• Journal of Animal Environmental Science
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• v.14 no.2
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• pp.129-138
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• 2008

This study was carried out to investigate the operating characteristics, water balance and chemical properties of compost during the composting with pig slurry on-farm trial. The composting plant with sawdust pile filteration was done in a forced aeration inside a house and equipped with a turning machine moving on a rails. The composting pit was 4.6m wide, 53m long and the maximum height was 2m. A field scale aerobic composting facility was tested the composting efficiency of high moisture pig slurry. The sawdust materials remained 6 months. Pig slurry was added to compost pile every other day during 6 months run. The temperature in compost pile and compost house, and input and output of moisture were measured during composting process. The result are summarized as follows; 1. The temperature of compost was varied in range of at $22.4^{\circ}C{\sim}71.1^{\circ}C$. After turning, the composting temperature decreased to $50^{\circ}C{\sim}36^{\circ}C$ during $3{\sim}5$ hours, and then raised to $64.5^{\circ}C$ 2. The temperature of compost house was maintained $20^{\circ}C{\sim}30^{\circ}C$, and relative humidity was varied in range of $50{\sim}99%$. 3. BOD, CODcr and SS of leachate water was reduced 89.5%, 81.2%, 97.5%, respectively. 4. The content of heavy metal in the final compost was lower those of Korea standards. 5. The amount of effluent was 10.2%. Total evaporation during composting Period were 74.8%. The amount of slurry per $1m^3$ sawdust was $3.16m^3$ without treatment of effluent output.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.124-130
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• 2006

Rice plant extracts of brown planthopper (BPH) resistant rice varieties, Jangseongbyeo (JSB) and Hwacheongbyeo (HCB) at different growth stages (seedling, tillering, heading and ripening) were sequentially fractioned using hexane, ethyl ether, ethyl acetate, butanol, and distilled water. The extracts were applied to BPH susceptible rice variety, Dongjjnbyeo (DJB), to investigate the insecticidal and repellent effects against BPH. BPH insecticidal effects were not clearly observed with almost all of the extract fractions obtained from both JSB and HCB varieties for 12 h, whereas the ethyl ether and hexane extract fractions showed about 10 to 30% of BPH mortality in 24 to 48 h of application periods. An effective BPH repellent activity was found with the applications of ethyl ether extract fractions obtained from JSB variety. The extract fractions obtained from HCB variety did not show any different repellence among the various fractions. The BPH repellent effects of the extract fractions obtained at different growth stages of either JSB or HCB varieties did not show any correlations. The effect of ethyl ether fraction on BPH repellent was continually increased by 30 h after treatment and thereafter decreased. In addition, the first sub-fraction separated by a flash column chromatography eluted with chloroform:methanol (9:1, v/v) from the BPH effective ethyl ether faction in JSB variety might be meaningful to repel BPH from BPH susceptible target rice plants. The results indicated that the ethyl ether fraction obtained from JSB was higher in repellent activity than in insecticidal activity, and suggesting that there might be specific substance(s) in the first sub-fraction (sF1) of the ethyl ether fraction in JSB that could provide repellent activity against BPH.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.514-520
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• 2014

In this study, the production potential of alternative coagulant ($Al_2(SO_4)_3$ solution) having the identical coagulation activity with respect to the commercial coagulant was investigated. The raw material of alternative coagulant was a spent catalyst including aluminium (waste activated alumina) generated in the manufacturing process of the polymer. The alternative coagulant was produced through a series of processes: 1) intense heat and grinding, 2) chemical polymerization and substitution with $H_2SO_4$ solution, 3) dissolution and dilution and 4) settling and separation. To determine the optimal operating conditions in the lab-scale autoclave and dissolver, the content of $Al_2O_3$ in alternative coagulant was analyzed according to changes of the purity of sulfuric acid, reaction temperature, injection ratio of sulfuric acid and water in the dissolver. The results showed that the alternative coagulant having the $Al_2O_3$ content of 7~8% was produced under the optimal conditions such as $H_2SO_4$ purity of 50%, reaction temperature of $120^{\circ}C$, injection ratio of $H_2SO_4$ of 5 times and injection ratio of water of 2.3 times in dissolver. In order to evaluate the coagulation activity of the alternative coagulant, the Jar-test was conducted to the effluent in aerobic reactor. As a result, in both cases of Al/P mole of 1.5 and 2.0, the coagulation activity of the alternative coagulant was higher than that of the existing commercial coagulant. When the production costs were compared between the alternative and commercial coagulant through economic analysis, the production cost reduction of about 50% was available in the case of the alternative coagulant. In addition, it was identified that the alternative coagulant could be applied at field wastewater treatment plant without environmental problem through ecological toxicity testing.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.85-97
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• 2012

To investigate the usefulness of freshwater alga Water-net (Hydrodictyon reticulatum, HR) as resources for production of fermentable sugars, the easiness of enzymatic saccharification was evaluated at first. When 6 plant materials (HR, Spirulina, Chlorella, Scenedesmus, Cladophora, Corn stover) were enzymatically hydrolyzed with 2% solid loading at the same condition, HR showed the highest ratio of saccharification based on glucose production. No milled HR was also completely saccharified at the amounts of optimal enzyme mixture. Glucose yield was not changed though the citrate buffer strength for saccharification was decreased from 0.1 M to 0.1 mM. Only about 10% yield reduction was observed compared to that of $120^{\circ}C$ treatment when HR was enzymatically hydrolyzed at room temperature. The saccharification was normally occurred at $37^{\circ}C$ and pH 6.5 which is general growth condition of fermentable microrganisms, suggesting that HR have a biomass characteristics applicable for the simultaneous saccharification and fermentation. The saccharification was occurred by more than 70~80% of one of the best condition although the supplied enzyme amounts was reduced to 1/10 volume. And the glucose yield by enzymatic hydrolysis was not decreased by 10% HR solid loading and began to decrease at more than 15% solid contents. Above these results show that HR is an interesting algal biomass which is relatively easy to be saccharified by hydrolyzing enzymes. In addition, HR is a flilamentous alga and very easy to be collected. Therefore, HR seems to be an useful and valuable resources in the economical production of fermentable sugars for manufacture of bio-chemical products.

• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.154-161
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• 1992

This experiment was carried oui to determine the relativeness between growth, yield characters and bio-informations as influenced by the spray and rest time intervals of nutrient solution. Tomato(Lycopersicon esculentum Mill.) were grown in aeroponic system on a misting schedule of continuously 60 sec, 30 sec and 10 sec at 10 min intervals with full strength Yamazaki's solution recommended for tomato production. The results obtained were as follows : 1. Leaf area was highest in the plot of 30 sec spray and 10 min rest while the forest one was the plot of 60 sec spray and 10 min rest. Growth characteristics in terms of dry weight of each organ, number of flower, number of flower setted and fruit dry weight were greater in the plot of 30 sec spray and 10 min rest than the other treatments. 2. The number of flower increased with decreasing dry weight but number of flower sorted was not significantly different among treatment except for the plot of 60 sec spray and 10 min rest. 3. Leaf dry weight and fruit dry weight were highly correlated so that 30 sec spray and 10 min rest plot which is the highest fruit dry weight showed the largest leaf area. Continuously sprayed plot reduced markedly the fruit dry weight compared with leaf area. Optimum spray and rest time of nutrient solution in the range of this experiment was determined as 30 sec spray and 10 min rest. 4. Solar radiation within glasshouse during daytime reduced severely compared with outdoor one and air temperature within greenhouse was higher than the leaf temperature of tomato plant. The changes of environmental factors, solar radiation, temperature were accompanied with the sensitive change of bio-informations of tomato leaf Especially differences of spray intervals of nutrient solution affected greatly to the changes of bio-informations : leaf water potential, stomatal resistance and leaf temperature etc. 5. The changing patterns of leaf growth as influenced by the spray and rest intervals of nutrient solution were closely related to the leaf water potential, stomatal resistance and leaf temperature. Feasibility was demonstrated that measurement of bio-information of tomato leaf as influenced by the change of environmental factors could be expected to the amount of growth and fruit yield.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.47-54
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• 2015

This research was conducted to investigate the changes in moisture retention capacities of expanded rice-hull (ERH)-based root media and their influences on the growth of mother and daughter plants in vegetative propagation of 'Seolhyang' strawberry. The proportion of water at the container capacity of ERH medium was in the range of 20 to 23%. This range was lower than the 60 to 66% of strawberry-specialized medium, the 30 to 34% of soil mother material (SMM) and the 30 to 35% of loamy sand. The moisture content of ERH was reduced to 10 to 12% at 8 hours after irrigation, and there were large variations among replications of ERH medium. Among four kinds of root media formulated to contain ERH, the medium of ERH + coir dust (CD) (55 + 45%, v/v) had 26.5 and 32.5% water contents at 20 and 40 days after irrigation to daughter plants, respectively. The m edia o f ERH + sandy loam (S L) and E RH + S MM showed similar trends i n moisture r etention. The pH and EC i n the all root media tested were in the range of 6.7 to 7.1 and 0.03 to $0.08dS{\cdot}m^{-1}$, respectively. The pHs and ECs measured at 20 and 40 days after irrigation were not significantly different in each root medium. Among the root media formulated to contain ERH, the growth of daughter plants was the highest in the treatment of ERH + SL (55 + 45%, v/v). As the blending rate of coir dust was elevated in the ERH + CD media, moisture retention capacity increased gradually, but the growth of daughter plants became worse even though the medium showed higher moisture retention capacity than other root media tested. The growth of roots and aboveground tissues of daughter plants deteriorated in the root media formulated by blending ERH + perlite (PE) at various ratios. The results of this research suggest the optimum formulations of root media and management of moisture content in raising of strawberry daughter plants when ERH is a component of root media.

• Applied Biological Chemistry
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• v.8
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• pp.87-93
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• 1967

1) For the micro-analysis of mercury in plant materials, the method of Furutani was shown to be the simplest and most efficient way and the recovery of the assay was about 98%. 2) When the rice grain was soaked in 1/1000 diluted solution of organo-mercury fungicide for 8 hours at the end of March, the amounts of mercury residues in the brown rice and unhulled rice were 8.8 to $9.5\;{\mu}g/g$ seeds and 10.1 to $10.7\;{\mu}g/g$ seeds, respectively. 3) By washing the treated rice seeds with running water for three days, tile residual mercury concentration was reduced to 1/4 to 1/5; thus the mercury residues were 1.86 to $1.92\;{\mu}g/g$ for brown rice and 1.96 to $2.93\;{\mu}g/g$ for unhulled rice. 4) The residual mercury was present more in the unhulled rice than in the brown rice, either before or after washing of the treated seeds. 5) Among the different rice varieties, no difference was observed in mercury residues by seed treatment and washing.

• Korean Journal of Microbiology
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• v.49 no.2
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• pp.137-145
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• 2013

This study was performed at 2 sites of Nak-Dong River to investigate the changes of nitrifiers depending on the presence and absence of organic pollutants (due to the effluents of domestic wastewater treatment plant, WWTP). Conventional chemical parameters such as T-N, $NH_4$-N, $NO_2$-N, $NO_3$-N were measured and the quantitative nitrifiers at the 2 sites were analyzed comparatively by fluorescent in situ hybridization (FISH) with NSO190 and NIT3, after checking the presence of gene amoA of ammonia oxidizing bacteria (AOB) and 16S rDNA signature sequence for Nitrobacter sp. that belongs to nitrite oxidizing bacteria (NOB). Also ${\alpha}{\cdot}{\beta}{\cdot}{\gamma}$-Proteobacteria were detected using FISH to get a glimpse of the general bacterial community structure of the sites. Based on the distribution structure of the ${\alpha}{\cdot}{\beta}{\cdot}{\gamma}$-Proteobacteria and the measurement of nitrogen in different phases, it could be said that the site 2 was more polluted with organics than site 1. Corresponding to the above conclusion, the average numbers of AOB and NOB detected by NSO160 and NIT3, respectively, at site 2 [AOB, $9.3{\times}10^5$; NOB, $1.6{\times}10^6$ (cells/ml)] was more than those at site 1 [AOB, $7.8{\times}10^5$; NOB, $0.8{\times}10^6$ (cells/ml)] and also their ratios to total counts were higher at site 2 (AOB, 27%; NOB, 34%) than those at site 1 (AOB, 18%; NOB, 23%). Thus, it could be concluded that the nitrification at site 2 was more active due to continuous loading of organics from the effluents of domestic WWTP, compared to site 1 located closed to raw drinking water supply and subsequently less polluted with organics.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.574-579
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• 2010

Waste nutrient solution (WNS) that was the drained nutrient solution of Horticultural Research Institute of Japan for culture tomato in perlite hydroponics showed $1.9-2.4dS{\cdot}m^{-1}$ of EC and 5.7-7.1 pH from April to July. Although ${NH_4}^+-N$ concentration of WNS decreased remarkably, the other nutrients did not change significantly, as compared with supplied solution. There were no significant differences in plant height, stem diameter, and the other growth characteristics of tomato plants grown by 2 fertigation nutrient solutions; BHF (Bountiful Harvest Fertilizer, 10% of N, 13% of $PO_4$, 13% of K, 0.05% of B, 0.05% of Zn, and 0.0023% of Cu that made in Korea) and Megasol (11% of N, 8% of $PO_4$, 34% of K, 0.032% of Mn, 0.002% of B, 0.048% of Fe, 0.0122% of Zn, and 0.0023% of Cu that made in Belgium.); however, the chlorophyll content of tomato leaf was highest in WNS. The fresh and dry weight of tomato plants were higher in 3 fertigation treatments than irrigation of tap water, while there were no significant differences in fresh and dry weight among the 3 fertigation treatments. The mineral content of tomato leaf also did not show any differences among the 3 fertigation treatments and any regular tendency in all minerals. Total yield, fruit weight and fruit numbers of tomato were higher in WNS, followed by Megasol, BHF and control, although there were not any difference among the 3 fertigation nutrient solution treatments. BER(blossom-end rot)of tomato fruits decreased in fertigation treatments, especially, fruits grown in WNS and BHF showed lower BER. However, the transpiration rate of leaf was higher in control, followed by BHF, WNS and Megasol, The fruit size and soluble solids content was higher in 3 fertigation nutrient treatments than control. These results suggest that WNS can be used for fertigation solution in tomato because yield and quality of tomato fruit grown in WNS fertigation treatment were similar to those in 2 fertigation nutrient solutions treatments(BHF, Megasol).

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.673-678
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• 2009

High-rate phosphorous removal by PAC (poly aluminum chloride) coagulation of A2O effluent was investigate to meet the stringent requirement of wastewater discharge from municipal wastewater treatment plant. A series of jar tests were conducted to find optimum coagulation condition and to enhance removal efficiency. The optimum volumetric concentration of PAC was 30 ppm (2.81mol Al/mol P by mol ratio). Only 17.2% of soluble P was removed for 30 minutes' settling without PAC addition, while this increased to 30.3% by dosing 10ppm PAC. It even increased conspicuously from 49.3% to 88.4% by increasing PAC dose from 20 ppm to 30 ppm. 92.4% of total P was removed by 30 ppm PAC, and the effluent concentration (0.3 mg/L) was acceptable for discharge. The optimum value of coagulation time, settling time, and pH were 4minutes, 20 minutes, and 7.0, respectively. It was not necessary to control pH of raw sample whose pH was 7.0. Soluble P removal was remarkably enhanced at pH 7.0. This implied that sweep floc formation by $Al(OH)_3$ was the main mechanism of coagulation for soluble P removal. Influent and effluent of secondary clarifier were tested for coagulation, and the effluent was better for high-rate P removal. It resulted in 0.18 mg/L of P and 95.4% of P removal by coagulation. It was favorable to recycle the treated water to coagulation tank and the optimum recycle ratio was 0.3.