Distribution of heavy metals in road dusts and their potential contribution of pollution near coastal areas

Heavy metals in 9 road dusts collected in a beach town of Busan, Korea, were assessed to investigate heavy metal distributions in road dust and to assess their potential effects to adjacent coastal environment. The road dusts are contaminated with heavy metals. The contamination level is relatively similar or higher than that of other polluted cities. Zn, Cu, Cr and Pb concentrations are higher than other elements, Li, Co, Ni, As and Cd, in road dusts from this area. Zn is most enriched metal in road dusts followed by Cd and Pb. The ratios of bioavailability fractions of heavy metals from road dust varied from 8%(Li) to 97%(Cu). The most extractable elements, by rain water, were Cu, Zn and Cr among the heavy metals in road dusts collected this area, indicating that those metals can be pollution source of the adjacent estuary.inated with heavy metals. The contamination level is relatively similar or higher than that of other polluted cities. Zn, Cu, Cr and Pb concentrations are higher than other elements, Li, Co, Ni, As and Cd, in road dusts from this area. Zn is most enriched metal in road dusts followed by Cd and Pb. The ratios of bioavailability fractions of heavy metals from road dust varied from 8%(Li) to 97%(Cu). The most extractable elements, by rain water, were Cu, Zn and Cr among the heavy metals in road dusts collected this area, indicating that those metals can be pollution source of the adjacent estuary.2

Potential Human Risk Assessment of PCBs and OCPs in Edible Fish Collected from the Offshore of Busan

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) contents in marine sediment and edible fish (4 species) from the estuary near the Yongho wharf in Busan were determined to assess their presence and their potential health risk to the local population through fish consumption was also assessed. Levels of ΣPCBs and ΣDDTs in marine sediment were 3.22~197.65 and 1.77~20.27 ng/g dw, respectively. HCHs and endosulfan sulfate concentrations in bottom sediment were 1.42~6.08, 0.56~13.89 ng/g dw, respectively. The bottom sediment in the offshore of the Yongho wharf may be characterized as semi-polluted status with potential adverse marine biological effects in terms of sediment quality guidelines of US NOAA. The mean concentrations of ΣPCBs in the tissues of olive flounder (Paralichthys olivaceus), Korean rockfish (Sebastes schlegelii), file fish (Stephanolepis cirrhifer) and abbysal searobin (Lepidotrigla abyssalis) were 67.37, 10.20, 48.26, 22.81 ng/g lw, respectively. DDTs and HCHs were also detected in all fish samples. Lifetime cancer risk and target hazard quotient to local residents due to those fish consumption were found to pose negligible cancer and non-cancer risk. 용호부두 인근의 해저퇴적물과 4종의 식용어류인 넙치, 우럭, 쥐치, 밑달갱이체내의 폴리염화비페닐(polychlorinated biphenyls, PCBs)및 유기염소계 농약(organochlorine pesticides or OCPs)의 오염수준과 공간적 분포현황을 규명하였고, 이를 토대로 지역주민의 어류섭취에 따른 PCBs 및 OCPs의 인체 노출을 파악하여 이로 인한 인체 건강에 미치는 위해성평가를 수행하였다. 용호부두 인근해역의 퇴적물에 존재하는 42종의 ΣPCBs 의 농도는 3.22~197.65 ng/g dw였다. ΣDDTs 의 농도는1.77~20.27 ng/g dw이었다. 그리고 HCHs, endosulfan sulfate 등이 각각 1.42~6.08, 0.56~13.89 ng/g dw수준이었다. 용호부두 인근해역의 퇴적물의 유기염소계 화합물함량의 미국 해양대기청(National Oceanic and Atmospheric Administration, NOAA)의 기준 중 악영향 기대수준인 PEL과 비교결과 0.1 ≤ mPELQ ≤ 0.5로 중간 정도의 오염도에 해당한다. 용호부두 인근해역에서 채취된 넙치, 우럭, 쥐치, 밑달갱이 근육 조직내의 PCBs의 평균함량은 67.37, 10.20, 48.26, 22.81 ng/g lw이었다. 모든 어류시료에서 ΣDDTs 와 ΣHCHs 의 농도범위는 각각 4.53~82.10, 2.94~22.98 ng/g이었으며, 다른 OCPs들도 모든 시료에서 미량으로 검출되었다. 용호부두 해역에서 채취된 넙치, 우럭, 쥐치, 밑달갱이의 섭취로 인한 PCBs 및 OCPs 오염도에 대한 정량적인 발암 및 비발암 위해 도는 US EPA 기준으로 보면 단기 및 장기적 인체 위해도 모두 무시할 만한 것으로 판단된다.22Nkc

Application of response surface method to carbamazepine removal in photo-ozonation reaction under alkaline condition

In this study, the photo-ozonation reaction for carbamazepine (CBZ) removal was investigated under alkaline conditions. Response surface methodology based on a central composite design was used to obtain the optimum experimental conditions, and examine both main and interaction effects of the photo-ozonation reaction variables such as O-3 concentration, H2O2 concentration and UV intensity. The level of O-3 concentration significantly influenced CBZ removal (p < 0.001). CBZ removal increased with increasing both O-3 and H2O2 concentration up to a certain level, whereas further increase in O-3 and H2O2 concentration resulted in an adverse effect due to the hydroxyl radical scavenging effect. The optimum conditions for complete CBZ removal at pH 9 were found to be 0.89 mg of O-3 l(-1), 4.85 mg of H2O2 l(-1) and 3.18 mW of UV intensity cm(-2), respectively.This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology (MEST) (No.2012-0005114).OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000005866/1SEQ:1PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000005866ADJUST_YN:YEMP_ID:A072570DEPT_CD:903CITE_RATE:1.122FILENAME:첨부된 내역이 없습니다.DEPT_NM:환경보건학과EMAIL:[email protected]_YN:NCONFIRM:

Distribution of brominated flame retardants and phthalate esters in house dust in Korea

We examined the levels of brominated flame-retardants (BFRs) including polybrominateddiphenyl ethers (PBDEs), tetrabromobisphenol-A (TBBPA), hexabromocydododecane (HBCD), and phthalates in indoor dusts in residential houses in Korea, and their distribution patterns depending on building characteristics. Mean concentrations of phthalate esters (1,825 mu g g(-1)) were significantly higher than that of BFRs (PBDE: 1,332 mu g g(-1), HBCDs: 459 mu g g(-1), and TBBPA: 213 mu g g(-1)), indicating more frequent use of phthalate-containing products such as PVC flooring in the Korean houses. PVC flooring house was associated with higher concentrations of DEHP (p = 0.001) and BBP (p = 0.012), indicating that exposure to phthalate was higher in the PVC flooring house. Building age was significantly related with levels of PBDEs especially BDE-47 (p = 0.062), BDE-203 (P = 0.007), DEHP (p = 0.004), and BBP (p = 0.070), respectively, indicating that older buildings can produce higher amounts of PBDEs and phthalates. Our study can provide important information on the sources of BFRs and phthalates in residential houses in Korea.OAIID:RECH_ACHV_DSTSH_NO:T201814839RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A072570CITE_RATE:1.087DEPT_NM:환경보건학과EMAIL:[email protected]_YN:YY

Characteristics of total and methyl mercury in precipitation in Seoul, Korea

To investigate the seasonal distribution of mercury (Hg) in precipitation in Seoul, Korea, event based total mercury (THg) and methyl mercury (MeHg) in precipitation samples were collected for one year. During sampling periods, volume weighted mean (VWM) concentration of THg and MeHg were 16.91 and 0.042 ng L-1 and wet deposition flux of THg and MeHg was 5.96 and 0.01 mu g m(-2), respectively. The proportion of MeHg in THg in the rainwater ranged from 0.01% to 2.22% with a mean value of 0.5%. The THg and MeHg concentration in precipitation was the highest in the winter, while wet deposition flux of THg and MeHg were highest in summer. There were significant negative correlations between THg and rain amount (p = 0.034), and between MeHg and the rain amount (p = 0.023), indicating that Hg concentrations in precipitation decreased as the amount of precipitation increased, especially in summer. THg concentration was higher when precipitation amount in one event was less than 20 mm, implying that 20 mm of precipitation can be a threshold value showing the Hg wash-out effect from the atmosphere. A significant correlation was observed between THg and NO3- (r(2) = 0.65) and Cl- ion (r(2) = 0.60), and between MeHg and SO42- ion (r(2) = 0.52) concentrations in precipitation. We also found a weak relationship between MeHg and DOC concentrations in precipitation.OAIID:RECH_ACHV_DSTSH_NO:T201916652RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A072570CITE_RATE:2.918DEPT_NM:환경보건학과EMAIL:[email protected]_YN:YN

Optimization of photolysis of diclofenac using a response surface methodology

This study investigates the effects of environmental parameters such as UV intensity (X-1, 2.1 similar to 6.3 mW/cm(2)), Fe(III) (X-2, 0 similar to 0.94 mg/L), NO3- (X-3, 0 similar to 20 mg/L) and humic acid (X-4, 0 similar to 30 mg/L) on the removal efficiency of diclofenac (DCF, Y), and optimization using a response surface methodology (RSM) based on Box-Behnken design (BBD). According to analysis of variance and t-test results (p < 0.001), the proposed quadratic BBD model based on a total of 29 experimental runs fitted well to the experimental data. Moreover, the determination coefficient (R-2 = 0.990) and adjusted determination coefficient (R-a(2) = 0.981) indicated that this model is adequate with a high goodness-of-fit. Variables of X-1, X-2 and X-3 had significant positive contributions (p < 0.001), while X-4 had significant negative contribution to the DCF removal (p < 0.001). A Pareto analysis showed that X-4 was the most important factor (57.18%) in DCF photolytic removal. The predicted and observed DCF removal were 94.98 and 94.2% under optimal conditions (X-1 = 6.29 mW/cm(2), X-2 = 0.75 mg/L, X-3 = 15.65 mg/L and X-4 = zero), respectively. The RSM not only gives valuable information on the interactions between these photoreactive species (UV intensity, Fe(III), NO3-, and humic acid) that influence DCF removal, but also identifies the optimal conditions for effective DCF removal in water.This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MEST) (No. 2010-0014222).OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000005866/2SEQ:2PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000005866ADJUST_YN:YEMP_ID:A072570DEPT_CD:903CITE_RATE:1.122FILENAME:첨부된 내역이 없습니다.DEPT_NM:환경보건학과EMAIL:[email protected]_YN:NCONFIRM:

Effects of molecular size fraction of DOM on photodegradation of aqueous methylmercury

This study investigated the photodegradation kinetics of MeHg in the presence of various size fractions of dissolved organic matter (DOM) with MW &lt; 3.5 kDa, 3.5 &lt; MW &lt; 10 kDa, and MW &gt; 10 kDa. The DOM fraction with MW &lt; 3.5 kDa was most effective in MeHg photodegradation. Increasing UV intensity resulted in the increase of photodegradation rate of the MeHg in all size of DOM fractions. Higher rates of MeHg degradation was observed at higher pH. For the portion of MW &lt; 3.5 kDa, the photodegradation rate of MeHg increased with increasing DOM concentration, indicating that radicals such as singlet oxygen (O-1(2)) radicals can be effectively produced by DOM. At higher portion of MW &gt; 3.5 kDa, the inhibition of MeHg degradation was observed due to the effect of DOM photo-attenuation. Our result indicates that radical mediated reaction is the main mechanism of photodegradation of MeHg especially in the presence of MW &lt; 3.5 kDa. Our results imply that the smaller molecular weight fraction (MW &lt; 3.5 kDa) of DOM mainly increased the photodegradation rate of MeHg. (C) 2017 Elsevier Ltd. All rights reserved.OAIID:RECH_ACHV_DSTSH_NO:T201721397RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A072570CITE_RATE:4.427DEPT_NM:환경보건학과EMAIL:[email protected]_YN:YN

Removal of Selected Micropollutants During Conventional and Advanced Water Treatment Processes

Micropollutants such as caffeine, carbamazepine, metoprolol (MTP), and sulfamethoxazole (SMZ), which are frequently detected in aquatic environments, were selected, and their removal and persistence using classical water treatment processes (coagulation, adsorption, and chlorination), and advanced oxidation processes (AOPs) (ozonation, UV photolysis, UV/H2O2, and UV/chlorine) were examined using liquid chromatographytandem mass spectrometry (LC-MS/MS). While SMZ was most effectively removed, MTP showed the lowest removal efficiency in all applied water treatments. During coagulation and adsorption processes, SMZ was effectively removed by electrostatic interaction. Chlorination was not effective for removal of the selected micropollutants. Among AOPs, UV/chlorine reaction showed the most effective removal (90-100%) for selected micropollutants, including MTP. Considering its persistence, MTP was proposed as an indicator micropollutant during water treatment.OAIID:RECH_ACHV_DSTSH_NO:T201721400RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A072570CITE_RATE:1.547DEPT_NM:환경보건학과EMAIL:[email protected]_YN:YN

Degradation mechanism of cyanide in water using a UV-LED/H2O2/Cu2+ system

In this study, we developed a UV-LED/H2O2/Cu2+ system to remove cyanide, which is typically present in metal electroplating wastewater. The results showed the synergistic effects of UV-LED, H2O2, and Cu2+ ions on cyanide removal in comparison with UV-LED photolysis, H2O2 oxidation, UV-LED/H2O2, and H2O2/Cu2+ systems. Cyanide was removed completely in 30 min in the UV-LED/H2O2/Cu2+ system, and its loss followed pseudo-first order kinetics. Statistically, both H2O2 and Cu2+ ions showed positive effects on cyanide removal, but Cu2+ ions exhibited a greater effect. The highest cyanide removal rate constant (k = 0.179 min(-1)) was achieved at pH 11, but the lowest was achieved at pH 12.5 (k = 0.064 min(-1)) due to the hydrolysis of H2O2 ( pK(a) of H2O2 = 11.75). The presence of dissolved organic matter (DOM) inhibited cyanide removal, and the removal rate constant exhibited a negative linear correlation with DOM (R-2 = 0.987). The removal rate of cyanide was enhanced by the addition of Zn2+ ions (from 0.179 to 0.457 min(-1)), while the co-existence of Ni2+ or Cr+6 ion with Cu2+ ion reduced cyanide removal. The formation of OH radicals in the UV-LED/H2O2/Cu2+ system was verified using an aminophenyl fluorescence (APF) probe. Cyanate ions and ammonia were detected as the byproducts of cyanide decomposition. Finally, an acute toxicity reduction of 64.6% was achieved in the system within 1 h, despite a high initial cyanide concentration (100 mg/L). In terms of removal efficiency and toxicity reduction, the UV-LED/H2O2/Cu2+ system may be an alternative method of cyanide removal from wastewaters. (C) 2018 Elsevier Ltd. All rights reserved.OAIID:RECH_ACHV_DSTSH_NO:T201814832RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A072570CITE_RATE:4.427DEPT_NM:환경보건학과EMAIL:[email protected]_YN:YN

Emission of greenhouse gases from waste incineration in Korea

Greenhouse gas (GHG) emission factors previously reported from various waste incineration plants have shown significant variations according to country-specific, plant-specific, and operational conditions. The purpose of this study is to estimate GHG emissions and emission factors at nine incineration facilities in Korea by Measuring the GHG concentrations in the flue gas samples. The selected incineration plants had different operation systems (i.e., stoker, fluidized bed, moving grate, rotary kiln, and kiln &amp; stoker), and different nitrogen oxide (NOx) removal systems (i.e., selective catalytic reduction (SCR) and selective non catalytic reduction (SNCR)) to treat municipal solid waste (MSW), commercial solid waste (CSW), and specified waste (SW). The total mean emission factors for A and B facilities for MSW incineration were found to be 134 +/- 17 kg CO2 ton(-1), 88 +/- 36 g CH4 ton(-1), and 69 +/- 16 g N2O ton(-1), while those for CSW incineration were 22.56 g CH4 ton(-1) and 259.76 g N2O ton(-1), and for SW incineration emission factors were 2959 kg CO2 ton(-1), 43.44 g CH4 tons and 401.21 g N2O ton(-1), respectively. Total emissions calculated using annual incineration for MSW were 3587 ton CO2-eq yr(-1) for A facility and 11,082 ton CO2-eq yr(-1) for B facility, while those of IPCC default values were 13,167 ton CO2-eq yr(-1) for A facility and 32,916 ton CO2-eq yr(-1), indicating that the emissions of IPCC default values were estimated higher than those of the plant-specific emission factors. The emission of CSW for C facility was 1403 ton CO2-eq yr(-1), while those of SW for D to I facilities was 28,830 ton CO2-eq yr(-1). The sensitivity analysis using a Monte Carlo simulation for GHG emission factors in MSW showed that the GHG concentrations have a greater impact than the incineration amount and flow rate of flue gas. For MSW incineration plants using the same stoker type in operation, the estimated emissions and emission factors of CH4 showed the opposite trend with those of NO2 when the NOx removal system was used, whereas there was no difference in CO2 emissions. (C) 2017 Elsevier Ltd. All rights reserved.OAIID:RECH_ACHV_DSTSH_NO:T201721398RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A072570CITE_RATE:4.005DEPT_NM:환경보건학과EMAIL:[email protected]_YN:YN