• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.479-487
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• 2018

The purpose of this study is to analyze photochemical activity of nursery seedlings under drought stress, using chlorophyll fluorescence reaction analysis. Young nursery seedlings of tomato (Lycopersicon esculentum Mill.) and cucumber (Cucumis sativa L.), were grown under drought stress for 8 days. Analysis of chlorophyll fluorescence reaction (OJIP) and parameters, were performed to evaluate photochemical fluctuation in nursery seedlings under drought stress. Chlorophyll fluorescence reaction analysis showed maximal recorded fluorescence (P) decreased from the 5 day after treatment in tomato seedlings, while an amount of chlorophyll fluorescence increased at the J-I step. Thus, physiological activity was reduced. In cucumber seedlings, maximal recorded fluorescence (P) and maximal variable fluorescence ($F_V$) lowered from the 4 day after treatment, and chlorophyll fluorescence intensity of J-I step increased. Chlorophyll fluorescence parameter analysis showed electron transfer efficiency of PSII and PSI were significantly inhibited with decreasing $ET2_O/RC$ and $RE1_O/RC$ from the 5 day after treatment, in tomato seedlings and from the 4 day after treatment, in cucumber seedlings. $ET2_O/RC$ and $PI_{ABS}$ significantly changed. In conclusion, 6 indices such as $F_V/F_M$, $DI_O/RC$, $ET2_O/RC$, $RE1_O/RC$, $PI_{ABS}$ and $PI_{TOTAL}ABS$ were selected for determining drought stress in nursery seedlings. Drought stress factor index (DFI) was used to evaluate whether the crop was healthy or not, under drought stress. Cucumber seedlings were less resistant to drought stress than tomato seedlings, in the process of drought stress.

• The Korean Journal of Ecology
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• v.16 no.1
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• pp.51-61
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• 1993

Crystal violet, a typical triphenylmenthane dye (N, N, N', N', N", N"-hexa methylparaosaniline), extensively used in textile dye, industry and research, has been suggested to cause tumor growth in botton-feeding fishes. For the isolation of crystal violet degrading bacteria, wastewaters were sampled from plants' wastewater treatment facility, textile treatment facility, textile wastewater treatment plant and etc.. The most efficient strain in crystal violet degrading bacteria was identified as Klebsiella oxytoca. Added sole carbon source in PAS minimal media was 10mg/l crystal violet, which incubated at 30。C, the degrading efficiency was maximum 12.3%. When fructose, glucose, sucrose and yeast-extract were added 0.01% in PAS media respectively, the degrading efficiency were all 96% within 24 hours.

• 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.

• KIEAE Journal
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• v.13 no.1
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• pp.125-131
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• 2013

This is a study on space planning of dental clinic by case analysis of 30 dental clinics that were cons tructed or designed in metropolitan area in recent years, It is analyzed as the following, required basic or additional rooms according to size divisions of gross floor area, relationship of treatment chair number and floor area, ratio of gross floor area and waiting zone, medical treatment zone, supporting zone, management zone, and zoning planning, space types of medical treatment zone, etc. This study can be used as basic data for planning of dental clinic and related future researches.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.191-198
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• 2018

Improper management and unsanitary approaches are implemented in disposal of leachate, which has resulted in groundwater pollution at village Uruli Devachi, Pune, India. Various physico-chemical treatment methods are commercially available for leachate treatment. However, the application of biological methods viz. phytoremediation to the municipal solid waste landfill leachate has been limited. We report the remediation ability of Typha aungstifolia and Acrorus calamus that is capable of reducing hazardous constituents from the landfill leachate. After 96 h of hydraulic retention time (HRT), it was observed that T. aungstifolia-treated sample showed high reduction potential in reducing biochemical oxygen demand, chemical oxygen demand, hardness, total dissolved solids, Na, Mg, Ca and Ni whereas A. calamus showed greater reduction capacity for alkalinity, Cl, Cu, Zn and Cr. Furthermore, it was also observed that T. aungstifolia withstood longer HRT than A. calamus. In situ application of T. aungstifolia and A. calamus for remediation of landfill leachate carries a tremendous potential that needs to be further explored.

• Korean Journal of Environmental Biology
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• v.32 no.3
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• pp.234-242
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• 2014

In this study, gametotoxicity and embryotoxicity experiments using Hemicentrotus pulcherrimus were carried out to investigate the ecotoxicological effects of bisphenol A (BPA). We examined the effects of BPA on fertilization and normal embryogenesis at various concentrations (0, 300, 500, 800, 1000, and 1500 ppb). The results demonstrated that the fertilization rates were not changed. The normal embryogenesis rates were gradually decreased in a dose-dependent manner, and were significantly lowered following 800 ppb BPA treatment ($EC_{50}$=1056.1 ppb, 95% Cl=981.8~1163.9 ppb). The observed effective concentration and the lowest observed effective concentration of the normal embryogenesis rate were 500 ppb and 800 ppb, respectively. The embryos showed retarded development at each tested concentration, indicating the fact the embryonic development was delayed due to the increasing concentrations of BPA. Furthermore, we examined the expression of glutathione S-transferase (GST) mRNA at various concentrations of BPA in H. pulcherrimus. Interestingly, it was found that the expression level of GST mRNA was significantly increased in the experimental group exposed to BPA. Based on these results, we suggested that BPA at greater than 800 ppb has a toxic effect during the early embryonic stages of H. pulcherrimus, and GST mRNA may be used as a biomarker for risk assessment of BPA contamination.

• The Korean Journal of Ecology
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• v.20 no.1
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• pp.43-49
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• 1997

Effects of addition of soil ameliorants on the growth and nutrient absorption of Zea mays, Miscanthus sinensis and Phytolacca americana were investigated. Acid soil from Yeocheon Industrial Complex were used for the control plot (AS). We made two treatment plots, acid soil + lime (AS + L) and acid soil + dolomite (AS+D). Ration of acid soil : soil ameliorants in freatment plot was 50 : 1(V:V). Acid soil and soil ameliorants were mixed thoroughly before use. Shoot length of corn in AS+L and AS+D was considerably increased by 141% and 137%, respectively, compared with that in AS. Pokeweed in AS+L and AS+D also increased by 183% and 152%, respectively, compared with that in AS. However, growth of Miscanthus sinensis showed slight difference between the control and the treatment plots. Biomass of corn and porkweed in the treatment plots were also greater than those in the control plots. During the growth experiment with corn, concentrations of Ca and Mg in soil were increased and A1 decreased with increased soil pH in the treatment plots. Amount of aluminum absorbed by corn in the control plot was greater than that in the treatment plots. In case of Miscanthus sinensis, however, aluminum absorption in the control plot was lower than those in the treatment plots.

• Journal of Environmental Health Sciences
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• v.39 no.5
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• pp.474-481
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• 2013

Objectives: This study was conducted to investigate the application of microbial fuel cells (MFCs) to the wastewater treatment systems employed in the Living Building Challenge. Methods: I reviewed a range of information on decentralized wastewater treatment technologies such as composting toilets, constructed wetlands, recirculating biofilters, membrane bioreactors, and MFCs. Results: The Living Building Challenge is a set of standards to make buildings more eco-friendly using renewable resources and self-treating water systems. Although there are various decentralized wastewater treatment technologies available, MFCs have been considered an attractive future option for a decentralized system as used in the Living Building Challenge. MFCs can directly convert substrate energy to electricity with high conversion efficiency at ambient and even at low temperatures. MFCs do not require energy input for aeration if using open-air cathodes. Moreover, MFCs have the potential for widespread application in locations lacking water and electrical infrastructure Conclusions: This paper demonstrated the feasibility of MFCs as a novel decentralized wastewater treatment system employed in the Living Building Challenge.

• KSBB Journal
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• v.28 no.2
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• pp.80-85
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• 2013

The bacterial community structure in a biological reactor fed influent from a wastewater treatment system was investigated by denaturing gradient gel electrophoresis (DGGE) and in situ hybridization. Sludges were collected from three biological reactors (aerobic, oxic, and anoxic tanks) at the M wastewater treatment facility (WTF). The influent of the MWTF consisted of mixed tannery wastewater (40~65%) and seafood wastewater (35~60%). The treatment processes resulted in a removal efficiency for BOD (biochemical oxygen demand) and COD (chemical oxygen demand) of 83.6~98.2% and 72.8~84.6%, respectively for tannery wastewater than for seafood wastewater resulted in greater survival of biomass in the biological reactors and a higher removal of BOD, COD, and T-N of about 8~18%. In contrast, addition of greater amounts of seafood wastewater decreased the amount of biomass in the bioreactors due to the increasing concentration of chromium from that wastewater and it also. The dominant bacterial species during the high seafood wastewater input period were Burkholderia cepacia (JX901049) and an uncultured bacterium (JF247555), while Pseudomonas geniculata (HQ256559) was dominant during the high tannery wastewater input period. Flavobacteriumsp. BF.107 (FM173271) and Hyphomicrobium zavarzinii (Y14306) were dominant under anoxic conditions.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.62-72
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• 2006

Biological health in aquatic environments has been assessed by several approaches using various bio-taxa. Especially, fish has been identified as one of the best ecological indicators for an integrative health assessments in aquatic environments. In this preliminary study, the necropsy-based approach using the Health Assessment Index (Adams et al., 1993; HAI, Blazer, 2000), was employed for the assessments of aquatic environments influenced by effluent water from wastewater disposal plants (WDP) near a urban stream (i.e., Cap-Stream). For the impact analysis from the effluents, we developed 10 metric necropsy-based model including $M_l\;skin,\;M_2\;fin,\;M_3\;thymus,\;M_4\;spleen,\;M_5\;hindgut,\;M_6\;kidney,\;M_7\;liver.\;M_8\;eyes,\;M_9\;gill,\;and\;M_{10}$ pseudobranch. We set up duplicate controls (natural upstream water plus 5 fishes in each control tank) and duplicate treatments (effluent water from the WDP plus 5 fishes in each treatment tank) in the laboratory. Preliminary results showed that HAI values in the controls were zero, indicating an excellent condition by the criteria of HAI, while the HAI values in the treatments ranged between 40 and 150, indicating a poor condition. Also, various health conditions, based on the index of biological integrity (IBI), species richness, tolerance guilds, and trophic guilds supported the HAI approach. The HAI approach, not applied in Korea, not may be used as an surrogate fer ecological health assessment in lotic ecosystems.