacter and Rhodanobacter at almost all operation scenarios, and thus were identified as major players in treatment of tidal salinity variation wastewater. Overall, this research proved that the MBR and hybrid MBBR-MBR systems could successfully treat urban wastewater subjected to tidal salinity variations. Nevertheless, more research is needed in order to enhance nitrogen removal performance under these conditions.

Effect of hydraulic retention time on the performance of a hybrid moving bed biofilm reactor-membrane bioreactor system for micropollutants removal from municipal wastewater

This study evaluated micropollutants removal and membrane fouling behaviour of a hybrid moving bed biofilm reactor-membrane bioreactor (MBBR-MBR) system at four different hydraulic retention times (HRTs) (24, 18, 12 and 6h). The results revealed that HRT of 18h was the optimal condition regarding the removal of most selected micropollutants. As the primary removal mechanism in the hybrid system was biodegradation, the attached growth pattern was desirable for enriching slow growing bacteria and developing a diversity of biocoenosis. Thus, the efficient removal of micropollutants was obtained. In terms of membrane fouling propensity analysis, a longer HRT (e.g. HRTs of 24 and 18h) could significantly mitigate membrane fouling when compared with the shortest HRT of 6h. Hence, enhanced system performance could be achieved when the MBBR-MBR system was operated at HRT of 18h.

Linkage of microbial kinetics and bacterial community structure of MBR and hybrid MBBR-MBR systems to treat salinity-amended urban wastewater.

Three pilot-scale bioreactors were started up and operated under salinity-amended urban wastewater feeding. The bioreactors were configured as membrane bioreactor and two different hybrid, moving bed biofilm reactor-membrane bioreactor and operated with a hydraulic retention time of 9.5 h, a solid residence time of 11.75 days and a total solids concentration of 2500 mg L-1 . The three systems showed excellent performance in suspended solids, BOD5 , and COD removal (values of 96-100%, 97-99%, and 88-90%, respectively), but poor nitrogen removal (values of 20-30%). The bacterial community structure during the start-up phase and the stabilization phase were different, as showed by β-diversity analyses. The differences between aerobic and anoxic biomass-and between suspended and attached biomass-were higher at the start-up phase than at the stabilization phase. The start-up phase showed high abundances of Chiayiivirga (mean values around 3-12% relative abundance) and Luteimonas (5-8%), but in the stabilization phase, the domination belonged to Thermomonas (3-14%), Nitrobacter (3-7%), Ottowia (3-11.5%), and Comamonas (2-6%), among others. Multivariate redundancy analyses showed that Thermomonas and Nitrosomonas were positively correlated with fast autotrophic kinetics, while Caulobacter and Ottowia were positively correlated with fast heterotrophic kinetics. Nitrobacter, Rhodanobacter, and Comamonas were positively correlated with fast autotrophic and heterotrophic kinetics. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1483-1495, 2017.

Moving bed biofilm reactor to treat wastewater

This review carries out a comparative study of advanced technologies to design, upgrade and rehabilitate wastewater treatment plants. The study analyzed the relevant researches in the last years about the moving bed biofilm reactor process with only attached biomass and with hybrid biomass, which combined attached and suspended growth; both could be coupled with a secondary settling tank or microfiltration/ultrafiltration membrane as a separation system. The physical process of membrane separation improved the organic matter and NH4 +-N removal efficiencies compared with the settling tank. In particular, the pure moving bed biofilm reactor–membrane bioreactor showed average chemical oxygen demand, biochemical oxygen demand on the fifth day and total nitrogen removal efficiencies of 88.32, 90.84 and 60.17%, respectively, and the hybrid moving bed biofilm reactor–membrane bioreactor had mean chemical oxygen demand, biochemical oxygen demand on the fifth day and total nitrogen reduction percentages of 91.18, 97.34 and 68.71%, respectively. Moreover, the hybrid moving bed biofilm reactor–membrane bioreactor showed the best efficiency regarding organic matter removal for low hydraulic retention times, so this system would enable the rehabilitation of activated sludge plants and membrane bioreactors that did not comply with legislation regarding organic matter removal. As the pure moving bed biofilm reactor–membrane bioreactor performed better than the hybrid moving bed biofilm reactor–membrane bioreactor concerning the total nitrogen removal under low hydraulic retention times, this system could be used to adapt wastewater treatment plants whose effluent was flowed into sensitive zones where total nitrogen concentration was restricted. This technology has been reliably used to upgrade overloaded existing conventional activated sludge plants, to treat wastewater coming from textile, petrochemical, pharmaceutical, paper mill or hospital effluents, to treat wastewater containing recalcitrant compounds efficiently, and to treat wastewater with high salinity and/or low and high temperatures.

Essential factors of an integrated moving bed biofilm reactor–membrane bioreactor: Adhesion characteristics and microbial community of the biofilm

This work aims at revealing the adhesion characteristics and microbial community of the biofilm in an integrated moving bed biofilm reactor–membrane bioreactor, and further evaluating their variations over time. With multiple methods, the adhesion characteristics and microbial community of the biofilm on the carriers were comprehensively illuminated, which showed their dynamic variation along with the operational time. Results indicated that: (1) the roughness of biofilm on the carriers increased very quickly to a maximum value at the start-up stage, then, decreased to become a flat curve, which indicated a layer of smooth biofilm formed on the surface; (2) the tightly-bound protein and polysaccharide was the most important factor influencing the stability of biofilm; (3) the development of biofilm could be divided into three stages, and Gammaproteobacteria were the most dominant microbial species in class level at the last stage, which occupied the largest ratio (51.48%) among all microbes.

Anaerobic/anoxic/oxic configuration in hybrid moving bed biofilm reactor-membrane bioreactor for nutrient removal from municipal wastewater

A membrane bioreactor (MBRp), a hybrid moving bed biofilm reactor-membrane bioreactor containing carriers in the anaerobic, anoxic and aerobic zones (hybrid MBBR-MBRap) and a hybrid moving bed biofilm reactor-membrane bioreactor which contained carriers only in the anaerobic and anoxic compartments (hybrid MBBR-MBRbp) were used in parallel and compared regarding the nutrient and organic matter removal from municipal wastewater. The hydraulic retention time (HRT) was 18h. A kinetic study for the heterotrophic and autotrophic bacteria, mainly nitrite-oxidizing bacteria (NOB), was carried out and related to the nutrient and organic matter removal. The hybrid MBBR-MBRap performed best regarding chemical oxygen demand (COD) and total phosphorus (TP) removals, with values of 85.82±2.12% and 81.42±3.85%, respectively. This system had a higher phosphorus release under anaerobic conditions and a higher phosphorus uptake under aerobic conditions. The highest TN removal efficiency was obtained for the hybrid MBBR-MBRbp, with a value of 61.39±10.71%.

New functional biocarriers for enhancing the performance of a hybrid moving bed biofilm reactor–membrane bioreactor system

In this study, new sponge modified plastic carriers for moving bed biofilm reactor (MBBR) was developed. The performance and membrane fouling behavior of a hybrid MBBR–membrane bioreactor (MBBR–MBR) system were also evaluated. Comparing to the MBBR with plastic carriers (MBBR), the MBBR with sponge modified biocarriers (S-MBBR) showed better effluent quality and enhanced nutrient removal at HRTs of 12h and 6h. Regarding fouling issue of the hybrid systems, soluble microbial products (SMP) of the MBR unit greatly influenced membrane fouling. The sponge modified biocarriers could lower the levels of SMP in mixed liquor and extracellular polymeric substances in activated sludge, thereby mitigating cake layer and pore blocking resistances of the membrane. The reduced SMP and biopolymer clusters in membrane cake layer were also observed. The results demonstrated that the sponge modified biocarriers were capable of improving overall MBBR performance and substantially alleviated membrane fouling of the subsequent MBR unit.

Behaviour of the solids retention time in relation to the operative variables in a hybrid moving bed membrane bioreactor treating urban wastewater

The present research studies the influence of the operative variable of a hybrid moving bed biofilm reactor–membrane bioreactor (hybrid MBBR–MBR) in the attached biomass, and analyses the effect of the variables on the evolution of solids retention time (SRT) treating real urban wastewater in a pilot-scale experimental plant. This was operated under mixed liquor suspended solids (MLSSs) between 2,414 ± 166 and 4,594 ± 47 mg/L, the temperature ranged between 5.00±1.58 and 27.88 ± 1.52°C and the regimes of 10 and 24 h HRT with 20, 35 and 50% of the filling ratio. The biofilm density changes between 2,618 ± 272 and 6,991 ± 843 mg/L of the carrier show statistically significant differences in relation to the operative variables, so it depends mainly on MLSS and temperature, and is not dependent on the filling ratio under the condition studied. The multivariable analysis showed that the most influential operative variables in the SRT were MLSS and temperature, so two models have been proposed to consider these effects. The SRT can be modelled in relation to the HRT and MLSS throughout the F/M rate with the hyperbola 5.469×(F/M)-0.833;2.1976×(F/M)-1.181;2.2831×(F/M)-1.207 for 20, 35 and 50% of the filling ratio, respectively. In relation to the temperature, the SRT increases linearly with it between approximately 5 and 30°C with linear coefficients that also increase with the filling ratio presenting the values of 0.2825, 0.3438 and 0.4615 d/°C to 20, 35 and 50% of the filling ratio, respectively.

Treatment of urban wastewater with pure moving bed membrane bioreactor technology at different filling ratios, hydraulic retention times and temperatures

Studies investigating the functioning and possible utility of new wastewater treatment technologies are urgently needed if the requirements of European Directive 91/271/EEC are to be met. Here, moving bed biofilm reactor-membrane bioreactor (MBBR-MBR) technology was studied in a pilot plant of 445 L volume with ultrafiltration membrane (ZW-10) under 10 h and 24 h of hydraulic retention time (HRT) and three filling ratios (20 %, 35 % and 50 %) at temperatures between 2.5 °C and 17.3 °C. Biofilm density ranged between 1510 ± 127 and 3775 ± 247 mg/L carrier. Temperature was the operative variable with most influence in the behaviour of biomass and in organic matter and nitrogen oxidation whereas the filling ratio affected mainly biofilm density. Removal of organic matter and nitrogen increased with the amount of biofilm in the carrier. The amount of biofilm attached under the highest filling ratio was reduced as a consequence of increased collision between carriers, indicating that an optimum rate of filling ratio in this process can be determined. The organic matter removal rate reached 86.4 % and 91.5 % in terms of COD and BOD5, respectively, and no less than 13.9 % and 13.7 % ammonia and total nitrogen content, respectively, was removed by the system.

Two-step nitrification in a pure moving bed biofilm reactor-membrane bioreactor for wastewater treatment: nitrifying and denitrifying microbial populations and kinetic modeling.

The moving bed biofilm reactor-membrane bioreactor (MBBR-MBR) is a novel solution to conventional activated sludge processes and membrane bioreactors. In this study, a pure MBBR-MBR was studied. The pure MBBR-MBR mainly had attached biomass. The bioreactor operated with a hydraulic retention time (HRT) of 9.5 h. The kinetic parameters for heterotrophic and autotrophic biomasses, mainly nitrite-oxidizing bacteria (NOB), were evaluated. The analysis of the bacterial community structure of the ammonium-oxidizing bacteria (AOB), NOB, and denitrifying bacteria (DeNB) from the pure MBBR-MBR was carried out by means of pyrosequencing to detect and quantify the contribution of the nitrifying and denitrifying bacteria in the total bacterial community. The relative abundance of AOB, NOB, and DeNB were 5, 1, and 3%, respectively, in the mixed liquor suspended solids (MLSS), and these percentages were 18, 5, and 2%, respectively, in the biofilm density (BD) attached to carriers. The pure MBBR-MBR had a high efficiency of total nitrogen (TN) removal of 71.81±16.04%, which could reside in the different bacterial assemblages in the fixed biofilm on the carriers. In this regard, the kinetic parameters for autotrophic biomass had values of YA=2.3465 mg O2 mg N(-1), μm, A=0.7169 h(-1), and KNH=2.0748 mg NL(-1).