Aerobic biodegradation of benzene and toluene under. The physical and chemical properties of a ground water aquifer seem to have a marked effect on microbial responses, and consequently on the biodegradation potential of water contaminants. Biodeterioration is sometimes described as a surfacelevel degradation that modifies the mechanical, physical and. The presence of benzene and phenol in the environment can lead to serious health effects in humans and warrant development of efficient cleanup strategies.
The method detection limits mdls for all analyses are listed in table 1. Jan 01, 1993 no biodegradation occurred under anaerobic conditions except when nitrate was provided as a terminal electron acceptor for microbial respiration. Biodegradation is considered to be a remedy for this issue and the usage of activated sludge is the most dominant method used among these days. Its optimal conditions for biodegradation of benzene were 20 c ph 9. Toxicological profile for benzene agency for toxic. Benzene, ethylbenzene, toluene, styrene, and the xylenes are among the 50 largestvolume industrial chemicals produced, with production figures of the order of millions of tons per year. The results obtained by this study suggest that biodegradation of methanol, benzene, and mxylene can readily occur in a saturated aerobic subsurface environment. Review polymer biodegradation and biodegradable polymers. Biodegradation of benzene was evaluated at different temperatures ranging from 5 to 60 c fig. Results from modeling the biodegradation data suggested that thiophene was cometabolized concomitantly with the biodegradation of benzene and that the biodegradation may be described by a modified model based on a traditional model with an inhibition term incorporated. Biodegradation tests a bottom sidearm with a silicon membrane and aluminum cap was used to remove samples from the flasks, using a sterile syringe and needle. Oxygenase genes putatively encoding the enzymes performing the initial steps in aerobic degradation of benzene, were detected in strain bc. To determine the molecular basis for this environmentally important process, we cloned. Methanogenic flowthrough aquifer columns were used to investigate the potential of bioaugmentation to enhance anaerobic benzene tolueneethylbenzenexylene btex degradation in groundwater contaminated with ethanolblended gasoline.
Bacterial aerobic degradation of benzene, toluene, ethylbenzene. National risk management research laboratory agency. Benzene, toluene and xylene were used as carbon sources. Biodegradation of fuel hydrocarbons benzene, toluene, ethylbenzene, and xylene btex compounds are readily biodegradable as primary substrates, although cometabolism of pxylene chang et al. No degradation occurred in bottles containing 0, 3. The system ultimately biodegraded all of the substrates within 144 h.
Benzene and potassium hydrogen phthalate khp with their immeasurable applications lead to tons of generated waste. Review polymer biodegradation and biodegradable polymers a. These results show that biodegradation of benzene and thus other petroleum hydrocarbons in the gasoline range, are subject to biodegradation in the spent ecs pads under landfill conditions. In the benzene aerobic biodegradation process, three intermediates are present. It may be subject to biodegradation in shallow, aerobic groundwaters, but probably not under anaerobic conditions. Rates of biodegradation were reduced by thepresence of soil.
Microcosms anaerobic microcosms were established in 125ml serum bottles which actually hold 125 ml when. The aim of the present work was to assess the potential of indigenous endophytic bacterial strains to degrade benzene and phenol. Biodegradation and kinetic study of benzene in bioreactor. Confirming in situ benzene biodegradation under anaerobic. Benzene, toluene and xylene biodegradation by pseudomonas putida ccmi 852 abstract and figures citations 65 references 21. Bhc by gas chromatography showed that the insecticide persisted longer in sterilized flooded soils than in nonsterilized flooded soils. Significant benzene biodegradation up to 88% was observed only in a column bioaugmented with the benzeneenriched methanogenic consortium, and this. Under denitrifying conditions there was apparent biodegradation of benzene, toluene, ethyl benzene, mxylene and pxylene but oxylene was not degraded. Biodegradation kinetics of benzene, toluene, and phenol as single and mixed substrates for pseudomonas putida f1 kenneth f. Biodegradation of benzene, toluene, and xylene btx in liquid. A great deal of research has been conducted on the use of different bacteria for benzene remediation.
Anaerobic bioremediation of benzene under sulfatereducing. Aerobic biodegradation of benzene, toluene andnaphthalene was studied in preequilibrated soilwaterslurry microcosms. A study of aerobic degradation of benzene by the microbial population of industrial wastewater treatment units showed only 4 mgl benzene remaining after 6 h with an initial dose of 50 mgl davis et al. Benzene degradation was induced by limiting oxygen available for microbial activity. Biodegradation of benzene was evaluated at various salt concentrations, ranging from 0 to 4 m fig. Monitoring and enhancing anaerobic benzene biodegradation in. These mentioned compounds are widely used as fuels and industrial solvents. Degradation of benzene and other aromatic hydrocarbons by. The literature compilation began with an electronic search of two files in srcs efdb, datalog and biolog, as sources of extensive biodegradation information. Table of contents abstract table of contents list of figures list of tables 1.
Oxo biodegradation is defined by cen the european standards organisation as degradation resulting from oxidative and cellmediated phenomena, either simultaneously or successively. Biodegradation of benzene, ethylbenzene, and xylene mixture in a date palm tree barkbased upflow biofilter rajamohan natarajan and jamila alsinani the performance of a date palm tree barkbased biofilter inoculated with mixed microbial consortia was investigated for the removal of a benzene ethylbenzenexylene mixture at a total inlet. Aerobic biodegradation of benzene, toluene, and xylene in a. Also, different electron acceptors were tried in the batch experiments. Substrate interactions during the biodegradation of benzene, toluene. The sem2 degraded 25 to 30 mol of benzene in 7 to 14 days with no apparent lag time in bottles containing 0. Biodegradation of benzene, toluene, and xylene btx in. Biodegradation of benzene a, ethylbenzene b, and m pxylenes c 2 p of. In a second step, toluene biodegradation in dehp by nonacclimated activated sludge was carried out for different volume fractions of dehp in water and five different toluene concentrations 4.
Benzene was fully degraded in the biotic plumestop system within the first seven days of the test, in contrast with 12. Apr 14, 2000 benzene oxidation under sulfatereducing conditions in columns simulating in situ conditions. Kinetics of aerobic biodegradation of benzene and toluene in. There was no effect of the concentration of benzene or toluene on the biodegradation time of benzene and toluene.
Biodegradation of naphthalene, btex, and aliphatic. Biodegradation of benzene and its derivatives by a psychrotolerant. The risk that benzene and toluene from spills of gasoline will impact drinking water wells is largely controlled by the natural anaerobic biodegradation of benzene and toluene. Aerobic biodegradation of benzene and toluene by pseudomonas putida f1 occurred. The monod model was also used to characterize phenol biodegradation by p. Biodegradation of the gamma isomer of benzene hexachloride in. Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. Yet, the number of bacteria detected in the endplume inoculum was comparable to the mid plume inoculum section 3. Effect of biofuels on biodegradation of benzene and toluene at gasoline spill sites figures.
Compound k halflife x specific day l days mgl firstorder coefficient kx lmg. The biodegradation ability of strain bda59 was evaluated with individual btex compounds benzene, toluene, ethylbenzene, or o, m, and pxylenes and a mixture in 160ml serum bottles containing 10 ml of msb medium and ye if appropriate under aerobic conditions in triplicate. Concomitant aerobic biodegradation of benzene and thiophene. Next to glucosyl residues, the benzene ring is the most widely distributed unit of chemical structure in nature 59, 2. Biodegradation characteristics of naphthalene and benzene. Kinetics of aerobic biodegradation of benzene and toluene. Several aerobic metabolic pathways for the degradation of benzene, toluene, ethylbenzene and xylene btex, which are provided by two enzymic systems dioxygenases and monooxygenases, have been identified. Pdf anaerobic benzene biodegradation linked to nitrate. Pdf biodegradation of benzene, toluene, ethylbenzene.
Biodegradation of aromatic compounds by escherichia coli. Description, properties, and degradation of selected volatile. Strain bda59 cells were cultured in r2a broth at 25c for. Biodegradation of benzene, toluene, ethylbenzene and xylenes. Jun 16, 2000 in the concentration ranges tested, toluene and benzene biodegradation kinetics were well described by the monod model. Benzene biodegradation linked to nitrate reduction was associated with cell growth. Benzene ring reduction requires a large input of energy and this metabolic capability has, so far, been reported only in bacteria. Biodegradation is a key process for the remediation of sites contaminated by petroleum hydrocarbons phcs, but this process is not well known for the semiarid coastal environments where saline conditions and continuous water level fluctuations are common. This paper attempts to address the importance of biodegradation for fuel and chlorinated solvent. Aet bioelectrochemicallyenhanced in situ biodegradation. Biodegradation of phenol and benzene by endophytic bacterial strains isolated from refinery wastewaterfed cannabis sativa environ technol. Biodegradation rates for fuel hydrocarbons and chlorinated.
Two different methanogenic consortia enriched with benzene or toluene and o xylene were used as inocula. The enrichment completely degraded benzene, toluene, ethylbenzene, and xylenes within 1 to 2 weeks. In mixture experiments, the rate of consumption of one substrate was found to be. Biodegradation of benzene in adsorbent pads under simulated. Biodegradation, principally under aerobic conditions, is an important environmental fate process for water and soilassociated benzene. Effect of biofuels on biodegradation of benzene and toluene at. Aerobic biodegradation of benzene and toluene under hypersaline. Enhanced anaerobic biodegradation of benzenetoluene. Prior art keywords nitrate aromatic hydrocarbons benzene electron acceptor soil prior art date 200209 application number nl1021458a other languages dutch nl inventor hubertus henricus ma rijnaarts. Pdf degradation of benzene by the heavymetal resistant. Biodegradation of benzene, toluene, ethylbenzene, and o. Spatial relationships between do and total benzene, toluene, and xylene btx were shown to be strongly correlated by statistical analyses and solute transport modeling. This study differs from the limited previous studies on the biodegradation of phcs in qatari coastal soils mainly by its findings on the. Benzene and toluene, as well as ethanol and other biofuels, are degraded under anaerobic conditions to the.
Benzene and toluene, as well as ethanol and other biofuels, are degraded under anaerobic conditions to the same pool of degradation products. Kinetics of benzene biodegradation by the coculture of dodecyl sulfate sds at ph 7. Jan 29, 2019 previously, two primary benzene biodegradation pathways with the conversions of benzene to phenol or benzene to cisdihydrobenzenediol as the result of the first oxidation have been proposed as. The experiments were designed tosimulate biodegradation at waste sites where sorptionreaches equilibrium before biodegradation becomesimportant. Table of contents chapter 1 general introduction 1 chapter 2 anaerobic benzene and toluene biodegradation studies with different electron acceptors in contaminated aquifer microcosms 27 chapter 3 anaerobic degradation of aromatic hydrocarbons with feiii, mniv or nitrate by the betaproteobacterium, georgfuchsia toluolica, gen. Biodegradation of benzene by halophilic and halotolerant. No biodegradation occurred under anaerobic conditions except when nitrate was provided as a terminal electron acceptor for microbial respiration.
According to these results, cells were adapted to 30 mgl benzene and 30 mgl toluene as a mixture for two times. Bull rogers department of chemical and bioresource engineering, colorado state university, fort collins, co 8052370. Biodegradation rates for mxylene and benzene in insitu columns from the midplume location were similar to microcosm rates. Biodegradation of benzene, toluene, ethylbenzene, and o, m. Benzene and toluene biodegradation with different dissolved. Kinetics of aerobic biodegradation of benzene and toluene in sandy aquifer material. Biodegradation of naphthalene, btex, and aliphatic hydrocarbons. Biodegradation of phenol and benzene by endophytic. Field and laboratoryderived pathways for the anaerobic biodegradation of the btex compounds benzene, toluene, ethylbenzene, and xylene 33 17. Where applicable, in situ biodegradation of the toxic petroleum hydro carbons benzene and toluene can serve as a cost effective groundwater cleanup method barker et. The biodegradation potential of methanol, benzene, and m. Effect of biofuels on biodegradation of benzene and. For example, benzene is degraded to catechol while toluene is degraded via several separate pathways to 3ethylcatechol with 3methylcatechol. To isolate bacteria responsible for the biodegradation of naphthalene, btex benzene, toluene, ethylbenzene, and o, m, and pxylene, and.
This demonstrates the existence of aerobic benzene bacterial biodegradation pathways under essentially anaerobic conditions. In this report, the degradation of benzene and other aromatic compounds catalyzed. Biodegradation of phenol and benzene by endophytic bacterial. Introduction biological treatment of contaminated aquifers is receiving increasing interest. The biodegradation of biomass offers some guidances. The complex aromatic polymer lignin comprises about 25% of the landbased biomass on earth, and the recycling of this and other plantderived aromatic compounds is vital for maintaining the earths carbon cycle. A benchscale treatability study was thus conducted at the center for environmental microbiology cem to investigate whether benzene contained within the adsorbent pad has the potential to biodegrade within a. Presented at 23rd national tanks conference and expo, march 19 21, 2012.
The process of biodegradation can be divided into three stages. Biodegradation kinetics of benzene and naphthalene in the. Laboratoryderived pathway for the aerobic biodegradation. Description, properties, and degradation of selected. The biodegradation of phenol and benzene would be a slow process even at optimum conditions and the iron oxide left in the cavity can act as a sorbent for a few inorganic species. Effect of ethanol and ethanol biodegradation products on.
Pdf biodegradation kinetics of benzene, toluene, and phenol. Aug 20, 2000 in the concentration ranges tested, toluene and benzene biodegradation kinetics were well described by the monod model. In the first of three experiments, the organic phase was loaded with 2. Scale up to 100l of anaerobic benzene culture for field scale applicationsin progress lab treatability studies underway for 4 sites indicate the dgg1 culture is effective under simulated site conditions. Although the enrichment was developed and maintained at 30.
Monods equation adequately described aerobic biodegradation rates of benzene and toluene by the microbial population of a sandy aquifer when these. Simultaneous biodegradation of benzene, toluene, and p. Whilst sometimes described as oxofragmentable, and oxodegradable. Benzene biodegradation was substantially enhanced 5x of control na for the two wells started in 2015, benzene concentrations decreased to and maintained at lower concentrations when comparing 4th quarter measurements for 2015 and 2016 roi measured 11 ft modifications to eredoxtm design minimize the influence from. Substrate interactions during the biodegradation of benzene.
Biodegradation of benzene in a batch reactor using. Biodegradation of benzene, toluene, ethylbenzene, and o, m, and pxylenes by the newly isolated bacterium comamonas sp. A highly enriched halophilic culture was established with benzene as the sole carbon source by using a brine soil obtained from an oil production facility in oklahoma. Microbial consortia formulation for the effective biodegradation of benzene, toluene, xylene and phenol dhanya vijayan1, jayachandran kochupurackal1, amith abraham1, and indu chandrasekharan nair2 addresses. Biodegradation of polycyclic aromatic hydrocarbon in petroleum oil.
Kinetics model for growth of pseudomonas putida f1 during. Biodegradation of benzene, ethylbenzene, and xylene. A cluster of bacterial genes for anaerobic benzene ring. Anaerobic biodegradation of individual btex components.
Toluene was the only hydrocarbon degraded within 3. Pdf biodegradation of benzene, toluene, ethylbenzene, and o. Biodegradation kinetics of benzene, toluene, and phenol as. Some microorganisms have developed mechanisms to degrade these compounds, but their aerobic and anaerobic degradation is inhibited in presence of heavy metals, such as mercury or lead. Jiang b1, zhou z, dong y, tao w, wang b, jiang j, guan x. These compounds are broken down by similar pathways to simple acids and aldehydes that are readily used for cell synthesis and energy 28. Although microbial growth on substrate mixtures is commonly encountered in bioremediation, wastewater treatment, and fermentation, mathematical modeling of mixed substrate kinetics has been limited. In addition, laboratory microcosm biodegradation experiments were performed to determine possible threshold limits for aromatic hydrocarbon oxidation under varying levels of. Pdf biodegradation of benzene by alkaliphilic bacteria under. Pdf kinetics of aerobic biodegradation of benzene and. Laboratoryderived pathway for the aerobic biodegradation of ethylbenzene 31 16.
Biodegradation of benzene, toluene and naphthalene in soil. Determination of the residual gamma isomer of benzene hexachloride. Degradation under denitrifying conditions occurred at a much slower rate than under oxygenated conditions. Journal of biotechnology 67 1999 99 112 biodegradation of benzene, toluene, ethylbenzene, and oxylene by a coculture of pseudomonas putida and pseudomonas fluorescens immobilized in a fibrousbed bioreactor hojae shim, shangtian yang department of chemical engineering, the ohio state uni6ersity, 140 west 19th a6enue, columbus, oh 43210, usa received 20 may 1998. Biodegradation of benzene in a batch reactor using indigenous. Effect of ethanol and ethanol biodegradation products on prospects for natural anaerobic biodegradation of benzene at gasoline spill sites. D biodegradation of aromatic compounds and tce by filamentous bacteriadominated consortium. The monooxygenase attacks methyl or ethyl substituents of the aromatic ring, which are subsequently transformed by several oxidations to corresponding substituted pyrocatechols or phenylglyoxal, respectively. Effect of biofuels on biodegradation of benzene and toluene. Confirming in situ benzene biodegradation under anaerobic conditions using stable isotope probing kerry sublette, dora taggart, and kate clark microbial insights, inc. Laboratoryderived pathway for the aerobic biodegradation of methyl. Benzene, toluene, ethylbenzene and the three xylene isomers are monoaromatic contaminants widely distributed on polluted sites. Keeping above fact in mind, the present work is formulated with the objective to evaluate the efficacy of the potential microbial species.
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