Byung-Jin Lim

Adsorption Characteristics of Heavy Metals using Sesame Waste Biochar

Little research has been conducted to explore the heavy metal removal potential of biochar. The adsorption characteristics of heavy metals by sesame waste biochar (pyrolysis at for 1 hour) as heavy metal absorbent were investigated. The sesame waste biochar was characterized by SEM-EDS and FT-IR, and heavy metal removal was studied using Freundlich and Langmuir equations. The removal rates of heavy metals were higher in the order of Pb>Cu>Cd>Zn, showing that the adsorption efficiency of Pb was higher than those of any other heavy metals. Freundlich and Langmuir adsorption isotherms were used to model the equilibrium adsorption data obtained for adsorption of heavy metals on biochar produced from sesame waste. Pb, Cu, Cd and Zn equilibrium adsorption data were fitted well to the two models, but Pb gave a better fit to Langmuir model. Heavy metals were observed on the biochar surface after adsorption by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Main functional groups were aromatic C=O ring (at , and ) by FT-IR analysis. Thus, biochar produced from sesame waste could be useful adsorbent for treating heavy metal wastewaters.

Evaluation of Aquatic Ecological Characteristics in Sinpyongcheon Constructed Wetlands for Treating Non-point Source Pollution

To evaluate the aquatic ecological characteristics in Sinpyongcheon constructed wetlands for treating nonpoint source pollution, the removal rates of nutrients in water, the total amounts of T-N and T-P uptakes by water plants, and chemical characteristics of T-N and T-P in sediment were investigated. The concentrations of BOD, COD, SS, T-N and T-P in inflow were 0.07~1.47, 0.60~2.65, 0.50~4.60, 1.38~6.26 and , respectively. The removal rates of BOD, COD, SS, T-N, and T-P were 14%, 6%, 18%, 24%, and 10%, respectively. The maximum amount of T-N uptake by water plants in August was for Phragmites communis TRIV in bed, for Typha orientalis PRESL in bed, respectively. The maximum amount of T-P uptake by water plants in August was for Phragmites communis TRIV in bed, for Typha orientalis PRESL in bed, respectively. Organic matter, T-N, and T-P contents in sediments were high in the order of bed > bed > bed. Microbial biomass C/N/P ratios in sediments in , , and were 78~110/3~6/1, 73~204/1~6/1, and 106~169/1~6/1, respectively.

Characteristics of Nutrients Release by Submerged Plants in Flood Control Reservoirs within Juam Lake

우리나라는 갈수기와 홍수기때의 강우량 차이가 크므로 주요 수원지의 저수율과 수위 변동에 큰 영향을 주고 있으며, 갈수기나 가뭄시에 노출된 호소 연안부에는 다양한 식물들이 자생하여 독특한 수면 생태계를 이루고 있다. 국내의 대부분의 댐과 저수지는 영양염류의 유입으로 여름과 초가을 고수온기에 부영양화 현상이 빈번하게 일어나고 있으며, 이러한 현상은 질소와 인 등의 영양염류와 환경요인 등의 다양한 인자와 밀접한 상관이 있다 (Cho et al., 1996; Lee and Kang, 2000). 호수내의 영양염류 증가에 영향을 주는 대표적인 오염원으로는 상류로부터 유입되는 점오염원 및 비점오염원과 호수내부에서 생산되는 유기물로 인한 부하로 알려져 있으며, 이 중 호수내부에서 생성되는 대표적인 오염원으로는 식물플랑크톤의 증가와 저수구역내 식물체의 침수로 인한 영양염류의 용출을 들 수 있다. 저수구역내에서 생장하는 식물들은 생장기 동안에는 수질과 토양 (퇴적층)으로 부터 영양성분을 흡수하여 생장하므로 수질정화 뿐만 아니라 토양 생태계 활성화에 다양한 이점이 있으나, 홍수기에는 저수율 상승으로 인해 식물들이 상당기간 침수되어 분해되면서 수중의 영양염류를 증가시켜 조류의 번식과 이취미 유발 요인 등으로 작용할 수 있고, 부영양화를 촉진시켜 안정적인 수자원 공급에 차질을 빚을 수 있다 (Cho, 2010; Lee and Bae, 2002; Lee and Kim, 2005; Lee and Park, 2005;).우리나라의 다목적댐은 건설 목적에 따라 저수량 관리를 효과적으로 하기 위하여 여름 홍수기 전에 수위를 최대한 낮추며, 여름 홍수기 이후에 높은 수위를 유지시켜

Estimation of Pollutant Load Delivery Ratio for Flow Duration Using L-Q Equation from the Oenam-cheon watershed in Juam Lake

The objective of this study is to provide pollutant loads delivery ratio for flow duration in Oenam-cheon watershed, which is upstream watershed of Juam Lake. To calculate the delivery ratio by flow duration, rating curves and discharge-loads curves using measured data were established, then Flow Duration Curve(FDC) and pollutant loads delivery ratio curves were constructed. The results show that the delivery ratios for BOD5 for abundant flow(Q95), ordinary flow(Q185), low flow(Q275), and drought flow(Q355) were 23.9, 12.7, 7.1, and 2.9%, respectively. The delivery ratios of same flow regime for T-N were 58.4, 31.2, 17.2 and 7.1%, respectively. While, the delivery ratios T-P were 17.3, 7.5, 3.4, and 1.1% respectively. In general, delivery ratio of high flow condition showed higher value due to the influence of nonpoint source pollution. Based on the study results, generalized equations were developed for delivery ratio and discharge per unit area, which could be used for ungaged watershed with similar pollution sources.

Evaluation of Treatment Efficiencies of Pollutants in Boknae Bio-Park Constructed Wetlands

Boknae Bio-park is a free water surface constructed wetlands to remove non-point source pollution. Boknae Bio-park constructed wetlands (CWs) consist of forebay, wetlands (1 st , 2 nd , and 3 rd wetlands), and micropool. The concentrations of BOD, SS, T-N and T-P in inflow were 1.87-4.23, 5.2-24.0, 4.94-15.59 and 0.10-0.75 mg L -1 in Boknae Bio-park CWs from April to December in 2008, respectively. The removal rates of BOD, SS, T-N and T-P in Boknae Bio-park CWs were 26, 43, 62 and 83%, respectively. The removal rates of BOD and SS in the spring and summer were higher than those in other seasons. The removal rates of T-N and T-P on spring were slightly higher than those in other seasons. The amounts of pollutants removal in Boknae Bio-park CWs were higher in the order of forebay > wetlands > micropool for BOD, wetlands > forebay > micropool for SS and wetlands > forebay > micropool for T-N. The amount of T-P removal was not significant different in all areas.

Event Mean Concentrations (EMCs) and First Flush Characteristics of Runoff from a Public Park in Korea

Characteristics of non-point source (NPS) pollution runoff from a public park in Gwangju, Korea were investigated. Results exhibited the highest pollutant concentrations at the start of the rainfall events due to their build-up and wash off processes. The average event mean concentrations (EMCs) were 27.8, 7.2, 56.3, 7.5, and 0.84 mg/L (range: 4.2–54.8 mg/L) for COD, (0.5–20.8 mg/L) for TOC, (22.3–138.4) for SS, (1.4–18.5 mg/L) for T-N, and (0.17–2.02 mg/L) for T-P, respectively. The study site presented a strong first flush effect for most rainfall events. However, no first flush effect was observed in rainfall events with small rainfall factors (e.g. intensity, amount, and runoff depth). On the other hand, the ratios of total pollution loads discharged by the first 20% of runoff volume were 32% for COD, 34% for TOC, 36% for SS, 42% for T-N, and 50% for T-P. Especially, MFF20 (mass first flush) values of T-N and T-P were larger than those of other pollutants (COD, TOC, SS), indicating that T-N and T-P are easily transported by stormwater runoff from the public park. First flush management of T-N and T-P, therefore, is required for efficient water quality management of the public park.

Removal and Release Velocities of Nutrients by Submerged Plants in Flood Control Reservoirs around Juam Lake

BACKGROUND: Eutrophication occurs occasionally in flood control reservoirs around Juam lake in summer and early autumn. Lakeside macrophyte which is one of internal pollutants effects on water quality when it is submerged during water surface is rising after rainy season. METHODS AND RESULTS: To improve water the quality of water from water supply source and to establish the management plan of submerged plants in flood control reservoirs around Juam Lake, the removal and release velocities of nutrients by submerged plants in site 1 and 2 were investigated. Removal or release velocity constant (K) of COD by Carex dimorpholepis Steud in column was 0.07~0.18 at 0~4 days after flooding, -0.23~-0.17 at 5~19 days after flooding and -0.28~0.03 at 20~33 days after flooding. Removal or release velocity constant (K) of T-N by Carex dimorpholepis Steud was 0.02 at 0~4(8) days after flooding, -0.13~-0.10 at 5(9)~33 days after flooding in column. Removal or release velocity constant (K) of T-P by Carex dimorpholepis Steud was 0.05~0.06 at 0~4 days after flooding, -0.14~-0.09 at 5~33 days after flooding. Release velocity constant (K) of nutrients by Miscanthus sacchariflorus Benth was lower than that by Carex dimorpholepis Steud. In site 1, the amount of nutrients release by Carex dimorpholepis Steud was 6,719 kg/month/area for COD, 2,397 kg/month/area for T-N and 466 kg/month/area for T-P. The amounts of nutrients release by Carex dimorpholepis Steud were higher than those by Miscanthus sacchariflorus Benth in both sites. CONCLUSION(s): The results of this study suggest that COD, T-N and T-P in water quality of Juam lake were strongly influenced by submerged plants in flood control reservoirs.

Degradation of Synthetic Dyeing Wastewater by Underwater Electrical Discharge Processes

Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems: underwater pulsed electrical discharge (UPED) and underwater dielectric barrier discharge (UDBD). Reactive Blue 4 (RB4) and Acid Red 4 (AR4) were used as model contaminants for the synthetic wastewater. The performance of the aforementioned systems was compared with respect to the chromaticity removal and the energy requirement. The results showed that the present electrical discharge systems were very effective for degradation of the dyes. The dependences of the dye degradation rate on treatment time, initial dye concentration, electrical energy, and the type of working gas including air, O2, and N2 were examined. The change in the initial dye concentration did not largely affect the degradation of either RB4 or AR4. The energy delivered to the UPED system was only partially utilized for generating reactive species capable of degrading the dyes, leading to higher energy requirement than the UDBD system. Among the working gases, the best performance was observed with O2. As the degradation proceeded, the concentration of total dissolved solids and the solution conductivity kept increasing while pH showed a decreasing trend, revealing that the dyes were effectively mineralized.

Evaluation of Flow-Pollutant Load Delivery Ratio Equations on Main Subwatersheds within Juam Lake

The objective of this study is to evaluate Flow-Pollutant load delivery ratio equations developed from rural watershed on main subwatersheds within Juam Lake. Two regression equations for BOD and three equations for T-P were evaluated on Bosung cheon, Dongbok cheon, Songgwang cheon, Naenam cheon, and Sinpyeon cheon. The results show that estimation of BOD delivery ratio using flow-delivery equation is reliable when relative composition of discharge load of pollutant sources of a watershed is similar to those of watershed where the equation developed. On the other hand, application of regression equation for T-P was feasible when the landuse pattern and relative composition of discharge load of pollutant sources of a watershed is similar to those of watershed where the equation developed.

Evaluation of Wastewater Treatment Efficiency in Dongbokcheon Constructed Wetlands for Treating Non-point Source Pollution at Different Treatment Time and Wastewater Loading

consisted of forebay, wetlands (1 st , 2 nd , 3 rd , 4 th , 5 th , 6 th , 7 th , and 8 th wetlands) and sedimentation pond. The concentrations of BOD, SS, T-N, and T-P in inflow ranged 0.85～3.14 mg L -1 , 3.33～9.70 mg L -1 , 0.64～5.33 mg L -1 , and 0.03～0.10 mg L -1 from April to October in 2008, respectively. The removal rates of BOD, SS, T-N, and T-P in Dongbokcheon CWs were 34%, 5%, 31%, and 13%, respectively. The removal rates of BOD and T-N were higher than those for SS and T-P. The amounts of pollutant removal in Dongbokcheon CWs were higher in the order of forebay > wetlands > sedimentation pond for BOD, sedimentation pond > wetlands > forebay for SS, sedimentation pond > forebay > wetlands for T-N. The amount of T-P removal in wetlands was higher than forebay and sedimentation pond.