• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.73-82
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• 2023

This study was conducted to investigate the effect of soil physico-chemical properties and crop growth responses for application of biochar derived from substrate with post harvest of oyster mushroom. The biochar was produced at 450~600℃ using a top-light up draft gasifier (TLUD) production system. As a result of elemental analysis, the biochar used was C 76.2%, H 2.5%, N 3.2%, and H/C was 0.39, which met the international certification standards for biocarbons (IBI) below 0.7. The chemical properties were 10.1 for pH, 1.0% for P₂O₅, 1.8% for K₂O, and 2.5% for CaO. The application rates of biochar were 0, 100, 200, 300, and 500 kg/10a. For cultivation of chinese cabbage and welsh onion, soil organic matter (OM), total nitrogen (T-N), total carbon (T-C), Ex.cation K contents and cation exchange capacity (CEC) in the treatments were increased compared to the no treatment. In addition, the bulk density was lowered and the porosity was increased, improving the soil physical properties in the treated soil. The growth of chinese cabbage and green onion increased with the application of biochar, but the yields of chinese cabbage and green onion did not significantly different among the treatments. Soil carbon sequestration in the treatments enhanced with increasing the amount of biochar application. It is expected to apply the biochar derived from spent oyster mushroom substrate in the eco-friendly farm soil management, improving soil physico-chemical properties.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.47-56
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• 2023

This study describes the successful synthesize strategy for the silica nanoparticles utilizing various water sources, including tap, industrial, and stream waters without using deionized water. Also, as-synthesized silica nanoparticles are employed as dispersive materials for the electro-responsive smart fluid application. Specifically, homogeneous silica nanoparticles with sizes of 500-700nm are successfully prepared in large scale at once (ca. 12.0 g) with the described experimental method and showing similar structural and chemical characteristics with silica nanoparticles synthesized using the deionized water. The size of silica nanoparticles are varied according to the ion conductivity differences of tap, industrial, stream water, and deionized water. The size of silica nanoparticles decresed with the increased ion conductivity, indicating the ion suppression of growth of silica nanoparticles. Moreover, as-synthesized silica nanoparticles from various water sources of electro-responsive characteristic are investigated by the smart fluid application. The smart fluids containing silica nanoparticles synthesized by tap, industrial, and stream water exhibited higher shear stress compared to the deionized water, owing to the more rigid fibril-like structures formed by the smaller silica nanoparticles. Conclusively, uniform silica nanoparticles from various water sources without any purification are able to successfully prepared without usage of deionized water and resulting silica nanoparticles manifested higher electro-responsive performance.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.55-62
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• 2017

In this study, we investigated the effect of seaweed (SW) addition on the anaerobic digestion of food waste (FW). Anaerobic batch experiments were carried out at various substrate concentrations (2.5 to 10.0 g VS/L) and mixing ratios (FW:SW=100:0, 75:25, 50:50, 25:75 and 0:100 on VS basis) of FW and SW. The methane yield of FW alone was 394, 377, 276, $49mL\;CH_4/g\;VS_{added}$ at each substrate concentration (2.5 to 10.0 g VS/L). In cases of co-digestion, methane yield decreased (up to 15 %) with increasing mixing ratio of SW at low substrate concentration (2.5 to 5.0 g VS/L), while it increased (up to 240 %) at high substrate concentration (7.5 to 10.0 g VS/L). The synergistic effect was calculated based on the amount of methane generated from the single-feedstock digestion of FW and SW. The synergistic effect was not found at 2.5 and 5.0 g VS/L. However, the synergistic effect increased (up to 25% = synergistic increment/total methane production at 10.0 g VS/L, FW:SW=50:50) with increasing the ratio of seaweed at 7.5 and 10.0 g VS/L. At 10.0 g VS/L of FW alone, the accumulated amount of organic acids was 7,426 mg COD/L, which was decreased to 2,346 mg COD/L by seaweed (FW:SW=50:50) addition. The reason for the synergistic effect was to control the production rate of the organic acids by adding SW that has a relatively lower biodegradability compared to FW.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.13-21
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• 2017

This study was carried out to evaluate the application effects of fish meal liquid fertilizer on soil characteristics and growth of cucumber for organic cultivation. Cucumber in greenhouse was transplanted on March $31^{th}$ in 2016, and the experimental treatments involve six treatments: No fertilizer, 0, 25, 50, and 100 mg/L N application by fish meal liquid fertilizer and chemical fertilizer. In the results of soil chemical property, application of 100 mg/L of fish meal liquid fertilizer showed a significant differences in pH, K, and Mg contents. The soil microbial community varied in relation to the fish meal liquid fertilizer treatments. Microbial biomass was lower in the chemical fertilizer than in the liquid fertilizer treatment. Result of principal component analysis obtained from Ecoplate showed that fish meal liquid fertilizer treatments, no liquid fertilizer, chemical fertilizer, and no fertilizer were divided into distinct groups, with the no fertilizer treatment located furthest from the other treatments. There were no significant differences in plant height of cucumber between the fish meal liquid fertilizer treatments and chemical fertilizer treatments. Also, the cucumber yield did not vary significantly between the concentrations of liquid fertilizers, and there were also no significant differences in the yield among the fish meal liquid and chemical fertilizer treatments. In conclusion, it is suggested that the application of fish meal liquid fertilizer can be used as a additional fertilizer for cucumber production with organic culture in greenhouse.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.131-140
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• 2000

Compostable household wastes(mainly food residues) were composted in a small bin for 30 days, in which compostable household wastes were fed every day and mixed thoroughly under aerobic conditions. Three small bins were employed. In the first bin only recycled compost was composted, in the second, compostable household wastes with recycled compost, and in the third compostable household wastes with recycled compost and vermiculture. The correct decomposition rate of each composting material was calculated during composting. Total reduced rate of the weight after 30 days was 57.32% when composting the compostable household wastes with recycled compost, and 64.71% when composting them with recycled compost and vermiculite. In the case of composting the compostable household wastes with the recycled compost, the total weight reduction rate for a day was 6.81% and the total decomposition rate 6.81%. Their difference was not great. But in the case calculated with only compostable household wastes the total weight reduction rate was 56.34% and the decomposition 6.79%. When compostable household wastes were composted with the recycled compost and vermiculite, the total weight reduction rate was 64.99% and the decomposition rate 1.48%, but the total weight reduction 4.36% and the decomposition rate 35.46% when calculated with only compostable household wastes. MgO, $K_2O$ and Cr concentrations in the composting mixture during the early composting time were higher when composted with vermiculite than without it, but organic matter, CaO, NaCl, and $P_2O_5$ concentrations were contrarily diluted because of their lower concentration of vermiculite when compostable household wastes were composted with vermiculite.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.120-129
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• 2003

The anodic alumina is synthesized using 0.3M oxalic acid and the barrier layers of the anodic alumina are removed using the 20wt% $H_2SO_4$ solution. The structure of the anodic alumina is analyzed by XRD and SEM. It is observed by SEM that the size of anodic alumina pore is about 60nm. And the uniformity of the anodic alumina surface under the 20wt% $H_2SO_4$ solution is poorer than the unifomity of the the normal anodic alumina surface. The anodic alumina and the carbon are used cathode and anode in$Cd(NO_3)_2{\cdot}4H_2O$, $Co(NO_3)_2{\cdot}6H_2O$ and $PbSO_4$ solutions. In this study, the constant D.C. electrical current is flowed in each solution for 24hours. It is found that the voltages so far as 4.6, 3.4 and 5.1V at $Cd(NO_3)_2{\cdot}4H_2O$, $Co(NO_3)_2{\cdot}6H_2O$ and $PbSO_4$ solutions increase with increasing the flowing current time and after the voltage does not change which values are 4.2, 2.7 and 2.4V, respectively. The amount of metal ions in solutions decrease with increasing the flowing current time until the flowing current time is 18hours and the metals are formed at the surface of anodic alumina. After the metal ions are removed using the anodic alumina, and $Cd^{2+}$, $Co^{2+}$ and $Pb^{2+}$ ions are removed again using flow cell with retriculate vitreous carbon(RVC) working electrode. The concentration of $Cd^{2+}$, and $Co^{2+}$ions decrease until the flowing time of the solutions is 20minutes and the concentration of $Pb^{2+}$ ion decreases until that time is 30minutes. In this case, the removal effects of $Cd^{2+}$, $Co^{2+}$ and $Pb^{2+}$ ions are 34.78, 28.79 and 86.38%, respectively. And it is possible that both $Cd^{2+}$ and $Co^{2+}$ions are adsorbed in pore of RVC at the same time and the removal effects of $Cd^{2+}$ and $Co^{2+}$ions are 32.30 and 31.37%.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.2
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• pp.17-28
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• 2022

The application of supplemental activated biochar pellet fertilizers (ABPFs) was evaluated by investigating key factors such as changes of surface paddy water and soil chemical properties and rice growth responses during the growing season. The treatments consisted of control, activated rice hull biochar pellet (ARHBP-40%), and activated palm biochar pellet (APBP-40%) applications. It was shown that the lowest NH₄⁺-N and PO₄^--P concentrations were observed in surface paddy water to the ARHBP-40%, while the NH₄⁺-N concentration in the control was abruptly decreased until 30 days after transplant in the soil. However, the lowest NH₄⁺-N concentration in the blended biochar application was 9.18 mg L^-1 at 1 day of transplant, but its ABPFs application was observed to be less than 1 mg L^-1 at 56 days after transplant. The lowest PO₄^--P concentration in paddy water treated ARHBP-40% ranged from 0.06 mg L^-1 to 0.08 mg L^-1 until 30 days after transplant among the treatments. For the paddy soil, the NH₄⁺-N concentration in the control was abruptly decreased from 177.7 mg kg^-1 to 49.4 mg kg^-1, while NO₃^--N concentration was highest, 13.2 mg kg^-1 in 14 days after transplant. The P₂O₅ concentrations in the soils increased from rice transplants until the harvesting period regardless of the treatments. The highest K₂O concentration was 252.8 mg kg^-1 in the APBP-40% at 84 days after transplant. For the rice growth responses, plant height in the control was relatively high compared to others, but grain yield was not significantly different between the control and ARHBP-40%. The application of ARHBP-40% can minimize nitrogen and phosphorous application rates into the agro-ecosystem.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.58-72
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• 2009

In this study, the organic matter and biomass was characterized by using respirometry based on ASM No.2d (Activated Sludge Model No.2d). The activated sludge models are based on the ASM No.2d model, published by the IAWQ(International Association on Water Quality) task group on mathematical modeling for design and operation of biological wastewater treatment processes. For this study, OUR(Oxygen Uptake Rate) measurements were made on filtered as well as non-filtered wastewater. Also, GC-FID and LC analysis were applied for the estimation of VFAs(Volatile Fatty Acids) COD(S_A) in slowly bio-degradable soluble substrates of the ASM No.2d. Therefore, this study was intended to clearly identify slowly bio-degradable dissolved materials(S_S) and particulate materials(X_I). In addition, a method capable of determining the accurate time to measure non-biodegradable COD(S_I), by the change of transition graphs in the process of measuring microbial OUR, was presented in this study. Influent fractionation is a critical step in the model calibrations. From the results of respirometry on filtered wastewater, the fraction of fermentable and readily biodegradable organic matter(S_F), fermentation products(S_A), inert soluble matter(S_I), slowly biodegradable matter(X_S) and inert particular matter(X_I) was 33.2%, 14.1%, 6.9%, 34.7%, 5.8%, respectively. The active heterotrophic biomass fraction(X_H) was about 5.3%.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.2
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• pp.107-120
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• 2005

To study the development of solid waste compost to use sewage sludge and paper mill sludge for reclaiming damage soil in forest, the changes of temperature, moisture, chemical properties, heavy metals and harmful compound during the aerobic decomposition were investigated, and the compost decomposition of final products investigated the round paper chromatography method and G.I(Germination index) value. The results were summarized as follows. Temperature was changed a little during early 5days because of air temperature too low. That was rapidly increased to over $50^{\circ}C$ at 4days after first turning and then decreased gradually fallen to $40{\sim}50^{\circ}C$ at 15days after aerobic decomposition in A and C treatments. The second turning was conducted at 18 days after aerobic decomposition, and then the temperature was little changed. At the compare first with terminal product, The moisture content was decreased all treatments but the change was little in A and B treatments. pH was decreased to below 1 in all treatments. EC was increased to below 5dS/m. The content of total carbon, C/N ratio, $NH_4{^+}-N$ were decreased with 4~7%, below 8 and below 500mg/kg in all treatments, respectively. The content of total nitrogen, $NO_3{^-}-N$, CEC were increased with below 0.5%, below 173mg/kg and over $30cmol^+/kg$ in all treatments, respectively. The content of heavy metals and harmful compound were similar during aerobic decomposition and suited to standard of 가 grade in all treatments. The result of round paper chromatography method and G.I. value, The C treatment concluded well aerobic decomposition. Especially, the G.I. value in C treatment was 64.1 and 66.2 at cabbage and grass, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.3
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• pp.117-125
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• 2002

This study experimented a possibility of advanced treatment through microorganism that converts $NH_3-N$ to organic nitrogen in wastewater contaminated by ammoniac nitrogen unlike conventional nitrogen removal process. After distributing three kinds of special bacteria that use $NH_3-N$ as a substrate, when those bacteria were cultured in no salt condition and salt condition (3% NaCl), M11 showed better growth in salt condition and M12 showed better growth in no salt condition. However M7l grew well in both no salt condition and salt condition. In the test of glucose effect, maximum growth and removal rate were observed in glucose concentration of 5g/L but in high concentration (1000mg/L as $NH_3-N$) of $NH_3-N$ growth and removal rate were low. Removal rate was the highest in 100mg/L $NH_3-N$ and the fact that concentration of $NO_2-N$ and $NO_3-N$ didn't increase assumed $NH_3-N$ was converted to organic nitrogen. Optimum concentration of $K_2HPO_4$ for phosphorous supply and buffer was 5g/L. Special bacteria distributed could use $NO_2-N$ and $NO_3-N$ as well as $NH_3-N$ as substrates. This study showed that when growth rate of bacteria was high removal rate also was high. It is possible to apply as a method to treat wastewater polluted by $NH_3-N$.