• Microbiology and Biotechnology Letters
• /
• v.45 no.4
• /
• pp.291-298
• /
• 2017

We compared the ingredients present in freeze-dried ground food samples with those present in hot air-dried and ambient ground food samples to optimize processing conditions for preserving nutrients in and for improving the ingestion of different foods. The freeze-dried ground sample of black bean showed 4.57% higher retention rate than the ambient ground sample of black bean. Mineral content was also significantly different between these two samples. Moreover, the freeze-dried ground sample of black bean contained 11.54% higher content of ${\beta}$-carotene, a precursor of vitamin A, than the ambient ground sample of black bean. Total anthocyanin content was 453.49 mg in the freeze-dried ground sample of Aronia compared with 158.98 mg in the ambient ground sample of Aronia. Contents of ${\beta}$-carotene and niacin increased by 129.47% and 439.39%, respectively, in the freeze-dried ground sample of grapefruit. Retention rates of proteins, carbohydrates, and niacin were 107.74%, 103.87%, and 156.52%, respectively, in the freeze-dried ground sample of germinated brown rice. Protein digestibility increased by 120.5% and 101.14% in the freeze-dried ground samples of Aronia and black bean, respectively, but did not increase in the freeze-dried ground samples of grapefruit and germinated brown rice.

• Journal of Korean Society of Water and Wastewater
• /
• v.11 no.1
• /
• pp.33-41
• /
• 1997

An attempt was made to enhance anaerobic treatment efficiency by adopting the anaerobic sequencing batch reactor(ASBR) process at a thermophilic temperature. Operational characteristics of the ASBR process were studied using laboratory scale reactors and concentrated organic wastewater composed of soluble starch and essential nutrients. Effects of fill to react ratio (F/R) were examined in the Phase I experiment, where the equivalent hydraulic retention time(HRT) was maintained at 5 days with the influent COD of 10g/L. A continuous stirred tank reactor(CSTR) was operated in parallel as a reference. Treatment efficiency was higher for the ASBRs because of continuous accumulation of volatile suspended solids(VSS) compared to the CSTR. However, the rate of gas production and organic removal per unit VSS in the ASBRs was much lower than the CSTR. This was caused by reduced methane fermentation due to accumulation of volatile acids(VA), especially for the case of low F/R, during the fill period. When the F/R was high, maximum VA was low and the VA decreased in short period. Consequently, more stable operation was possible with higher F/R. Effects of hydraulic loading rate on the efficiency was studied in the Phase II experiment, where the organic loading rate was elevated to 3333mg/L-d with the F/R of 0.12. Reduction of organic removal along with rapid increase of VA was observed and the stability of reaction was seriously impaired, when the influent COD was doubled. However, operation of the ASBR was quite stable, when the hydraulic loading rate was doubled and a cycle time was adjusted to 12 hour. It is essential to avoid rapid accumulation of VA during the fill period in order to maintain operational stability of the ASBR.

• Environmental Engineering Research
• /
• v.25 no.1
• /
• pp.1-17
• /
• 2020

With benefits to the human health, environment, economy, and energy, anaerobic digestion (AD) systems have attracted remarkable attention within the scientific community. Anaerobic digestion system is created from (bio)reactors to perform a series of bi-metabolism steps including hydrolysis/acidogenesis, acetogenesis, and methanogenesis. By considering the physical separation of the digestion steps above, AD systems can be classified into single-stage (all digestion steps in one reactor) and multi-stage (digestion steps in various reactors). Operation of the AD systems does not only depend on the type of digestion system but also relies on the interaction among growth factors (temperature, pH, and nutrients), the type of reactor, and operating parameters (retention time, organic loading rate). However, these interactions were often reviewed inadequately for the single-stage digestion systems. Therefore, this paper aims to provide a comprehensive review of both single-stage and multi-stage systems as well as the influence of the growth factors, operating conditions, and the type of reactor on them. From those points, the advantages, disadvantages, and application range of each system are well understood.

• Journal of Forest and Environmental Science
• /
• v.34 no.2
• /
• pp.196-198
• /
• 2018

This study aimed to evaluate the effectiveness of jellyfish chips in promoting the survival and growth of Pinus thunbergii seedlings in a coastal area based on a five-year field investigation from 2012 to 2016. Seedling survival rate was significantly higher in the treatment (96%) than in the control (75%) group in 2012. Furthermore, the height of five-year-old seedlings after plantation in 2012 was significantly greater in the treatment (3.41 m) than in the control (2.32 m) group (t=10.151; p-value<0.01). These results revealed that jellyfish chips can improve soil condition by enhancing moisture retention during the early growth stages and supplying nutrients to the seedlings over time. Our findings indicated that jellyfish chips could be used effectively as an organic fertilizer for growing coastal disaster prevention forests.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.5
• /
• pp.426-432
• /
• 2000

Field experiment was performed from August 1996 to December 1999 to examine the feasibility of constructed wetland system for sewage treatment in rural areas. A pilot system was installed in Konkuk University and the effluent of septic tank for school building was used as an influent to the wetland treatment basin. The system was composed of sand and reed, and operated continuously including winter time. Average removal rate of about 70% was observed for BOD, COD, and SS, about 50% for T-P, and about 25% for T-N. The reason for poor T-N removal might be due to high loading rate and short retention time. The system demonstrated satisfactory effluent concentration and stable performance in growing season. And it also worked adequately in wintertime even below $10^{\circ}C$ without freezing, and removal was still significant. The amount removed in BOD, COD, and SS was almost the same as in the growing season, and the amount removed in nutrients was about half of the one in growing season. Overall performance of the experimental system was compared with existing data base (NADB, 1994), and it was within the range of general system performance. As study period increased, removal rates for BOD, COD, SS, and T-P were consistently maintained and even enhanced, but removal rate for T-N decreased slightly. Wetland system was thought to be a feasible alternative for sewage treatment in rural area considering its low cost and low maintenance requirement. However, the effluent of the experimental wetland system often exceeded current effluent water quality standards, therefore, further treatment could be required if the effluent should be discharged to public waters. Wetland system of interest locates in rural area and is a part of rural ecosystem, therefore, ultimate disposal of reclaimed sewage for agricultural purpose or subsequent land treatment might be available and further research in this matter is recommended.

• Journal of Korean Society on Water Environment
• /
• v.24 no.5
• /
• pp.556-562
• /
• 2008

We divided the downstream of South-Han River into three water zones, such as river zone, transition zone and lacustrine zone depending on the flow rate, and elucidated the major effect factors on the growth of phytoplankton and the sources of organic matters in each water zone. The difference of chlorophyll-a concentration which represents the standing crop of phytoplankton was statistically significant among the water zones. From the results of bivariate correlation analysis between chlorophyll-a concentration and water quality parameters in each water zone, the outflow of Chungju dam and hydraulic retention time of Lake Paldang which are directly related with the flow rate seemed to have obvious impact on phytoplankton growth in the downstream of South-Han River. The concentration of nutrients such as phosphorus and nitrogen exceeded the criterion of eutrophication and did not showed significant relationship with chlorophyll-a concentration. There were strong correlations between $BOD_5$ and chlorophyll-a concentrations in transition and lacustrine zone showing autochthonous production of phytoplankton was dominant source of organic matters in these zones especially in dry seasons. The results of this study show that the control of abundance of phytoplankton is the key target for reduction of the organic pollution in the downstream of South-Han River.

• Journal of Korean Society of Water and Wastewater
• /
• v.11 no.2
• /
• pp.112-127
• /
• 1997

The purpose of this study is to get optimum operating factors of Upflow Anaerobic Sludge Blanket (UASB) reactor by introducing methods that make it to reduce inhibition possible in each process wastewater treatment. The used substrates, concentrated corn starch liquid (CSL) wastewater, modified starch, filtering and decoloring wastewater, ion refining wastewater, and mixed wastewater including modified starch and not including modified starch, are generated from molasses process. The seeding sludge is the digested sludge that had been applied to molasses wastewater. Batch test to reduce the inhibition factors that might be existed in each wastewater was examined. Based on the this test, the optimum operating factors according to alkalinity and pH variation was studied through the continuous test using three 5.5 L UASB reactor. The first reactor added $NaHCO_3$ to control alkalinity. The hydraulic retention time (HRT) reduced to 8 hours and the organic loading rate increased gradually. The second reactor changed the pH of influent from 7.0 to 6.0 using NaOH. The third reactor was operated without changes to compare the above two reactors. As the result, the inhibition in concentrated CSL wastewater was removed by adding iron (II). When trace metals were added to mixed wastewater not including modified starch, the digestability by gas production rate increased to more fifty percentage than mixed wastewater that was not adding the trace metals. The reason that the inhibition did not decreased in spite of adding trace metals and nutrients was influenced by high concentration generated during the acid fermentation. The UASB reactors using the mixed wastewater with the most effective performance were operated as 500 mg/L as $CaCO_3$ alkalinity and 6.0 pH at steady state, and at this time, the gas production rates were 283 and 311mL gas/g $COD_{added}$. The COD removal rates were 84.7 and 86.3%, respectively.

• Journal of Korean Society on Water Environment
• /
• v.20 no.5
• /
• pp.457-465
• /
• 2004

The objective of this study is to evaluate the possibility to apply the Moving Bed Biofilm Reactor(MBBR) in the activated sludge treatment process with existing aerobic HRT. Optimal operation conditions were assumed according to the analysis of organic matter and nutrients removal efficiencies depending on loading variations. The process was operated under different conditions: RUN I(HRT=7.14hr, $I{\cdot}R=100%$), RUN II(HRT=6.22hr, $I{\cdot}R=100%$), RUN III(HRT=6.22 hr, $I{\cdot}R=150%$), RUN IV(HRT=6.22hr, $I{\cdot}R=200%$), the TBOD removal efficien cies are 88%, 88.5%, 94.6%, 97.6%, respectively. Overall TSS removal efficiency is 90%, and it is increasing in RUN IV. In the case of Nitrogen, the highest removal efficiency of 90% was observed in RUN III and RUN IV, Nitrification and Denitrification rates are 0.013-0.016kg $NH_3-N/kg$ Mv-d and 0.009-0.019kg $NO_3/kg$ Mv-d, respectively. Phosphorus removal efficiencies are 89.6% in RUN I, 91.5% in RUN II, 84.3% in RUN III, and 76.4% in RUN IV. The process under shorter SRT yields better performance in terms of phosphorus removal. It was noticed that to achieve the effluent phosphorus concentration ofless than 1mg/L and removal efficiency higher than 80%, SRT should not be longer than 10 days. Experimental result shows that HRT of 6.22 hours is suitable for this treatment process, and, as a result, the aerobic reactor including moving media and DO depletion tank have a sufficient effect to the process performance.

• Proceedings of the Korean Society of Environment and Ecology Conference
• /
• 2003.10a
• /
• pp.105-126
• /
• 2003

In Korea most of annual rainfall is concentrated in several episodic heavy rains during the season of summer monsoon and typhoon. Because of uneven rainfall distribution many dams have been constructed in order to secure water supply in dry seasons. The Han River system has the most dams among Korean rivers, and the river is a series of dams now. Reservoirs need different strategy of water quality control from river water. Autochthonous organic matter and phosphorus should be the major target to be controlled in lakes. In this Paper some problems are discussed that makes efforts of water quality improvement ineffective in lakes of Korea, even after the substantial investment to wastewater treatment facilities.1) Phosphorus is the key factor controlling eutrophication of lakes and the reduction ofphosphors should be the major target of water treatment. However, water quality management strategy in Korea is still stream-oriented, and focused on BOD removal from sewage. Phosphorus removal efficiency remains as low as 10-30%, because biological treatment is adopted for both secondary treatment and advanced treatment. The standard for TP concentration of the sewage treatment plant effluent is 6 mgP/l in most of regions, and 2 mg/l in enforced region near metropolitan water intake point. TP in the effluents of sewage treatment plants are usually 1-2 mg/1, and most of plants meet the effluent regulation without a further phosphorus removal process. The generous TP standard for effluents discourages further efforts to improve phosphorus removal efficiency of sewage treatment. Considering that TP standard for the effluent is below 0.1 mg/l in some countries, it should be amended to below 0.1 mg/l in Korea, especially in the watershed of large lakes.2) Urban runoff and combined sewer overflow are not treated, even though their total loading into lakes can be comparable to municipal sewage discharges on dry days. Chemical coagulation and rapid settling might be the solution to urban runoff in regard of intermittent operation on only rainy days.3) Aggregated precipitation in Korea that is concentrated on several episodic heavyrains per year causes a large amount of nonpoint source pollution loading into lakes. It makes the treatment of nonpoint source discharge by methods of other countries of even rain pattern, such as retention pond or artificial wetland, impractical in Korea.4) The application rate of fertilizers in Korea is ten times as high as the average ofOECD countries. The total manure discharge from animal farming is thought to be over the capacity of soil treatment in Korea. Even though large portion of manure is composted for organic fertilizer, a lot of nutrients and organic matter emanates from organic compost. The reduction of application rate and discharge rate of phosphorus from agricultural fields should be encouraged by incentives and regulations.5) There is a lot of vegetable fields with high slopes in the upstream region of the HanRiver. Soil erosion is severe due to high slopes, and fertilizer is discharged in the form of adsorbed phosphorus on clay surface. The reduction of soil erosion in the upland area should be the major preventive policy for eutrophication. Uplands of high slope must be recovered to forest, and eroded gullies should be reformed into grass-buffered natural streams which are wider and resistant to bank erosion.

• Korean Journal of Organic Agriculture
• /
• v.15 no.4
• /
• pp.413-424
• /
• 2007

This trial was carried out to determine effects of TMR(Total Mixed Ration) in comparison to conventional diet on feed intake, digestibility, and nitrogen retention in Korean black goats. Twelve Korean black goats were allotted to treatments in four groups of three goats and the they were housed in separate metabolism cages for 21 days. Treatments included conventional diet(A: rice straw and commercial concentrates) as a control group and three TMR groups(B: rice straw and commercial TMR; C: 30% organic whole barley silage and rice straw with organic grain; D: 60% organic whole barley silage with organic grain). The results obtained are summarized as follows. Dry matter intake, fecal excreta, digestible dry matter, metabolic intake and feed intake of BW were significantly higher(p<0.05) compared with A, B, C treatment. The digestibility for most of nutrients except NFC was significantly higher(p<0.05) for D treatment than the others. On the other hand, the digestibility of NFC was higher for B treatment than for the others, even if it was not significantly different across treatments. Nitrogen intake was lower for D treatment, but the significant differences were not found across treatments. N retention rate was higher for B treatment with significant difference. For the blood composition, HDL cholesterol and Immunoglobulin G were significantly higher(p<0.05) for C, D treatment than the others. The results showed that, in comparison with A treatment(conventional diet) and B treatment(commercial TMR), dry matter intake, nutrient digestibility and N retention rate were not lower in C treatment(30% organic whole barley silage) and HDL cholesterol was increased after experiment. Therefore, it could be concluded that TMR with organic whole barley silage might contribute to the production of a high quality and safer meat in goat production.