Bioreactor Treatment Research Articles

Brief review of operation of anaerobic wastewater treatment with membrane bioreactors

In recent years, anaerobic membrane bioreactor (AnMBR) technology has been considered as a very appealing alternative for wastewater treatment due to its significant advantages over conventional anaerobic treatment and aerobic membrane bioreactor (MBR) technology. The paper provides an overview of the current status of the anaerobic membrane bioreactor technology with a special emphasis on its performance and drawbacks when applied for domestic and municipal wastewater treatment. According to the reported data, the renewable energy produced at the plants (i.e. from methane) covered the energy demand for membrane filtration while the excess energy can be further utilized. Anaerobic membrane bioreactors are an attractive technology that needs further research efforts and applications at an industrial scale.

Membrane bioreactors for treatment of galvanic wastewater

The article speaks about the membrane methods applied for treatment of galvanic sewage. It reveals the main features and peculiarities, which determine the maintenance of various types of membranes for industrial wastewater treatment. Ultrafiltration is a method that uses a membrane to separate by size ions of heavy metals, petroleum products, macromolecules and suspended solids. Application of ceramic membranes in ultrafiltration plants allows implementing of various technological processes with resource-saving opportunities, such as treatment of galvanic workshops sewage with efficiency of 99% and entire restoration of the worked out solutions. Nanofiltration is a process of membrane filtration of wastewater, which ensures the removal of multi-charged ions from water, depending on the size. Reverse osmosis is a process that is used to desalinate the bulk of dissolved salts in wastewater of various industries. In addition, this process is used to ensure the purification of effluents from organic and inorganic compounds, suspended solids and high molecular weight compounds.

Membrane Bioreactors Used for Treatment of Food Industry Effluents

Effluents from the food industry determine pollution problems due to high COD and BOD concentrations. Compared to other industrial divisions, food industry requires large amounts of water. In this study, MBR was based on submerged hollow fibers membranes functioning by low vacuum. Two phases of bioreactor treatment were carried out with different HRTs (2-8) and (2-24) hours. Sixteen water samples collected from the influent and the effluent of the bioreactor during the two phases. NaOCl compound was added during the backwashing process for all tests, and the same compound was added with mixed liquid for the second test at period 24 hour of aeration. The samples were tested for twelve water quality tests: temperature, Dissolved Oxygen, pH, Turbidity, Total Suspended Solids, Mixed Liquor Suspended Solids, Chemical Oxygen Demand, Biochemical Oxygen Demand, Nitrate Nitrogen, Ammonium Nitrogen, Total Phosphate, and Ortho Phosphate. The results indicated that the bioreactor system can be used efficiently to treat industrial wastewater from the food industry. The efficiency of the technology was evaluated with sodium hypochlorite addition to removing the adherent bacteria on the surface area of hollow fibers. The results showed that the bioreactor under the conditions of the second phase was excellent in removing Turbidity, TSS, COD, and BOD5 with a removal efficiency 99.96%, 89.52%, 93.56%, and 99.36% respectively, when added 82 ml of NaOCl in the bioreactor tank, and was a good removing of TP, and Ortho-P with removal efficiency 60.76% and 48.95% respectively. Otherwise, a negative effect of NaOCl on both of NO3-N and NH4-N was obtained in term of removal where the minimum removal efficiency was observed when adding 82 ml of NaOCl under the conditions of the second phase.

Characterization of transport through polymers for fracking fluid treatment and organic acid concentration in extractive membrane bioreactors

AbstractBACKGROUNDThe water‐intensive practice of hydraulic fracturing produces wastewater containing a variable matrix of organic and inorganic compounds, including ions and ionizable organic compounds. Extractive membrane bioreactors (EMBs) operating with tailored polymer membranes can selectively sequester and/or transport these solutes for biological treatment. Four grades of Hytrel™ tubing were compared for their suitability in EMB systems, based on the polymers' thermodynamic affinity for solutes and their ability to transport or speciate ionic wastewater constituents.RESULTSOf the four Hytrel™ grades compared, high water content types (30% and 54% equilibrated water content) facilitated the transport of ionic species through the tubing, with all monovalent species being transported through both high‐water content grades, and lack of transport through the low‐water content tubing (3% and 5%). Undissociated organic acids were transported through all tubing types and dissociated acids were able to permeate only high‐water content grades. Using this differential ability to transport/not transport an organic acid depending on its dissociation state, a low‐water content Hytrel™ grade of tubing was able to concentrate a dilute butyric acid solution by 220% after 48 h.CONCLUSIONThe use of polymeric tubing for EMB applications for the treatment of hydraulic fracturing wastewater requires knowledge of both solute affinity and water content for complex waste streams, both of which affect the capability to transport organic and ionic species. © 2018 Society of Chemical Industry

Effects of Hydraulic Loading Rate on Nutrients Removal from Anaerobically Digested Swine Wastewater by Multi Soil Layering Treatment Bioreactor.

A multi soil layering (MSL) treatment bioreactor was developed aiming at nutrients removal from anaerobically digested swine wastewater (ADSW). The start-up of the MSL bioreactor and its performance in nutrients removal at different hydraulic loading rate (HLR) were investigated. Results showed that the MSL bioreactor was successfully started up after operation for 28 days, and at this time, the removal efficiencies of ammonia-N, total nitrogen (TN) and total phosphorus (TP) in the ADSW reached 63.6%, 58.5%, and 46.5%, respectively. The MSL bioreactor showed a stable performance during the whole working process with varying HLR from 80 to 200 L/(m2·day). Maximum removal efficiencies of ammonia-N, TN and TP were obtained at 160 L/(m2·day), and was appeared as 94.2%, 94.4%, and 92.5%, respectively. It was worth noting that iron scraps were the key factor that enhanced the independent capability of the MSL bioreactor in TP removal, because there was only 21.4–25.8% of the TP was removed when the MSL bioreactor run with no iron addition.

Suitability of nutrients removal from brewery wastewater using a hydroponic technology with Typha latifolia

BackgroundThis study aims to assess suitability of hydroponic technology for treatment of brewery wastewater in a hydroponic bioreactor using Typha latifolia. Triplicated hydroponic bioreactor treatment units were designed, constructed and operated at a hydraulic retention time of 5 days with different surface loadings and mean hydraulic loading rate 0.023 m3 m−2d− 1. Young T. latifolia shoots were collected in the vicinity of study site. Wastewater characteristics, plant growth and nutrient accumulation during experiment were analyzed as per APHA standard methods and nutrient removal efficiency was evaluated based on inlet and outlet values.ResultsT. latifolia established and grew well in the hydroponics under fluctuations of wastewater loads and showed a good phytoremedial capacity to remove nutrients. Significant removal efficiencies (p < 0.05) varied between 54 and 80% for Total Kjeldahl Nitrogen, 42 and 65% for NH4+ -N, 47 and 58% for NO3− -N, and 51 and 70% for PO43−-P. The system improved the removal up to 29% compared to control and produced biomass of 0.61–0.86 kg dry weight (DW) m− 2. Nutrients retained were up to 21.17 g N kg− 1 DW and 2.87 g P kg− 1 DW.ConclusionThe significant nutrients reduction obtained and production of biomass led us to conclude that hydroponics technology using T. latifolia has suitability potential for treatment of brewery wastewater and similar agro-industrial wastewaters. Thus it could be considered as a promising eco-friendly option for wastewater treatment to mitigate water pollution. Integration of treatment and production of biomass needs further improvement.

Continuous degradation of an organic pollutant using heterogeneous magnetic biocatalyst and CFD analysis of the process

Abstract GOx/Fe3O4/TiO2 on natural kissiris support was produced by consecutive preparation of TiO2/kissiris and Fe3O4/TiO2/kissiris followed by immobilization of Glucose Oxidize (GOx). This magnetic biocatalyst was used for continuous elimination of Malachite Green (MG) from aqueous solution in a packed bed reactor through bio-Fenton reaction. The biocatalyst was characterized by FT-IR, EDX and SEM analyses. Residence time distribution (RTD) of MG in the reactor was measured and parameters of the Langmuir-Hinshelwood kinetics model were obtained for the decolorization process. Hydrodynamics of the packed bed reactor were investigated via a thorough computational fluid dynamics (CFD) simulation using Eulerian approach in axisymmetric space and results were validated using experimental RTD curves and decolorization efficiencies. Ultimately, process simulation was utilized to obtain design parameters of the packed bed reactor in recirculating mode with 99.1% decolorization efficiency. The knowledge obtained through this study can be used to design and scale-up continuous and efficient bioreactors for treatment of wastewater.

Characteristics of Bioaerosols Emitted from WWTP with SBR Treatment Process

Sampling sites were located in a wastewater treatment plant (WWTP) with a sequencing batch reactor activated sludge process to investigate the characteristics of bioaerosol emissions. The results indicated that bioaerosols were detected from each treatment section of the WWTP, and concentrations of bioaerosols were in the range of 82-1525 CFU·m-3. The coarse screen, aeration tank, and sludge dewatering house were the main sources of bioaerosols. The dominant species in each treatment section was Cyanobacteria, and the other main bacterial taxa were Aeromonas, Peptostreptococcaceae, Moraxellaceae, Chroococcidiopsis, Sphingomonas, Arcobacter, and Acinetobacter. Among the identified bacterial genera, Aeromonas, Arcobacter, Acinetobacter, and Sphingomonas were potential pathogens. Bioaerosol concentration and abundance decreased along the vertical and horizontal directions. Appropriate temperature and relative humidity benefited the survival of bioaerosols in the air (P<0.01), whereas a negative relationship between bioaerosol concentration and wind speed was observed (P<0.05). Although exposure risks caused by bioaerosols were negligible in this study, the accumulation of bioaerosols would increase potential health risks. The bioreactor for odor treatment could effectively reduce bioaerosol emissions.

Association of robust nitrogen removal with spatiotemporal nitrifying bacterial community dynamics in a new bioreactor for treatment of simulated livestock wastewater with high ammonia content

AbstractBACKGROUNDDifferent types of nitrogen‐containing wastewater have been treated with dewatered alum sludge (DAS) or neutralized used acid (NUA) or with a combined DAS–NUA biofilter. The connections between the spatiotemporal structures of ammonia‐oxidizing bacteria (AOB) and nitrite‐oxidizing bacteria (NOB) and the nitrogen removal performance of DAS–NUA biofilter have not been fully clarified. To address this issue, AOB and NOB genetic characteristics response to nitrogen conversions in a laboratory‐scale DAS–NUA biofilter were investigated.RESULTSThe spatiotemporal distribution of the AOB in DAS was heterogeneous in the bioreactor. The trends observed in its structure were a function of depth along the flowpaths and time. However, AOB in NUA and NOB in both substrates were time and space independent. The spatial and temporal behavior of nitrifying bacteria mainly depended on the pH, followed by dissolved oxygen. The Shannon indexes of AOB and NOB and the relative abundances of Nitrosomonas and Nitrobacter had significantly negative relationships with NH+4–N and total nitrogen concentrations in effluents.CONCLUSIONSThe Shannon indexes of AOB and NOB and the relative abundances of Nitrosomonas and Nitrobacter were the key indicators of nitrogen removal and have implications for effective nitrogen attenuation strategies. © 2018 Society of Chemical Industry

The microbial community structure change of an anaerobic ammonia oxidation reactor in response to decreasing temperatures.

In anaerobic ammonium oxidation (anammox) systems, temperature may regulate the activity of functional bacteria (e.g., anammox bacteria) and the composition of the microbial population, ultimately determining the performance of the anammox reactor. Knowledge of the dynamic changes in nitrogen removal rates and the microbial anammox community at low and/or ambient temperature is still limited. This study explored the response of an anammox sequencing batch reactor (SBR) to a gradient of decreasing temperature (33, 25, 20, 15, 10°C), followed by recovery to 22°C, over 360days. Particularly, the specific anammox activity (SAA) and microbial community were assessed. The anammox reaction in the SBR remained stable and efficient at 20-33°C, with a total nitrogen removal load of 0.4g-NL-1day-1 and an SAA of > 0.32g-Ng-VSS-1day-1; 10°C was the turning point for the anammox bacterial metabolic activity, at which the SAA decreased by 91% compared with that at 33°C. After the temperature was returned to 22°C, the anammox activity recovered to 0.24g-Ng-VSS-1day-1. The apparent activation energy for the anammox reaction was 68.4kJmol-1 at 10-33°C and 152.9kJmol-1 at 10-20°C. High-throughput sequencing results revealed that Kuenenia was the dominant species of anammox bacteria, and Kuenenia had a higher tolerance to low temperature than Candidatus Brocadia and Candidatus Jettenia. This study clearly shows the effectiveness of anammox bioreactors for treatment of wastewater at ambient temperatures of 15-33°C.

Application of membrane bioreactor in wastewater treatment: A mini review

Membrane bioreactor (MBR) is credible and promising technology methods for industrial wastewater treatment and recycle it to use in different applications. Today MBR has many domestic and industrial applications and it is popular among the types of conventional treatment methods. The main drawback in the operation of MBR is membrane fouling, that drive to the decrease in permeate flux so need some technique to clean the membrane. In spite of more than a decade of significant advances in improvement of fouling reduction technique, various physical and mechanical methods are still necessary to be improved to limit the membrane fouling problems. In this review, the advantages and disadvantages of membrane bioreactor, fundamental of membrane fouling that is affected by some factors and methods of controlling membrane fouling were discussed.

Using nano-attapulgite clay compounded hydrophilic urethane foams (AT/HUFs) as biofilm support enhances oil-refinery wastewater treatment in a biofilm membrane bioreactor

Petroleum refinery wastewater (PRW) treatments based on biofilm membrane bioreactor (BF-MBR) technology is an ideal approach and biofilm supporting material is a critical factor. In this study, BF-MBR with nano-attapulgite clay compounded hydrophilic urethane foams (AT/HUFs) as a biofilm support was used to treat PRW with a hydraulic retention time of 5 h. The removal rate of 500 mg/L chemical oxygen demand (COD), 15 mg/L NH4+ and 180 NTU of turbidity were 99.73%, 97.48% and 99.99%, which were 23%, 20%, and 6% higher than in the control bioreactor, respectively. These results were comparatively higher than that observed for the sequencing batch reactor (SBR). The death rate of the Spirodela polyrrhiza (L.) irrigated with BF-MBR-treated water was 4.44%, which was similar to that of the plants irrigated with tap water (3.33%) and SBR-treated water (5.56%), but significantly lower than that irrigated with raw water (84.44%). The counts demonstrated by qPCR for total bacteria, denitrifiers, nitrite oxidizing bacteria, ammonia oxidizing bacteria, and ammonia-oxidizing archaea were also higher in BF-MBR than those obtained by SBR. Moreover, the results of 16 s rRNA sequencing have demonstrated that the wastewater remediation microbes were enriched in AT/HUFs, e.g., Acidovorax can degrade polycyclic aromatic hydrocarbons, and Sulfuritalea is an efficient nitrite degrader. In summary, BF-MBR using AT/HUF as a biofilm support improves microbiome of the actived sludge and is reliable for oil-refinery wastewater treatment.

Response of treatment performance and microbial community structure to the temporary suspension of an industrial anaerobic bioreactor

In this study, a novel type of mesophilic anaerobic bioreactor—an expanded granular sludge bed (EGSB)—was utilized to explore the effect of suspending reactor operation on the treatment performance and the microbial community structure. The parameters of performance and bacterial community before and after a four-week suspension were compared for the starch processing wastewater treatment bioreactor. The results indicate that the removal rate of the organic matter remained higher than 90%, although the biomass significantly decreased after restarting the reactor. However, the relatively stable microbial community structure before the suspension was altered significantly during the restart and post-running stages. This change was primarily due to variability in satellite species and the substitution effect of different dominant bacteria. For example, some non-major carbohydrate-degrading bacteria that were sensitive to nutrition deficiency, such as Desulfovibrio and Geobacter, were dramatically reduced after the suspension. In contrast, the stress of starvation stimulated the reproduction of hydrolytic bacteria, such as Macellibacteroides. However, the high bacterial diversity index (6.12–6.65) and the longstanding core species, including Chloroflexi, Cloacimonetes, Ignavibacteriae, Thermotogae and Euryarchaeota, maintained the functional stability of the reactor. Consequently, although the total bacteria decreased significantly after reactor operation was suspended, sufficient functional bacteria supported by the high diversity, as well as the longstanding core species, guaranteed the effective degradation after suspension.

Industrial wastewater treatment in internal circulation bioreactor followed by wetlands containing emergent plants and algae.

Wastewater treatment based on ecological principles is a low cost and highly desirable solution for the developing countries like Pakistan. The present study evaluated the effectiveness of biological treatment systems including Internal Circulation (IC) anaerobic bioreactor and constructed wetlands (CWs) containing macrophytes and mixed algal cultures for industrial wastewater treatment. The IC bioreactor reduced COD (52%), turbidity (89%), EC (24%) of the industrial wastewater. However, the effluents of IC bioreactor did not comply with National Environmental Quality Standards (NEQS) of Pakistan. Post-treatment of IC bioreactor effluents was accomplished in CW containing macrophytes (Arundo donax and Eichhornia crassipes) and mixed algal culture. The CWs planted with macrophytes lowered the concentrations of COD (89%) and turbidity (99%). CWs with algal biomass were not effective in further polishing the effluent. Inhibition of algal biomass growth was observed due to physicochemical characteristics of wastewater. The integrated treatment system consisting of IC bioreactor and macrophytes was found more suitable option for industrial wastewater treatment.

A study of the effect of embedding ZnO-NPs on PVC membrane performance use in actual hospital wastewater treatment by membrane bioreactor

In this work, an anti-biofouling polyvinyl chloride/zinc oxide (PVC/ZnO) membrane was prepared using the phase precipitation method for application in a University of Cape Town membrane bioreactor-submerged membrane bioreactor (UCT-MBR) for treatment of actual hospital wastewater. Effects of various ZnO nanoparticle (NPs) amounts (i.e. 0.1, 0.2, 0.3, and 0.4 g) on membrane properties were studied. The hypothesis of this effort was that ZnO would act as an anti-biofouling material, thus overcoming the formation of a bio-cake layer on the PVC-ZnO membrane surface, which in turn greatly extends the long-term of the membrane. The performance of the PVC membranes with ZnO-NPs in a submerged membrane bioreactor (SMBR) was systematically investigated. The characteristics of PVC/ZnO membranes were inspected via scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, and pollutant removal efficiency. It was found that the ZnO nanoparticles clearly influenced the structural morphology of the membranes. The addition of 0.1 g of ZnO nanoparticles resulted in a significant increase in the mean roughness by about 140%, with smaller mean pore size and narrow pore size distribution. The addition of ZnO nanoparticles, up to 0.3 g, had a positive effect on the hydrophilicity of the PVC/ZnO membrane with decreasing the contact angle (CA) value by 17.775°. The pure water permeability (PWP) of the membrane improved by 315% with addition of 0.1 g of ZnO. The cake layer build-up on the membrane surface was reduced from 52.8 to 10.42 μm with an increase of ZnO nanoparticles up to 0.3 g, as 0.4 g ZnO had no further effect on the cake layer thickness. The long-term of PVC-0.3 g NPs was improved up to 70 days before membrane cleaning compare with 29 days for neat PVC membrane. Chemical oxygen demand (COD) removal efficiency of UCT-MBR process was approximately similar and around 73.5% for all membranes.

Performance and Kinetics Evaluation of Integrated Suspended Growth Bioreactor Treating Beverage Industry Wastewater

In this research, feasibility of using a continuous flow integrated suspended growth bioreactor (i-SGBR) pilot plant was explored to treat beverage industry wastewater. The bioreactor treatment units comprise of three sequentially arranged suspended growth bioreactors with anoxic (ANX-C), aerobic (AER-C), and aerobic digester chambers (AD-C). Clarifier (CLR) was installed as last chamber to settle sludge. Parameters such as total chemical oxygen demand (TCOD) were monitored and validated with biochemical oxygen demand (BOD5). Other parameters measured include soluble COD (sCOD), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), total suspended solids (TSS), and pH. Transformational behavior of aerobic metabolic performance for extended aeration process was investigated by operating regimes of variable aerobic hydraulic retention time (HRT) and organic loading rate (OLR) between 20 and 30 h and 0.49–0.79 kg COD/m3 day, respectively. Solids retention time (SRT) between 20 and 40 days was operated. The aim was to generate data for bacterial growth and substrate utilization kinetics from modified Monod’s model. Removal of TCOD, BOD5, and TSS were achieved in the range of 95.2–97.9% (Influent 995 ± 21–1028 ± 25 mg/L and Effluent 21 ± 2–4.9 ± 3 mg/L), 98–98.7% (Influent 489 ± 19–507 ± 7 mg/L and Effluent 27 ± 2–41 ± 1.8 mg/L), and 91.2–94.6% (Influent 500 ± 23–653 ± 11 mg/L and Effluent 6.3 ± 7–41 ± 1.8 mg/L), respectively. The maximum substrate utilization rate (k), half velocity constant (Ks), growth yield co-efficient (Y), and decay coefficients (kd) were determined as 2.81 days−1, 979 mg sCOD/L, 0.72 mg VSS/mg sCOD, and − 0.0172 day−1, respectively. Maximum specific growth rate (μmax) was found as 2.03 days−1. Treatment efficiencies declined with reduction of HRT and with increased OLR applied to the bioreactor. The aerobic digester (AD) achieved between 9.8% (Influent 15,021 mg/L) and 18.6% (10,893 mg/L) MLVSS reduction, where performance decreased with additional solids concentration from influent aerobic digester (IAD). i-SGBR has accomplished effective removal of pollutants and simultaneous sludge degradation of beverage industry wastewater. Kinetic parameters obtained could be useful for design and modeling of aerobic treatment unit to improve effluent quality.

Membrane Bioreactor Performance during Processing of a Low Carbon to Nitrogen Ratio Municipal Wastewater

The performance of a pilot-scale hollow fiber submerged membrane bioreactor (MBR) for biological treatment of a low carbon/nitrogen ratio domestic wastewater was evaluated during 120 days of operation. The MBR system was operated under alternating aeration, periodic feeding and external organic carbon source addition in order to achieve the legislation disposal limits. Experiments were contacted under three carbon/nitrogen (COD/TKN) ratios, i.e. 3.66 ± 1.3, 4.37 ± 1.34 and 8.3 ± 1.03, where a low strength wastewater was treated in the absence and presence of raw wastewater or glycerol as external carbon source. At the end of the experimental period, biological oxygen demand (BOD5) and chemical oxygen demand (COD) removal was extremely high, reaching efficiencies and effluent concentrations of 99.2 ± 0.4 and 97.4 ± 2.4%, and 3.7 ± 1.1 and 14.7 ± 11.0 mg/L, respectively. Total Kjeldahl Nitrogen (TKN) and NH4+-N removal efficiencies were determined as 89.2 ± 3.9 and 97.0 ± 0.9%, with the corresponding effluent concentrations being equal of 7.9 ± 2.3 and 1.7 ± 0.5 mg/L, respectively. Denitrification was enhanced by adding glycerol, resulting in an effluent NO3−-N concentration of 1.9 ± 0.9 mg/L. The release of soluble microbial products (SMP) was favored over extracellular polymeric substances (EPS) under low COD/TKN ratio, although this trend was inverted under high COD/TKN ratio conditions. MBR effluent quality was found to be suitable for unlimited reuse.

Does the biological treatment or membrane separation reduce the antibiotic resistance genes from swine wastewater through a sequencing-batch membrane bioreactor treatment process

Swine wastes are the reservoir of antibiotic resistance genes (ARGs), which can potentially spread from swine farms to the environment. This study establishes a sequencing-batch membrane bioreactor (SMBR) for ARG removal from swine wastewater, and analyzes the effect of biological treatment and membrane separation on the ARG removal at different solid retention times (SRTs). The SMBR removed 2.91 logs (copy number) of ARGs at a short SRT (12 days). Raising the SRT reduced the removal rates of the detected genes by the biological treatment. Under the relative long SRT (30 days), ARGs and mobile genetic elements (MGEs) were maximized within the reactor and were well removed by membrane separation, with the average genes removal rate of 2.95 (copy number) and 1.18 logs (abundance). At the relatively low SRT, the biological treatment showed the dominant ARG removal effect, while the membrane separation took the advantages of ARG removal especially at the relatively long SRT. The ARG profile was related to the shift of the microbial community structure. The ARGs coexisted with the functional bacteria (ammonia oxidizing bacteria, nitrite oxidizing bacteria and denitrifiers), suggesting they are hosted by the functional bacteria.

Wastewater treatment in membrane bioreactors. Features and application

Membrane bioreactors nowadays are intensively applied in wastewater treatment worldwide. Such type of treatment systems have a large scope of implementation at facilities of different capacity. Small space demand allows placing them in conditions of limited area available. Treatment using of MBR is a combination of sludge treament and membrane filtration. Although the idea of replacing the conventional sedimentation tank activated sludge was attractive, it was difficult to adjust complex process operation of wastewater treatment due to three factors: high cost of membranes, low economic value of grey wastewater, as well as the rapid loss of membrane performance due to the pollution of her pores. Membrane module is used for the separation of sludge liquor that is an alternative to common sedimentation in secondary clarifiers. The article reveals the main features of membrane bioreactors application, concerning its advantages and disadvantages.

Phycoremediation of textile wastewater using indigenous microalgae

Abstract The recognition that environmental pollution is a worldwide threat to public health and environmental degradation has given rise to new initiatives for environmental restoration for both economic and ecological reasons. There are several methods to treat the dye contaminated industrial wastewater; of which biological treatment methods are economical and environmentally friendly. The bacteria and fungi remediation of dye pollutants has been well characterized over a period of more than 30 years. So, finding other biological methods in addition to bacteria and fungi is great important in the world. As a result, investigating and evaluating Phycoremediation techniques of dye wastewater (bioremediation using Microalgae) have gained a great deal of attention because of their versatility and capacity than bacteria and fungi. The aim of the research is to study Phycoremediation of Textile Wastewater Using indigenous Microalgae. Physico-chemical parameters such as color, pH, total dissolved solid (TDS), biochemical oxygen demand (BOD) and chemical oxygen demand of the waste were determined with ASTM standard methods before and after bioremediation. Photo bioreactor systems were used for Phycoremediation treatment techniques. PH, incubation time and temperature effects were determined on a photo bioreactor treatment and optimal experimental condition was ascertained. Instrumental analytical techniques (UV-Vis, FTIR) were used to determine percent decolorizations of dye wastewater before and after bioremediation; and the actual break down of the dye functional groups. The maximum reductions of the basic parameters; COD, BOD and TDS were obtained 91.50%, 91.90% and 89.10% respectively. The optimum operating conditions in the photo bioreactor system were found incubation time 20 days, 30°C; with 10% of inoculums at a pH of 8. Under these conditions, a maximum of 82.6% decolorization was achieved in 20 days. The experimental investigations evidently tell us algae undoubtedly have the potential to rapidly, efficiently and effectively remove dyes wastewater.