• KSBB Journal
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• v.14 no.2
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• pp.141-145
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• 1999

The study was conducted for the efficient utilization of biomaterials such as Chestnut shell which was wasted tremendously as an agricultural by-products. This biomaterials were examined for their removal rate of heavy metal ions as adsorbents in wastewater by batch adsorption experiments. In this experiment, the heavy metal ions used were $\Cd^{2+},\;Fe^{2+},\;Cr^{6+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$. The range of time for the removal rates of heavy metal ions were observed about 10 min. The range of high pH for the removal rates of $\Cd^{2+},\;Fe^{2+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$ ere observed 7.0-9.0. The range of high pH for the removal rate of $Cr_{6+}$ was observed 2. In the case of raw chestnut shell, the removal rates of $\Fe^{2+},\;Mn^{2+},\;Cu^{2+}$ and $Pb^{2+}$ were above 70 percent. The removal rates of heavy metals in formaline pretreated chestnut shells except $Cd_{2+}$ were above 50 percent and in phosphorylating chestnut shells except $Cr_{6+}$ were above 60 percent. Chestnut shells pretreated by formaline and phosphorylating were not so good enough for improvement of removal rates with pH change in mixed heavy metal solution.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.85-91
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• 2014

In this study, the water quality purification of new medias which were NPS media, hyugato, mineral stone, charcoal for applying soil media of Integrated Management Practices (IMPs) of Low Impact Development (LID) were evaluated. The influent concentrations of COD, T-N, and T-P were 117.8 mg/L, 17.1 mg/L, and 2.062 mg/L, respectively. The infiltration capacities of NPS media, hyugoto, mineral stone, charcoal, and gravel were $7.1{\times}10m/s$, $7.3{\times}10^{-5}m/s$, $7.9{\times}10^{-5}m/s$, $6.0{\times}10^{-5}m/s$, respectively. All media meet criteria of infiltration capacity as surface soil layer at IMPs which is over $1.0{\times}10^{-5}m/s$. Maximum removal rates of COD, T-N, and T-P occurred at Charcoal with 98 % of COD removal rate, NPS with 78 % of T-N removal rate, and hyugato with 75 % fo T-P removal rate, respectively. For more high removal efficiency of all water quality item, the mixed media which is 4.5(NPS media): 1(charcoal) : 4.5 (hyugato) as volume ratio was evaluated. The infiltration capacity of mixed media was $7.9{\times}10^{-5}m/s$ and met the criteria of infiltration as surface soil layer. The water quality removal efficiencies of mixed media were very high with showing 70 % for COD, 85 % for T-N, and 71 % for T-P. The mixed media could purify the water quality of surface runoff and was recommended to used at the LID site of ground water quality problem.

• Journal of environmental and Sanitary engineering
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• v.12 no.2
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• pp.1-12
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• 1997

This research aims to develop biofilm process for the nutrient removal of piggery wastewater. The developed process is the four stage anoxic-oxic biofilm process with recirculation of the final effluent. In summery, the results are as follows: 1. Nitrification in the piggery wastewater built up nitrite because of the high strength ammonia nitrogen. The nitrification of nitrobacter by free ammonia was inhibited in the total ammonia nitrogen loading rate with more than 0.2 kgNH$_{3}$-N/m$^{3}$·d. 2. The maximal total ammonia nitrogen removal rate was obtained at 22$\circ $C and without being affected by the loading rate. But total oxidized nitrogen production rate was largely affected by loading rate. 3. Autooxidation by the organic limit was a cause of the phosphorus release in the aerobic biofilm process. But the phosphorus removal rate was 90 percent less than the influent phosphorus volumetric loading rate of above 0.1 kgP/m$^{3}$·d. Therefore, the phosphorus removal necessarily accompanied the influent loading rate. 4. On the anoxic-oxic BF process, the total average COD mass balance was approximately 67.6 percent. Under this condition, the COD mass removal showed that the cell synthesis and metabolism in aerobic reactor was 42.8 percent and that the denitrification in anoxic reactor was 10.7 percent, respectively.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.3-10
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• 2006

In this study, the of MBBR(moving bed biofilm reactor) process for Phosphorus Removal efficiency depending on seasons and the factors affecting phosphorus removal efficiency in the process is evaluated. As a result of experiment, T-P removal efficiency has its highest value in winter, (80.8%). and T-P removal efficiency has its lowest value in autumn, (49%). Optimum SRT for Phosphorus Removal revealed is about 8.8 days and process performs more efficiently as the temperature decreases. It is accepted that nitrate to anaerobic zone is affecting the Phosphorus removal process. With increasing the organic loading rate, Phosphorus removal efficiency also increases. Also, an experiment has been conducted to find out the highest efficiency according to Media existence and it has revealed that Media addition provides better phosphate removal.

• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.44-56
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• 1998

This study was performed to investigate the reaction characteristics of piggery wastewater for biological nutrient removal. The reaction characteristics were discussed the fraction of organics, the behavior of nitrogen, nitrification, denitrification, and the behavior of phosphorus. The fraction of readily biodegradable soluble COD was 11-12 percent. The ammonia nitrogen was removed via stripping, nitrification, autotrophic cell synthesis, and heterotrophic cell synthesis. The removal percents by each step were 12.1%, 68.9%, 15.0%, and 4.0%, respectively. Nitrification inhibition of piggery wastewater was found to occur at an influent volumetric loading rate over 0.2 NH$_{3}$-N kg/m$^{3}$/d. Denitrification rates were the highest in the raw wastewater and the lowest in the anaerobic effluent. The denitritation of piggery wastewater came out to be possible, and the rate of organic carbon consumption decreased about 10 percent. The phosphorus removed was released in the form of ortho-p in the aerobic fixed biofilm reactor, it was caused by autooxidation. The synthesis and release of phosphorus were related to the ORP and the boundary value for the phase change was about 170mV. In the synthesis phase, the phosphorus removal rate per COD removed was 0.023mgP$_{syn}$/mgCOD$_{rem}$. The phosphorus contents of the microorganism were 4.3-6.0% on a dry weight basis.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.103-111
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• 2000

Ozonation and advanced oxidation($H_2O_2/O_3$) process were investigated under various experimental conditions to improve the efficiency of biological filter used for the treatment of recycled wastewater from aquaculture. Ammonia removal followed the first-order reaction whose reaction rate constant(k) was $2.0{\times}10^{-2}min^{-1}$ in ozonation. The ammonia removal rate increased according as the bicarbonate alkalinity is increased. About 46% $NH_3$ was oxidized by ozone at 200 mg/L as $CaCO_3$. When alkalinity existed in wastewater, ammonia removal rate by advanced oxidation was very low due to the inhibition effect of bicarbonate. However, when initial pH was adjusted to about 8.2 by 0.1 N KOH, ammonia removal rate was improved higher than that by ozonation. Especially. ammonia removal rate was the highest at $H_2O_2/O_3$ of 0.25 and about 90% of ammonia was removed in 30 min at this ratio as pH was maintained over 9. In the case of wastewater containing ammonia and organic constituents, ammonia removal efficiency by both ozonation and advanced oxidation decreased seriously because organic constituents consumed the oxidant faster than ammonia. In addition the optimal $H_2O_2/O_3$ ratio was changed. Like ammonia removal, DOC(dissolved organic carbon) increased for first 10 min and then decreased slowly because the particulate organic constituents were oxidized rapidly and then produce DOC. Even when the ammonia concentration by twice, oxidation of DOC was not retarded.

• Journal of Environmental Health Sciences
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• v.20 no.2
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• pp.22-27
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• 1994

This study is to discuss the factors influenced on the removal efficiency of a high-strength organic wastewaters investigated using the polypropyrene media which appropriate to attach microorganism in the tube type fixed biofilter reactor. The results obtained in the experiment were as follows: 1. The kinetics of reaction rate (k') were 0.125, 0.135, 0.155 varing initial COD 720, 1280, 1630 mg/l in batch reactor. 2. In the range of pH 4.0 ~12.0 was obtained the removal efficiency of COD higher than 85%. It was proved that variation of pH (4.0 ~12.0) was nothing to do with the removal efficiency of substrate in continuous reactor. 3. Temperature to obtain removal efficiency of COD higher than 85% was 10 ~ 40$\circ$C. Removal efficiency of COD was no less than those at high temperature. 4. In the continuous reactor, the volumetric loading of COD for removal efficiency higher than 95% had to be 0.5~1.5 kg COD/m$^3$.d below. And then the HRT was 8 hrs. 5. In comparison with the activated sludge process, the tube type fixed biofilter process was excellent in removal efficiency of substrate and sludge production rate.

• KSBB Journal
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• v.16 no.5
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• pp.466-473
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• 2001

A bacterium was isolated from soils in Suwon, Korea for the purpose of H$_2$S removal using a biofilter system. The isolate was gram-negative, rod-shaped, catalase-positive, motile, and the isolated bacterium showed a positve in utilizing energy sources including citrate, mannitol, sucrose, fructors, and trehalsoe. Based on its biochemical characteristics it was identified as Burkholderia(Pseudomonas) cepacia. The growth rate of the bacterium in thiosulfate medium with yeast extract was 0.15 hr$\^$-1/ and generation time was 4.6 hr. The cell productivity was 8.05 mg/L$.$h and the isolate grew logarithmically up to 12 hr. The maximum rate of sulfur oxidation was 0.18 g-S/L$.$h. The optimum pH and temperature for the growth of the bacterium were 7.0 and 30$\^{C}$, respectively. The pH range for the growth of B. cepacia was 5.0-8.0. The oxidation rate of thiosulfate was lowered by a substrate thiosulfate when the concentration was higher than 0.12 M. both growth rate and sulfur oxidation rate of Burkholderia(Pseudomonas) cepacia was enhanced about 1.5 times with the addition of 0.2% yeast extract. The removal of hydrogen sulfide was investigated by immobilized B. cepacia with Ca-alginate. The maximum rate removal for H$_2$S was 6.25 g$.$㎤ $.$h$\^$-1/ when 12 L/h of flow rate was supplied. From this study suggest the immobilized B. cepacia could have a potential for H$_2$S removal.

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.387-389
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• 2001

• KSBB Journal
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• v.6 no.2
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• pp.115-121
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• 1991

A number of experiments were conducted in order to investigate the COD removal rate according to the biofilm thickness in a Fluidized-Bed Biofilm Reactor(FBBR). The following conditions were fixed during the experiments: superficial upflow velocity was 0.47cm/sec, operating temperature was $22{\pm}1{\circ}C$ and pH was about $7{\pm}0.1$. The synthetic wastewater based on glucose was used as a substrate. The COD removal efficiencies were shown as 73% and 95%, respectively, when organic loading rate was increased from $10kgCOD\;/\;{\textrm{m}^3}$.day to $80kgCOD\;/\;{\textrm{m}^3}$.day. Andrew's model of substrate removal rate which was commonly used in fixed-biofilm reactor was transformed and applied in this FBBR experiment to predict substrate removal rate and gave 85% agreement with the experimental values.