The effect of nitrate on ethylene biofiltration.
This study investigated the effects of filter media types and nitrate (NO(3)(-)) concentrations in nutrient solutions on C(2)H(4) biofiltration. A new nutrient solution with zero NO(3)(-) concentration was supplied to two perlite-bed biotrickling filters, two perlite-bed biofilters, and two GAC (Granular Activated Carbon)-bed biofilters, while the other with 2 g L(-1) of NO(3)(-) was used for the other two GAC biofilters. All reactors underwent a total test duration of over 175 days with an EBRT (Empty Bed Residence Time) of 30 s, inlet gas flow rate of 7 L min(-1), and inlet C(2)H(4) concentrations of 20-30 mg m(-3). NO(3)(-) concentration and media type significantly affected the C(2)H(4) removal efficiencies in all types of biofiltration. The perlite media with no NO(3)(-) achieved C(2)H(4) removal efficiencies 10-50% higher than the others. A NO(3)(-) concentration as high as 2 g L(-1) in the original nutrient solution may act as an inhibitor that suppresses the growth or activity of C(2)H(4) degraders. In addition, the perlite media resulted in higher C(2)H(4) removal efficiencies than GAC media, because the hydrophilic surface of the perlite leads to a higher moisture content and thus to favorable microbial growth.
Department of Agricultural and Biological Engineering, Purdue University, 225 South University St., West Lafayette, 47907-2093 IN, USA. lee323@alumni.purdue.edu
Sang-Hun
SH
Lee
Congna
C
Li
Albert J
AJ
Heber
D000393:Air Pollutants / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000254:growth & development; D019149:Bioreactors / Q000382:microbiology*; D004867:Equipment Design; D005030:Ethylenes / Q000302:isolation & purification*; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000737:chemistry*; D013997:Time Factors; D055549:Volatile Organic Compounds / Q000302:isolation & purification*
D000393:Air Pollutants; D005030:Ethylenes; D009566:Nitrates; D055549:Volatile Organic Compounds; C036216:ethylene