Showing papers on "Bioreactor published in 2020"
TL;DR: In this article, an up-flow packed bed bioreactor (UFPBBR) with immobilized Rhodococcus opacus onto biochar loaded polyurethane foam (PUF) as the packing material for treating biomass gasification wastewater (BGWW).
94 citations
TL;DR: The key players were found to be the cyanobacteria Limnothrix and Cephalothrix, the colony forming photosynthetic eukaryotes within Chlamydomonadaceae, and the biofilm producing bacteria Zoogloea and Thauera.
64 citations
TL;DR: Results demonstrated that the incubation of strain IS0293 enhanced the nitrate removal efficiency of the bioreactor, and would be valuable to develop an effective technology for nitrate-laden surface water under aerobic conditions.
60 citations
TL;DR: The results indicated that low-temperature treatment of dairy wastewater is feasible at 15 °C, but that reactor configuration remains extremely important.
55 citations
TL;DR: Gel immobilization of anammox appears the best alternative to the natural process of biofilm formation and granulation and dissolution of the gel beads refrains its application for long term bioprocess.
50 citations
TL;DR: It was found a membrane-based bioreactor can achieve both wastewater secondary treatment and pre-treatment for advanced oxidation process, so both MBR-AOP and MBBR-MBR -AOP treatments have a great potential to produce high quality reclaimed water.
50 citations
TL;DR: This review discusses bioreactor-based methods for industrial hydrocarbon-containing wastewater treatment using different (e.g., stirred-tank, membrane, packed-bed and fluidized-bed) constructions, and some advantages of fluidization-bed bioreactors over other types of reactors are shown.
Abstract: This review discusses bioreactor-based methods for industrial hydrocarbon-containing wastewater treatment using different (e.g., stirred-tank, membrane, packed-bed and fluidized-bed) constructions. Aerobic, anaerobic and hybrid bioreactors are becoming increasingly popular in the field of oily wastewater treatment, while high concentrations of petroleum hydrocarbons usually require physico-chemical pre-treatments. Most efficient bioreactor techniques employ immobilized cultures of hydrocarbon-oxidizing microorganisms, either defined consortia or mixed natural populations. Some advantages of fluidized-bed bioreactors over other types of reactors are shown, such as large biofilm–liquid interfacial area, high immobilized biomass concentration and improved mass transfer characteristics. Several limitations, including low nutrient content and the presence of heavy metals or toxicants, as well as fouling and contamination with nuisance microorganisms, can be overcome using effective inocula and advanced bioreactor designs. The examples of laboratory studies and few successful pilot/full-scale applications are given relating to the biotreatment of oilfield wastewater, fuel-contaminated water and refinery effluents.
50 citations
TL;DR: This study demonstrates an innovative approach for attaining partial nitritation in an acidic bioreactor operating at slightly low pH, based on the hypothesis that acid-tolerant ammonia-oxidizing bacteria (AOB) can produce nitrite and protons to self-sustain free nitrous acid (HNO2) at a ppm-level, as an inhibitor of nitrite-oxids bacteria (NOB).
Abstract: Partial nitritation providing a suitable effluent for subsequent anammox is a critical step in a two-stage autotrophic nitrogen removal system. This study demonstrates an innovative approach for attaining partial nitritation in an acidic bioreactor operating at a slightly low pH (i.e., 5-6). This approach is based on our hypothesis in this study that acid-tolerant ammonia-oxidizing bacteria (AOB) can produce nitrite and protons to self-sustain free nitrous acid (FNA, NO + H ↔ HNO) at a parts per million level, as an inhibitor of nitrite-oxidizing bacteria (NOB). With influent nitrogen of about 200 mg/L and operating conditions of high dissolved oxygen, long sludge retention time, and moderate temperature, a lab-scale acidic bioreactor with FNA up to 2 mg of HNO-N/L successfully established stable nitrite accumulation in the effluent for 200 days, with an average ratio [NO/(NO + NO)] exceeding 95%. A 16S rRNA amplicon sequencing analysis showed that was the dominant AOB in the biomass of the bioreactor, while and , two typical nitrifying genera in neutral wastewater treatment, both disappeared after the startup of partial nitritation. Kinetic characterization revealed that had a substrate affinity of 11.4-16.5 mg of total ammonia (NH + NH)/L. It also revealed that less than 3.5 mg of HNO-N/L FNA did not inhibit AOB activity significantly. Acidic operation is economically attractive because it can be achieved via acidophilic ammonia oxidation without adding chemical acid. However, hazardous gas, nitric oxide (NO), should be removed from gas produced by acidic nitrifying bioreactors.
49 citations
TL;DR: EMBR is reviewed including its potential applications in wastewater treatment, denitrification process, and waste gas treatment, and challenges and outlook of EMBR are discussed.
49 citations
TL;DR: In this article, the performance of a full-scale internal circulation (IC) bioreactor inoculated with anaerobic granular sludge for the treatment of dairy wastewater for 91 days was pointed out.
48 citations
TL;DR: The SNAD bioreactor achieved the effective removal for nitrogen and COD under high DO conditions in recirculating aquaculture system.
TL;DR: In this paper, a micro-photo bioreactor has been used for the treatment of simulated dairy wastewater by micro-algae chlorell, which has been shown to work well in the case of synthetic dairy wastewater.
Abstract: The present study demonstrates a construction procedure of a micro-photo bioreactor which has been used for the treatment of the simulated dairy wastewater (henceforth; SDW) by micro-algae chlorell...
TL;DR: A significant correlation between COD fractions removed via methanogenesis and sulfidogenesis and the COD/SO42- ratio was found, indicating that the increase of this ratio is beneficial to the methanogenic archaea activity.
TL;DR: By coupling anaerobic ammonium oxidation with nitrite/nitrate-dependent anaerobe methane oxidation (n-DAMO), up to 85% of dissolved methane and more than 99% of nitrogen were removed in parallel in a biofilm system and can potentially be applied to reduce the carbon footprint and to save the organic carbon consumption in WWTPs.
Abstract: Anaerobic technologies have been proposed as a promising solution to enhance bioenergy recovery and to transform a wastewater treatment plant (WWTP) from an energy consumer to an energy exporter. However, 20-60% of the methane produced remains dissolved in the anaerobically treated effluent, which is a potent greenhouse gas and is easily stripped out in the aeration tank. This study aims to develop a solution using dissolved methane to support denitrification, thus simultaneously enhancing nitrogen removal and achieving beneficial use of dissolved methane. By coupling anaerobic ammonium oxidation (anammox) with nitrite/nitrate-dependent anaerobic methane oxidation (n-DAMO), up to 85% of dissolved methane and more than 99% of nitrogen were removed in parallel in a biofilm system. Mass balance was conducted during both long-term operation and short-term batch tests, which indicated that n-DAMO bacteria and n-DAMO archaea indeed contributed jointly to the methane removal. The 16S rRNA gene amplicon sequencing further showed the co-presence of n-DAMO bacteria and n-DAMO archaea, while anammox bacteria were detected with a low relative abundance. This proposed technology can potentially be applied to reduce the carbon footprint and to save the organic carbon consumption in WWTPs.
TL;DR: A novel energy-saved electro-Fenton membrane bioreactor process could provide an envisaging prospective and promising method for practice wastewater membrane treatment.
Abstract: A novel electro-Fenton membrane bioreactor was constructed to investigate the effect of electro-Fenton on mitigating membrane fouling. Herein, porous carbon (PC), carbon nanotubes (CNTs) and Fe2+ were spun into hollow fiber membranes (Fe-PC-CHFM), then served as cathode and filtration core simultaneously. The H2O2 can be in situ produced by O2 reduction with electro-assistance, and further induce hydroxyl radicals (•OH) generation with loaded Fe2+ on the surface of Fe-PC-CHFM. In addition, Fe3+/Fe2+ cycle can be realized effectively by the electro-assistance, avoiding ferrous iron addition. During over 100-day operation, the electro-Fenton membrane bioreactor achieved 93% of COD and 88% of NH4+-N removal at a HRT of 8 h. At the end of operation, the membranes in electro-Fenton membrane bioreactor still exhibited obviously mesh-like structure similarly to initial level. Importantly, merely 15 min with an operation voltage of -0.8 V was sufficient to completely recover permeate flux of the fouled Fe-PC-CHFM. The energy consumption used for membrane fouling control was barely 8.64 × 10-5 kW·h/m3. Therefore, this novel energy-saved electro-Fenton membrane bioreactor process could provide an envisaging prospective and promising method for practice wastewater membrane treatment.
TL;DR: The high removal efficiency and stable microbial structure in HfMBR suggest it is a potentially effective technique for high-toxic azo dyes removal from textile wastewater.
TL;DR: Overall, these findings confirmed anammox, sequentially combined with PN and PDN via aerobic/anoxic strategy, as a promising alternative for mainstream anamm ox.
Abstract: This study developed an innovative process for the treatment of low-ammonium wastewater in a single-stage bioreactor over 250 days. Partial nitritation-anammox and partial denitritation-anammox (PN/A-PDN/A) processes were combined under aerobic/anoxic operation, and a high nitrogen removal efficiency (94.6%) was obtained at a nitrogen removal rate of 0.54 kg N m-3 d-1 and a chemical oxygen demand to total inorganic nitrogen (COD/TIN) ratio of 0.28. Mass balance analysis identified anammox as the dominant nitrogen removal pathway, achieving 88.3% nitrogen loss. The abundance of anammox bacteria and their bioactivity rapidly increased and were effectively maintained, as indicated by qPCR and bioactivity tests. The PN/A-PDN/A process provided two pathways of nitrite production for anammox, which favored the enrichment of anammox bacteria and stable processing. In addition, the enrichment of anammox bacteria was promoted by selective floc discharge since anammox bacteria are mainly located in granules (relative abundance of 29.64 ± 7.89%). Competitive organisms (including heterotrophic bacteria and nitrite oxidizing bacteria), enriched in flocs, were washed out. Overall, these findings confirmed anammox, sequentially combined with PN and PDN via aerobic/anoxic strategy, as a promising alternative for mainstream anammox.
TL;DR: In this article, the effect of different physical cleaning strategies on the membrane performance in a gravity-driven membrane bioreactor treating primary wastewater was investigated using optical coherence tomography (OCT).
TL;DR: In this paper, the performance of anaerobic membrane bioreactors (AnMBR) for textile wastewater treatment was investigated and the membrane foulants were investigated in detail, which may be used in the design and operation of real scale plants.
Abstract: Treatment and the recovery of textile wastewater are important due to their high volume and toxicity. Although several studies have been conducted on the use of membrane bioreactors (MBR) for textile wastewater treatment, they have mainly focused on synthetic wastewater or aerobic MBRs. However, anaerobic MBR (AnMBR) offers potential advantages of high color removal with lower energy consumption. In this context, this study aims at investigating the performance of AnMBR for the treatment of real textile wastewater. In addition to treatability studies, the membrane foulants were investigated in detail, which may be used in the design and operation of real scale plants. The permeate COD and color concentrations were decreased down to 70 mg/L and 150 Pt-Co, respectively. In the GPC analysis, pollutants with molecular weights greater than 15 kDa detected in the supernatant were removed by the dynamic cake layer developed on the membrane and only low molecular weight organics appeared in the permeate. AnMBR was operated successfully at a flux of 4.1 ± 0.7 LMH with a cleaning cycle of once a week. The impact of physical and chemical cleaning of the fouled membrane on the TMP elevation rate was also evaluated to determine the cleaning efficiency.
TL;DR: Under these conditions, the dissolution kinetics were stable, even when iron was provided only by the comminuted PCBs, and the bioleaching performance was satisfactory.
TL;DR: Until recently, membrane fouling in anaerobic membrane bioreactors (AnMBRs) was generally understood based on and by extrapolating from well-studied aerobic membrane bioresistors (AeMBRs).
Abstract: Until recently, membrane fouling in anaerobic membrane bioreactors (AnMBRs) was generally understood based on and by extrapolating from well-studied aerobic membrane bioreactors (AeMBRs). Clearly, ...
TL;DR: New insights are brought into green biotechnology regarding vinasse utilization, which is frequently discharged in soils, rivers, and lakes causing adverse effects on agricultural soils and biota, as well as the cotton gin waste recovery.
Abstract: Laccases are very interesting biocatalysts of recognized importance for several industrial applications. Its production by Trametes versicolor, a white-rot fungus, was induced by a combination of cotton gin wastes (1%), a lignocellulosic waste, and vinasse (15%), an industrial by-product from sugarcane industry. The use of these agro-industrial wastes are interesting, since it helps in reducing the enzyme production costs, due to their low cost and wide availability, as well as the environmental contamination issues, due to their improper disposal. Thus, laccase production was studied in submerged fermentation of T. versicolor using these agro-industrial wastes (cotton gin waste and vinasse) as carbon source and an additional nitrogen source (0.1% peptone). Three different bioreactors were evaluated for laccase production, such as BioFlo 310 bioreactor, aluminium tray and Erlenmeyer flasks to achieve high levels of laccase production. The highest specific production of laccase was found in BioFlo 310 bioreactor with 12 days of fermentation (55.24 U/mg prot.), which has been shown to be closely related to the oxygen supply to the microorganism through aeration of the fermentation medium. This study brings new insights into green biotechnology regarding vinasse utilization, which is frequently discharged in soils, rivers, and lakes causing adverse effects on agricultural soils and biota, as well as the cotton gin waste recovery.
TL;DR: Results show that magnetite addition could enhance the performance of anaerobic digesters treating high salinity wastewater, and caused the enrichment of many bacterial genera known to form robust biofilms.
TL;DR: This study introduced industrial potato by-product as an alternative carbon source for the woodchip denitrification process, and the encouraging results may pave the way toward growth of blue bioeconomy using the RAS.
TL;DR: In this paper, the effect of different algae and activated sludge (AS) ratios on the chemical oxygen demand (COD), N-NH4+ and P-PO43− removal was studied.
Abstract: Conventional wastewater treatment systems demand a high cost mechanical aeration. Using algal-bacterial systems helps to reach a cost-efficient treatment method by eliminating mechanical aeration, since algae produce the oxygen needed for treatment process. In this study, two groups of experiments were performed for domestic wastewater treatment processes. For the first group, semi-continuous microalgae-bacterial photo-bioreactors were cultivated. Chlorella Vulgaris and activated sludge (AS) were used as microalgae and bacterial inoculums, respectively. The effect of different algae and AS ratios on the chemical oxygen demand (COD), N-NH4+ and P-PO43− removal was studied. The removal efficiency of COD was above 93 % for the three tested algae and AS inoculum ratios (5:1, 1:1, and 1:5). The reactor with algae: AS inoculum ratio of 5:1 achieved the highest final N-NH4+ and P-PO43− removal efficiencies (88.0 ± 1.0 % and 84.0 ± 1.0 %, respectively). Furthermore, the highest biomass concentration (1.96 g L-1 from initial amount of 0.3 g L-1) was observed in the reactor with algae: AS ratio of 5:1. The ratio of 5:1 (algae: AS) was found as the optimum ratio which promoted the cooperation between microalgae and AS for nutrient removal. For the second group of experiments, the optimum ratio of 5:1 (algae: AS) was used in a membrane bioreactor, and the results showed that this reactor enhanced the final removal efficacies from 88 to 98 % and from 84 to 89 % for N-NH4+ and P-PO43-, respectively.
TL;DR: In this paper, the potential of biological treatment employing a microbial community under MBR laboratory-scale conditions to decolourize reconstituted textile wastewater in order to be reused was investigated.
TL;DR: In this paper, the performance and removal mechanisms of a novel lab-scale multiple draft tubes air-laying loop membrane bioreactor (Mt-ALMBR) for treating high-strength ampicillin pharmaceutical wastewater under different temperatures (7, 16, 24, 36 and 48) were investigated.
TL;DR: In this work, the potential and limitations of pure oxygen aeration are reviewed, and the effect of the system's operational parameters and the mixed liquor characteristics on oxygen transfer, and vice versa, are determined.
TL;DR: In this article, the authors present a methodology to estimate and compare cost impacts related to utilities as well as medium composition, using simple design equations and accessible data, in order to identify cost-effective production strategies using bioreactors.
TL;DR: Very good potential is demonstrated of the fungal-pelleted airlift bioreactor system for removal of selenite from wastewater using the fungus Asergillus niger KP isolated from a laboratory scale inverse fluidized bedBioreactor.
Abstract: This study investigated the removal of selenite from wastewater using the fungus Asergillus niger KP isolated from a laboratory scale inverse fluidized bed bioreactor. The effect of different carbon sources and initial selenite concentration on fungal growth, pellet formation and selenite removal was first examined in a batch system. The fungal strain showed a maximum selenite removal efficiency of 86% in the batch system. Analysis of the fungal pellets by field-emission scanning electron microscopy, field-emission transmission electron microscopy and energy-dispersive X-ray spectroscopy revealed the formation of spherical-shaped elemental selenium nanoparticles of size 65–100 nm. An increase in the initial selenite concentration in the media resulted in compact pellets with smooth hyphae structure, whereas the fungal pellets contained hair like hyphae structure when grown in the absence of selenite. Besides, a high initial selenite concentration reduced biomass growth and selenite removal from solution. Using an airlift reactor with fungal pellets, operated under continuous mode, a maximum selenite removal of 94.3% was achieved at 10 mg L−1 of influent selenite concentration and 72 h HRT (hydraulic retention time). Overall, this study demonstrated very good potential of the fungal-pelleted airlift bioreactor system for removal of selenite from wastewater.