Regeneration of a Compost Biofilter Degrading High Loads of Ammonia by Addition of Gaseous Methanol

Abstract

The long-term stability of a biofilter loaded with waste gases containing NH 3 concentrations larger than 100 ppmv was studied in a laboratory-scale compost reactor. At an empty bed residence time (τ) of 21 sec, elimination capacities of more than 300 g NH 3 /m 3 /day were obtained at elimination efficiencies up to 87%. Because of absorption and nitrification, almost 80% of the NH 3 -N eliminated from the waste gas could be recovered in the compost as NH 4The high elimination capacities could be maintained as long as the NH 4 + / NO x -concentration in the carrier material was less than 4 g NH 4 + /NO x --N/kg wet compost. Above this critical value, osmotic effects inhibited the nitrifying activity, and the elimination capacity for NH 3 decreased. To restore the biofilter performance, a carbon source (methanol) was added to reduce NH 4 + /NO x -accumulated in the compost. Results indicate that methylotrophic microorganisms did convert NH 4 + /NO x -into biomass, as long as the NO 3 -content in the compost was larger than 0.1 g NO 3 --N/kg compost. Removal efficiencies of CH 3 OH of more than 90% were obtained at volumetric loads up to 11,000 g CH 3 OH/ m 3 /day. It is shown that addition of CH 3 OH is a suitable technique for regenerating the compost material from osmotic inhibition as a result of high NH 3 loading. The biofilter was operated for 4 months with alternating loading of NH 3 and CH 3 OH.

Degradation of Isobutanal at High Loading Rates in a Compost Biofilter

“…Table 1 30 all BFs normally operate under these stationary phase conditions, without net growth of the microorganisms, unless N is regularly supplied. This is also in accordance with the results of Demeestere et al, 18 who found that N limitation occurred in a methanol-degrading BF at nitrate concentrations Ͻ0.09 g NO 3…”

Operational and microbiological aspects of a bioaugmented two‐stage biotrickling filter removing hydrogen sulfide and dimethyl sulfide

“…This inoculation procedure was performed by dosing methanol at a loading rate of 1.43 g L À1 d À1 , allowing rapid growth of Hyphomicrobium VS (Pol et al, 1994). The abundance of methanol-degrading microorganisms in the environment is not surprising, because methanol biofiltration has been reported to be very efficient without inoculation (Demeestere et al, 2002;Krailas et al, 2000;Mohseni and Allen, 2000;Yang et al, 2002). Examples of heterotrophs capable of growth on methanol are members of the genera Pseudomonas, Sphingomonas, Alcaligenes, Methylosinus, and Methylobacterium (Doronina et al, 1997;Kang et al, 2001;Pineda et al, 2004;Sines et al, 1994;Stepnowski et al, 2004).…”

Biological Treatment of Waste Gases Containing Inorganic Compounds

“…Given its high solubility and low Henry's law constant (K H 25 º C = 27 mol kg −1 bar −1 ; Dean 1992), ammonia is mainly retained in biofilters by absorption into the aqueous biofilm phase formed on the solid media. As described above, nitrification by autotrophic bacteria (e.g., Nitrosomonas and Nitrobacter) generally is the main microbiological process for the degradation of ammonia in the biofilm (e.g., Sakano and Kerkhof 1998;Burgess et al 2001;Demeestere et al 2002). Ammonia is essentially mineralized in the form of nitrate and nitrite ions, which are retained in the biofilter material.…”

“…There have been many studies involving the biofiltration of ammonia-contaminated waste gas streams (e.g., Chung et al 1997;Lee et al 2001;Demeestere et al 2002). Table 12.2 provides a list of some of the studies conducted with biofilters containing organic-and inorganic-based packing materials.…”

“…Biofilters have been used to treat malodorous gases at wastewater treatment plants since the early 1950s, and are now being used to treat a wide range of waste gases, including volatile organic compounds (VOCs; e.g., Shareefdeen and Baltzis 1994;Devinny et al 1999;Mohseni and Allen 2000), and inorganic odorous compounds such as NH 3 , H 2 S, and amines (e.g., Demeestere et al 2002;Malhautier et al 2003). More recently, biofiltration has been investigated for the treatment of other inorganic air pollutants such as NO x (e.g., Flanagan et al 2002).…”