title: Biodegradation of BTEX in a fungal biofilter: influence of operational parameters, effect of shock-loads and substrate stratification.
abstract: The effect of relative humidity (RH: 30% to >95%) of a gas-phase mixture composed of benzene, toluene, ethylbenzene and para-, meta- and ortho-xylenes (BTEX), inlet concentrations (0.2-12.6 g m(-3)), and empty bed residence times (EBRTs) (48-144 s) was tested in a fungi-dominant biofilter. A maximum elimination capacity (EC(max)) of 244.2 gBTEX m(-3) h(-1) was achieved at a total inlet loading rate (ILR(T)) of 371.2 gBTEXm(-3) h(-1) (RH: 65%). The transient-state response was tested by increasing the ILR(T), in two steps, from ~50 to 850 gm(-3) h(-1) and from ~50 to 320 g m(-3) h(-1), at a constant EBRT of 41.7s. Increasing the ILR(T) reduced the total BTEX removal efficiency (RE(T)) from >97% to 35%, and from >90% to 60% during medium and high shock-load, respectively. When subjected to short (4d) and long-term (7d) shut-down periods, the biofilter was able to recover high EC(max) of, respectively, 200 and 72 gBTEX m(-)3 h(-1) after resuming operation.
authors.affiliation: Chemical Engineering Laboratory, Faculty of Sciences, Rúa da Fraga 10, University of La Coruña, 15008 La Coruña, Spain.
authors.forename: Eldon R
authors.initials: ER
authors.lastname: Rene
authors.forename: Balsam T
authors.initials: BT
authors.lastname: Mohammad
authors.forename: María C
authors.initials: MC
authors.lastname: Veiga
authors.forename: Christian
authors.initials: C
authors.lastname: Kennes
mesh_terms: D001554:Benzene / Q000302:isolation & purification*; D001555:Benzene Derivatives / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D002245:Carbon Dioxide / Q000032:analysis; D005093:Exophiala / Q000502:physiology*; D005374:Filtration / Q000295:instrumentation*; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D044367:Phase Transition; D013379:Substrate Specificity; D013997:Time Factors; D014050:Toluene / Q000302:isolation & purification*; D014992:Xylenes / Q000302:isolation & purification*
chemical_list: D001555:Benzene Derivatives; D014992:Xylenes; D002245:Carbon Dioxide; D014050:Toluene; D001554:Benzene; C004912:ethylbenzene