• Environmental Engineering Research
• /
• v.22 no.3
• /
• pp.266-276
• /
• 2017

A life cycle impact assessment was applied in an industrial waste incineration plant to evaluate the direct and indirect environmental impacts based on toxicity and non-toxicity categories. The detailed life cycle inventory of material and energy inputs and emission outputs was compiled based on the realistic data collected from a local industrial waste incineration plant, and the Korean life cycle inventory and ecoinvent database. The functional unit was the treatment of 1 tonne of industrial waste by incineration and the system boundary included the incineration plant and landfilling of ash. The result on the variation of the impact by the unit processes showed that the direct impact was decreased by 79.3, 71.6, and 90.1% for the processes in a semi dry reactor, bag filter, and wet scrubber, respectively. Considering the final impact produced from stack, the toxicity categories comprised 91.7% of the total impact. Among the toxicity impact categories, the impact in the eco-toxicity category was most significant. A separate estimation of the impact due to direct and indirect emissions showed that the direct impact was 97.7% of the total impact. The steam recovered from the waste heat of the incineration plant resulted in a negative environmental burden.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.78-78
• /
• 2019

The aim of the study was to determine the antioxidant activities of the plants with origin of Vietnam. The Embelia scandens (Lour.) Mez which is a species of plant in the family Myrsinaceae and Cornus hongkongensis Hemsl., which is a species of plant in the family Cornaceae were tested for antioxidant activities. Samples were prepared using 95% ethanol using DPPH assay for assessing the antioxidant activity. Ascorbic acid was used for positive control for DPPH assay. DPPH assay experiment showed that extracts of the Embelia scandens (Lour.) Mez and Cornus hongkongensis Hemsl. might have anti-oxidant activity 4.77 times and 5.65 times higher, respectively, compared to control. To determine the cell toxicity, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used. MTT assay experiment showed that Embelia scandens (Lour.) Mez might have 13.1% more toxicity whereas Cornus hongkongensis Hemsl. might have 47.3% less toxicity compared to control. Taken together, these experiments showed that Cornus hongkongensis Hemsl. extracts might have significantly higher antioxidant activities and relatively lower toxicity, compared to control.

• Environmental Analysis Health and Toxicology
• /
• v.11 no.1_2
• /
• pp.31-39
• /
• 1996

Leachate from municipal solid waste (MSW) landfill, effluent from leachate treatment plant, and ground water sample from a monitoring well near landfill site were tested for an acute toxicity. Microtox toxicity test was used for testing the acute toxicity of leachate and other samples. EC$_{50}$ values which a concentration of pollutant for reducing 50% light output from luminescent bacteria, Photobacterium phosphoreum were determined to assess the toxicity of pollutants as well as the relative toxicity. In addition, characteristics of leachate were studied and compared to those of phenol and pentachlorophenol (PCP) which are typical aquatic toxic pollutants. For leachate, EC$_{50}$ for 30 min incubation was 10.8%, while for phenol and PCP, 46 ppm and 1.2 ppm, respectively. the relative toxicity of treated leachate by in situ aeration with activated sludge was reduced to more than 75% of toxicity of the untreated leachate. Microtox toxicity test was failed to figure out EC$_{50}$ values for groundwater from a monitoring well since the relative toxicity of the unconcentrated sample was too low to estimate EC$_{50}$. Addition of activated carbon to leachate was reduced the relative toxicity. The reduction Pattern of the relative toxicity of leachate by mechanical aeration was similar to that of PCP, but different from that of phenol. These findings suggest that the toxicity of leachate may come from PCP-like toxic compounds rather than phenol-like one. In conclusion, the process of aeration with activated sludge might be very important to reduce the environmental toxicity of leachate. And Microtox test could be a reasonable bioassay for screening and monitoring the environmental toxicity of leachate from municipal solid waste landfill as well as for determining the reduction efficiency of the leachate toxicity by various treatment processes in leachate treatment plant.

• Journal of Ecology and Environment
• /
• v.41 no.11
• /
• pp.318-327
• /
• 2017

Background: A typical sewage treatment plant is designed for organic and nutrient removal from municipal sewage water and not targeted to eliminate micropollutants such as pesticides, pharmaceuticals, and nano-sized metals which become a big concern for sustainable human and ecological system and are mainly discharged from sewage treatment plant. Therefore, despite contaminant removal by wastewater treatment processes, there are still remaining environmental risks by untreated pollutants in STP (sewage treatment plant) effluents. This study performed aquatic toxicity tests of raw wastewater and treated effluents in two sewage treatment plants to evaluate toxicity reduction by wastewater treatment process and analyze concentration of contaminants to reveal potential toxic factors in STP effluents. Methods: Water samples were collected from each treatment steps of two STPs, and acute and chronic toxicity tests were conducted following USEPA (United States Environmental Protection Agency) and OECD (Organization for Economic Cooperation and Development) guidelines. Endpoints were immobility for mortality and reproduction effect for estrogenicity. Results: Acute $EC_{50}s$ (median effective concentration) of influents for Seungki (SK) and Jungnang (JN) STPs are $54.13{\pm}32.64%$ and $30.38{\pm}24.96%$, respectively, and reduced to $96.49{\pm}7.84%$ and 100%. Acute toxicity reduction was clearly correlated with SS (suspended solids) concentration because of filter feeding characteristics of test organisms. Chronic toxicity tests revealed that lethal effect was reduced and low concentration of influents showed higher number of neonates. However, toxicity reduction was not related to nutrient removal. Fecundity effect positively increased in treated wastewater compared to that in raw wastewater, and no significant differences were observed compared to the control group in JN final effluent implying potential effects of estrogenic compounds in the STP effluents. Conclusions: Conventional wastewater treatment process reduced some organics and nutritional compounds from wastewater, and it results in toxicity reduction in lethal effect and positive reproductive effect but not showing correlation. Unknown estrogenic compounds could be a reason causing the increase of brood size. This study suggests that pharmaceutical residues and nanoparticles in STP effluents are one of the major micropollutants and underline as one of estrogenic effect factors.

• The Korean Journal of Pesticide Science
• /
• v.21 no.1
• /
• pp.33-41
• /
• 2017

Susceptibility and persistence of Japanese pine sawyer, Monochamus alternatus adults, and acute contact toxicity, foliage contact toxicity, and residual toxicity to honeybee, Apis mellifera were evaluated by using 5 kinds of neonicotinoid pesticides. All neonicotinoids pesticides showed over 80% mortality 48 hour after body spray treatment. However, only 2 kinds of acetamiprid ME and acetamiprid+buprofezin showed over 80% mortality in the twig dipping treatment. All of the five neonicotinoides pesticides used in M. alternatus adults showed residual effect of 60-80% mortality, but the efficacy decreased rapidly after 1 day of treatment. Acetamiprid ME showed the lowest toxicity in the acute and foliage contact toxicity test of A. mellifera. The residual toxicity of leaves on A. mellifera was very low in acetamiprid ME and acetamiprid+buprofezin. However, the residual toxicity of all pesticides treatments decreased to 10-30% after 1 day of treatment and further decreased with time. These results indicate that acetamiprid ME among five neonicotinoid agents showed a high insecticidal activity in the M. alternatus adults, while it exhibited relatively low contact and residual toxicity in the A. mellifera. It is thought that acetamiprid ME can be effectively used for the control of the M. alternatus adults as vector of pine wilt disease.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.79-79
• /
• 2019

The aim of the study was to determine the antioxidant activities of the plants with origin of Vietnam. The Manglietia insignis (Wall.) Blume, which is a species of plant in the family Magnoliaceae and Tirpitzia sinensis (Hemsl.) Hallier f., which is a species of plant in the family Linaceae were tested for antioxidant activities. Samples were prepared using 95% ethanol using Nitric Oxide (NO) assay for assessing the anti-inflammatory activity. NO assay experiment showed that extracts of the Manglietia insignis (Wall.) Blume and Tirpitzia sinensis (Hemsl.) Hallier f. might have the 36.2% more anti-inflammatory activity and 59.5% more anti-inflammatory activity, respectively, compared to control. To determine the cell toxicity, MTT (3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide) assay was used. MTT assay experiment showed that the Manglietia insignis (Wall.) Blume and Tirpitzia sinensis (Hemsl.) Hallier f. might have the 31.0% less toxicity and 8.52% more toxicity, respectively, compared control. Taken together, these experiments showed that Manglietia insignis (Wall.) Blume extracts might have significantly higher anti-inflammatory activities and relatively lower toxicity, compared to control.

• Journal of Korean Society on Water Environment
• /
• v.28 no.3
• /
• pp.467-472
• /
• 2012

In this study, water quality and acute toxicity using Daphnia magna were analyzed to investigate the eco-toxicological substances identified as statistical analysis and propose a management plan for the effluent of Banwol industrial complex, Ansan, Gyeonggi-do. Cu, Zn, F, Mn concentrations in the effluent far exceeded the US standards to protect the aquatic ecosystem and eco-toxicity values were 5 ~ 22 TU. However, concentrations of heavy metals significantly decreased after Ansan public wastewater treatment plant operating a biological treatment and toxicity values were 0 TU. Zn, Cr, F and Cu in the effluent showed very strong and strong positive correlations with eco-toxicity values, respectively. Regression analysis resulted in an equation between toxicity and Zn, TU = $4.884{\times}Zn$ (mg/L) -0.391 showing Zn concentration should be managed less than 0.285 mg/L to keep the eco-toxicity (TU) less than 1.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.74-74
• /
• 2019

The aim of the study was to determine the antioxidant activities of the plants with origin of the Far East. The Carlemannia tetragona Hook f., which is a species of plant in the family Carlemanniaceae and Celastrus virens which is a species of plant in the family Celastraceae were tested for antioxidant activities. Samples were prepared using 95% ethanol using DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical) assay for assessing the antioxidant activity. Ascorbic acid was used for positive control for DPPH assay. DPPH assay experiment showed that extracts of the Carlemannia tetragona Hook. f., and Celastrus virens might have anti-oxidant activity 54.5% and 258% higher, respectively, compared to control. To determine the cell toxicity of these plant extracts, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used. MTT assay experiment showed that Carlemannia tetragona Hook. f., and Celastrus virens might have less toxicity 23.3% and 27.5%, respectively, compared to control. Taken together, these experiments showed that Celastrus virens extracts might have much higher antioxidant activities than Carlemannia tetragona Hook. f., with relatively lower toxicity. This implies that this study might provide a basis to develop a new powerful antioxidant candidate for human diseases therapeutics.

• Journal of Korean Society of Water and Wastewater
• /
• v.8 no.3
• /
• pp.9-18
• /
• 1994

Activated sludge pilot plant testing was conducted to determine the ability of a well-designed activated sludge treatment system to remove chromic toxicity from the bleached kraft pulp mill effluent. Removals of conventional(BOD and SS) and nonconventional(resin and fatty acids, color, AOX) pollutants were estimated. The pilot plant was operated at steady state for about 10 weeks at an F/M of 0.28 and a sludge age of 8.4 days. The average MLSS concentration was 4,309mg/l, of which volatile fraction was 57%. During the operation period, the BOD removal reaction rate(k) was determined to be 8.2/day at $30^{\circ}C$. The BOD removal was 84 percent, which was 3 to 6 percent lower than expected for full-scale treatment. The chronic toxicity of the activated sludge effluent was tested by employing both Dinnel and the BML protocols. It was found that the pilot plant could achieve in excess of 90 percent reduction in chronic echinoderm toxicity. The data show slight reduction of color and AOX across the activated sludge system. The pilot system, however, demonstrated on excellent removal of resin and fatty acids.

• The Korean Journal of Pesticide Science
• /
• v.12 no.4
• /
• pp.382-390
• /
• 2008

This study was performed to evaluate the acute toxicity and residual toxicity of the 69 kinds of agrochemicals (41 insecticides, 18 fungicides, and 10 acaricides) against honeybee, Apis mellifera and bumblebee, Bombus terrestris. According to the IOBC standard, the toxicity showed below 30% was classified as non-toxic. Among 41 insecticides, five insecticides (acetamiprid, chlorfenapyr, thiacloprid, milbemectin, and buprofezin+amitraz) against the honeybee; eight insecticides (methomyl, thiodicarb, acetamiprid, chlorfenapyr, thiacloprid, abamectin, spino sad, buprofezin+amitraz) against the bumblebee did not show any toxic effect. Therefore, it thought to being safe. Other 18 fungicides and 10 acaricides were safe against the honeybee and bumblebee. In residual toxicity against the honeybee, eight insecticides (dichlorvos, methomyl, imidachlorprid, emamectin benzoate, spinosad, cartap hydrochloride, chlorfenapyr, and endosulfan) among 41 insecticides tested were safe at three days after treatment; however, sixteen insecticides (dimethoate, fenitrothion, fenthion, methidathion, phenthoate, pyraclofos, fenpropathrin, clothianidin, dinotefuran, thiamethoxam, abamectin, acetamiprid+ethofenprox, acetamiprid+indoxacarb, bifenthrin+imidacloprid, ethofenprox+phenthoate, imidacloprid+methiocarb) still remain high toxicity at eleven days after treatment. Against the bumblebee, residual toxicity showed as safe in seven insecticides (dimethoate, methidation, a-cypermethion, ethofenprox, indoxcarb, chlorpyrifos+a-cypennethrin, esfenvalerate+fenitrochion) at three days after treatment; however, eight insecticides (fenitrothion, pyraclofos, clothianidin, fipronil, acetamiprid+ethofenprox, chlorpyrifos+bifenthrin, ethofenprox+phenthoate, imidacloprid+methiocarb) still showed high toxicity at seven days after treatment. From above results, it will be useful information to select insecticides being safe and effective against the honeybee and bumblebee.