• Journal of Korean Society of Water and Wastewater
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• v.7 no.1
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• pp.5-12
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• 1993

The objectives of this paper are to present data to illustrate how an advanced digestion process, two-phase digestion, can provide superior performance in terms of waste stabilization efficiency and net energy recovery. As the result, it is possible to separate enrichment cultures of acidogenic and methanogenic organisms in isolated environments by kinetic control involving manipulation of dilution rates. In single-phase digestion process, HRT and COD loading for effective operation were 14.29 days and 2.33kg $COD/m^3$ day, but two-phase digestion may be conducted efficiently at 7 days of HRT and 5.71kg $COD/m^3$ day of loading. Data from this studies showed that the two-phase process is better than single-phase digestion under all test conditions when compared on the bases of gas yield and production rate, reductions of COD and VS, buffer capacity, and unconverted volatile acids in the effluent.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.781-785
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• 2012

This study was carried out to treat the thermal elutriated acids of piggery wastewater using UASB process. The UASB reactor was operated at an organic loading rate (OLR) of $7.4\;kgCOD/m^3-day$ (6.5 ~ 9.0). During the start-up period, the low COD removal efficiency (20%) was caused by shock loading and instability in the reactor. It was mainly due to the high concentration amounts of ammonia nitrogen, which caused inhibitory and toxic effects to toward the anaerobic bacteria. In steady state, the UASB reactor showed a SCOD removal efficiency of 71% and a VS removal efficiency of 39%. The gas production and methane content were 1.3 L/day $(0.21\;m^3\;CH^4/kg$ COD removed) and 77%, respectively.

• KSBB Journal
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• v.15 no.6
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• pp.578-583
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• 2000

Biofiltration has been identified as a promising method of odor, VOCs and air toxic removal from waste gas streams because of low capital and operating cost, low energy requirements and an absence of residual products requiring further treatment of disposal. Because biofiltration units are microbial systems in-corporationg microorganisms grown on a porous solid media like compost, peat, soil and mixtures of these materials, there is a need to study of the adsorptive behavior of these supports. The purpose of this study was to investigate the major parameters of adsorptive process. We adsorbed VOCs onto peats and bark, and examined the correlations between the interphase mass transfer coefficients and transfer units, at different stream flow rates, VOCs inlet concentrations and bed lengths.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.71-72
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• 2020

γ-dicalcium silicate (γ-C2S) is characterized by its strong carbonation reactivity and has the prospect to be utilized as a building material with the added benefit of CO2 capture. This paper aims to point out the impact of γ-C2S on the microstructure characteristics and mechanical properties of GGBFS paste, and mortar samples. Three curing conditions including un-carbonation, natural carbonation, and accelerated carbonation were applied to the research. Besides, hydration products after the carbonation process are also detected. What's more, the carbonation treatment method also meets the requirement of capture more greenhouse gas and recycles the waste products of metallurgy.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.474-484
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• 2005

Biological treatment is a promising alternative to conventional air pollution control methods. Bioreactors for air pollution control have found most of their success in the treatment of dilute and high flow waste air streams containing volatile organic compounds and odor compounds. They offer several advantages over traditional technologies such as incineration or adsorption. These include lower treatment costs, absence of formation of secondary pollutants, no spent chemicals, low energy demand and low temperature treatment. The most widely used bioreactor for air pollution control is biofilter, but it has several limitations. In the past years major progress has been accomplished in the development of vapor phase bioreactor, in particular biotrickling filters. Biotrickling filters are more complex than biofilters, but are usually more effective, especially for the treatment of compounds which are difficult to degrade or compounds that generate acidic by-products. While the level of understanding of biotrickling filtration process for VOCs still remains limited, the evident success of biotreatment of VOC in air stimulated the pursue of acitve research. This paper presents fundamental and theoretical/practical aspect of air pollution control in biotrickling filter. Special emphasis is given to the operating parameters and the factors influencing performance for air pollution control in biotrickling filter.

• Journal of Environmental Science International
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• v.17 no.11
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• pp.1265-1271
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• 2008

Aerated submerged bio-film (ASBF) pilot plant has been developed. The presented studies optimized an inexpensive method of enhanced wastewater treatment. The objectives of this research were to describe pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF reactor in plug-flow reactor (PFR) and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophs and autotrophs in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research also investigated the efficiency of dissolved organic matter and ammonia nitrogen removals in the ASBF. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min.

• Asian Journal of Atmospheric Environment
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• v.11 no.3
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• pp.139-152
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• 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 the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.60-68
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• 2000

Biofiltration is an environmentally-sound technology for elimination of VOCs and odorous compound from low-concentration, high-volume waste gas streams because of its simplicity and cost-effectiveness. It can be appled to the treatment of gases from publicly owned treatment works, composting facilities, landfill sites, and soil vapor extraction systems. The ability to design an effective biofilter system involves a combination of fundamental biofilter knowledge, practical experience, and bench- and pilot-scale testing. The objective of this paper was to review principle, design parameters, operational conditions, case studies, and economy of biofiltration through literature.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.418-421
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• 2003

Surfactant enhanced in-situ soil flushing was peformed to remediate the soil and groundwater at an oil contaminated site, and the effluent solution was treated by the chemical treatment process including DAF(Dissolved Air Flotation). A section from the contaminated site(4.5m$\times$4.5m$\times$6.0m) was selected for the research, which was composed of heterogeneous sandy and silt-sandy soils with average Hydraulic conductivity of 2.0$\times$10$^{-4}$ cm/sec. Two percent of sorbitan monooleate(POE 20) and 0.07% of iso-prophyl alcohol were mixed for the surfactant solution and 3 pore volumes of surfactant solution were injected to remove oil from the contaminant section. Four injection wells and two extraction wells were built in the section to flush surfactant solution. Water samples taken from extraction wells and the storage tank were analyzed by GC(gas-chromatography) for TPH concentration with different time. Five pore volumes of solution were extracted while TPH concentration in soil and groundwater at the section were below the Waste Water Discharge Limit(WWDL). Total 18.5kg of oil (TPH) was removed from the section. The concentration of heavy metals in the effluent solution also increased with the increase of TPH concentration, suggesting that the surfactant enhanced in-situ flushing be available to remove not only oil but heavy metals from contaminated sites. Results suggest that in-situ soil flushing and chemical treatment process including DAF could be a successful process to remediate contaminated sites distributed in Korea.

• Resources Recycling
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• v.27 no.2
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• pp.68-76
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• 2018

EAF (Electric arc furnace) dust is an important secondary resource such as zinc, lead, and iron. Recycling of EAF dust is benefit to solving disposal and environmental problems caused by the heavy metals entrained in the dust. In this study, pyrometallurgical treatment technology of EAF dust reviewed for the improvement of conventional process and development of new process. The existing technologies categorized into four groups: those by rotary kiln process, rotary hearth furnace (RHF) process, shaft type process, and reduction smelting process. The product of these processes are ZnO and Fe or slag as a waste. Their mechanisms for the production of ZnO from EAF dust were carbothermic reduction and oxidation of zinc gas with air.