• Journal of Environmental Science International
• /
• v.11 no.8
• /
• pp.819-827
• /
• 2002

Laboratory scale experiments were conducted to evaluate the performance of a biofilter for eliminating dimethyl sulfide(DMS). A commercial compost/pine bark nugget mixture served as the biofilter material for the experiments. The gas flow rate and DMS concentration entering the filter were varied to study their effect on the biofilter efficiency. The operating parameters, such as the residence time, inlet concentration, pH, water content, and temperature, were all monitored throughout the filter operation. The kinetic dependence of the DMS removal along the column length was also studied to obtain a quantitative description of the DMS elimination. High DMS removal efficiencies(>95％) were obtained using the compost filter material seeded with activated sludge. DMS pollutant loading rates of up to 5.2 and 5.5 g-DMS/m$^3$/hr were effectively handled by the upflow and downflow biofilter columns, respectively. The macrokinetics of the DMS removal were found to be fractional-order diffusion-limited over the 9 to 25 ppm range of inlet concentrations tested. The upflow column had an average macrokinetic coefficient(K$\_$f/) of 0.0789 $\pm$ 0.0178 ppm$\^$$\sfrac{1}{2}$//sec, while the downflow column had an average coefficient of 0.0935 $\pm$ 0.0200 ppm$\^$$\sfrac{1}{2}$//sec. Shorter residence times resulted in a lower mass transfer of the pollutant from the gas phase to the aqueous liquid phase, thereby decreasing the efficiency.

• Journal of Life Science
• /
• v.10 no.1
• /
• pp.14-21
• /
• 2000

The experiments were performed using both batch and continuous column reactors. Batch biodegradation studies were performed under aerobic conditions to determine the biodegradable fraction of the natural organic matter (NOM) source. NOM source was evaluated for its biodegradability at three different UV irradiation conditions and compared to its biodegradability without UV irradiation. In continuous experiments, system operating parameters of empty bed contact time (EBCT), recycle ratio, and influent concentration affected the extent of biofiltration in the biofilters. The effluent UV254/DOC ratios fro the biologically active columns were consistently lower than the influent values, which indicated that the dissolved organic carbon (DOC) removed by biodegradation was not a significant part of the UV-absorbable material. The increase in UV254/DOC ratio was caused by the DOC decrease across the biofilter because there was essentially no difference between the feed and effluent UV254 absorbance values over time. The results of this research showed that biofiltration was an effective method for removing the biodegradable fraction of NOM from water supplies.

• Journal of Animal Environmental Science
• /
• v.12 no.1
• /
• pp.29-34
• /
• 2006

The effects of turning frequency were examined on the efficiency of composting lime treated excess sludge amended with sawdust from the activated sludge process after a liquid/solids separation process. The raw and excess sludge from the activated sludge process associated with the hog wastewater treatment system is a significant problem and composting is an effective method far reducing the pollution potential of hog wastewater sludge. The coagulant used sludge composting and ammonia emissions from composting are not well established. The effect of compost properties such as high total carbon, C/N ratio and pH value on performance of composting sludge and biofiltration of ammonia from composting process were investigated. The ammonia emission was not significantly increased during composting. The ammonia concentrations of the exhaust air of composter were ranged from 0.5 and 7 ppm about 12 days after composting. The performance of the hog wastewater sludge composting was the most sensitive to chemical treated sludge properties such as high total carbon and high C/N ratio of the initial compost mixes. Temperature in compost and ammonia emission were not greatly affected by the turning frequency.

• Asian Journal of Atmospheric Environment
• /
• v.11 no.3
• /
• pp.139-152
• /
• 2017

Excessive amounts of volatile organic compounds (VOCs) and odorants discharged into the environment are highly dangerous to human health as well as to ecological systems. Biological treatments of waste gas streams, called biofiltration, containing VOCs and odorous compounds has gained much attention because biofilters are more cost effective and environmentally friendly than conventional air pollution control technologies. This review provides an overview of biotrickling filtration, which is a type of biofiltration including continuous trickled-water flow inside filter media, for VOC and odor abatement. The configuration, design, cost effectiveness, removal capacity and environmental impact of this techniques and the future research and development needs in this area are all considered.

• Journal of Environmental Science International
• /
• v.15 no.2
• /
• pp.133-139
• /
• 2006

Soil biofiltration is an environmentally-sound technology for elimination of VOCs, odorous and NOx compounds from a low concentration, high volume waste gas streams because of its simplicity and cost-effectiveness. This study was performed to evaluate effect of removal of gaseous NOx using a soil and a yellow soil. Over $60\%\;and\;48\%$ of NOx from a soil and a yellow soil was removed at the inlet NO concentrations of $423\~451$ppb, respectively. The bio-filter using a soil media was capable of purifying NOx with a different natural processes. Although some of the processes are quite complex, they can broadly be summarized as adsorption into soil pore water, and biochemical transformations by soil bacteria. When the filteration bio-reactor was applied to a soil and a yellow soil, effective NOx removal was obtained for several times and months. These results show that a soil biofilter can be of use as an alternative advanced NOx treatment system.

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.384-387
• /
• 2003

We measured the inlet concentration of odorous gases from the food-waste composting facility for 90 days. In consequence of this survey, we ascertained that the gaseous concentration was detected $10{\sim}100ppm$ in operating time, but $0{\sim}10ppm$ in a shutdown of the facility. The initial removal efficiency of this biofilter was roughly represented 80%, however, 90% before and after twenty days. We have thought that this biofilter accomplished the treatment of those odorous gases effectively, because the pressure-drop was not exceeded a value of $20mmH_2O$ after 90 days.

• 한국생물공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.247-251
• /
• 2005

This research was performed for developing of biological treatment process of odor gas such as MEK, $H_{2}S$, and toluene, which is generated from the food waste recycling process. To establish the operational conditions of odor gas removal by small-scale biofiltration equipment, it was continuously operated by using toluene as a treating odor object. When the odor treating microorganisms were adhered to fibril form biofilter, high removal efficiency over 93% was obtained by biofilm formation. At 400 ppm of inlet odor gas concentration and 10 sec of retention time, the removal efficiency was 76% and 93% in 1st stage reactor and 2nd stage reactor, respectively. However, the removal efficiency remained over 97% at the operational conditions above 15 sec of retention time.

• 한국생물공학회:학술대회논문집
• /
• 2005.10a
• /
• pp.456-462
• /
• 2005

The objective of this study was to develop a removal process by which $H_2S$ could be biologically removed from the odoriferous gases generated in the waste food recycling process. In order to develop this process we were first required to select a proper biofilter support protocol. When the selected biofilter equipment was then tested suing a synthetic odoriferous gas containing 600 ppm of $H_2S$, we noted a maximal removal rate of 658 $g-H_2S/m^3{\cdot}hr$, using polypropylene fibrils as supporting materials. Under identical experimental conditions, we obtained a value of 411.2 $g-H_2S/m^3{\cdot}hr$, using polyurethane as a support material. We also conducted a trial in which volcanic stone was utilized as a support material, and in this trial, we logged a maximal 105.1 $g-H_2S/m^3{\cdot}hr$ removal rate. As the result of our experiments, we concluded that polypropylene fibrils constituted the ideal material for the removal of $H_2S$ gas via biological treatment.

• Journal of Soil and Groundwater Environment
• /
• v.10 no.1
• /
• pp.35-42
• /
• 2005

This research was investigated the applicability of the biofiltration technology for the removal of volatile organic carbons (VOCs) produced from the bioremediation of oil contaminated soil. Diesel was used as surrogate for oil and, two types of biofilter systems made of ceramic and polymer media were compared for the removal efficiencies of diesel VOCs at different inlet concentrations and space velocity (SV) conditions. During the first 30-d operation, the removal efficiencies of the biofilter packed with polymer and the biofilter packed with ceramic were investigated at constant SV of $153\;h^{-1}$ When inlet concentrations of diesel VOCs were below 10 ppmv, the average removal efficiencies of the polymer biofilter and the ceramic biofilter were average $67\%\;and\;75\%$, respectively. When the inlet concentration increased to 30 ppmv, the VOC removal efficiency in the polymer biofilter was $80\%$, while the average removal efficiency in the ceramic biofilter was $60\%. Effect of the inlet concentration and SV on the removal efficiency of total diesel VOCs was investigated. As SV increased from $153\;h^{-1}$ to $204\;h^{-1}$ and $306\;h^{-1}$, the removal efficiency of total diesel VOCs was decreased gradually. The average removal efficiency of the biofilter packed with polymer carrier was decreased from $82\%\;to\;80\%\;and\;77\%$. The biofilter packed with polymer carrier showed that the removal efficiency of benzene and toluene were maintained within the range of $81\%\~86\%$. In contrast, for the biofilter packed with ceramic carrier, when SV increased from $153\;h^{-1}$ to $204\;h^{-1}$ and $306\;h^{-1}$, the removal efficiency of benzene decreased from $87\%\;to79\%\;and\;74\% . respectively. The removal efficiency of toluene decreased from $80\%\;to\;77\%\;and\;76\%$ at SV of $153\;h^{-1},\;204\;h^{-1}\;and\;306\;h^{-1}$, and $306\;h^{-1}$, respectively.

• Journal of Applied Biological Chemistry
• /
• v.51 no.6
• /
• pp.307-314
• /
• 2008

To explore the optimal conditions for the removal of $H_{2}S$ gas by biofiltration, various conditions, including inlet $H_{2}S$ concentration, flow rate, moisture, and cell number, were examined. Heterotrophic bacteria were isolated from the compost of the animal excreta. A strain that effectively removed $H_{2}S$ was selected and identified as Rhodococcus rhodochrous B261 by analysis of its 16S rDNA sequence. A cell number of $10^{7}\;cfu/g^{-}compost$ was sufficient to dominate the microbiota, and an effective removal was observed at $H_{2}S$ gas concentrations below 220 mg/L. The moisture content of 33-38% was suitable for activation of the microbial activity and delaying the desiccation. Higher flow rates resulted in lower removal rates of the $H_{2}S$ gas. Under the conditions of $10^7\;cfu/g^{-}compost$, $H_{2}S$ gas concentrations of 220 mg/L, and moisture content of 33-38%, the inlet $H_{2}S$ gas concentrations of 120 and 400 mg/L were completely removed for 34 and 12 days, respectively. The amount of sulfur removed was $2.99{\times}10^{-9}H_{2}S-S/cell$, which was suggested as the amount of sulfur removed by a single cell. The biofilter consisting of the compost and R. rhodochrous B261 could be suitable for a long-term biofilteration for the removal of $H_{2}S$ and other malodorous compounds.