Removal of methanol from air in a low-pH trickling monolith bioreactor

Novel Bioreactors for Waste Gas Treatment

“…Rene et al ( 2010c ) showed that the pressure drop values increased to a maximum value of 7.2 cm H 2 O in a monolith bioreactor inoculated with the fungus Sporothrix variecibatus , during the biotreatment of gasphase styrene. Similar observations were also reported in a previous study with methanol in monolith bioreactor and it was postulated that regular washing, by temporarily increasing the fl ow rate of the trickling liquid for a short period, of the monolith would remove the excess biomass and will allow for a long-term, stable operation (Jin et al 2008 ) .…”

“…The design of conventional biofi lters have varied and improved over the past 50 years. Also a number of extensive reviews and studies about the technical aspects of biofi ltration have been published in the past few years (Kennes and Thalasso 1998 ;Rene et al 2004 ;Estévez et al 2005 ;Mohammad et al 2007 ;Jin et al 2006aJin et al , 2008Rene et al 2009a ;Kennes et al 2009b ) . 3.6 Schematic of a biofi lter; peat and compost based biofi lters have been used commercially for treating large volumes of air containing biodegradable volatile organic compounds at low concentrations (<200 ppm v ), but fi lter bed clogging, channelling and fl ow-maldistribution have often been reported 3 Novel Bioreactors for Waste Gas Treatment A wide variety of both organic and inorganic compounds such as alcohols, aldehydes, ketones, hydrocarbons, carboxylic acids, H 2 S and NH 3 have been treated in biofi lters (Leson and Winer 1991 ;Jin et al 2005 ;Prado et al 2008 ;Kennes et al 2009a ) .…”

“…3.9 ) is a reactor in which the biomass is attached on a plastic, ceramic or metal structure with uniform parallel channels separated by thin walls. Commercially available monolith supports can be tailored to meet the needs of a relatively inexpensive, light weight, inert, bioreactor packing that provides a high specifi c surface area, i.e., surface to volume ratio, to greatly improvise the mass transfer rate of pollutant (Jin et al 2006b(Jin et al , 2008Rene et al 2010c ) .…”

“…3.9 . Monolith bioreactors have only been tested recently for the removal of both hydrophilic and hydrophobic VOCs from waste-gases (Jin et al 2006b(Jin et al , 2008Fang and Govind 2007 ;Rene et al 2010c .h, suggests the extent of mineralization possible for hydrophilic VOCs in such a monolith reactor, a load that is often not treatable in biofi lters and biotrickling fi lters, at such low-pH. Fang and Govind ( 2007 ) tested an activated carbon coated monolith reactor having porous channel walls, made of porous cordierite to support biomass, under diffusive-and convective fl ow conditions to treat gas-phase toluene at low concentrations.…”

“…As the name implies, two-stage reactors exploit the inherent advantages of different processes used for waste-gas treatment, by adjusting the operation strategy as reactors connected in series or in one modifi ed reactor confi guration having different pollutant removal mechanisms (Kennes and Veiga 2001 ;Jin et al 2008 ;Rene et al 2009bRene et al , 2010b . Two-stage reactors are preferable for certain operating conditions and waste-gas characteristics, as given here; (i) when the waste-gas contains a mixture of inorganic and organic pollutants, and some of their degradation end-products are highly acidic, (ii) when it is desired to maintain different microbial species in the bioreactors for the removal of a mixture of pollutants, and (iii) for the treatment of exceedingly high loading rates of the pollutants, which could inhibit microbial activity in the biological reactor.…”