• Journal of Korean Society for Atmospheric Environment
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• v.34 no.4
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• pp.554-566
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• 2018

The rice husk contains nutrients which can be easily utilized by microorganisms, and also has a water retaining ability, which played a crucial part in enabling it to become a biofilter media. In this study, we evaluated the applicability of rice husk pellet bio-scrubber as a microbiological carrier. The pelletization experiment of rice husk as a biological media was performed using PVA and EVA binder. Also, the feasibility tests of rice husk as a biological media for odor removal were carried out in order to know whether rice-husk contains useful components as a media for microbiological growth or not. Lastly, a combined test for odor gas absorption and biological oxidation was conducted using a lab scale bio-filter set-up packed with rice-husk pellets as wet-scrubber. The major components of the rice husk were carbon, hydrogen, nitrogen, and oxygen, while carbon acted as the main ingredient which comprised up to 23.00%. The C : N : P ratio was calculated as 45 : 1 : 2. Oxygen uptake rate, yield and decay rate of the rice husk eluent was calculated to be $0.0049mgO_2/L/sec$, 0.24 mgSS/mgCOD and 0.004 respectively. The most stable form of rice husk pellets was produced when the weight of the rice husk, EVAc, PVAc, and distilled water was 10 : 2 : 0.2 : 10. The prepared rice husk pellets had an apparent density of 368 g/L and a porosity of 59.00% upon filling. Dry rice husks showed high adsorption capacity for ammonia gas but low adsorption capacity for hydrogen sulfide. The bio-filter odor removal column filled with rice husk pellets showed more than 99.50% removal efficiency for NH3 and H2S gas. Through the analysis of circulation water, the prime removal mechanism is assumed to be the dissolution by water, microbial nitrification, and sulfation. Finally, it was confirmed that the microorganisms could survive well on the rice husk pellets, which provided them a stable supply of nutrients for their activity in this long-term experiment. This adequate supply of nutrients from the rice husk enabled high removal efficiency by the microorganisms.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.77-86
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• 2022

Various odor reduction systems are being operated at pig houses to improve livestock odor issues. However, the quantitative evaluation of odor reduction efficiency is not sufficiently conducted. The analysis of factors that affect the reduction efficiency also has not been sufficiently conducted. Therefore, in this study, the reduction efficiency of representative odor reduction facilities (bio-curtain, scrubber) operated by domestic pig houses was evaluated. The odor reduction efficiency was evaluated by sampling the air before and after the odor reduction facility in 6 pig houses. Livestock odors were evaluated for complex odors, ammonia, hydrogen sulfide, and VOC. To find factors for reduction efficiency, temperature, humidity, pH of washing resolution, type of washing water, and ventilation rate was measured. As a result, it was found that the scrubber system had the highest reduction efficiency. The reduction efficiency was found to be affected by the scrubber's washing resolution, filler, operating conditions, and size. Bio-curtains may have problems such as deterioration of fan performance due to ventilation fan load, groundwater pollution, and excessive use of groundwater.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.519-522
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• 2006

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.468-474
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• 2005

SOx and NOx are known major precursors of acid rain and thus the abatement of their emissions is a major target in air pollution control. To obtain basic data on the removal process of simultaneous $SO_2/NO$, the optimal reaction condition and the composition of reaction solution for simultaneous removal of $SO_2/NO$, ware investigated using a bubble column reactor. Pilot scrubber was consisted of scrubber, filter and control box. Dust removal rate was 83, 92, and 97% with catalyst flux of 0.5, 0.8, 1.5 L/min, respectively Average dust removal efficiency with a kind of nozzle was about 94 and 90% in STS FF6.5 (5/8in.) and 14 of P.P W(1.0in.), respectively Dust and $SO_2$ were removed more than 98-96% regardless of reactor number. In the case of NO gas, removal yield of 83.3% was achieved after 48 hours in 1 stage, also removal yield of 95.7% was reached in 2 stages. In tile case of application of STS (5/8 in.) and P.P (1.0 in.) as used fill packing, removal efficiency was reached higher than 98% without related to of kind of fill packing.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1763-1766
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• 2003

Algal growth studies of Chlorella strains were conducted in a batch mode with bench type experiments. Carbon dioxide fixation rates of the following green microalgae were determined: Chlorella sp. H84, Chlorella sp. A2, Chlorella sorokiniana UTEX 1230, Chlorella vulgaris, and Chlorella pyrenoidosa. C. vulgaris, among other strains of microalgae, showed the highest growth rate (1.17 optical density/5 days). Cultivating conditions for C. vulgaris that produced the highest growth rate were at concentrations of 243 ${\mu}g\;CO_2$/mL, 10 mM ammonia, and 1 mM phosphate, with an initial pH range of 7-8.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.491-498
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• 2009

We studied to develop high-efficiency removal system of odor and VOCs(Volatile Organic Compounds) from environmental infrastructure facilities and oil refineries, painting facilities and so on. It can replace RTO and RCO. We tried an removal experiment for VOCs (toluene, xylene, benzene, MEK(methyl ethyl ketone), ethanol, formalin etc. and odor compounds (hydrogen sulfide, etc.). In process, as pre-treatment we used the scrubber with vortex flow (Multi-scrone) to remove the hydrophilic VOCs and as post-treatment, used fibrous bio-filter to remove the hydrophobic VOCs. This hybrid system remove with high efficiency both the hydrophilic VOCs and hydrophobic VOCs. And we tried to make this system to be compact. In experiment using Multi-scrone, contact time is 2~3 seconds and absorption scrubbing water is diaphragm-type electrolysis water. hydrophilic VOCs like ethanol and relatively hydrophilic odor compounds like hydrogen sulfide is excellent, these substances has been removed almost completely, respectively 95~99%, 93~97%. And for MEK, formalin also Showed a high removal efficiency, respectively 78~90%, 72~85%. But in experiment using Multi-scrone, the hydrophobic VOCs like BTX showed a low removal efficiency, respectively 16~22%, 12~18%, 8~16%. In hydrophobic VOCs, toluene removal experiment using fibrous bio-filter, early efficiency was low but after 10days, adaptation period showed high efficiency 85~95%. but in the mixed phase, toluene and MEK efficiency reduced 5~10%. this show microorganism treat first MEK easy to remove. The removal efficiency for MEK using the fibrous biofilter was stable, 80~92%. This hybrid system is also high economical efficiency for RTO. This system reduce more than 50% the cost of equipment and maintenance. As a result, we expect this technology is in the limelight as high efficiency treatment of VOCs in mid-low price.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.103-110
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• 2017

In Concentrated Animal Feeding Operations(CAFOs), emission of ammonia from stored manure contributes negatively on the wellness of livestock. In CAFOs facilities, indoor aerial ammonia concentration oftentime surpasses the critical level potentially harmful to livestock's immune system. Understandably, numerous researches to control aerial ammonia have been conducted in countries where CAFOs were practiced for many decades. Some innovative technologies, such as scrubber, bio-filter, and additives emerged, as a result. Among them, microbial additives became popular in Korea, due to an easiness of use and affordability. However, microbial additives still have some weaknesses. Their price is still high enough to discourage farmers who run a small scale farm and their effectiveness are still questioned by many users and researchers. In the present study, we found soluble carbohydrates, such as sugar, glucose, and molasses, when supplemented to pig slurry manure, can mitigate ammonia emission. To be more specific, pig manure slurry(120kg), stored in container(200L), was supplemented with sugar at 0.1%(w/w) and was, subsequently, monitored for pH and aerial ammonia for next 10 days. From this experiment, it was found that the sugar supplementation was effective in mitigating the aerial ammonia concentration (33% in average) when monitored daily. Also, the pH of manure slurry was maintained at relatively low level(8.2) in sugar-supplemented manure slurry while it was elevated to 8.5 in untreated slurry. Conclusively, the obtained data suggest that soluble carbohydrate can mitigate ammonia emission by acidifying manure slurry. Additionally, it can be suggested that soluble carbohydrates, such as sugar, glucose, and molasses, can be reasonable choices for animal farmers who have been looking for an alternative choice to replace expensive microbial additives.