Biological and chemical analyses of a laboratory-scale biofilter for oxygenate bioremediation in simulated groundwater

Purswani, Jessica; Silva-Castro, Gloria Andrea; Guisado, Isabel M.; González‐López, Jesús; Pozo, Clementina

doi:10.1007/s13762-013-0348-3

Cited by 8 publications

(6 citation statements)

References 28 publications

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“…Among the existing chemical compounds in use fuels of most countries could be noted to MTBE (Zhang et al 2019). Despite the bans in some countries, it has become the second most common organics detected contamination in municipal groundwaters (Levchuk et al 2014, Purswani et al 2014, Abbasi et al 2020). The American environmental protection agency has been representing the recommended allowable limit of 20 to 40 µg/L for drinking water on the basis of threshold limits of smell and taste and has been placed this substance among compounds that is probable carcinogen for humans (Hu et al 2008).…”

Section: Introductionmentioning

confidence: 99%

WITHDRAWN: Removal of MTBE From Groundwater Using A PRB of ZVI/Sand Mixtures: Role of Nitrate And Hardness

Ghayurdoost

Assadi

Mehrasbi

2021

Preprint

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In this study, the efficiency of the permeable reactive barrier (PRB) in a column reactor using zero-valent iron (ZVI) particles and sand mixture in the removal of methyl tert-butyl ether (MTBE) from aquatic phases was investigated. The main operating parameters influence reactor performance such as pH, reaction time, pollutant content, catalyst load, hydraulic loading rate, and the reaction rate constant was evaluated. The results showed that the efficiency of process decreased with increasing pH, inflow, and pollutant concentration. In this case, the optimal conditions were obtained at pH=7, flow rate=0.23 m3/m2.d and C0=1 mg/L, which achieved a remarkable removal efficiency up to 90.32%. The being of high nitrate and hardness concentrations as intervening factors were led to reduce process efficiency to less than 44.61% and 51.4%, respectively. Lack of interfering factors had a considerable effect on the reaction rate of MTBE reduction that is approximately 2.65 and 4.11 times higher than in the presence of calcium hardness and nitrate, respectively. The PRB can be operated to remediate groundwater containing hydrocarbons based on filling media and hydraulic conditions.

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Section: Introductionmentioning

confidence: 99%

WITHDRAWN: Removal of MTBE From Groundwater Using A PRB of ZVI/Sand Mixtures: Role of Nitrate And Hardness

Ghayurdoost

Assadi

Mehrasbi

2021

Preprint

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“…Basic and applied research on MTBE biodegradation has increased in order to develop new technologies to treat contaminated ecosystems such as membrane bioreactor treating 5 mg l −1 MTBE in mixed liquor, upflow fixed‐bed reactors or an aerated submerged biofilter treating 100 mg l −1 of spiked groundwater to observe microbial events in recent groundwater spills . Among ex‐situ practices for MTBE‐contaminated groundwater bioremediation, those based on the use of fixed biofilms have gained great prominence, since protection provided by the biofilm matrix allows for higher cell survival following adaptation to confer an increased production rate or enabling the acquisition of specific enzymes for toxic compound degradation . However, the results offered by these studies revealed significant losses of oxygenate by air‐stripping as well as slow growth and poor biomass yield of MTBE degraders, especially when a pure culture was used as the bioreactor inoculum.…”

Section: Introductionmentioning

confidence: 99%

An extractive membrane biofilm reactor as alternative technology for the treatment of methyl tert‐butyl ether contaminated water

Guisado

Purswani

González‐López

et al. 2016

Biotechnology Progress

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Among the strategies developed for contaminated groundwater bioremediation, those based on the use of bacteria adhering to inert supports and establishing biofilms have gained great importance in this field. Extractive membrane biofilm reactor (EMBFR) technology offers productive solutions for the removal of volatile and semi-volatile compounds. EMBFR technology is based on the use of extractive semipermeable membranes through which contaminants migrate to the biological compartment in which microorganisms with pollutant biotransformation and/or mineralization capacities can grow, forming an active biofilm on the membrane surface. The objective of this study was to assess the use of three bacterial strains (Paenibacillus sp. SH7 CECT 8558, Agrobacterium sp. MS2 CECT 8557, and Rhodococcus ruber EE6 CECT 8612), as inoculum in a lab-scale EMBFR running for 28 days under aerobic conditions to eliminate methyl tert-butyl ether (MTBE) from water samples. Three different hydraulic retention times (1, 6, and 12 h) were employed. MTBE degradation values were determined daily by a gas GC-MS technique, as well as suspended bacterial growth. The biofilm established by the bacterial strains on the semipermeable membrane was detected by Field-Emission Scanning Electron Microscopy (FESEM) at the end of each experiment. The acute toxicity of the treated effluents and biomedium was determined by Microtox assay (EC ).The results achieved from the MTBE degradation, biofilm formation, and toxicity analysis indicated that bacterial strains MS2 and EE6 were the best options as selective inoculum, although further research is needed, particularly with regard to their possible use as a mixed culture. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1238-1245, 2016.

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“…DD8, R. ruber EE6, Agrobacterium sp. MS2, and Paenibacillus etheri SH7 T (Guisado et al, 2013 , 2015 , 2016 ; Purswani et al, 2014 ). The function, observed in our HT-Growth method as growth yield and rate in different xenobiotic compounds, will help determine which bacterial consortium is suitable as an inoculum for a biofilm-based remediating reactor.…”

Section: Methodsmentioning

confidence: 99%

“…Biofilms form in the interfaces of different density states, and have been found in “extreme” environments such as glacier-fed streams (Wilhelm et al, 2013 ) or near hydrothermal vents (Hall-Stoodley et al, 2004 ). Their resistance to external changes make biofilms the potentially leading bacterial-state for bioremediation (Fortin and Deshusses, 1999 ; Kharoune et al, 2001 ; Purswani et al, 2014 ). One of the most important decisions when selecting a microbial inoculum is whether to use an existing mixed-microbial population (e.g., sludge from a prior existing bioreactor) or select pure microbial cultures.…”

Section: Introductionmentioning

confidence: 99%

BSocial: Deciphering Social Behaviors within Mixed Microbial Populations

et al. 2017

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Ecosystem functionality depends on interactions among populations, of the same or different taxa, and these are not just the sum of pairwise interactions. Thus, know-how of the social interactions occurring in mixed-populations are of high interest, however they are commonly unknown due to the limitations posed in tagging each population. The limitations include costs/time in tediously fluorescent tagging, and the number of different fluorescent tags. Tag-free strategies exist, such as high-throughput sequencing, but ultimately both strategies require the use of expensive machinery. Our work appoints social behaviors on individual strains in mixed-populations, offering a web-tool (BSocial http://m4m.ugr.es/BSocial.html) for analyzing the community framework. Our quick and cheap approach includes the periodic monitoring of optical density (OD) from a full combinatorial testing of individual strains, where number of generations and growth rate are determined. The BSocial analyses then enable us to determine how the addition/absence of a particular species affects the net productivity of a microbial community and use this to select productive combinations, i.e., designate their social effect on a general community. Positive, neutral, or negative assignations are applied to describe the social behavior within the community by comparing fitness effects of the community against the individual strain. The usefulness of this tool for selection of optimal inoculum in biofilm-based methyl tert-butyl ether (MTBE) bioremediation was demonstrated. The studied model uses seven bacterial strains with diverse MTBE degradation/growth capacities. Full combinatorial testing of seven individual strains (triplicate tests of 127 combinations) were implemented, along with MTBE degradation as the desired function. Sole observation of highest species fitness did not render the best functional outcome, and only when strains with positive and neutral social assignations were mixed (Rhodococcus ruber EE6, Agrobacterium sp. MS2 and Paenibacillus etheri SH7), was this obtained. Furthermore, the use of positive and neutral strains in all its combinations had a significant higher degradation mean (x1.75) than exclusive negative strain combinations. Thus, social microbial processes benefit bioremediation more than negative social microbial combinations. The BSocial webtool is a great contributor to the study of social interactions in bioremediation processes, and may be used in other natural or synthetic habitat studies.

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Biological and chemical analyses of a laboratory-scale biofilter for oxygenate bioremediation in simulated groundwater

Cited by 8 publications

References 28 publications

WITHDRAWN: Removal of MTBE From Groundwater Using A PRB of ZVI/Sand Mixtures: Role of Nitrate And Hardness

WITHDRAWN: Removal of MTBE From Groundwater Using A PRB of ZVI/Sand Mixtures: Role of Nitrate And Hardness

An extractive membrane biofilm reactor as alternative technology for the treatment of methyl tert‐butyl ether contaminated water

BSocial: Deciphering Social Behaviors within Mixed Microbial Populations

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