• Journal of Korean Society of Water and Wastewater
• /
• v.33 no.1
• /
• pp.79-86
• /
• 2019

In order to measure the filtration characteristics of a cotton ball shape filter, the experiments of suspended solids(SS) surrogate material selection and filtration performance have been carried out in this study. Between the two materials of powdered activated carbon(PAC) and powdered red-clay, PAC is more suitable surrogate material in terms of experimental criteria and particle size distribution in the non-point source pollutants removal system. As a result of the filtration experiments with the cotton ball shape filter, the initial headloss was about 8 cm, and the headloss slightly increased over filtration time. The Kozeny-Carman equation was used to analyze the changes of pressure and porosity during the filtration. The initial porosity was calculated as 0.945 and it decreased to 0.936 at the end of design filtration time. As the filtration continued, the SS concentration of the filtered water gradually increased and the SS removal rate gradually decreased. When the SS target removal efficiency is assumed to be 80%, the cumulative SS removal capacity is expected as $28.8kg/m^2$. This means the volume loading rate of the cotton ball shape filter can be $115m^3/m^2$ when the typical SS concentration of non-point source water pollution is assumed as 250 mg/L.

• Food Science and Preservation
• /
• v.22 no.3
• /
• pp.421-427
• /
• 2015

Oriental melon (Cucumis melo L. var. makuwa) has been widely consumed as various processed foods, such as dried products, jelly, wine, juice, and vinegar, in Asian countries. In fruit processing, blanching and pressure treatments affect its quality, such as antioxidant activities, sensory characteristics, and etc. This study was conducted to evaluate the effects of blanching and pressure pre-treatments on oriental melon wine-making (BP, blanching and pressure filtration; BNP, blanching and non-pressure filtration; NBP, non-blanching and pressure filtration; and NBNP, non-blanching and non-pressure filtration). Physicochemical properties and antioxidant capacities by ${\alpha}$, ${\alpha}$-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric ion reducing antioxidant power (FRAP) assay, and total phenolic and total flavonoid contents were measured for comparison of the different pre-treatment methods. After the aging process, the alcohol contents and pH values showed no statistical differences, whereas the amount of soluble solids, reducing sugar, and titratable acidity were slightly different among the pre-treatments (p<0.05). The samples with blanching pre-treatment showed higher antioxidant capacities than those of other pre-treatments. In the sensory evaluation, the BNP was the best in overall acceptability. Thus, this study showed that the blanching treatment enhanced the antioxidant capacities and sensory qualities of the oriental melon wine.

• Journal of Forest and Environmental Science
• /
• v.17 no.1
• /
• pp.29-36
• /
• 2001

Compared to other industries, pulp and paper industry use a lot of water. As a result, a large amount of the waste water is discharged in the pulp and paper industry. This study was investigated to prevent the environmental pollution terribly faced with our society nowadays. In the waste water of pulp and paper, there are so many things in the waste water, like fiber, filler, and other organic solvent etc. so we must remove them from our environment. This study was investigated to experiment on test of impressed filtration with the kind and quantity of coagulant and the variance of pressure. In this study, we used feds, alums. $CaCl_2$, polymer as a coagulant and these pressure was 49, 98, 147, 196kpa. According to this study, we measured the speed of filtration and turbidity, measuring filtrated water. According to the values, we know the fact that as the consistency of coagulant and pressure were high, the filtration was good.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.7
• /
• pp.391-402
• /
• 2017

Particulate matter becomes an important issue in the environmental society recently so that it is necessary to evaluate that the commercial application of baghouse systems for effective control of fine particulates is viable. A laboratory-scale baghouse experimental apparatus with filter bags made of PTFE felt or PTFE felt coated with PTFE membrane is used to investigate the filtration performances of fine particulates. Experiments by changing filtration velocity, inlet dust concentration, and average dust particle size show that the dust collection efficiency becomes higher at lower filtration velocity, higher inlet dust concentration and larger average dust particle size. The total pressure drop through the filter media and dust layer becomes higher at higher filtration velocity and higher inlet dust concentration. The dust collection efficiency is higher and the pressure drop is lower at a baghouse with filter bags coated with PTFE membrane than that without membrane coating. From the result that the dust collection efficiency of $PM_{2.5}$ in a reasonable filtration velocity range during off-line pulsing at a baghouse with PTFE felt bag filters coated with PTFE membrane is as high as 99.99%, it is confirmed that the use of baghouse is an effective measure to control the fine particulates.

• Journal of Korean Society for Atmospheric Environment
• /
• v.17 no.E2
• /
• pp.53-59
• /
• 2001

A hybrid dust-collector combining electrostatic charging with fabric filtration method was developed, and its performance characteristics were evaluated in this study. Charged particles build porous dendritic structure on the surfaces of filter by electrostatic attraction, increasing the collection efficiency of dust particles and reducing the pressure drop through the deposited dust layer and filter media. The cleaning performance of the dust layer is improved because the dendritic structured dust layer can be removed more easily by pulse jet cleaning flow. The results of the experiment showed a reduction of fine particle emission of 37% and the energy saving of 13% by precharging dust particles before filtration.

• Membrane and Water Treatment
• /
• v.14 no.1
• /
• pp.11-18
• /
• 2023

This work addresses the development of microfiltration ceramic membrane from alumina using extrusion method. The membranes were sintered at different temperatures ranging between 1000 and 1300℃. The alumina was characterized with thermogravimetric analysis, particle size distribution, X-ray diffraction, Fourier transform infrared spectrometer and scanning electron microscope analysis. Subsequently, the effect of sintering temperature on the membrane properties such as porosity, flexural strength, and pure water permeability was investigated and optimized for the sintering temperature. It is observed that with increasing sintering temperature, the porosity of the membranes decreases and the flexural strength, and pure water permeability of the membranes increase. The uncoated and coated membranes were compared at constant flux mode of filtration. Under the turbidity solution recirculation alone at 100 NTU, trans-membrane pressure (TMP) of uncoated membrane remained constant when the filtration flux was below 121 Lm^-2 h ^-1 , while the coated membrane was 111 Lm_-2 h ^-1 . Although suction pressure increased more rapidly at higher turbidity, coated membrane filtration showed better removal efficiency of the turbidity.

• Journal of Korean Society for Atmospheric Environment
• /
• v.22 no.2
• /
• pp.191-199
• /
• 2006

Animal feedstuff handling is one of the major fugitive dust sources in the port of Incheon. For the effective control of fugitive dusts emitting from the port of Incheon, dust control facilities with bag filter systems should be designed properly considering the characteristic of the fugitive dusts including those from animal feedstuffs. The ultimate goal of this study is thus to develop the optimum fugitive dust control system which will be applicable for the renovation of the port. As the first step to achieve this longstanding goal, filtration characteristics of soybean shell, the largest dust sources in the port, were investigated with the specially designed filter testing apparatus for this study. The variables tested for the experiments included filter materials, dust concentrations, relative humidities, and filtration velocities. Also, the filtration characteristics of the other animal feedstuffs such as sunflower seed shell, tapioca, and palm shell were investigated to determine $K_2$ as a function of filtration velocity. The information on $K_2$ will be used to design the optimum bag filter systems for animal feedstuffs handling in the port.

• Journal of Korean Society on Water Environment
• /
• v.20 no.6
• /
• pp.652-656
• /
• 2004

Both surface wash and backwash are considered as one of the most important methods that can improve the filtration efficiency in the existing water treatment plant. This study has mainly focused on the improvement of filtering efficiency by controlling surface wash and backwash time, and water level before backwash (when drained up to the trough, when drained up to 10 cm above filter bed, and when drained below 10 cm filter bed). Filtration efficiency was shown a little bit of differences depending on the operating conditions like surface wash injection pressure, the distance control between filter bed and the facility, and the types of surface wash. When the water level before backwash was reached up to 10 cm below filter bed after draining, however, the filtration velocity and the turbidity removal efficiency in the filter bed was improved. When the surface wash followed by backwash is longer, it showed a similar result. Because the proper adjustment of surface washing time makes filtration efficiency higher, therefore, it is necessary to set up the backwash time moderately.

• Korean Chemical Engineering Research
• /
• v.45 no.3
• /
• pp.264-268
• /
• 2007

The filtration performance of micron-sized metal fibrous filter was improved by synthesizing carbon nanotubes grown on the surface of metal fibers. The carbon nanotubes are grown with bush-like nanostructures covered around the micron-fibers or web-like nanostructures crossing between the fibers at different synthetic conditions. Filtration efficiency of CNT-metal-filter was measured and compared with the efficiency of the raw metal filter without CNTs. The developed CNT-metal-filter has higher filtration efficiency without significant difference in pressure drop compared with the conventional metal filter, which is because the carbon nanotubes function as the trap of pollutant nanoparticles.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.3
• /
• pp.297-306
• /
• 2003

Works were focused on back pressure characteristics of ceramic fiber filter on DPF (Diesel Particulate Filter) system and experiments were performed to select appropriate filter which can filter particulates. Filters were installed on metal -support tube which has openings for exhaust gas flow. Ceramic fiber filters with high specific surface area and adequate high temperature strength are commercially available for filtration of diesel particulates and in -situ hot regeneration. Thus, ceramic blanket and ceramic board which are used as insulating media were applied to filter and filtration apparatus was installed on exhaust gas line connected to 2.0 L diesel engine. Alternating filter structure to adapt DPF system, collection efficiency test of diesel particulates was measured. In case of ceramic blanket, pressure drop was low, caused by the destruction of soft structures. Also, particulate collection efficiency was decreased depending on loading time. In case of ceramic board, structure design was altered to reduce back pressure on DPF system. Structure design was altered to induce Z-flow by making 10 mm and 5 mm holes on the surface of media. Alteration of 5 mm hole showed that media have low back pressure but particulate collection efficiency was 77%, while 10 mm hole showed that of 90%.