Biotreatment Of Wastewater Research Articles

Towards a novel bioreactor technology for treating fungicide-rich wastewaters from the fruit packaging industry

The fruit processing industry is an important economic sector worldwide, whereas a wide range of plant pathogens affects the shelf life of fruits, resulting in great economic losses. Post-harvest fungicides are often applied in the fruit processing industry to address post-harvest infections. However, various fungicides have been reported to exhibit toxicity to aquatic and terrestrial non-target organisms. Thus, effective technological solutions are needed to treat fungicide-containing wastewaters generated by the fruit packaging industry. Regarding biological methods, few approaches have been explored to deplete high-strength fungicide-based wastewaters derived from the post-harvest treatment of fruits. Despite the application of post-harvest fungicides for several decades, we are still missing the implementation of a full-scale biobased system to treat fungicide-rich wastewater generated by the fruit-packaging industry. On the other hand, fixed and fluidized bed bioreactors compared to suspended solids systems result in higher removal efficiencies. Based on the advantages of such bioreactor technology and the recent findings regarding the depuration of post-harvest fungicides in these biosystems, immobilized cell bioreactors appear to be a promising biological approach to treat persistent fungicides present in fruit packaging wastewater. However, bioreactors technology scaling up for the biotreatment of fungicide-rich wastewaters from the fruit packaging industry is challenging. Towards this direction, “Minotaur”, a 3-year research project financed by EU and Greek funds, is on the way to develop a full-scale bioreactor technology for treating fungicide-based wastewaters.

Bio-treatment of Industrial Oil Wastewater by Individual or Consortium Bacterial Species.

Discharge of wastewaters without treatment into aquatic and land habitats represents a global environmental problem. This study was aimed to biologically treat oil wastewater by using bacterial isolates individually or in consortium. Twenty bacterial species were isolated from industrial oil wastewater, only four of which were found to have the ability to degrade oil and grease. These isolates were identified according to morphological and biochemical profiles as, Bacillus cereus ATCC 14579, Bacillus cereus, Aeromonas sobria and Klebsiella pneumonia. The ability of Bacillus cereus ATCC 14579, Bacillus cereus, Aeromonas sobria and Klebsiella pneumoniae to treat oil wastewater after 2, 4, 6 days was investigated in single and consortium cultures. The ability of Bacillus cereus ATCC 14579 for treatment oil wastewater was higher than others bacterial isolates. The treatment efficiency of Bacillus cereus ATCC 14579 was 53.1% for EC, 52% for TDS, 92.2% for TSS, 91.2% for COD, and 93.2% for O&G. The treatment efficiency of oil wastewater by bacterial consortium was better than single bacterial culture.

Advances in the treatment of phosphorus-containing wastewater

In recent years, many rivers, lakes and oceans around the world have exposed to diverse contaminants or red tides due to excessive discharge of nutrients such as nitrogen and phosphorus. The high content of phosphorus often leads to the nutrition of water body. Water resources have been seriously threatened, which has brought great impact on environment and public health. Therefore, the removal of phosphorus from wastewater attracts more and more attention. This work reviewed the forms, hazards and treatment of phosphorus in wastewater, and focuses on the methods of phosphorus-containing wastewater such as chemical precipitation, adsorption, ion exchange, membrane separation and biological methods. With the current economic and development of world, the bio-treatment of phosphorus-containing wastewater will become a research trend in the future, and the research and development of new technologies for phosphorus-containing wastewater will be an important topic for the treatment of phosphorus-containing wastewater in the future.

BIOELECTROCHEMICAL TREATMENT MECHANISMS OF PETROLUME REFINERY WASTEWATER IN INTEGRATED SYSTEM OF MICROBIAL FUEL CELL-CONSTRUCTED WETLAND

Three identically designed systems named designate as MFC-CW, CW1,and CW2 were constructed and setup in this study for simultaneous biotreatment of real petroleum refinery wastewater (PRW) and bioelectricity generation. The three systems were planted with emergent wetland plant of Canna indica. These systems were operated simultaneously in a single batch mode to identify the dominant mechanism for organics removal from PRW. The operation period for each cycle was 8 days. Results demonstrated that maximum removal efficiency of the organic content represented as chemical oxygen demand (COD) were 96.5%, 89.3%, and 91% observed in MFC-CW, CW1, and CW2, respectively, whereby, the highest power generated in MFC-CW only was 12.36 mW/m2. The potential convergence of the results in the three systems indicated that the dominant mechanism of organic content removal from PRW was via bioelectrochemical reactions by the anodic biofilm in the MFC.

Green sustainable technology for biotreatment of actual dairy wastewater in constructed wetland

AbstractBACKGROUNDDue to the environmental problems caused by food processing wastewaters and their complex and expensive treatment methods, it becomes mandatory to seek a sound, sustainable and environmentally friendly solution such as constructed wetland (CW). This study aimed to investigate the potential of treating real dairy wastewater in CW. Six horizontal subsurface flow CW microcosms were set up using different conventional and cost‐effective supporting media, which were gravel, soil and sand. All the CWs were fueled continuously with real fresh dairy wastewater. Five of the six CW microcosms were planted with Canna indica. The remaining CW microcosm was kept unplanted and was considered as a control microcosm.RESULTSThe results revealed significant removal efficiencies of organic matter (as chemical oxygen demand) up to 89.92%, 97.6%, 95.8%, 97.2%, 97.3% and 98.2%, for CW1, CW2, CW3, CW4, CW5 and CW6, respectively. Also, high removal efficiencies of ammonium were observed in the range of 98.4–82.0%, whereas removal efficiencies of total suspended solids were in the range of 99.2–93.4%.CONCLUSIONThe results demonstrated that the dominant mechanisms for organics and ammonium removal were biodegradation processes. These promising results confirmed the validity of using constructed wetland as a sustainable cost‐effective approach for dairy wastewater treatment. © 2020 Society of Chemical Industry

Multifaceted roles of microalgae in the application of wastewater biotreatment: A review.

Microalgae have become imperative for biological wastewater treatment. Its capability in biological purification of wastewaters from different origins while utilizing wastewater as the substrate for growth has manifest great potentials as a sustainable and economical wastewater treatment method. The wastewater grown microalgae have also been remarked in research to be a significant source of value-added bioproducts and biomaterial. This paper highlights the multifaceted roles of microalgae in wastewater treatment from the extent of microalgal bioremediation function to environmental amelioration with the involvement of microalgal biomass productivity and carbon dioxide fixation. Besides, the uptake mechanism of microalgae in wastewater treatment was discussed in detail with illustrations for a comprehensive understanding of the removal process of undesirable substances. The performance of different microalgae species in the uptake of various substances was studied and summarized in this review. The correlation of microalgal treatment efficacy with various algal strain types and the bioreactors harnessed for cultivation systems was also discussed. Studies on the alternatives to conventional wastewater treatment processes and the integration of microalgae with accordant wastewater treatment methods are presented. Current research on the biological and technical approaches for the modification of algae-based wastewater system and the maximization of biomass production is also reviewed and discussed. The last portion of the review is dedicated to the assertion of challenges and future perspectives on the development of microalgae-based wastewater treatment technology. This review serves as a useful and informative reference for readers regarding the multifaceted roles of microalgae in the application of wastewater biotreatment with detailed discussion on the uptake mechanism.

Effect of light intensity and wavelength on nitrogen and phosphate removal from municipal wastewater by microalgae under semi-batch cultivation

ABSTRACT Domestic, agricultural and industrial water activities lead to organic and inorganic pollution of the environment. Biotreatment of municipal wastewater with the potential production of biomass is a valuable feature of microalgae. In this study we evaluated the effects of wavelength and light intensity on phosphate and ammonium removal on the one hand, and biomass and protein production on the other hand by Spirulina platensis in municipal wastewater treatment under semi batch cultivation. S. platensis was inoculated at 40% in artificial wastewater open pond system. Red, blue and purple light with 3800, 4800 and 5800 lux light intensity under 12 h light and 12 h darkness were investigated. Cultivation was conducted in semi-batch conditions; after four days cultivation, one third of the culture was replaced with fresh medium. The highest biomass and protein concentrations were observed under blue light at 5800 lux light intensity, 5.45 and 3 g/l respectively cumulatively; while the highest amount of phosphate and ammonium removal were about 145 and 218 mg/l under purple light at 5800 lux intensity, respectively. The amounts of biomass and protein produced, as well as phosphate and ammonium removed, are therefore impacted by wavelength, light intensity, results show that light intensity and wavelength can be customized to reach on the one hand the highest biomass and protein production, and on the other hand to maximize the removal of phosphorous and ammonium.

EFFECT OF PETROLUME REFINERY WASTEWATER ON PLANT GROWTH IN INTEGRATED MICROBIAL FUEL CELL-CONSTRUCTED WETLANDS SYSTEMS

Three identically designed microbial fuel cell-constructed wetland (MFC-CW) systems were constructed and setup in this study for simultaneous biotreatment of petroleum refinery wastewater (PRW) and bioelectricity generation. MFC-CW1 and MFC-CW2 were planted with Canna indica, and Phragmites australis, respectively. MFC-CW3 was unplanted and considered as the control. These three systems were operated simultaneously in a batch mode for two cycles to evaluate the effect of PRW biotreatment on the growth and development of the selected plants and the potential of generated bioelectricity as well. The operation period for each cycle was 8 days. Results demonstrated that maximum removal efficiency of the organic content represented as chemical oxygen demand (COD) were 98.75%, 97.67%, and 97.83% observed in MFC-CW1, MFC-CW2, and MFC-CW3, respectively, whereby, the highest power generation were 19.86, 19.04, and 18.7 mW/m2, respectively. On the other hand, both types of plants exhibited notable growth and new sprouts appearance. The potential convergence of the results in the three MFC-CWs, and the healthy growth of both types of plants clearly and potentially indicated that the dominant mechanism of organic pollutant removal was via biodegradation process by the anodic biofilm in the MFC rather than being removed by phytoremediation process.

Effective biotreatment of acidic mine water and hospital wastewater using fluidized-bed reactors

A laboratory-scale sulfate-reducing fluidized bed reactor at a controlled mesophilic condition of ±28 °C examined the biotreatment process of real acid mine drainage and hospital wastewater. In an attempt to substitute the carbon source, the study used the hospital wastewater in this regard. In this study, there was no supplement of carbon source during the treatment, but only the hospital wastewater provided the dissolved organic carbon. The process evaluated a biological treatment efficiency in stepwise phases, monitoring the effect of retention time, influent pH, and sulfates. The overall removal for the effluent COD concentrations and sulfate were between 39.5 mg/l and 42 mg/l at COD/SO42− ratio of 0.68 and hydraulic retention time of 8 h. The overall COD oxidation and sulfate reduction performance of the reactor was recorded as an average of 96 % and 97 %, correspondingly. The sulfide concentration averaged 235 mg/l, and the alkalinity generated in sulfidogenic organic from hospital wastewater neutralized the acid in mine water. The metal removal efficiencies documented at HRT of 8 h, were all above 98 %. The biological treatment further recorded the removal efficiencies of 44 % for naproxen and 55 % for ibuprofen pharmaceutical compounds as an additional advantage to the system.

A review of physical relationships between form and function in wastewater biotreatment and a new theory relating activated sludge and biofilm systems behaviour

AbstractIn this review paper, a physical systems analysis based on thermodynamics has been applied to the observed behaviour of activated sludge as a physical system. The origin of the microecology of activated sludge and its relationship to biofilms and the metabolic consequences of the extracellular polysaccharide (EPS) formation are explained for the first time. Feast‐famine conditions are shown to be the leading candidate for the evolution of the ability of biofilm forming bacteria and activated sludge ‘floc‐formers’ to form EPS. The basis for competition for RBCOD between low F:M filamentous heterotrophic bacteria and ‘floc‐forming’ heterotrophic is presented and its relationship to activated sludge bulking described.

Brewery wastewater treatment using cyanobacterial-bacterial settleable aggregates

This study investigated the bioremediation of brewery wastewater using a cyanobacterial-bacterial consortium dominated by the filamentous cyanobacterium Leptolyngbya sp. in aggregate form. The influence of pH and temperature on total biomass growth was investigated to increase biomass concentration and pollutant removal. The cyanobacterial-bacterial aggregates exhibited high removal efficiency for dissolved chemical oxygen demand (d-COD) (90%), nitrates (80%), orthophosphate and total phosphorus (70%) and ammonium (90%), when grown under the optimum pH (uncontrolled) and temperature (28 ± 1 °C) conditions. The biochemical composition of the microbial consortium in terms of proteins, carbohydrates and lipids was studied during wastewater biotreatment. Up to 45% carbohydrates was observed in the microbial mass at the end of cultivation, thus making the produced biomass suitable for the production of bioethanol. The synthesis of cyanobacterial-bacterial extracellular polymeric substances (EPS) was also evaluated. EPS improved the settling efficiency of aggregates that showed 99% efficiency after 30 min. Finally, the phytotoxic potential as well as the toxic effects of both raw and treated brewery wastewaters on the fairy shrimp Thamnocephalus platyurus was assessed, revealing a significant decrease in the toxic potential of the treated brewery wastewaters.

Desalination of actual wetland saline water associated with biotreatment of real sewage and bioenergy production in microbial desalination cell

The microbial desalination cell (MDC) can be considered as a great promising technique for the production of clean water due to the potential energy saving through the desalination process. This study assesses for the first time the desalination potential of actual wetland saline water simultaneously with biotreatment of real domestic wastewater and bioenergy generation in a continuous flow triple-compartments MDC. Two types of membranes were used in the MDC, the cation exchange membrane (CEM) and anion exchange membrane (AEM) to separate the three chambers. The results demonstrated complete removal of organic matter from real domestic wastewater. Maximum observed desalination efficiency of the actual wetland saline water achieved 93.7% with power generation and columbic efficiency of 527 mW/m2 and 31.14%, compared to 373 mW/m2 and 44.4%, respectively observed with synthetically prepared saline water. The observed promising results in this study highly encourages the application of the suggested approach for desalination of wetland saline waters.

Whole Genome Sequencing and Comparative Genomic Analyses of Lysinibacillus pakistanensis LZH-9, a Halotolerant Strain with Excellent COD Removal Capability.

Halotolerant microorganisms are promising in bio-treatment of hypersaline industrial wastewater. Four halotolerant bacteria strains were isolated from wastewater treatment plant, of which a strain LZH-9 could grow in the presence of up to 14% (w/v) NaCl, and it removed 81.9% chemical oxygen demand (COD) at 96 h after optimization. Whole genome sequencing of Lysinibacillus pakistanensis LZH-9 and comparative genomic analysis revealed metabolic versatility of different species of Lysinibacillus, and abundant genes involved in xenobiotics biodegradation, resistance to toxic compound, and salinity were found in all tested species of Lysinibacillus, in which Horizontal Gene Transfer (HGT) contributed to the acquisition of many important properties of Lysinibacillus spp. such as toxic compound resistance and osmotic stress resistance as revealed by phylogenetic analyses. Besides, genome wide positive selection analyses revealed seven genes that contained adaptive mutations in Lysinibacillus spp., most of which were multifunctional. Further expression assessment with Codon Adaption Index (CAI) also reflected the high metabolic rate of L. pakistanensis to digest potential carbon or nitrogen sources in organic contaminants, which was closely linked with efficient COD removal ability of strain LZH-9. The high COD removal efficiency and halotolerance as well as genomic evidences suggested that L. pakistanensis LZH-9 was promising in treating hypersaline industrial wastewater.

Utilization of microalgae for self-regulation of extracellular polymeric substance production

Extracellular Polymeric Substance (EPS) production in relation to carbohydrate and protein compositions is an important key in wastewater bio-treatment and microalgal harvesting. The influence of microalgal cultivation conditions on EPS production is well-documented in previous studies, but there continues to be a research gap that involves the effect of the initial concentration of microalgae added in media culture. This study aimed at investigating the impact of various initial microalgae concentrations on the behavior of carbohydrate and protein compositions constituting EPS. This study is important as it helps to enhance EPS production that associate with its applications. The total carbohydrate on average obtained was 31.1 mg L−1 and protein 25.6 mg L−11. Results revealed that the compositions of carbohydrates and proteins were not regulated by initial concentrations of microalgae. However, the difference in the behaviour of the EPS is noticed in the loosely bound-EPS (LB-EPS) and tightly bound-EPS (TB-EPS). The dominant production of carbohydrates in LB-EPS was approximately 2.2 times higher than in TB-EPS. As a conclusion, it was found the effect of monosaccharide fraction was primarily derived by glucose and arabinose components in both layers. The contents of monosaccharide components were analytically stable around 21.70 mg. L−1 after their self-regulation except for glucose in LB-EPS.

Functionalized Gold and Silver Bimetallic Nanoparticles Using Deinococcus radiodurans Protein Extract Mediate Degradation of Toxic Dye Malachite Green.

BackgroundBiodegradation of toxic organic dye using nanomaterial-based microbial biocatalyst is an ecofriendly and promising technique.Materials and MethodsHere, we have investigated the novel properties of functionalized Au-Ag bimetallic nanoparticles using extremophilic Deinococcus radiodurans proteins (Drp-Au-AgNPs) and their degradation efficiency on the toxic triphenylmethane dye malachite green (MG).Results and DiscussionThe prepared Drp-Au-AgNPs with an average particle size of 149.8 nm were capped by proteins through groups including hydroxyl and amide. Drp-Au-AgNPs demonstrated greater degradation ability (83.68%) of MG than D. radiodurans cells and monometallic AuNPs. The major degradation product was identified as 4-(dimethylamino) benzophenone, which is less toxic than MG. The degradation of MG was mainly attributed to the capping proteins on Drp-Au-AgNPs. The bimetallic NPs could be reused and maintained MG degradation ability (>64%) after 2 cycles.ConclusionThese results suggest that the easily prepared Drp-Au-AgNPs have potential applications as novel nanomedicine for MG detoxification, and nanomaterial for biotreatment of a toxic polyphenyl dye-containing wastewater.

Effect and ameliorative mechanisms of polyoxometalates on the denitrification under sulfonamide antibiotics stress

The environmental risks of the sulfonamide antibiotics have attracted much attention recently. In this study, the inhibition effects of sulfadiazine (SDZ) on denitrification electron transfer system (ETS) and ameliorative mechanisms of phosphomolybdic acid (PMo12) were first explored. When denitrification was under 2 mg/L SDZ stress, experiments indicated that PMo12 enhanced NO3–-N reduction efficiency and rate from 68.30% to 100.00% and 124.22 to 184.59 N/g VSS/h, respectively. Electron transfer rate and consumption efficiency in denitrification ETS were enhanced to ameliorate SDZ inhibition, which was due to the more secreted riboflavin and cytochrome c and the increased denitrifying enzymes activity with PMo12 mediation. In addition, the microbial growth inhibition and cell membrane damage were ameliorated due to the more EPS surrounding microbe with PMo12 mediation. Higher diversity of denitrifying microbe with PMo12 mediation also promoted denitrification under SDZ stress. This work provided promising strategy to ameliorate antibiotics inhibition in the wastewater bio-treatment.

Biotreatment of high-salinity wastewater: current methods and future directions.

Saline wastewaters are usually generated by various industries, including the chemical, pharmaceutical, agricultural, and aquacultural industries. The discharge of untreated high-salinity wastewater may cause serious environmental pollution and damage the aquatic, terrestrial, and wetland ecosystems. For many countries, the treatment of saline wastewater has become an important task. Generally, saline wastewaters are treated through physical and chemical methods. However, these traditional techniques are associated with higher treatment costs and the generation of byproducts. In contrast, biotreatment techniques are environmentally friendly and inexpensive. This review highlights the sources and environmental concerns of high-salinity wastewater and illustrates the latest problems and solutions to the use of biological approaches for treating saline wastewater. Although high salinity may inhibit the effectiveness of aerobic and anaerobic biological wastewater treatment methods, such strategies as selecting salt-adapted microorganisms capable of degrading pollutants with tolerance to high salinity and optimizing operating conditions can be effective. This mini-review may serve as a reference for future efforts to treat high-salinity wastewater.

Recent developments in textile wastewater biotreatment: dye metabolite fate, aerobic granular sludge systems and engineered nanoparticles

Textile wastewater (TWW) represents a major source of pollution worldwide, carrying high organic loads, recalcitrant azo dyes and engineered nanoparticles (ENP), namely silver nanoparticles (AgNP). The development of cost-efficient, environmentally-friendly TWW treatment solutions is critical. Despite the successful biodecolorization of azo dyes under anaerobic conditions, clear evidence for subsequent aerobic biodegradation of the often toxic breakdown sulfonated aromatic amines is scarce. Moreover, the debatable AgNP toxicity mechanisms, and apparent AgNP retention in activated sludge have raised concerns regarding eventual negative impacts on wastewater treatment efficiency. The aerobic granular sludge (AGS) technology, which has recently been scaled-up and implemented for the treatment of domestic wastewater and some industrial wastewaters, seems highly promising for TWW treatment, due to the high biomass retention capacity, anaerobic/anoxic/aerobic microenvironments within granules and enhanced tolerance towards high organic loads and toxic compounds. A review of the existing literature on AGS application to TWW treatment is presented, with a focus on the removal of azo dyes and their metabolites and ENP. The applicability of AGS to dye-containing synthetic and real TWW has been tested in different SBR systems. Their hydrodynamic regimens and operational conditions have been optimized, namely regarding granulation, long-term stability, azo dye decolorization and biodegradation of aromatic amines. Although promising results have been published regarding AGS resistance towards ENP (particularly AgNP), their long-term effects on the physical stability, biochemical properties and microbial community of AGS deserve more investigation. Overall, this review provides relevant support for the application of AGS SBRs in TWW treatment as a potential sustainable alternative to avoid the pollution of natural water bodies with synthetic dyes and ENP.

Modeling the formation of microorganism-derived dissolved organic nitrogen (mDON) in the activated sludge system

Microorganism-derived dissolved organic nitrogen (mDON) represents a significant and inevitable portion of dissolved organic nitrogen (DON) in the wastewater biotreatment processes. In the existing method, mDON concentrations are indirectly measured by the values of DON concentrations from the reactors with DON-free influent. However, this becomes problematic when influent contains DON. Especially when the real wastewater is involved, the paucity of the direct methods to quantitatively measure mDON is a major barrier to further research. This limitation is due to the difficulty of segregating mDON from the other nitrogenous organics, e.g., influent DON. In this study, we propose the ASM-mDON model based on ASM #1, which incorporates the production and consumption of mDON in the activated sludge processes to predict the mDON concentrations. In four independent lab-scale tests, our model was established and calibrated to obtain the accurate values of mDON (R2 = 0.929, p < 0.05), and the validity and applicability of the model were successfully examined by comparing the simulated and measured data. Moreover, the universality of the ASM-mDON model was further confirmed by simulating mDON production in a full-scale wastewater treatment plant. A reasonable prediction of mDON formation was shown in a full-scale test (1.98 ± 0.71 mg/L in June and 1.51 ± 0.54 mg/L in July) and is indirectly supported by an algal bioassay (p < 0.05, t-test). This study provides a useful approach to the efficient and accurate evaluation of mDON formation, which will improve current strategies designed to minimize the effluent mDON in wastewater bioprocesses.

Advanced Bioreactor Treatments of Hydrocarbon-Containing Wastewater

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.