Isolation, screening and identification of bacterial strains for degradation of predigested distillery wastewater

Three bacterial isolates from the activated sludge of a distillery wastewater treatment plant identified as Xanthomonas fragariae, Bacillus megaterium and Bacillus cereus were found to remove COD and colour from anaerobically digested distillery wastewater in the range of 55 to 68% and 38 to 58% respectively.     

Fungal remediation of Amarula distillery wastewater

Amarula Cream is an alcoholic beverage derived from the distillation of fermented marula fruit and to date there is no scientific data as to the characteristics of the distillery wastewater generated from its production. The wastewater was found to have a chemical oxygen demand (COD) of 27 g/l, a pH of 3.8, a high concentration of phenolic compounds (866 mg/l) and a high suspended solids content (10.5 g/l), all of which could adversely affect biological treatment. Full-strength wastewater was treated using shake-flask monocultures of four white rot fungi (Trametes pubescens MB 89, Ceriporiopsis subvermispora, Pycnoporus cinnabarinus or Phanerochaete chrysosporium) at pH 5.0 with no additional carbon or nitrogen supplements. Trametes pubescens performed the best with regards to degrading phenolic compounds, COD and colour, while P. cinnabarinus improved the pH to the greatest extent. Laccase synthesis was only detected in the T. pubescens and C. subvermispora cultures. Six wastewater concentrations (100, 80, 60, 40, 20 and 10%) were assessed at pH 4.5 to establish an optimum concentration for remediation and laccase production by T. pubescens. Similar COD removal efficiencies (71–77%) and phenolic removal efficiencies (87–92%) were achieved at all concentrations. The phenolic removal efficiencies improved by approximately 5% compared to the screening experiment at pH 5.0, indicating that the laccase was more efficient at pH 4.5. The pH became more basic as a result of treatment and the colour decreased for samples below 60% wastewater concentration. The maximum laccase activity (1063 ± 26 units/l) was obtained in the 80% wastewater concentration. This study has resulted in the first characterization of Amarula distillery wastewater and showed that it has a high phenolic compound concentration, COD and suspended solids content. It was possible to biologically treat the wastewater at full strength using a number of white-rot fungi just by raising the pH.     

Recycle in upflow anaerobic sludge blanket reactor on treatment of real textile dye effluent

The discharge of textile wastewater containing dye in the environment is varying for both toxicology and esthetical reasons as dyes impede light penetration, damage the quality of the receiving streams. Upflow anaerobic sludge blanket reactor with anaerobic digester sludge treating starch wastewater has been used to investigate the removal efficiency of chemical oxygen demand (COD) and colour of textile dye wastewater. In this study, the starch and textile dye wastewater was mixed at 70 and 30%, respectively, and the experiments were carried out with recycle of treated wastewater at different percentage as 10, 20, 30 and 40. Maximum removal of COD and colour was 96% and 93.3%, respectively, at 30% recycle. At various OLR and HRT, the maximum removal of COD, colour was 95.9%, 93% at 6.81 kg COD/m³d and 96%, 93% with 24 h of HRT. The maximum production of biogas at 24 h of HRT with 30% recycle was about 355 l/d. The Volatile fatty acid/Alkalinity ratio of methanogenic reactor was found to be 0.049–0.053. The result provided evidence, the starch and dye wastewater have wide variation in their characteristics was treated on combination, this new technology supports the effective utilization of starch waste in destruction of dye.     

Biodegradation of olive oil mill wastewaterby Coriolus versicolor and Funalia trogii:effects of agitation,initial COD concentration,inoculum size and immobilization

The biodegradation of olive oil mill wastewater (OOMW) by Coriolus versicolor and Funalia trogii was investigated. Initial COD concentration, agitation and inoculum size were all found to be significant for biodegradation. Adding glucose, sulphate or nitrogen had no effect on biodegradation. During growth in optimum conditions, C.versicolor removed approximately 63% COD, 90% phenol and 65% colour within 6 days and F. trogii removed approximately 70% COD, 93% phenol and 81% colour of the OOMW used. The fungi also excreted large amounts of extracellular laccase into the medium. High biodegradation yields were also obtained by fungi immobilized in calcium alginate gels.     

Biodegradation of olive oil mill wastewaterby Coriolus versicolor and Funalia trogii:effects of agitation, initial COD concentration, inoculum size and immobilization

The biodegradation of olive oil mill wastewater (OOMW) by Coriolus versicolor and Funalia trogii was investigated. Initial COD concentration, agitation and inoculum size were all found to be significant for biodegradation. Adding glucose, sulphate or nitrogen had no effect on biodegradation. During growth in optimum conditions, C.versicolor removed approximately 63% COD, 90% phenol and 65% colour within 6 days and F. trogii removed approximately 70% COD, 93% phenol and 81% colour of the OOMW used. The fungi also excreted large amounts of extracellular laccase into the medium. High biodegradation yields were also obtained by fungi immobilized in calcium alginate gels.     

Performance of anaerobic contact filter in series for treating distillery spentwash

Investigations were carried out by using rigid polyurethane foam as a packing material in the anaerobic contact filter (series) to treat distillery spentwash. The effect of hydraulic retention time (HRT) in treatment efficiency of reactor (I) and (II) was evaluated at different initial substrate concentrations ranging from 1500 mg/l to 19,000 mg/l. The effect of toxic parameters such as sulphate present in the distillery spentwash and the corresponding parameters such as total sulphide and un-ionized hydrogen sulphide generated during digestion of wastewater were evaluated to assess the reactor performance. The results showed that at 4 d HRT the overall COD removal percent ranged from 98% to 73% for an influent COD of 1500 mg/l to 19,000 mg/l. The overall performance of COD removal percent in reactor (I) and (II) at 2, 3 and 4 d HRT's were investigated. At 3 d HRT the reactor (II) showed a higher COD removal percent when compared to reactor (I), which clearly shows the role of hydraulic retention time in degradation of the organic matter present in the wastewater above an influent COD concentration of 5000 mg/l.     

Sustainable power generation from floating macrophytes based ecological microenvironment through embedded fuel cells along with simultaneous wastewater treatment

Miniatured floating macrophyte based ecosystem (FME) designed with Eichornia as the major biota was evaluated for bioelectricity generation and wastewater treatment. Three fuel cell assemblies (non-catalyzed electrodes) embedded in FME were evaluated with domestic sewage and fermented distillery wastewater in continuous mode for 210 days. Fermented distillery effluents from biohydrogen production (dark-fermentation) process exhibited effective power generation with simultaneous waste remediation. Two fuel cell assemblies (A1 and A2) showed effective bioelectricity generation. Increasing the organic load of wastewater showed good correlation with both power generation (A1, 211.14 mA/m²; A2, 224.93 mA/m²) and wastewater treatment (COD removal, 86.67% and VFA removal 72.32%). Combining A1 and A2 assemblies depicted stabilized performance with respect to current and voltage along with significant decrease in ohmic and activation losses. FME also exhibited effective removal of nitrates, colour and turbidity from wastewater. The studied miniatured ecological system facilitates both energy generation and wastewater treatment with a sustainable perspective.     

Anaerobic fluidized bed reactor with sepiolite as support for anaerobic treatment of vinasse

Summary An anaerobic fluidized bed reactor, using sepiolite as support, for the treatment of distillery wastewater was started-up using a stepped loading regime with addition of methanol. Six different steady states at hydraulic retention times between 0.5 and 2.48 days were studied achieving a COD removal efficiency of 70.5 to 88.6%.     

Identifying an interfering factor on chemical oxygen demand (COD) determination in piggery wastewater and eliminating the factor by an indigenous Pseudomonas stutzeri strain

AIMS: This study attempted to demonstrate nitrite interference on chemical oxygen demand (COD) determination in piggery wastewater, and the capability of aerobic denitrification of the SU2 strain which is capable of promoting the efficiency of nitrogen and COD removal from piggery wastewater. METHODS AND RESULTS: This study was performed in a 17-litre reactor with a 30% packing ratio, with a ratio of immobilized SU2 cells to sludge of 100:1. The ratio of aeration to nonaeration was 4 : 1.5. Removal efficiency of COD was 86.8%. Removal efficiency of BOD and SS was higher than 90%, and removal efficiency of NH4+-N and TKN was almost 100%. CONCLUSIONS: NO2- -N interference is significant when its concentration in piggery wastewater exceeds 100 mg l-1. COD in piggery wastewater can be indirectly reduced following nitrite reduction by SU2 strain. SIGNIFICANCE AND IMPACT OF THE STUDY: Utilizing immobilized SU2 cells in coordination with an SBR system simultaneously reduces nitrite and COD concentrations.     

Treatment of spentwash using chemically modified bagasse and colour removal studies

Studies were carried out on derivatisation of bagasse into an ion exchange material and application of this chemically modified bagasse in the treatment of distillery wastewater. It was found that CHPTAC bagasse with HCl treatment and DEAE-bagasse in its free base form were most effective in colour removal and the mechanism of colour removal indicated significant contribution of both, the conventional ion exchange and the chemical sorption.     

Evaluation of the efficacy of upflow anaerobic sludge blanket reactor in removal of colour and reduction of COD in real textile wastewater

The upflow anaerobic sludge blanket (UASB) reactor was evaluated for its efficacy in decolourization and reduction in chemical oxygen demand (COD) of real textile wastewater (RTW) under different operational conditions. The efficiency of UASB reactor in reducing COD was found to be over 90%. Over 92% of colour removal due to biodegradation was achieved. The activities of the anaerobic granules were not affected during the treatment of textile wastewater. Cocci-shaped bacteria were the dominant group over Methanothrix like bacteria in textile wastewater treatment. Alkalinity, volatile fatty acids (VFA) content and pH in effluents indicated that the anaerobic process was not inhibited by textile wastewater. It is concluded that UASB reactor system can effectively be used in the treatment of textile wastewater for the removal of colour and in the reduction of COD.     

Microbiological Activities of Coenzyme Forms of Vitamin B12

A novel quinoline-degrading strain, named K4, was isolated from activated sludge of a coking wastewater treatment plant and identified as Brevundimonas sp. on the basis of its 16s rDNA gene sequence analysis. Its optimum temperature and pH for quinoline degradation were 30 °C and pH 9.0, respectively, and during the biodegradation process, at 100 mg/L initial quinoline concentration, an inoculation amount of 8% (OD600 of 0.23) was the optimal strain concentration. In addition, the kinetics of free K4 strains for quinoline degradation showed that it followed a zero-order equation. Furthermore, compared with free K4 strains, immobilized K4 strains’ potential for quinoline degradation was investigated by adding both of them into SBR reactors for actual coking wastewater treatment on operation over 15 days. The results showed that bioaugmentation by both free and immobilized K4 strains enhanced quinoline removal efficiency, and especially, the latter could reach its stable removal after a shorter accommodation period, with 94.8% of mean quinoline removal efficiency.     

A Bacillus thuringiensis strain producing a polyglutamate capsule resembling that of Bacillus anthracis

Bacillus thuringiensis serovar Monterrey strain BGSC 4AJ1 produced a microscopically visible capsule that reacted with a fluorescent antibody specific for the poly-gamma-d-glutamic acid (PGA) capsule of Bacillus anthracis. PGA capsule biosynthesis genes with 75%, 81%, 72%, 65% and 63% similarity, respectively, to those of the B. anthracis capBCADE cluster were present on a plasmid (pAJ1-1). Strain BGSC 4AJ1, together with five strains of Bacillus cereus that hybridized to a PGA cap gene probe, were analyzed phylogenetically using six housekeeping genes of a B. cereus multilocus sequence typing scheme. Bacillus thuringiensis BGSC 4AJ1 shared four identical alleles with B. anthracis and was the second most closely related to this bacterium of the 674 isolates in the multilocus sequence typing database. The other cap+ strains were distributed among various lineages of Clade 1 of the B. cereus group.     

Performance and spatial succession of a full-scale anaerobic plant treating high-concentration cassava bioethanol wastewater

A novel two-phase anaerobic treatment technology was developed to treat high-concentration organic cassava bioethanol wastewater. The start-up process and contribution of organics (COD, total nitrogen, and NH4 +-N) removal in spatial succession of the whole process and spatial microbial diversity changing when sampling were analyzed. The results of the start-up phase showed that the organic loading rate could reach up to 10 kg COD/m(3)d, with the COD removal rate remaining over 90% after 25 days. The sample results indicated that the contribution of COD removal in the pre-anaerobic and anaerobic phases was 40% and 60%, respectively, with the highest efficiency of 98.5%; TN and NH4 +-N had decreased to 0.05 g/l and 0.90 g/l, respectively, and the mineralization rate of total nitrogen was 94.8%, 76.56% of which was attributed to the anaerobic part. The microbial diversity changed remarkably among different sample points depending on the physiological characteristics of identified strains. Moraxellaceae, Planococcaceae, and Prevotellaceae were dominant in the pre-anaerobic phase and Bacteroidetes, Campylobacterales, Acinetobacter, Lactobacillus, Clostridium, and Bacillus for the anaerobic phase. Methanosarcinaceae and Methanosaeta were the two main phylotypes in the anaerobic reactor.     

Treatment of high strength distillery wastewater (cherry stillage) by integrated aerobic biological oxidation and ozonation

The performance of integrated aerobic digestion and ozonation for the treatment of high strength distillery wastewater (i.e., cherry stillage) is reported. Experiments were conducted in laboratory batch systems operating in draw and fill mode. For the biological step, activated sludge from a municipal wastewater treatment facility was used as inoculum, showing a high degree of activity to distillery wastewater. Thus, BOD and COD overall conversions of 95% and 82% were achieved, respectively. However, polyphenol content and absorbance at 254 nm (A(254)) could not be reduced more than 35% and 15%, respectively, by means of single biological oxidation. By considering COD as substrate, the aerobic digestion process followed a Contois' model kinetics, from which the maximum specific growth rate of microorganisms (mu(max)) and the inhibition factor, beta, were then evaluated at different conditions of temperature and pH. In the combined process, the effect of a post-ozonation stage was studied. The main goals achieved by the ozonation step were the removal of polyphenols and A(254). Therefore, ozonation was shown to be an appropriate technology to aid aerobic biological oxidation in the treatment of cherry stillage.     

Reclamation of municipal domestic wastewater by aquaponics of tomato plants

In search of low-cost eco-tech for the reclamation of municipal domestic wastewater, tomato plants (Lycopersicum esculentum) were cultivated on the floating bed of pulp-free coconut fiber over four different concentrations of wastewater (25%, 50%, 75% and 100%) and groundwater as control, in 10 L plastic bucket for two months. The study revealed that PO₄-P was removed by 58.14-74.83% with maximum removal at 50% wastewater. More than 75% removal of NO₃-N was observed in all treatments. Both COD and BOD were reclaimed highest at 100% wastewater by 61.38% and 72.03%, respectively. Ammonium-N concentration was subsided below the toxic level in all the treatments. The population of coliform bacteria (Escherichia coli) was reduced to 91.10-92.18% with maximum efficiency at 100% wastewater. Growth performance was observed relatively better at 100% wastewater. Crop production as the value addition of this technology was also recorded maximum at 100% wastewater. The bioaccumulation of Cd and Ni in tomato crop was far below the threshold level, but the bioaccumulation of Pb and Cr was above the safe level by 80 times and 660 times, respectively. The aquaponically reclaimed water can be reused in agriculture, aquaculture and industries.     

Evaluation of colour removal in synthetic saline wastewater containing azo dyes using an immobilized halotolerant cell system

Studies were carried out to evaluate the colour removal capacity of a moderately halotolerant bacterium, Bacillus firmus, in synthetic saline wastewater medium (SSWM) under static condition. The bacterial strain effectively decolourized Polar red B (an azo dye) in a wide range of sodium chloride (1-6%, w/v), dye (5-100 mg/L) and SDS (0.1-5.0 mg/L) concentrations and at pH range of 6-10 after 24 h of incubation. Cell immobilization studies indicated that colour removal was significantly higher (p < 0.05) in immobilized halotolerant cell systems than with free cells of B. firmus especially at salt concentrations higher than 4%. Results suggest the potential of using the immobilized halotolerant cell system for effective treatment of dye-contaminated saline wastewaters.     

Removal of hexavalent chromium in tannery wastewater by Bacillus cereus

Bacillus cereus was used to remove chromium (Cr(VI)) from medium containing tannery wastewater under different conditions. The maximum rate of Cr(VI) removal was attained at a temperature of 37?°C, pH of 7.0-9.0, and biomass of 20 g/L when the initial Cr(VI) concentration was less than 50?mg/L. Under the optimum conditions, the Cr(VI) in tannery wastewater was treated with each cellular component of B. cereus to detect its ability to reduce Cr(VI). The results showed that the removal rate of Cr(VI) for the cell-free extracts could reach 92.70%, which was close to that of the whole cells (96.85%), indicating that the Cr(VI) reductase generated by B.?cereus is primarily intracellular. Additionally, during continuous culture of the B. cereus, the strain showed good consecutive growth and removal ability. After treatment of 20?mg/L Cr(VI) for 48?h, the B. cereus was observed by SEM and TEM-EDX. SEM images showed that the B.?cereus used to treat Cr(VI) grew well and had a uniform cellular size. TEM-EDX analysis revealed large quantities of chromium in the B. cereus cells used to treat Cr(VI). Overall, the results presented herein demonstrate that B. cereus can be used as a new biomaterial to remove Cr(VI) from tannery wastewater.     

Decolorization of alcohol distillery wastewater by thermotolerant white-rot fungi

To detect thermotolerant fungus strain for decolorization of alcohol distillery wastewater (WAD), 38 fungus strains were studied. Ability of ligninolytic enzyme production was examined at 35 and 43 degrees C on agar media containing 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) and MnCl2. At 43 degrees C, four of Pycnoporus coccineus strains showed their higher potential for WAD decolorization both on agar media and in liquid media. Immobilized mycelia on polyurethane foam removed total phenol about threefold higher than free mycelia did in shaking condition at 43 degrees C. Moreover, color removed by immobilized mycelia nearly 50% higher than free mycelia did.     

Mechanism, kinetics and application studies on enhanced activated sludge by interior microelectrolysis

Enhanced activated sludge by interior microelectrolysis (EAIM) was studied to treat textile wastewater, kinetics, mechanism and application of which were also discussed in comparison with traditional activated sludge and interior microelectrolysis, respectively. The results of kinetics study indicated three different processes all followed first-order kinetics well. In EAIM, three impact factors take effects on COD removal, which are flocculation, activated sludge and electrophoresis and redox. In terms of assumption of no interaction among three COD removal mechanisms, 49.6% of the total COD removal is ascribed to flocculation, 30.1% to activated sludge and 20.3% to electrophoresis and redox. EAIM showed its advantages in COD removal efficiency, extensive adaptability to complex composition and wide range of pH. EAIM-aerobic process provided an efficient and economic performance for dealing with textile wastewater.