• Journal of Wetlands Research
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• v.21 no.4
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• pp.384-391
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• 2019

Nutrients in stormwater runoff have raised concerns regarding water quality degradation in the recent years. Low impact development (LID) technologies are types of nature-based solutions developed to address water quality problems and restore the predevelopment hydrology of a catchment area. Two LID facilities, infiltration trench (IT) and infiltration planter (IP), are known for their high removal rate of nutrients through sedimentation and vegetation. Long-term monitoring was conducted to assess the performance and cite the advantages and disadvantages of utilizing the facilities in nutrient removal. Since a strong ionic bond exists between phosphorus compounds and sediments, reduction of total phosphorus (TP) (more than 76%), in both facilities was associated to the removal of total suspended solids (TSS) (more than 84%). The efficiency of nitrogen in IP is 28% higher than IT. Effective nitrification occurred in IT and particulate forms of nitrogen were removed through sedimentation and media filters. Decrease in ammonium- nitrogen (NH₄-N) and nitrite-nitrogen (NO₂-N), and increase in nitrate-nitrogen (NO₃-N) fraction forms indicated that effective nitrification and denitrification occurred in IP. Hydrologic factors such as rainfall depth and rainfall intensity affected nutrient treatment capabilities of urban stormwater LID facilities The greatest monitored rainfall intensity of 11 mm/hr for IT yielded to 34% and 55% removal efficiencies for TN and TP, respectively, whereas, low rainfall intensities below 5 mm resulted to 100 % removal efficiency. The greatest monitored rainfall intensity for IP was 27 mm/hr, which still resulted to high removal efficiencies of 98% and 97% for TN and TP, respectively. Water quality assessment showed that both facilities were effective in reducing the amount of nutrients; however, IP was found to be more efficient than IT due to its additional provisions for plant uptake and larger storage volume.

• Korean Journal of Ecology and Environment
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• v.37 no.3 s.108
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• pp.344-354
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• 2004

A pilot study was performed from September 2000 to April 2004 to examine the feasibility of the wetland-pond system for the agricultural reuse of reclaimed water. The wetland system was a subsurface flow type, with a hydraulic residence time of 3.5 days, and the subsequent pond was 8 $m^3$ in volume (2 m ${\times}$ 2 m ${\times}$ 2 m) and operated with intermittent-discharge and continuous flow types. The wetland system was effective in treating the sewage; median removal efficiencies of $BOD_5$ and TSS were above 70.0%, with mean effluent concentrations of 27.1 and 16.8 mg $L^{-1}$, respectively, for these constituents. However, they did often exceed the effluent water quality standards of 20 mg $L^{-1}$. Removal of T-N and T-P was relatively less effective and mean effluent concentrations were approximately 103.2 and 7.2 mg $L^{-1}$, respectively. The wetland system demonstrated high removal rate (92 ${\sim}$ 90%) of microorganisms, but effluent concentrations were in the range of 300 ${\sim}$ 16,000 MPN 100 $mL^{-1}$ which is still high for agricultural reuse. The subsequent pond system provided further treatment of the wetland effluent, and especially additional microorganisms removal in addition to wetland-pond system could reduce the mean concentration to 1,000 MPN 100 $mL^{-1}$ from about $10^5$ MPN 100 $mL^{-1}$ of wetland influent. Other parameters in the pond system showed seasonal variation, and the upper layer of the pond water column became remarkably clear immediately after ice melt. Overall, the wetland system was found to be adequate for treating sewage with stable removal efficiency, and the subsequent pond was effective for further polishing. This study concerned agricultural reuse of reclaimed water using natural systems. Considering stable performance and effective removal of bacterial indicators as well as other water quality parameters, low maintenance, and cost-effectiveness, wetland- pond system was thought to be an effective and feasible alternative for agricultural reuse of reclaimed water in rural area.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.60-65
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• 2001

'Shinil' pear cultivar (Pyrus pyrifolia Nakai) which was originated in a cross between 'Shinko' (non-patented, released in 1941) and 'Hosui' (non-patented, released in 1972) in 1978 was released as a middle season harvest variety. Its usual picking time coincided with 'Chuseok' season which is one of the most famous national holiday in Korea. The fruit showed high soluble solids content and good appearance. The cultivar was preliminarily selected in 1991, and its regional adaptability was evaluated in the name of 'Wonkyo Na-13' at 9 sites for four years from 1992, and finally selected and named in 1995. 'Shinil' is medium in tree vigor like 'Hosui' and spreading in tree habit as 'Niitaka', a leading cultivar in Korea, and consistently very productive. It has high resistance to black rot caused by Alternaria kikuchiana and pear necrotic spot caused by pear necrotic spot virus. Its full bloom is one day earlier than that of 'Niitaka' cultivar and harvest time is September 25 at Suwon area which is 3 days later than that of 'Hosui'. Fruit is round in shape with a deep medium stalk cavity and medium calyx basin and has attractive light yellow brown skin color. The fruit weight ranges between 300 and 400 g, which is similar to 'Chojuro', 'Shinko', and 'Hosui'. Soluble solid content is approximately at the level of 13-14 Brix, which is higher than that of 'Chojuro'. The flesh is cream-white, very juicy, and light grit with soft and fine texture.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.274-283
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• 2023

Buffer zones, an example of nature-based solutions, offer wide range of environmental, social and economic benefits due to their multifunctionality when applied to watershed areas promoting blue-green connectivity. This study evaluated the effects of buffer zone application to the water quality of Yongdam reservoir tributaries. Particularly, the challenges and improvement of the buffer zone design were identified and suggested, respectively. Water and soil samples were collected from a total of six sites in Yongdam reservoir from September 2021 to April 2022. Water quality analyses revealed that among the sites monitored, downstream of Sangjeonmyeon Galhyeonri (SG_W_D2) was found to have the highest concentration for water quality parameters turbidity, total suspended solids (TSS), chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN). This finding was attributed to the algal bloom observed during the sampling conducted in September and October 2021. It was found through the soil analyses that high TN and TP concentrations were also observed in all the agricultural land uses implying that nutrient accumulation in agricultural areas are high. Highest TN concentration was found in the agricultural area of Jeongcheonmyeon Wolpyeongri (JW_S_A) followed by Jucheonmyeon Sinyangri (JS_S_A) while the lowest TN concentration was found in the original soil of Sangjeonmyeon Galhyeonri (SG_S_O). Among the types of buffer zones identified in this study, Type II-A, Type II-B and Type III were found to have blue-green connectivity. However, initially, blue-green connectivity in these buffer zone types were not considered leading to poor design and poor performance. As such, improvement in the design considering blue-green network and renovation must be considered to optimize the performance of these buffer zones. The findings in this study is useful for designing buffer zones in the future.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.502-507
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• 2009

This study was conducted to establish the minimum harvesting time of 'Campbell Early' grape with girdling of 8 years old vines by the investigation of fruit quality. Girdling was performed as 5~7mm width at 1.0m height with a Y-trellis system on July 5th at Gimcheon, Gyeongbuk province. Skin color, soluble solids contents, sugar content, organic acid, and titratable acidity were analyzed every seven days period after the girdling. From 14 days after the girdling, pericarp color changed quickly as compared to the control, and also decreased b value and increased a value of Hunter L were observed. The content of organic acids decreased quickly as 0.85% as compared to the control's one, 1.10%. Sugar-acid ratio increased rapidly from the 21days as 15.1 against 10.8 of the control at harvesting time. After 14days, sugar content was abruptly increased such as fructose and glucose, that is 7days faster than the control. In harvesting time, their contents were high as $64.5mg{\cdot}g^{-1}FW$ and $61.0mg{\cdot}g^{-1}FW$ as compared to $56.1mg{\cdot}g^{-1}FW$ and $53.7mg{\cdot}g^{-1}FW$ of the control respectively. Among the content of organic acids, malic acid decreased quickly than the control's one in coloring time. The content of tartaric acid was obviously lower as $4.13mg{\cdot}g^{-1}FW$ than the control's one, $5.96mg{\cdot}g^{-1}FW$ in harvesting time. From these results, we assume that the harvesting of girdled 'Campbell Early' grape should be started in 42days after the girdling, when sugar-acid ratio is above 15.

• Korean Journal of Ecology and Environment
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• v.44 no.3
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• pp.303-313
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• 2011

Field observations and culture experiments have been carried out during the rainy season (on the 6th, 8th and 27th July 2009) to examine changes in the primary productivity and associated plant pigments in the estuary of the Seom-jin River. Primary productivity was determined at four sampling stations along the salinity gradient. On 6th July (before heavy rain) primary productivity ranged from 689~1,169 mgC $m^{-2}$ $d^{-1}$. On the 8th, just after more than 216.5 mm of precipitation, euphotic layers at all stations were reduced to very shallow water because of the high concentration of suspended solids in the water. This resulted in dramatically decreased primary productivity down to as low as 12~32 mg C $m^{-2}$ $d^{-1}$. However, after the rain, primary productivity on the 27th ranged from 266~999 mgC $m^{-2}$ $d^{-1}$, demonstrating a fast recovery in the upper stream water to similar productivity levels to those before the rainy season. Concentration of fucoxanthin in the water was highest on the 6th July. Before the rain, concentration of the zeaxanthin, increased as the salinity decreased. Immediately after the heavy rain, the Chl b (Chlorophytes) concentration was higher at all sites than before the rainy season. The concentration of fucoxanthin decreased after the heavy rain. At the downstream site, peridinin (Dinoflagellates) were found. During the rainy season, the diatoms contributed to the primary productivity at all sites. However, after the rainy season, Chl b (Chlorophytes) and Peridinin (Dinoflagellates) increased, demonstrating the enhanced contribution of those species in addition to diatoms.

• Journal of Life Science
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• v.27 no.8
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• pp.909-918
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• 2017

Ice plant (Mesembryanthemum crystallinum L.) was fermented in brine in the form of mulkimchi (IPMB), and its contents of organic acid and cyclitols and biological activities were compared with those before fermentation. The pH of the IPMB continuously decreased until the sixth day of fermentation. The lactic acid yield was greatest on the fourth day. D-pinitol in ice plant mulkimchi solids (IPMS) decreased during fermentation. However, myo-inositol and D-chiro-inositol increased. The radical scavenging activities of ABTS and DPPH, in addition to the activity of FRAP, of the IPMS extract were generally higher after fermentation, with the activities highest on the fifth ($79.09{\pm}0.69%$), fourth ($87.55{\pm}1.21%$), and sixth ($78.72{\pm}0.99%$) days of fermentation, respectively, when treated with 1 mg/ml of the extract. As shown by a lipid/MA assay, antioxidant activity was generally higher after fermentation. The viability of BNL CL.2 cells damaged by t-BHP, $H_2O_2$, and ethanol was $14.19{\pm}0.98$, $13.80{\pm}2.25$, and $25.89{\pm}2.90%$, respectively. When treated with $200{\mu}g/ml$ of IPMS extract, the cell viability was $57.06{\pm}4.52%$ on the first day, and $66.06{\pm}1.36%$ on the fourth day, and $50.07{\pm}04.85%$ on the sixth day of fermentation. Hepatocyte protective effects did not increase significantly after fermentation. ${\alpha}-glucosidase$ inhibitory activity was quite high, with a range of $83.52{\pm}2.69$ to $92.79{\pm}2.16%$, and the activity increased gradually in all the groups over the fermentation period. There was no clear correlation between ${\alpha}-amylase$ inhibitory activity and fermentation.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.494-499
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• 2007

The quality and functional properties of red ginseng in relation to steaming and drying conditions were evaluated. Fresh ginseng (5-year roots), cultivated in the Punggi region, were steamed for 2.5, 3.5, or 4.5 hr, and then dried by hot-air (60-$65^{\circ}C$/24 hr and $40^{\circ}C$,/3-4d) freezing ($-80^{\circ}C$/56 hr), and infrared (900 W/$62^{\circ}C$/68 hr). Hunter#s yellowness (b-value) and browning indexes (420 nm) of the samples were higher in the rootlets than in the main roots. Furthermore, these same index values were found to be high in the order of 3.5, 4.5, and 2.5 hr and infrared, hot-air, and freezing for steaming and subsequent drying, respectively. Analysis of soluble solids, total phenolics, total flavonoids, acidic polysaccharides, and electron donating abilities of the steamed and dried samples showed that 3.5hr of steaming with infrared drying was optimal. However, crude saponin contents were not influenced by steaming and drying conditions. The contents of $ginsenoside-Rg_l$, -Re, -Rf and $-Rb_2$, which were the major components in the samples, were reduced with steaming time, while the amounts of $-Rg_3$ and $-Rh_2$ increased, reaching the highest levels at 3.5 and 4.5 hr in the main roots and rootlets, respectively. The contents of $-Rg_3$ and $-Rh_2$ were similar in both the freeze-dried and hot-air dried samples.

• Korean Journal of Organic Agriculture
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• v.23 no.2
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• pp.267-280
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• 2015

The study was conducted to evaluate effects of time and degree of defoliation on growth of 'Wonhwang' pear (Pyrus pyrifolia Nakai) trees managing with low pesticides as well as regrowth of cuttings in vitro. Treatments included degree of defoliation (20% and 60%) with time of defoliation (Early-Aug, End-Aug, and Early-Sep); Early-Aug (20%), Early-Aug (60%), End-Aug (20%), End-Aug (60%), Early-Sep (20%), Early-Sep (60%), and No defoliation. No defoliation and Early-Sep (20%) defoliation increased growth of water sprouts and new shoots, which were improved by delayed defoliation or 20% of defoliation. Total-C, total-N, B, and free sugar contents increased in No defoliation-shoots but decreased in End-Aug (60%)-shoots. Delayed defoliation increased total-C, total-N, and free sugar in shoots, with high contents of C, K, Ca, Mg, and B observed for 20% of defoliation-trees. Fruit yield and weight or fruit length increased in No defoliation, End-Aug (20%) defoliation, and Early-Sep (20%) defoliation, but reduced in End-Aug (60%). Fruit soluble solids content reduced in defoliation in August. Time of defoliation did not affect the fruit yield and fruit quality, while degree of defoliation influenced yield and fruit weight and length. Defoliation at End-Aug (60%) mostly increased the leakage rates of the stem cuttings at $-18^{\circ}C$ and $-21^{\circ}C$ in vitro and reduced the germination rates at $-24^{\circ}C$ and $-27^{\circ}C$. Under comparison of time and degree of defoliation, the Early-Sep defoliation increased germination rates of the stem cuttings at $-27^{\circ}C$ in vitro, and 60% of defoliation decreased the germination rates compared to the 20% of defoliation.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.212-220
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• 2014

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP), a known ethylene action inhibitor, on fruit quality and incidence of physiological disorders during simulated marketing period in Asian pears (Pyrus pyrifolia Nakai) of early-season cultivar 'Hanareum' and mid-season cultivar 'Manpungbae'. Flesh firmness was decreased abruptly at 15 days after shelf-life in untreated fruit of early-season cultivar 'Hanareum' which showed less than 19N, although those of 1-MCP-treated fruits were kept high value (>28N) during 15 days of shelf-life. However, there were no distinct firmness changes during 30 days of shelf-life in mid-season cultivar 'Manpungbae' pear. Two pear cultivars did not show any considerable differences in quality indices such as soluble solids content, titratable acidity and skin color during the shelf-life regardless of 1-MCP treatment. The reduction of ethylene production level by 1-MCP treatment did not appeared in 'Hanareum' pear. Meanwhile, 1-MCP treated 'Hanareum' pears showed significantly low respiration rate during shelf-life. On the other hand, the inhibitory effect of 1-MCP was not remarkable in mid-season 'Manpungbae' pears. 1-MCP treatment completely blocked the incidence of physiological disorders including core browning and mealiness symptom during shelf-life only in early-season 'Hanareum' pears, and reduced considerably the pithiness disorder regardless of 1-MCP concentration. Consequently, we concluded that the treatment efficacy of 1-MCP is largely cultivar-dependent and the use of $1{\mu}L{\cdot}L^{-1}$ 1-MCP was recommended for the keeping quality and the prevention of physiological disorders only in early-season Asian pear 'Hanareum'.