• ALGAE
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• v.19 no.2
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• pp.115-122
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• 2004

The epilithic algal communities on the artificial substrata (unglazed ceramic tiles) were investigated from 5th July to 24th July 1999 with two or three days intervals for elucidating the effects of the experimental acidification. They were harvested inside the mesocosm with and without the acid treatment on Togyo reservoir within the Civilian Passage Restriction Line near Demilitarized Zone (DMZ) in Korea. After the colonization of epilithic algal community, their standing crops revealed different patterns outside and inside the mesocosm. However the time lapse of 5 days was observed on the inside with acid treatment. The dominant species were different: Achnanthes minutissima was outside but Coenochloris polycocca was inside and inside with acid treatment. The differences in floral composition were also found. Achnanthes minutissima which has been the most important species in the colonization by the epilithic algal community of the mesocosm was less important at the lower pH. Coenochloris polycocca is a species well adapted to low pH.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.133-138
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• 2001

Increased base cation loss and Al mobilization, a consequence of soil acid neutralization responses, are common in air polluted areas showing forest decline. The prediction models of acid neutralization responses were developed by using indicators of soil acidification level(pH, and base saturation) in order to assess the forest soil sensitivity to acidification. The soil acidification level was greatest in Namsan followed by Kanghwa, Ulsan, and Hongcheon, being contrary to regional total $ANC_H$ pattern through soil columns leached with additional acid ($16.7mmol_c\;H^+/kg$), Both base exchange and Al dissolution were main acid neutralization processes in all study regions. There were low base exchange and high Al dissolution in the regions of the low total $ANC_H$. The $ANC_M$ by sulfate adsorption was greatest in Hongcheon compared with other regions even though the AN rate was very low as 6.4%. Coefficients of adjusted determination of simple and multiple regression models between soil acidification level indicators and the acid neutralization responses were more than 0.52(p<0.04) and 0.89(p<0.01), respectively. The result suggests that soil pH and base saturation are available indicators for predicting the acid neutralization responses. These prediction models could be used as an useful method to measure forest soil sensitivity to acidification.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.397-402
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• 2006

The treatment characteristics of leachate produced from pretreatment facilities like composting and feeding were investigated in a mesophilic anaerobic treatment. Experiments were performed in two phase which were acidification and methane fermentation. The acidification step was optimized for OLR from 1 to $4.5kg\;COD/kg\;VS{\cdot}day$ without adding NaOH. As experiment dates became longer, the solubilization ratio of particles increased up to 30% over 70 days. TVA was generated up to maximum 9,970mg HAc/L at OLR of $2kg\;COD/kg\;VS{\cdot}day$. But TVA was generated to minimum 6,519mg HAc/L at OLR of $4.5kg\;COD/kg\;VS{\cdot}day$. The acidification ratio was analyzed from 10.9% to 3.8% at OLR of $2kg\;COD/kg\;VS{\cdot}day$ and $4.5kg\;COD/kg\;VS{\cdot}day$ respectively. After 55 days, salt contents in the acid fermenter were accumulated and stabilized at the concentration of 3,150mg/L. Sodium ion($Na^+$) concentration was stabilized at 1,300mg/L. At methane fermentation step, biogas was generated up to 750ml and 937.5ml at the feeding volume of 20ml and 25ml respectively for acid fermented liquid during 25 days. About 80% of total biogas was generated during early 15 days and 95% were generated during 18 days respectively. After 25 days of the BMP test, acetic acid was removed approximately 97% and 98%, in case of those two experimental conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.3
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• pp.212-216
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• 2015

This study was conducted to assess the efficacy of slurry acidification in reducing ammonia emission from manure storage and application. The non-fermented cattle manure (NFC) and swine slurry (SS) were acidified by sulfuric acid and stored in an acryl chamber for 168 and 96 hours, respectively. Ammonia emitted from the chamber was collected using an acid trap system. The amount of ammonia emission was significantly reduced when the livestock manures were treated with sulfuric acid. The absolute amount of ammonia in NFC increased rapidly starting from 48 h and 72 h in the control (pH 8.6) and acidified NFC (pH 6.5), respectively. The absolute amount of ammonia was the highest at 96 h ($3.65g\;kg^{-1}h^{-1}$) in the control and at 144 h ($2.34g\;kg^{-1}h^{-1}$) in pH 6.5 NFC. The cumulative ammonia content in the control continuously increased until 96 h and was maintained until 168 h, whereas the increase rate of emission gas accumulation in acidified NFC was much less throughout the experimental period. Acidification of SS mitigated ammonia emission as proven in NFC. The cumulative amount of ammonia emission was decreased by 49.4% and 92.3% in the acidified SS at pH 6.5 and pH 5.5, respectively, compared to the control at 96 h after treatment. These results indicate that ammonia emission can be significantly reduced by sulfuric acid treatment of livestock manure during processing and the subsequent land application.

• ALGAE
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• v.28 no.2
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• pp.173-183
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• 2013

Sodium hypochlorite (NaOCl) is widely used to disinfect seawater in power plant cooling systems in order to reduce biofouling, and in ballast water treatment systems to prevent transport of exotic marine species. While the toxicity of NaOCl is expected to increase by ongoing ocean acidification, and many experimental studies have shown how algal calcification, photosynthesis and growth respond to ocean acidification, no studies have investigated the relationship between NaOCl toxicity and increased $CO_2$. Therefore, we investigated whether the impacts of NaOCl on survival, chlorophyll a (Chl-a), and effective quantum yield in three marine phytoplankton belonging to different taxonomic classes are increased under high $CO_2$ levels. Our results show that all biological parameters of the three species decreased under increasing NaOCl concentration, but increasing $CO_2$ concentration alone (from 450 to 715 ${\mu}atm$) had no effect on any of these parameters in the organisms. However, due to the synergistic effects between NaOCl and $CO_2$, the survival and Chl-a content in two of the species, Thalassiosira eccentrica and Heterosigma akashiwo, were significantly reduced under high $CO_2$ when NaOCl was also elevated. The results show that combined exposure to high $CO_2$ and NaOCl results in increasing toxicity of NaOCl in some marine phytoplankton. Consequently, greater caution with use of NaOCl will be required, as its use is widespread in coastal waters.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.315-322
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• 2007

The purpose of this study was to investigate the biodegradability and performance of organic removal and methane production rate when treating piggery wastewater using a granule of two-phase anaerobic process applied UASB. BMP test was conducted as simple means to monitor relative biodegradability of substrate and to determine methane production of an organic material. The two-phase anaerobic process is consisted of a continuous flow stirred-tank reactor (CFSTR) for the acidification phase and an Upflow Anaerobic Sludge Blanket reactor (UASB) for the methanogenesis. The acidogenic reactor played key roles in reducing the periodically applied shock-loading and in the acidification of the influent organics. A stable maximum biogas production rate was 400mL. The methane contents ranged from 73 to 80% during the experimental period. It is known that most of the removed organic matter was converted to methane gas, and the produced biogas might be high quality for its subsequent use.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.431-436
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• 2001

The extractable sulfate content and sulfate adsorption capacity in soils of four Pinus densiflora stands were measured to assess the soil acidification sensitivity to acid deposition. The soluble sulfate content in organic horizon which reflects the previous deposition of sulfur oxides was much higher for Namsan and Ulsan than Kanghwa and Hongcheon. In mineral soils, however, the extractable sulfate content was the greatest for Ulsan followed by Kanghwa, Namsan and Hongcheon due to the interactive effect of previous deposition and soil adsorption of sulfate. Adsorption rates of specifically adsorbed sulfate(proportion of insoluble sulfate to total extractable sulfate) for Namsan, Kanghwa and Ulsan affected by acid deposition were 16.6%, 56.8% and 37.4%, respectively, so that the soil in Namsan had the highest acidification sensitivity to acid deposition. For sulfate adsorption isotherm($RE=mX_i-b$), the significantly positive correlations between added sulfate($X_i$) and adsorbed sulfate(RE) were found only in mineral soil(p<0.05) over all regions. The regression coefficient(m) that means soil sulfate adsorption capacity by 0-30cm depth was 0.16, 0.24, 0.25 and 0.32 in $mmol_c\;kg^{-1}$ for Namsan, Kanghwa, Ulsan and Hongcheon, respectively, indicating that soil acidification sensitivity is the highest for Namsan. The added sulfate($X_i$) that could make the adsorbed sulfate(RE) null was 3.81, 2.17, 4.96 and 0.65 in $mmol_c\;kg^{-1}$ for Namsan, Kanghwa, Ulsan and Hongcheon, respectively and the values of former three regions considerably exceeded the realistic sulfate deposition.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.331-339
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• 2007

The purpose of this study was to investigate the biodegradability and performance of organic removal and methane production rate when treating piggery wastewater using a pilot scale two-phase anaerobic system operated up to a volumetric rate of $10m^3/day$. The pilot scale two-phase anaerobic process is consisted of a continuous-flow stirred-tank reactor (CFSTR) for the acidification phase and an Upflow Anaerobic Sludge Blanket reactor (UASB) for the methanogenesis. The acidogenic reactor played key roles in reducing the periodically applied shock-loading and in the acidification of the influent organics. The acidogenic CFSTR was operated at organic loading rates (OLR) between 1.8 and $14.4kgCOD/m^3{\cdot}day$, and the UASB reactor was operated between 0.5 and $5.6kgCOD/m^3{\cdot}day$. A stable maximum biogas production rate was $81m^3/day$ and the methane conversion rate of the organic matter varied from 0.30 to $0.42L\;CH_4/g\;COD_{removed}$(0.40) at hydraulic retention time (HRT) above 3.5days. The methane contents ranged from 73 to 82% during the experimental period. It is known that most of the removed organic matter was converted to methane gas, and the produced biogas might be high quality for its subsequent use.

• Animal Bioscience
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• v.34 no.9
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• pp.1479-1490
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• 2021

Objective: Our recent findings confirmed the effectiveness of sodium metabisulfite (SMB) in controlling the growth of undesirable microorganisms in fruit and vegetable discards (FVD); however, lactic acid bacteria (LAB) are susceptible to its antibacterial effects. Two series of experiments were conducted to enable the survivability of LAB during silage fermentation of a total mixed ration (TMR) containing SMB-treated FVD. Methods: In Exp. 1, the objective was to isolate a strain of LAB tolerable to the toxic effect of SMB. In Exp. 2, the SMB load was minimized through its partial replacement with a chemical mixture (CM) based on sodium benzoate (57%), potassium sorbate (29%), and sodium nitrite (14%). FVD was treated with SMB + CM (2 g each/kg biomass) and added to the TMR at varying levels (0%, 10%, or 20%), with or without KU18 inoculation. Results: The KU18 was screened as a presumptive LAB strain showing superior tolerance to SMB in broth medium, and was identified at the molecular level using 16S rRNA gene sequence analysis as Lactobacillus plantarum. Inoculation of KU18 in TMR containing SMB was not successful for the LAB development, biomass acidification, and organoleptic properties of the resultant silage. In Exp. 2, based on the effectiveness and economic considerations, an equal proportion of SMB and CM (2 g each/kg FVD) was selected as the optimal loads for the subsequent silage fermentation experiment. Slight differences were determined in LAB development, biomass acidification, and sensorial characteristics among the experimental silages, suggesting the low toxicity of the preservatives on LAB growth. Conclusion: Although KU18 strain was not able to efficiently develop in silage mass containing SMB-treated FVD, the partial substitution of SMB load with the CM effectively alleviated the toxic effect of SMB and allowed LAB development during the fermentation of SMB + CM-treated FVD in TMR.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.353-361
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• 2013

An in situ mesocosm experiment was designed to investigate how exposure to ocean acidification by increased carbon dioxide affected the growth of juvenile oliver flounder (Paralichthys olivaceus). A total of 447 individuals were reared in the mesocosm experimental devices deployed at sandy-muddy bottom in the southern coast of East Sea for 43 days and divided into two groups: treatment group (223 individuals, $6.32{\pm}0.75$ cm, high-$CO_2$ environment) and control group (224 individuals, $6.34{\pm}0.84$ cm, natural $CO_2$ environment). The average values of pH and $CO_2$ concentration in the treatment device were $7.63{\pm}0.13$ and $1660{\pm}540$ ${\mu}atm$, respectively, while those in the control device were $8.07{\pm}0.05$ and $514{\pm}65$ ${\mu}atm$, respectively. There was no significant difference in mortality rate between treatment and control group, and the mortalities in two groups gradually decreased during the study period. But, the increase of size and weight of juvenile oliver flounder was higher in control group than treatment group, i.e., weight gain or growth rate was higher in control group. These results suggested that high $CO_2$ environments could have a significant negative influence on the early growth of juvenile oliver flounder.