In:
International Journal of Chemical Reactor Engineering, Walter de Gruyter GmbH, Vol. 6, No. 1 ( 2008-01-22)
Abstract:
This work deals with microbial growth onto filter media and focuses on the ability of microbial communities to proliferate onto filter media. Two microorganism types are studied: microorganisms from activated sludge of wastewater treatment plant (SM) and a toluene specific consortium (TSC). The filter media considered for this study contain activated carbon fibres (ACF), combined volatile organic compounds (VOC), particles treatment purposes, activated carbon fibres felt (ACFF) and activated carbon and cellulose fibres felt (AC2F2). Using a static growth procedure during 10 days under 100 % relative humidity, artificially contaminated filters are submitted to microbial colonisation. The final concentration of microorganisms per gram of filter have been assessed using a method developed in the lab, based on filter protein content assay. The average surface charge of inocula and filter's fibres are measured to assess the influence of microorganisms adhesion on contamination. The influence of soot particles on TSC proliferation onto AC2F2 filter is then studied. Zeta measures enable the assessment of the implication of soot in microorganisms adhesion onto filter fibres. Consequences of microbial contamination on filter permeability and downstream particles released have then been assessed in a filtration device. Results demonstrate a better resistance of AC2F2 to microbial colonisation. However, SM have more difficulties to proliferate on ACFF than TSC, whereas SM colonise easier AC2F2 than TSC. Charge surface assay has defined an optimal electrostatic compatibility for TSC and AC2F2 and a minimum for SM and ACFF. When soot is added to TSC solution before introduction in AC2F2, high contamination shapes were observed whereas only a slight one occur without soot addition. Zeta potential measures show favourable charge conditions for adhesion of soot on AC2F2 fibres and TSC on soot particles. The soot may thus have played an interface role in microbial adhesion onto media. This means that electrostatic compatibility between particles is a good approach for assessing microbial adhesion onto filters but could not explain the whole mechanism of microbial proliferation. Other parameters like nutrition preferences are certainly involved. The contamination have induced filter characteristics modification. Permeability have decreased until 20 % with microbial concentration. Colonised filters have released up to 450 microbial particles/cm3. Such a release was only observed when AC2F2 was contaminated with fungi using spore as the reproduction vector (inoculum containing TSC and soot).
Type of Medium:
Online Resource
ISSN:
1542-6580
DOI:
10.2202/1542-6580.1675
Language:
Unknown
Publisher:
Walter de Gruyter GmbH
Publication Date:
2008
detail.hit.zdb_id:
2112754-2
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