• Journal of Korean Society on Water Environment
• /
• v.33 no.5
• /
• pp.572-579
• /
• 2017

Increased impervious surface caused by rapid urbanization serves to produce the discharge of non-point source pollutants such as total suspended solid (TSS). There exist various methods of removing TSS, including a filtration process using granular media (a well-known method to be practically used after the consideration of removal efficiency, clogging, and backwashing efficiency). To determine the TSS removal capability of the filter, we initially performed lab-scale experiments which assessed flow rates, influent concentrations, permeability co-efficients, the particular shapes of suspended solids and potential clogging, and also evaluated TSS removal efficiency when applied to filtration facility in a pilot-scale. In low filtration flux condition, the removal efficiency of suspended solids was more than 95 %, while decreased to 83% in high filtration flux. Regarding the clogging aspect of the experiment, total cumulative solids were loaded up to $19.15kg/m^2$, and TSS removal efficiency was noted to commence to decrease when the loaded solids exceeded $9.0kg/m^2$. It was also noted, however, that superior efficiency was maintained for six hours. In addition, for pilot-scale experiment, the removal efficiency was still high enough (83.4 %) for the solid concentration of 140 ~ 343 mg SS/L and after backwashing, head loss was recovered to 92 ~ 95 % during two hour filtration. With these results, It was confirmed that lifetime of the filter applied to the test was prolonged due to the high treatment efficiency and good backwashing efficiency for the cumulative solids load.

• Journal of the Korean GEO-environmental Society
• /
• v.12 no.12
• /
• pp.5-12
• /
• 2011

Macro- and micro-behaviors of soluble granular media during dissolution process is investigated by numerical analysis. Soluble media are represented by assemblies of non-soluble particles and soluble particles with the different soluble particles contents. Dissolutions of particles are implemented by reducing sizes of soluble particles. The numerical simulations results exhibit that the vertical displacements increase to certain times and become constant while the porosities still increase until no soluble particles are present. However, the porosities and vertical displacements increase with the increase of soluble particles content. The microscopic views show that the fabrics of media change during dissolution process until the certain times, the higher soluble particles contents, and the larger change in fabric.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.6
• /
• pp.601-608
• /
• 2008

The objective of this study was to evaluate the effect of ozonation as pretreatment on the removal of dissolved or biodegradable organic matter(DOM or BOM), the variance of DOM fractionation, and microbial regrowth by pilot-scale granular activated carbon processes in which adsorption and biodegradability was proceeding due to long time operation. Regardless of point of ozonation applied, GAC processes with ozonation(i.e., Ozonation combined with GAC Filter-adsorber; Pre O$_3$ + F/A, Ozonation combined with GAC adsorber; Post O$_3$ + GAC) compared with GAC processes without ozonation(i.e., GAC Filter-adsorber; F/A, GAC adsorber; GAC) removed approximately 10 to 20% more of DOC, hydrophilic DOM(HPI), BDOC and AOC after long period of operation that biological activity was assumed to happen. Ozonation was not found to have a significant effect on the removal of DOC, but caused the decrease of AOC by approximately 20%. It was found that the fixed bacterial biomass on GAC media did not show a significant difference between the GAC with ozonation and GAC without ozonation as pre-treatment, whereas the HPC of column effluent was more biostable at Post O$_3$ + GAC compared with F/A or GAC.

• Korean Chemical Engineering Research
• /
• v.46 no.5
• /
• pp.994-1001
• /
• 2008

Freundlich isothermal adsorption parameters, applicable to such biofilter-model as process-lumping model(Lim's model), for sterilized granular activated carbon(GAC), sterilized compost and sterilized equal volume mixture of GAC and compost were obtained and were compared each other, assuming that adsorbents are enclosed by water layer, in order to construct robust process-lumping biofilter model effective for wide-range of hydrophilic volatile organic compounds(VOC). In this investigation 0.04, 0.08, 0.12, 0.16, 0.2, 0.4, 0.8 and 1.0ml of ethanol were added to three kinds of adsorbent-media and were placed at $30^{\circ}{\cdots}$ under the wet condition of the media, which was the same as biofilter operating condition, until the adsorption reached the condition of equilibrium before each adsorbed amount of ethanol was obtained. Then adsorption capacity parameters(K) and adsorption exponents of Freundlich adsorption isotherm equation, which simulates the adsorbed amount of ethanol equilibrated with the ethanol concentration of the condensed water in the pore of the media, were constructed for sterilized granular activated carbon(GAC), sterilized compost and sterilized equal volume mixture of GAC and compost as (0.7566 and $5.070{\times}10^{-7}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.7566}$), (0.8827 and $1.000{\times}10^{-8}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.8827}$) and (0.5688 and $5.243{\times}10^{-6}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.5688}$), respectively. These Freundlich isothermal adsorption parameters were applicable to the adsorption characteristics of biofilter media enclosed with bio-layer. The order of magnitude of the ratio of ethanol-air/water partition coefficient and toluene-air/water partition coefficient was almost consistent to that of ethanol-adsorbed amounts in this experiment with compost and in the investigation of Delhomenie et al. on toluene-adsorption to wet compost.

• Membrane Journal
• /
• v.28 no.4
• /
• pp.252-259
• /
• 2018

An acidic, real metal-plating wastewater was treated by a fluidized bed membrane reactor introduced with granular activated carbon (GAC) as fluidized media. With GAC fluidization, there was no increase in suction pressure with time at each flux set-point applied. At neutral solution pH, much less fouling rate was observed than acidic pH under GAC fluidization. Higher solution pH resulted in the increase in particle size in metal-finishing wastewater, thus producing a less dense cake structure on membrane. More than 95% of chemical oxygen demand was observed from the fluidized bed membrane reactor under GAC fluidization. Total suspended solid concentration in membrane permeate was near zero. At the raw wastewater pH, no removal of copper and chromium by the fluidized bed membrane reactor was observed. As the pH was increased to 7.0, removal efficiency of copper and chromium was increased considerably to 99 and 94%, respectively. Regardless of solution pH tested, more than 95% of cyanide was removed possibly due to the strong adsorption of organic-cyanide complex on GAC in fluidized bed membrane reactor.

• Horticultural Science & Technology
• /
• v.18 no.4
• /
• pp.508-512
• /
• 2000

Growth of red pepper (Capsicum annuum) 'Kumtap', tomato (Lycoperisocon esculentum) 'Seokwang', petunia (Petunia hybrida) 'Madness Rose', and pansy (Viola tricolor) 'Magestic Giant' in mixtures of chestnut woodchips and granular rockwool at 25:75, 50:50, or 75:25 (v/v) was examined. Chestnut woodchips were soaked in water for 48 hours or aged in open field for 6 months in order to remove substances impeding plant growth. A commercial plug medium was used as the control. All treatments showed in a similar result in red pepper, petunia, and pansy. Plant height, fresh weight, dry weight, and chlorophyll content in media containing chestnut woodchips, especially in higher proportions, were poorer as compared to those in the control. On the contrary, height, fresh weight, and dry weight of tomato seedlings in media containing woodchips were significantly higher than those in the control. For petunia, pansy, and red pepper, six month ageing in open field of woodchips was more favorable for growth than 48 hour water soaking. Emergance of petunia seed was inferior, especially when woodchip content was higher, to the other crops with a resultant growth suppression. From the results, chestnut woodchips proved to be a practical material as a medium component only in tomato plants.

• Journal of Bio-Environment Control
• /
• v.11 no.3
• /
• pp.108-114
• /
• 2002

Cellular glass foam (CGE), the reprocessed glass, has a possibility as a component of vegetative propagation media of floricultural crops due to the its excellent air and water permeability, similar to that of perlite. An experiment was conducted to evaluate the rooting and growth thereafter of Kalanchoe blossfeldiana ‘Gold Strike’in media containing various volume ratios of granular rockwool, peat-moss, CGF and perlite. The particle size of CGF and perlite was 2.0~4.0mm and 1.2~4.0mm, respectively. Cuttings were rooted in a fog tunnel with a mean temperature of 18.2$^{\circ}C$ and RH of 66.7％ under a long day regime (14 h per day light period). Height, length of the longest root, stem diameter, no. of leaves, leaf area, percentage of rooted cuttings, shoot and root fresh weights, shoot and root dry weights, total chlorophyll concentration and physicochemical properties were measured. Cuttings rooted 100% in all treatments. Physicochemical properties in CGF and perlite-containing media showed little differences. The growth of rooted plants in the CGF-containing media was similar or rather superior to that in perlite-containing media. Consequently, CGF has a possibility as a vegetative propagation medium of Kalanchoe. To make wider commercial use of CGF, more demonstrative experiments and analyses are necessary.

• Microbiology and Biotechnology Letters
• /
• v.18 no.3
• /
• pp.260-267
• /
• 1990

The mechanism of enzymatic hydrolysis of raw corn starch by the purified glucoamylase and a - amylase in an agitated bead reaction system was studied by investigating the changes of sugar profiles produced by each enzyme, the granular structure of raw corn starch, the amount of enzyme adsorption on residual starch, and the amylose content in residual raw starch. The sugar profiles produced by the action of exo-type glucoamylase or endo-type $\alpha$ -amylase in an agitated bead system were not recognizably differed with those produced in reaction system without bead. Without enzyme the intergenic microcrystalline structure of starch granule was not changed by the simple mechanical impact of solid media, but it was cleaved. However, starch granule was fragment into large number of small particles by the synergistic action of enzyme and attrition-milling media, identified to be the major saccharification enhancing mechanism along with the increased amount of enzyme adsorption. The amylose content decreased more readily in an agitated bead reaction system, especially by $\alpha$ -amylase.

• Journal of Bio-Environment Control
• /
• v.12 no.3
• /
• pp.160-165
• /
• 2003

This study was carried out to investigate the effect of several substrates; used rockwool, several spent mushroom composts, and common used media, such as rockwool and vermiculite, on growth and fruit quality of cucumber. Cucumber grew dramatically in the rockwool+peatmoss (1:2 v/v) (RP) and fine granular rockwool in hydroponic system using Yamaztiki's solution for cucumbers. The yield of cucumber fruit was highest in recycled winter mushroom compost (RW), and followed by 100% perlite (Par), recycled oyster mushroom compost (RO), and RR but there was no significant difference among these three media. Soluble solid and firmness were higher in Per and vermiculite (Ver), and any difference was not found among the others. Vitamin C was not influenced by kind of substrate. The results confirm that several reused or recycled substrates have high possibilities for use as medium for hydroponic culture in cucumber.

• Water Engineering Research
• /
• v.3 no.2
• /
• pp.75-84
• /
• 2002

An Euler-Lagrange two-phase flow model is presented fur simulation sheet-flow transport under wave and current. The flow is computed by solving the Reynolds Averaged Navier-Stokes equation in conjunction with the k-$\varepsilon$ turbulence model for turbulence closure. The sediment transport is introduced as a motion of granular media under the action of unsteady flow from the Lagragian point of view. In other word, motion of every single particle is numerically traced with Movable Bed Simulator (MBS) code based on the Distinct Element Method (DEM), in which the frequent interparticle collision of the moving particles during the sheet-flow transport is sophisticatedly taken into account. The particle diameter effect on time-dependent developing process of sheet-flow transport is investigated, by using three different diameter sizes of sediment. The influence of an imposed current on oscillatory sheet-flow transport is also investigated. It is concluded that the sediment transport rate increases due to the relaxation process related to the time-lag between flow velocity and sediment motion.