Laboratory-scale biofiltration of acrylonitrile by Rhodococcus rhodochrous DAP 96622 in a trickling bed bioreactor

Abstract

Acrylonitrile (ACN), a volatile component of the waste generated during the production of acrylamide, also is often associated with aromatic contaminants such as toluene and styrene. Biofiltration, considered an effective technique for the treatment of volatile hydrocarbons, has not been used to treat volatile nitriles. An experimental laboratory-scale trickling bed bioreactor using cells of Rhodococcus rhodochrous DAP 96622 supported on granular activated carbon (GAC) was developed and evaluated to assess the ability of biofiltration to treat ACN. In addition to following the course of treatability of ACN, kinetics of ACN biodegradation during both recycle batch and open modes of operation by immobilized and free cells were evaluated. For fed-batch mode bioreactor with immobilized cells, almost complete ACN removal (>95%) was achieved at a flow rate of 0.1 microl/min ACN and 0.8 microl/min toluene (TOL) (for comparative purposes this is equivalent to 6.9 mg l(-1) h(-1) ACN and 83.52 mg l(-1) h(-1) TOL). In a single-pass mode bioreactor with immobilized cells, at ACN inlet loads of 100-200 mg l(-1) h(-1) and TOL inlet load of approximately 400 mg l(-1) h(-1), with empty bed retention time (EBRT) of 8 min, ACN removal efficiency was approximately 90%. The three-dimensional structure and characteristics of the biofilm were investigated using confocal scanning laser microscopy (CSLM). CLSM images revealed a robust and heterogeneous biofilm, with microcolonies interspersed with voids and channels. Analysis of the precise measurement of biofilm characteristics using COMSTAT agreed with the assumption that both biomass and biofilm thickness increased along the carbon column depth.

Effect of the chemical composition of filter media on the microbial community in wastewater biofilms at different temperatures

“…have also been observed in granular activated carbon to remove acrylamide in a laboratory scale trickling filter bioreactors by Zhang and Pierce. 59 TDR also supported the growth of Aquabacterium , Stenotrophomonas , Rhizobacter and Erythromicrobium (Fig. 7a).…”

Gas-phase Photocatalytic Oxidation of Acrylonitrile on Sulphated TiO2: Continuous Flow and Transient Study

“…This volatile organic compound (VOC) is detected as an in-door air component emitted by commercial fibrous polymeric materials, resins and smoking tobacco [2,3]. Traditional VOCs control technologies include adsorption [4], thermal incineration at temperatures of 1000-1200°C, catalytic incineration at temperatures of 250-500°C [5][6][7] and bio-filtration [8][9][10] suffering from high operating costs, secondary waste stream problems and narrow range of working conditions (bio-filtration).…”

Research into acetone removal from air by biofiltration using a biofilter with straight structure plates

“…Zhang and Pierce [ 14 ] have also used the bacterium Rhodococcus to degrade VOCs and the results of their research have shown a treatment efficiency of about 90%. Italian and Tunisian scientists also used the bacterium Rhodococcus for VOC removal.…”