• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.310-315
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• 1999

The feasibility of an absorbent biofilter system was examined for rural wastewater treatment. Hydraulic loading rates varied from 50 to 250 cm/day. Effluent of the septic tank was fed into the absorbent biofilter, and small ventilation fan was provided to supply air at the rate of 250 L/min to aerate the biofilter. The biofilter system demonstrated high removal rates for $BOD_5$ and TSS at the loading rate of 150 cm/day, generally meeting the Korean effluent water quality standard of 20 mg/L applicable to both. The nutrient removal was less satisfactory than the results of $BOD_5$ and TSS, but it was within the expected range of biological treatment processes. Considering the abnormally high influent concentration of nutrients during the experiment, better performance results could have been obtained if ordinary domestic wastewater was used. The system performance was not significantly affected by the hydraulic loading up to 150 cm/day, which is far more than the loading limit of the sand filter systems. Maintenance requirement was minimal, and no problems with noise, odor, flies or sludge arose. Since the biofilter system can be operated at a distance, operation in remote rural area and multi-system connected to one control office might be advantageous to the rural area. Overall, considering the cost-effectiveness, stable performance, and minimum maintenance, the biofilter system was thought to be a competitive alternative to treat wastewater in Korean rural communities.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.471-478
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• 2012

The role of moisture absorptive capacity of pre-silage material and its relationship with silage effluent in high moisture by-product feedstuffs (HMBF) is assessed. The term water retention capacity which is sometimes used in explaining the rate of effluent control in ensilage may be inadequate, since it accounts exclusively for the capacity of an absorbent incorporated into a pre-silage material prior to ensiling, without consideration to how much the pre-silage material can release. A new terminology, 'potential water retention capacity' (PWRC), which attempts to address this shortcoming, is proposed. Data were pooled from a series of experiments conducted separately over a period of five years using laboratory silos with four categories of agro by-products (n = 27) with differing moisture contents (highest 96.9%, lowest 78.1% in fresh matter, respectively), and their silages (n = 81). These were from a vegetable source (Daikon, Raphanus sativus), a root tuber source (potato pulp), a fruit source (apple pomace) and a cereal source (brewer's grain), respectively. The pre-silage materials were adjusted with dry in-silo absorbents consisting wheat straw, wheat or rice bran, beet pulp and bean stalks. The pooled mean for the moisture contents of all pre-silage materials was 78.3% (${\pm}10.3$). Silage effluent decreased (p<0.01), with increase in PWRC of pre-silage material. The theoretical moisture content and PWRC of pre-silage material necessary to stem effluent flow completely in HMBF silage was 69.1% and 82.9 g/100 g in fresh matter, respectively. The high correlation (r = 0.76) between PWRC of ensiled material and silage effluent indicated that the latter is an important factor in silage-effluent relationship.

• Journal of the Korean Ceramic Society
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• v.40 no.3
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• pp.273-278
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• 2003

The effects of content and particle size of sewage sludge slag on the sound absorption was investigated and the physical$.$mechanical properties of porous ceramics for sound absorbent material was studied. The physical$.$mechanical properties of specimens have depended on sintering temperature and slag content without particle size effect of slag. As water glass content increase and particle size of slag decrease at the same slag content, physical$.$mechanical properties of them have been improved. The bulk density and compressive strength of specimens with the batch composition of 77∼89 wt% of slag content and particles with 1∼3 mm, and sintered at 1,050$^{\circ}C$ for 2 h were 1.48∼1.71 and 86∼163 kgf/$\textrm{cm}^2$, respectively. The specimens with 1∼3 mm and <1 mm of particles size showed good sound absorption property at low frequency and high frequency region. With increasing thickness of specimens, sound absorption properties at low frequency region were increased.

• Hwankyungkyoyuk
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• v.2 no.1
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• pp.92-99
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• 1991

According to our secondary school curriculum for natural science and technical circles, there be used 353 of chemical reagents including 24 kinds of harmful and toxicant components. At present, most school are discharging their school laboratory waste water without any chemical and physical treatments. So as to solve the environmental problem for water pollution, this study tried to research a kind of adsorbant utilizing saw dust, wasted wood sources and designed the simple processing system using the adsorbent. This adsorbent was made by extracting lignin substances from raw saw dust under the solution of 0.5N-NaOH at the temperature of $100^{\circ}C$. Their metal removed rates was measured not only by processing of column and vessel. but also by comparing the standard solution and real waste water. The results were proved as more than 90(%) of the adsorptive efficiency on the average from Pb, Cd, Cu except Cr(VI)in case of the school experimental waste water soaked in vessels a long with 4g of the adsorbent for 24 hours. The new processing system enables to remove most harmful and toxicant metals by filtering, sedimenting and adsorbing at the low cost.

• Polymer(Korea)
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• v.34 no.5
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• pp.434-441
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• 2010

Sodium polyacrylate (PAANa) was synthesized by inverse emulsion polymerization method to absorb excess water in concrete. Liquid paraffin was used as a continuous phase. Acrylic acid (AA) was neutralized by aqueous sodium hydroxide solution (8 M). Different amount of N,N'-methylene bisacrylamide (MBA) was used as a crosslinking agent to change crosslinking density of the synthesized PAANa. The size distribution of synthesized particles was measured by particle size analyzer. Swelling ratio of crosslinked PAANa was evaluated from the equation in D. I. water, cement aqueous solution, and $Ca(OH)_2$ aqueous solution. The FTIR spectroscopy was used to characterize $Ca^{2+}$ ion interaction with PAANa. Incorporation of 1.0 wt% PAANa into cement increased compressive and flexural strength approximately 30% and 10%, respectively, compared with those of ordinary portland cement.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.5
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• pp.583-589
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• 1988

Condensation of water vapor into an absorbent liquid of LiBr-water solution falling over a bank of water cooled horizontal tubes was investigated theoretically. The governing conservation equation for a re-defined physical transport phenomena were solved numerically using a finite difference method. Raw parameters were used in this study, since reliable experimental data is required prior to a dimensionless parametric study. The average values of wall heat transfer coefficient and interfacial absorption rate were defined to see the system performance. Other parameters include tube diameter, streamwise coordinate (and number of tubes in row), mass flow rate, and the wall temperature. The effects of these quantities on the absorption processes and suggestions for a rational system design have been presented.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.995-1000
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• 2011

The bioremediation potential of crude oil by Polyporus sp. S133 pre-grown in wood meal was investigated in two separate experiment trials; liquid medium and soil. The effect of three nutrients (glucose, polypeptone, and wood meal), oxygen flow, and some absorbent on the efficiency of the process was also evaluated. Degradation of crude oil in soil was significantly increased with an addition of oxygen flow and some absorbent (kapok and pulp). The highest degradation rate of crude oil was 93% in the soil with an addition of 10% kapok. The present study clearly demonstrates that, if suitably developed, Polyporus sp. S133 could be used to remediate soil contaminated with crude oil.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.19-20
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• 2021

In order to reduce the emission of harmful substances that degrade indoor air quality, the Ministry of Environment strengthened the standards for the content of VOCs in paints to supply and sell eco-friendly paints. In this related study, an eco-friendly paint mixed with a powder-type absorbent material was prepared and its characteristics were reviewed. As the amount of powder-type absorbent material increased, the workability (viscosity, peeling, etc) decreased. Accordingly, this study aims to examine which particle size is suitable according to the particle size of the granular adsorbent while improving the problem of the powdery adsorbent by using the granular adsorbent. As an experimental plan, the particle size of granular activated clay is selected to be 0.250, 0.425, 0.710(mm), and the decrease rate of VOCs concentration and impact resistance are reviewed. As a result of the experiment, as the particle size of the granular activated clay increased, the decrease rate of the VOCs concentration increased and the impact resistance improved. Therefore, considering the problems that occur after actual painting, the particle size of granular activated clay of 0.425mm is suitable.

• The Journal of the Korean dental association
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• v.57 no.5
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• pp.264-268
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• 2019

Objectives: This study aimed to measure the water sorption / solubility of Biodentine, composite resin and glass ionomer cement. Materials and Methods: The materials used in this study were Biodentine(BD), Filtek Z250(FZ) and Ketac Molar(KM). Twenty disc-shaped specimens of each material were prepared of 6mm diameter and 1mm thickness. All specimens were desiccated for 24 hours and weighed(m1). After then, They were immersed in distilled water and stored at $37^{\circ}C$. 1 week later, They were washed with running water, wiped with absorbent paper and weighed(m2). Finally, They were dried for 24 hours and weighed(m3). Water sorption and solubility, net water uptake were calculated. Results: KM and BD showed high water sorption than FZ(P<0.05). KM and BD exhibited similar water sorption(P<0.05). BD exhibited high solubility than KM(P=0.012). BD exhibited high net water uptake than FZ(P=0.008). Conclusion: Biodentine showed higher water sorption, solubility and net water uptake than Filtek Z250 and Ketac Molar. Within limitation of this study, it is not recommended to use Biodentine for permanent restoration.

• Polymer(Korea)
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• v.32 no.6
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• pp.537-543
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• 2008

Crosslinked agar-g-poly(acrylic acid) (x-agar-g-PAA) super absorbent with a water absorbency ($Q_{H2O}$) of approximately 660 g/g was synthesized by the copolymerization of agar with an acrylic acid monomer. KPS and MBA were used as the initiator and crosslinker, respectively. Grafting was performed in air. Infrared spectroscopy was used to identify the product of copolymerization. The optimum conditions to synthesize the x-agar-g-PAA superabsorbent were 0.1 g of agar, 0.1 g of the KPS initiator, for 15 min; 50% AA monomer, 0.005 g of the MBA crosslinker, for a propagation time of 5 min; and 1 M NaOH for 15 min to allow for saponification. The reaction temperature was $80{^\circ}C$.