Membrane Bioreactor Membrane Research Articles

Novel membrane bioreactor with iron-tannin-framework based membrane for effluent quality improvement and fouling control

A 10 L membrane bioreactor (MBR) was constructed with novel iron-tannin-framework ultrafiltration membrane (ITUM) for membrane fouling mitigation and effluent quality improvement. Compared to commercial ultrafiltration membrane (CUM) in the same MBR, ITUM exhibited hydrophilicity with a contact angle of 64.18° (71.36° for CUM), resulting the permeance of ITUM (50.2 L m-2h−2 bar−1) 1.8 times higher than CUM. During 70-day operation, ITUM was consistently run at lower transmembrane pressure. After operation, the polyethersulfone (PES) peak intensity of ITUM reduced less than 1 % (85 % for CUM), which indicated a thinner sludge layer on ITUM. Meanwhile, the average effluent chemical oxygen demand concentration for ITUM and CUM achieved 16.69 and 17.60 mg L-1 in stable phase, respectively. For NH4+-N, it could reach 0 and 0.04 mg L-1. 16 s RNA results showed that Saccharibacteria accounted for 1.48 % and 1.20 % on ITUM and CUM, respectively. According to first-principles density functional theory simulations, simulated adsorption energies was −1.330 eV for gram-positive bacteria (such as Saccharibacteria). It was −0.867 eV for Fe(Ⅲ) to gram-negative bacteria. It suggests that ITUM could easily attract microorganisms with the ability of polysaccharide degradation, while reducing this type of pollutants deposition on membrane. Therefore, the ITUM received a more superior effluent quality and membrane fouling resistance.

Effect of magnetic field coupled magnetic biochar on membrane bioreactor efficiency, membrane fouling mitigation and microbial communities

The excitation by magnetic field was established to mitigate the membrane fouling of magnetic biochar (MB)-supplemented membrane bioreactor (MBR) in this study. The results showed that the transmembrane pressure (TMP) increase rates decreased by about 8 % after introducing the magnetic field compared with the magnetic biochar-MBR (MB-MBR). Membrane characterization suggested that the flocs in the magnetic field-magnetic biochar-MBR (MF-MB-MBR) formed a highly permeable developed cake layer, and a fluffier and more porous deposited layer on membrane surface, which minimized fouling clogging of the membrane pores. Further mechanistic investigation revealed that the decrease in contact angle of fouled membrane surface in MF-MB-MBR, i.e. an enhanced membrane hydrophilicity, is considered important for forming highly permeable layers. Additionally, the magnetic field was demonstrated to have a positive effect on the improvement of the magneto-biological effect, the enhancement of charge neutralization and adsorption bridging between sludge and magnetic biochar, and the reduction of formation of extracellular polymeric substances (EPSs), which all yielded sludge flocs with a large pore structure conducive to form a fluffy and porous deposited layer in the membrane surface. Furthermore, high-throughput sequencing analysis revealed that the magnetic field also led to a reduction in microbial diversity, and that it promoted the enrichment of specific functional microbial communities (e.g. Bacteroidetes and Firmicutes) playing an important role in mitigating membrane fouling. Taken together, this study of magnetic field-enhanced magnetic biochar for MBR membrane fouling mitigation provides insights important new ideas for more effective and sustainable operation strategies.

Research of BP Neural Network Based on GA-WOA Algorithm Optimization in MBR Membrane Pollution Simulation

For the membrane fouling problem faced by the MBR (Membrane Bio-Reactor) system, an intelligent model is constructed to predict the membrane fouling. The BP neural network has strong self-learning, self-adaptive and generalization capabilities and is widely used in the prediction of MBR membrane pollution, but membrane fouling is a complex dynamic process, which is difficult to simulate accurately by classical mathematical models. Aiming at this problem, the GA-WOA hybrid algorithm was introduced to optimize the BP neural network, and the MBR membrane fouling prediction model was constructed. The simulation results show that the BP neural network model optimized by GA-WOA hybrid algorithm is more suitable and accurate than that optimized by whale optimization algorithm in predicting MBR membrane fouling.

Green Solvent Cleaning Removes Irrecoverable Foulants from End-of-Life Membranes in Membrane Bioreactors: Efficacy and Mechanisms.

Removal of irrecoverable foulants, which cannot be removed by conventional chemical cleaning, from end-of-life (EOL) membranes remains a substantial challenge due to the strong interaction between the foulants and membrane matrix. Herein, we developed a green solvent cleaning strategy based on Hansen solubility parameters to achieve the removal of irrecoverable foulants from the EOL polyvinylidene fluoride (PVDF) membranes serving for 6 years in a large-scale membrane bioreactor (MBR). We selected methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (MDMO) as the green solvent due to its strong interaction with the PVDF material, which might enable the substitution of binding sites of irrecoverable foulants. After the MDMO cleaning, the water permeance of the EOL membrane recovered from 47.6 ± 4.7 to 390.9 ± 8.2 L m-2 h-1 bar-1 (with a flux recovery ratio of ∼100%), with its rejection ability and stability maintained. The main components of irrecoverable fouling were humic acid-like substances revealed by spectroscopic characterization. Molecular dynamic simulation further elucidated the cleaning mechanisms: the strong interaction of MDMO-PVDF enabled substitution of binding sites of irrecoverable foulants by MDMO, followed by desorption of the irrecoverable foulants from PVDF and diffusion of the irrecoverable foulants into the bulk phase of MDMO. Evaluation in a lab-scale MBR treating real municipal wastewater verified the reusability of green solvent cleaned-EOL membranes. This study provides a novel, effective, and green cleaning strategy to remove irrecoverable foulants and prolong the service life of membranes in MBRs, facilitating sustainable wastewater treatment using membrane-based processes.

Membrane Fouling Prediction Based on Tent-SSA-BP.

In view of the difficulty in obtaining the membrane bioreactor (MBR) membrane flux in real time, considering the disadvantage of the back propagation (BP) network in predicting MBR membrane flux, such as the local minimum value and poor generalization ability of the model, this article introduces tent chaotic mapping in the standard sparrow search algorithm (SSA), which improves the uniformity of population distribution and the searching ability of the algorithm (used to optimize the key parameters of the BP network). The tent sparrow search algorithm back propagation network (Tent-SSA-BP) membrane fouling prediction model is established to achieve accurate prediction of membrane flux; compared to the BP, genetic algorithm back propagation network (GA-BP), particle swarm optimization back propagation network (PSO-BP), sparrow search algorithm extreme learning machine(SSA-ELM), sparrow search algorithm back propagation network (SSA-BP), and Tent particle swarm optimization back propagation network (Tent–PSO-BP) models, it has unique advantages. Compared with the BP model before improvement, the improved soft sensing model reduces MAPE by 96.76%, RMSE by 99.78% and MAE by 95.61%. The prediction accuracy of the algorithm proposed in this article reaches 97.4%, which is much higher than the 48.52% of BP. It is also higher than other prediction models, and the prediction accuracy has been greatly improved, which has some engineering reference value.

Membrane bioreactors for hospital wastewater treatment: recent advancements in membranes and processes.

Discharged hospital wastewater contains various pathogenic microorganisms, antibiotic groups, toxic organic compounds, radioactive elements, and ionic pollutants. These contaminants harm the environment and human health causing the spread of disease. Thus, effective treatment of hospital wastewater is an urgent task for sustainable development. Membranes, with controllable porous and nonporous structures, have been rapidly developed for molecular separations. In particular, membrane bioreactor (MBR) technology demonstrated high removal efficiency toward organic compounds and low waste sludge production. To further enhance the separation efficiency and achieve material recovery from hospital waste streams, novel concepts of MBRs and their applications are rapidly evolved through hybridizing novel membranes (non hydrophilic ultrafiltration/microfiltration) into the MBR units (hybrid MBRs) or the MBR as a pretreatment step and integrating other membrane processes as subsequent secondary purification step (integrated MBR-membrane systems). However, there is a lack of reviews on the latest advancement in MBR technologies for hospital wastewater treatment, and analysis on its major challenges and future trends. This review started with an overview of main pollutants in common hospital waste-water, followed by an understanding on the key performance indicators/criteria in MBR membranes (i.e., solute selectivity) and processes (e.g., fouling). Then, an in-depth analysis was provided into the recent development of hybrid MBR and integrated MBR-membrane system concepts, and applications correlated with wastewater sources, with a particular focus on hospital wastewaters. It is anticipated that this review will shed light on the knowledge gaps in the field, highlighting the potential contribution of hybrid MBRs and integrated MBR-membrane systems toward global epidemic prevention.

Assessment of mixed matrix membranes (MMMs) incorporated with graphene oxide (GO) for co-treatment of wastewater and landfill leachate (LFL) in a membrane bioreactor (MBR)

Membrane bioreactors show promising features for the co-treatment process of landfill leachate (LFL) and wastewater. However, the high fouling potential of the membranes is still a challenge for treating LFL. A promising approach for membranes fouling mitigation is the incorporation of hydrophilic nanostructures such as graphene oxide (GO) in the structure of polymeric membranes. Nonetheless, long-term tests with GO-incorporated membranes for the treatment of high-strength wastewater under practical conditions are still missing. Thus, in the present study, membranes of polyethersulfone (PES) and PES-GO were synthesized by phase inversion method and successfully implemented in a lab-scale MBR system for LFL and synthetic wastewater co-treatment. Preliminary membrane characterization revealed that the addition of GO resulted in a more restrictive and hydrophilic superficial layer. These properties contributed for PES-GO to obtain high rejection and antifouling properties for humic acid (HA) and bovine serum albumin (BSA) in model solutions. However, no significant differences in the performance of PES-GO and PES membranes for organic removal were observed during the MBR operation. PES-GO exhibited enhanced adsorptive anti-fouling potential which resulted in an increase of the reversible fouling ratio when compared to PES. Though, the incorporation of GO had a low impact on the external anti-fouling potential, which could be resulted from the complex characteristics of LFL. Regarding membranes stability after long exposure to sodium hypochlorite solution, PES-GO exhibited loss of hydrophilicity and presented significant indication of pitting-like damage on the active layer, which could be associated with the GO oxidation by chlorine. Thereby, the findings of this study can be used to develop future strategies involving the use of GO-incorporated membranes in MBRs for the treatment of LFL and complex wastewater.

Study of membrane fouling mechanism during the phenol degradation in microbial fuel cell and membrane bioreactor coupling system

This study evaluated the feasibility of phenol degradation in microbial fuel cell (MFC) and membrane bioreactor (MBR) coupling system, and explored the mechanism of MBR membrane fouling. Four aspects were researched in open and closed circuit conditions: the degradation capacity of the coupling system, the increase of trans-membrane pressure (TMP), and the adhesion of phenol degradation products and microorganisms on the membrane. The results showed that the degradation of phenol and COD in the closed circuit coupling system was higher than that in the open circuit. The micro-electric field can inhibit the growth of TMP and keep dodecamethylcyclohexasiloxane away from the membrane, meanwhile can also reduce the abundance and species diversity of microorganisms. Nevertheless, the micro-electric field could not completely eliminate the membrane fouling due to the fact that the phenol degradation product of ethanethiol, microorganisms of Proteobacteria and Actinobacteria were more favorable on the membrane.

Formation of disinfection by-products during sodium hypochlorite cleaning of fouled membranes from membrane bioreactors.

Periodic chemical cleaning with sodium hypochlorite (NaClO) is essential to restore the membrane permeability in a membrane bioreactor (MBR). However, the chlorination of membrane foulants results in the formation of disinfection by-products (DBPs), which will cause the deterioration of the MBR effluent and increase the antibiotic resistance in bacteria in the MBR tank. In this study, the formation of 14 DBPs during chemical cleaning offouled MBR membrane modules was investigated. Together with the effects of biofilm extracellular polymeric substances (EPS), influences of reaction time, NaClO dosage, initial pH, and cleaning temperature on the DBP formation were investigated. Haloacetic acids (HAAs) and trichloromethane (TCM), composed over 90% of the DBPs, were increasingly accumulated as the NaClO cleaning time extended. By increasing the chlorine dosage, temperature, and pH, the yield of TCM and dichloroacetic acid (DCAA) was increased by up to a factor of 1–14, whereas the yields of haloacetonitriles (HANs) and haloketones (HKs) were decreased. Either decreasing in the chlorine dosage and cleaning temperature or adjusting the pH of cleaning reagents toward acidic or alkaline could effectively reduce the toxic risks caused by DBPs. After the EPS extraction pretreatment, the formation of DBPs was accelerated in the first 12 h due to the damage of biofilm structure. Confocal laser scanning microscopy (CLSM) images showed that EPS, particularly polysaccharides, were highly resistant to chlorine and might be able to protect the cells exposed to chlorination.Electronic Supplementary MaterialSupplementary material is available in the online version of this article at 10.1007/s11783-021-1389-3 and is accessible for authorized users.

Aerobic granular sludge (AGS) scouring to mitigate membrane fouling: Performance, hydrodynamic mechanism and contribution quantification model

Aerobic granular sludge (AGS) has been proven to have a low fouling potential in membrane bioreactor (MBR). Nevertheless, AGS scouring effect on mitigating membrane fouling remains poorly investigated. The main objective of this study is to examine AGS-MBR performance, to reveal the AGS scouring mechanism and quantify its contribution rate to membrane fouling mitigation, from the views of theory and experiment. Above all, AGS-MBR exhibited a low fouling rate ((transmembrane pressure (TMP) kept below 20 kPa) without membrane cleaning and a higher removal of organics and nutrients than conventional MBR during 80 days’ sludge granulation process. Then, flocculent sludge (FS) with various AGS ratios was applied to simulate the sludge granulation phase. When AGS ratio increased from 0% to 100%, the permeate flux gradually elevated from 40.0 L m−2h−1 to 92.9 L m−2h−1, and fouling resistance decreased from 9.0 × 10−12m−1 to 3.9 × 10−12m−1 benefiting from the loose structure and high porosity of AGS fouling layer. Meanwhile, the scouring effect produced by AGS on the membrane fouling mitigation was investigated. Based on the momentum conservation, a new hydrodynamic model was developed to explain the scouring mechanism of AGS. The scouring stress, proportional to the total amount of AGS depositing on the membrane surface, effectively reinforced the collision between AGS and FS, and reduced their deposition on the membrane surface by friction with the membrane; thus it was further conducive to membrane fouling mitigation. Moreover, a novel contribution quantification model was proposed for analyzing the contribution rate of AGS scouring effect to mitigate membrane fouling. AGS scouring possessed a significant contribution rate (39.9%) for fouling mitigation, compared with AGS structure (50.3%) and hydraulic stress (9.7%). In final, this study provides an in-depth understanding to mitigate the MBR membrane fouling by the unique advantages of sludge granulation.

Cleaning decision model of MBR membrane based on Bandelet neural network optimized by improved Bat algorithm

The membrane fouling is an important factor of restricting wide application of MBR (Membrane Bio-Reactor), which causes the fall of membrane flux and reduces the membrane cleaning period. So the Bandelet neural network is proposed through combining Bandelet transform and neural network, which predicts membrane flux and its recovery rate for making proper membrane cleaning decision. Firstly, the main affecting factors of membrane fouling are discussed. Secondly, the architecture of Bandelet neural network is designed with Bandelet function and its scale function as activation functions of hidden and output layers respectively. Thirdly, the improved Bat algorithm is established, which is applied to improve the optimization effect of parameters of Bandelet neural network. Finally, the simulation analysis is carried out, the improved bat algorithm has higher performance than the traditional bat algorithm through analyzing the single objective optimization problem from 2018 CEC competition, the optimal number of nodes in hidden layer is confirmed based on comparison analysis and statistical tests. The proposed BNN-IBA has obvious superiority in prediction accuracy and speed according to prediction simulation results of membrane fouling of MBR, which has better prediction results than other state-of-art prediction models optimized by the novel optimal algorithms. In addition, the proper membrane cleaning period and method are confirmed according to the prediction results of membrane flux and its recovery rate.

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.

Research on Operation Efficiency and Membrane Fouling of A2/O-MBR in Reclaimed Water Treatment.

Taking the public building domestic wastewater as an example, the combination of the MBR (membrane bioreactor) process and the traditional A2/O (anaerobic-anoxic-oxic) process was established and analyzed in terms of the removal effect of the pollutants, the impact of the microbial community changes on the process, the MBR membrane fouling, the cleaning methods, and the cleaning performance. The results indicated that the effluent water quality of the domestic wastewater treated with the A2/O-MBR process was stable and met the emission requirement to the natural water body. There was good microbial diversity in raw water, the anaerobic tank, the anoxic tank, the aerobic MBR tank and the disinfection tank, and the aerobic MBR tank has a wide variety of aerobic microorganisms, which elevates the removal of organics and the nitrification of ammonia nitrogen and ensures the qualification of nitrogen and phosphorus indexes of the system effluent water. For the fouled membrane, the surface of the contaminated membrane was covered by macromolecular contaminants, causing the membrane flux to drop, and after different cleaning methods to the membrane were compared, it was discovered that the combined use of cleaning agents had better effects than the single ones, and the cleaning method of sodium hydroxide followed by hydrochloric acid showed the best effect, achieving a membrane flux restoration ratio above 80% after cleaning.

Inhibition of biofouling in membrane bioreactor by metabolic uncoupler based on controlling microorganisms accumulation and quorum sensing signals secretion.

Biofouling is a limiting bottleneck in the development of membrane bioreactor (MBR) since the birth of this technology. Recently, the biofouling control strategy based on interfering with the bacterial quorum sensing (QS) system is highly desirable for biofouling control in MBR. In this study, three lab-scale parallel MBR systems were operated over 100 days to investigate the inhibitory effect of a metabolic uncoupler (3,3',4',5-tetrachlorosalicylanilide, TCS) on biofouling and the potential mechanism for biofouling control. Compared to the control MBR, the fouling cycle duration of MBR 2 with 100μg/L TCS extended over two times. The attached biomass on membrane in MBR 2 decreased over 50% at the end of each operating period, which indicated that the addition of TCS significantly mitigated microorganisms accumulation on membrane. The content of interspecies QS signal (autoinducer-2) and intraspecific QS signals (N-octanoyl-dl-homoserine lactone, C8-HSL) was reduced by the TCS, suggesting the secretion of QS signals in MBR were affected by uncoupler. Although the addition of TCS induced brief fluctuations of extracellular proteins and polysaccharides, microorganisms seemed to rapidly acclimatize to the presence of TCS and then the secretion of extracellular polymeric substances (EPS) was inhibited by 100μg/L TCS. The continuous operation of MBR was not be affected by the low-concentration uncoupler via the analysis of substrate removal and sludge growth. This study systematically evaluated the effect and inhibitory efficiency of TCS on biofouling, biomass accumulation, QS signals, EPS and treatment performances, demonstrating the feasibility of metabolic uncoupler for biofouling control in MBR.

Study on Operational Conditions to Minimize Membrane Fouling in Membrane Bioreactor (MBR) System for Wastewater Treatment-Preliminary Pilot Tests

In this study, effect of antiscalant usage on minimizing of membrane fouling due to high water hardness during wastewater treatment tests run by a pilot-scale membrane bioreactor (MBR) system. The membranes used in these studies were Kubota flat sheet MBR membranes made from polyethylene with a pore size of 0.4 micrometer. Preliminary tests were carried out with tap water for sixty days of operation. To investigate the applicability and the effect of antiscalant usage, four experiments (two experiments with tap water and two experiments with wastewater) were carried out and each experiment lasted for 29 days. The tests were carried out in the presence and in the absence of antiscalant. Fouling on MBR membranes was investigated by monitoring flux decline versus time. In tap water tests, unstable flux was observed initially then a flux decline due inorganic scaling. On the other hand, the flux was almost constant up to end of the experiment in the presence of antiscalant. During wastewater tests (in the absence of antiscalant), the flux decline was observed within ten days of operation while during wastewater tests in presence of antiscalant, the flux did not decline until twenty days of operation. The use of antiscalant did not influencethe efuent quality. According to the quality analyses results for MBR efuent, removal efciencies for COD, PO4-P, and total N were 95%, 98% and 40%, respectively. In addition,99% of total suspended solid rejection and 98% of color rejection were obtained in the presence or absence of antiscalant.

Removal of bioavailable dissolved organic nitrogen in wastewater by membrane bioreactors as posttreatment: Implications for eutrophication control

Bioavailable dissolved organic nitrogen (ABDON) is the component of dissolved organic nitrogen (DON) which supports the growth of algae. Previous research indicates that a membrane bioreactor (MBR) is effective in reducing DON, however, its ability to remove ABDON remains unknown. The present study investigated three full-scale MBRs (membrane type: hydrophilic polyvinylidene fluoride and membrane pore size: 0.04–0.1 µm) as posttreatment for the removal of ABDON. Results showed that the concentrations of ABDON were not significantly different between influent and effluent at each MBR (p = 0.067–0.614, t-test). Analysis of DON molecular composition via ultrahigh resolution mass spectrometry provides supporting evidence that bacterial biomass produced/released ABDON during the biological processes, which would be one of the possible reasons for the low removal efficiency of ABDON (<0%−14.0%) occurred in the MBR process. Overall, MBRs as posttreatments would have a smaller-than expected impact on primary productivity in receiving waters since a substantial fraction of DON stimulating algal growth cannot be removed by this treatment.

Composite Multi Wall Carbon Nano Tube Polydimethylsiloxane Membrane Bioreactor for Enhanced Bioethanol Production from Broomcorn Seeds

Broomcorn seed (Sorghum vulgare) was used as raw material for bioethanol production. Optimum conditions were obtained from response surface method. Broomcorn seed flour (45 g/l) was treated by alkaline treatment and dual enzymatic hydrolysis (0.7 g/l of α- amylase and 0.42 g/l of amyloglucosidase). The hydrolyzed total sugar of 25.5 g/L was used in conventional bioethanol production (8.1 g/l) using Saccharomyces cerevisiae. Enhanced bioethanol production was performed in membrane bioreactor (MBR) in integrated batch fermentation and membrane pervaporation process. Application of commercial polydimethylsiloxane/polyethyleneterephthalate/polyimide (PDMS/PET/PI) membrane in MBR resulted in ethanol concentration of 10.15 g/l in broth and 70.2 g/l in cold trap of MBR. Cell concentration in broth was increased from 7.2 in conventional fermentation to 9.05 g/l in MBR. In addition, ethanol production in MBR using fabricated membrane having ethanol separation factor of 8.7; ethanol concentration in broth and cold trap were 11.1 and 88.5 g/ l, respectively. Also the cell concentration of 10.2 g/l was obtained in MBR with fabricated membrane. In MBR, surface modified multi wall carbon nano tube (MWCNT) coated on membrane having ethanol separation factor of 10.2, resulted ethanol concentration of 11.9 and 110 g/l in broth and cold trap, respectively. Finally, for MBR using modified membrane the cell concentration of 11.01 g/l was obtained. Based on a comparison study, maximum ethanol separation and yield were obtained for modified membrane having MWCNT and the surface was modified by corona treatment.

Research on Prediction of MBR Membrane Fouling Based on Adaptive Simulated Annealing Genetic Algorithm

In the Research of prediction of Membrane Bio-Reactor (MBR) Membrane Fouling, we have used Simulated Annealing (SA) and support vector machine (SVM) [9][10] to establish the model to predict MBR Membrane Fouling[1]. An experimental research demonstrates that SVM model based on SA (SA-SVM) has better predicted precision than SVM model based on Genetic Algorithm (GA-SVM). However, in the process of optimization parameters of predictive model of MBR membrane fouling model using SA, we found that SA has two problems: a slowness of convergence rate and the parameters selection is sensitive. Therefore, we introduce a Genetic Algorithm (GA) and combine SA with the GA, Adaptive Simulated Annealing Genetic Algorithm (ASAGA), to optimize the input data of MBR Membrane Fouling predictive model. This algorithm remains both the strong global searching ability of GA and the good local searching ability of SA. Calculation shows that the ASAGA-SVM predictive model of MBR Membrane Fouling matches well and higher predictive precision than SA-SVM predictive model of MBR Membrane Fouling.

New insight into fate and fouling behavior of bulk Dissolved Organic Matter (DOM) in a full-scale membrane bioreactor for domestic wastewater treatment

Dissolved Organic Matter (DOM) and active biomass concentrations from a full-scale membrane bioreactor (MBR) treating domestic wastewater were investigated during a period of 488 days. Bulk DOM is known to be a major membrane foulant in MBR. Active biomass activity, which depends on operating parameter variations, is a major source of DOM, due to soluble microbial product (SMP) secretion. To establish the link between DOM, active biomass concentration, operating conditions, and later membrane fouling, heterotrophic and autotrophic bacteria were first quantified using respirometric measurements. Comparing their evolution with operating conditions and parameters using Principal Component Analysis (PCA), SRT and temperature were identified as the parameters with the most impact on active biomass concentrations. Proteins from Biopolymers and humic substance (HS + BB) concentrations were quantified using a 3DEEM pseudo-quantitative method. Active biomass and DOM concentration fluctuations were similar, confirming that DOM was mainly constituted by SMP produced by the active biomass, and consequently dependent on SRT and temperature modifications. HS + BB were produced eight times faster than Proteins from BP and therefore accumulated faster on the membrane despite their low membrane rejection. Consequently, large amounts of HS + BB can accumulate, modifying the initial membrane properties. The membrane resistance evolution was dependent on Proteins from Biopolymers accumulation and these molecules showed no fouling propensity modifications despite seasonal variations. As a consequence, this study strongly emphasized the interest of using a 3DEEM pseudo-quantitative method for on-line application in order to follow the full-scale MBR process and membrane fouling.

Optimization of Wastewater of Batik Buaran Pekalongan by Using Photocatalytic Membrane Bioreactor

The purpose of this study is to determine the final COD concentration reduction by changing COD and MLSS concentration on the performance of submerged membrane bioreactor (MBRs) as a waste treatment of Batik in Buaran Pekalongan. The method is covers the process of seeding, the acclimatization process and the main process. Description of the process that we take an active mud from IPLT Buaran Pekalongan, then we analyze the sludge MLSS, MLVSS, COD, BOD, and TSS. After that we enter the active sludge in the bath nursery that has been given aerator (a tool for aeration) and made provision in the form of NPK nutrients and glucose at a ratio of 1:10. Activated sludge from the acclimatization process is inserted into the MBRs (membrane bioreactor submerged) that is equipped with an aerator. Then prepare influent(waste to be lowered concentration of COD). How, liquid waste of Batik Pekalongan Buaran COD diluted concentration of 10,000 mg / l and 15,000 mg / l, and then inserted in influent tub. After that liquid waste of Batik Buaran Pekalongan influent flowed into Photocatalytic Membrane Bioreactor, of MPB effluent flowed into the tub (result).