Ik-Won Choi

Competitive adsorption and selectivity sequence of heavy metals by chicken bone-derived biochar: Batch and column experiment

The objective of this research was to evaluate adsorption of heavy metals in single- and ternary-metal forms onto chicken bone biochar (CBB). Competitive sorption of heavy metals by CBB has never been reported previously. The maximum adsorption capacities of metals by CBB were in the order of Cu (130 mg g−1) > Cd (109 mg g−1) > Zn (93 mg g−1) in the single-metal adsorption isotherm and Cu (108 mg g−1) >> Cd (54 mg g−1) ≥ Zn (44 mg g−1) in the ternary-metal adsorption isotherm. Cu was the most retained cation, whereas Zn could be easily exchanged and substituted by Cu. Batch experimental data best fit the Langmuir model rather than the Freundlich isotherms. In the column experiments, the total adsorbed amounts of the metals were in the following order of Cu (210 mg g−1) > Cd (192 mg g−1) > Zn (178) in single-metal conditions, and Cu (156) > Cd (123) > Zn (92) in ternary-metal conditions. Results from both the batch and column experiments indicate that competitive adsorption among metals increases the mobility of these metals. Especially, Zn in single-metal conditions lost it adsorption capacity most significantly. Based on the 3D simulation graphs of heavy metals, adsorption patterns under single adsorption condition were different than under competitive adsorption condition. Results from both the batch and column experiments show that competitive adsorption among metals increases the mobility of these metals. The maximum metal adsorption capacity of the metals in the column experiments was higher than that in the batch experiment indicating other metal retention mechanisms rather than adsorption may be involved. Therefore, both column and batch experiments are needed for estimating retention capacities and removal efficiencies of metals in CBB.

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.

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

Biosorption of Heavy Metal in Aqueous Solution by Heavy Metal Tolerant Microorganism Isolated from Heavy Metal Contaminated Soil

This study was conducted to find out a useful bioremediation technology for heavy metal contaminated soil and water. We isolated strain CPB from heavy metal contaminated soil and evaluated the tolerance level and adsorption capacity of strain CPB to heavy metals (Strain is not determined yet). Strain CPB showed variable tolerance limit to different kinds heavy metal or concentrations of heavy metals. The growth of strain CPB was significantly inhibited by mixed heavy metals (Cd+Cu+Pb+Zn) than that of by single heavy metal. Strain CPB showed high binding capacity with Pb (Pb>Cd>Cu>Zn). In general, strain CPB showed high uptake of heavy metals such as Pb, Cd and Cu. It was observed that the capacity of heavy metal uptake from mixture of heavy metals was reduced in comparison with single heavy metal treatment. But total contents of heavy metal bound with cell in mixed heavy metal showed higher than in single heavy metal treatment. Heavy metal adsorption in cells was affected by several external factors, such as temperature and pH etc.. The optimum temperature and pH of the adsorption of heavy metal into cells were ca. and pH ca. , respectively. A large number of the electron dense particles were found mainly on the cell wall and cell membrane fractions, which was determined by transmission electron microscope. Energy dispersive X-ray spectroscopy revealed that the electron dense particles were the heavy metal complexes the substances binding with heavy metals.

Effect of Biochar Application on Rice Yield and Greenhouse Gas Emission under Different Nutrient Conditions from Paddy Soil

AbstractThis study was conducted to investigate the effect of biochar application on rice yield and greenhouse gases in nutrient-poor soil (NPS) and nutrient-rich soil (NRS). The treatment conditions for NPS and NRS plots were control (C), Ffertilizer (F), and sesame straw biochar + F (BC) treatments. The rice yields were higher in the order of BC(421.8  g m−2)>F>C for the NPS plot and BC(802.4  g m−2)>C>F for the NRS plot. CH4 flux with the NPS plot was similar to that of the NRS plot, whereas N2O flux in the NRS plot was greater than in the NPS plot in all tested treatments. The global warming potential in biochar application treatments was lower, with the global CH4+N2O fluxes decreased by 25.0–36.8% for the NPS plot and 16.7–39.4% for the NRS plot, compared with the corresponding other treatments. These results suggest that biochar application in NPS and NRS will enhance rice productivity and reduce CH4 and N2O fluxes.

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.

Evaluation of Fertilizer Value of Animal Cadavers for Agricultural Recycling

To evaluate fertilizer value of animal cadavers for agricultural recycling, fertilizer components of animal cadavers by pig and poultry were investigated using rendering and alkali (KOH) treatment methods. Total nitrogen concentrations in meat waste by pig and poultry using rendering treatment method were 7.80% and 9.30%, respectively. Total nitrogen concentration in meat waste of pig by KOH treatment method was lower than that by rendering treatment method. Organic matter concentrations in meat waste of pig and poultry ranged 87.8~97.4%. Total phosphorus concentrations in bone waste of pig using rendering and KOH treatment methods ranged 5.59~11.18%. Animal cadavers contains nitrogen, phosphorus, potassium and other nutrients essential to plant growth. The results of this study suggest that animal cadavers can supply some of the nutrient requirements of crops and is a valuable fertilizer as well.

Effects of Application of Liquid Pig Manure on Yield of Green manure in Single and Companion Cropping

To evaluate the effects of liquid pig manure (LPM) on green manure crop yields, plant height and biomass of green manure crops were investigated in single and companion cropping. Green manure crops used for this experiment were Hordeum vulgare L. (green barley) and Vicia villosa roth (hairy vetch). Field experiment was designed with LPM 1.65 (LPM of + single and companion green crops), LPM 3.3 (LPM of + single and companion green crops) and LPM 6.6 (LPM of 6.6 + single and companion green crops). In single cropping, plant height were high in LPM 3.3. In companion cropping, plant height were high in LPM 6.6. Thus, we found that application of LPM is general enough to reduce use of chemical fertilizer. Also, optimum application level in single cropping would be LPM 3.3 and in companion cropping would be higher than LPM 3.3.

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.

Evaluation of Fertilizer Value of Biochars Using Water Plants

To develop biochar for soil conditioner using water plants, characteristics of nutrients release of biochars were investigated under different water plants, manufacturing times and manufacturing temperatures. Under different water plants for manufacturing biochar, the concentrations of T-N and in the water with biochars were higher in the order of CRXDM > ZIZLA > PHRCO > TYHOR > MISSA. The concentrations of in the water were in the order of TYHOR CRXDM > ZIZLA > PHRCO > MISSA. Under different manufacturing times for biochar, the concentrations of T-N, and in the water with biochars were higher in the order of 2 hr > 30 min 1 hr. The concentrations of T-N, and in the water with biochars were on the order of > > under different manufacturing temperatures. Total amounts of T-N and releases in the water with biochars were higher in the order of CRXDM > ZIZLA > PHRCO > TYHOR > MISSA. Using biochars by water plants, total amounts of releases in the water with biochars were on the order of CRXDM > ZIZLA > MISSA >PHRCO > TYHOR. The results of this study suggest that biochars by water plants can supply some of the nutrient requirements of crops and can be a valuable fertilizer.