Publications by authors named "Sunjoon Kim"

Iron phosphate-based coating and iron silicate-based coating were used to inhibit the oxidation of sulfide minerals in rainy and submerged environments. The inhibiting effectiveness of coating agents on the oxidation of iron sulfide minerals was investigated using pyrite and rock samples resulting from acid drainage. The film formed with both surface-coating agents was identified by pyrite surface analysis.

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Nano Fe(III) oxide (FO) was used as an amendment material in CO-assisted pyrolysis of spent coffee grounds (SCG) and its impacts on the syngas (H & CO) generation and biochar adsorptive properties were investigated. Amendment of FO led to 153 and 682% increase of H and CO in pyrolytic process of SCG, respectively, which is deemed to arise from enhanced thermal cracking of hydrocarbons and oxygen transfer reaction mediated by FO. Incorporation of FO successfully created porous structure in the produced biochar.

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  • This study examined the environmental impacts of sulfamethazine (SMZ) and sulfamethoxazole (SMX) using the green microalga Scenedesmus obliquus.
  • The calculated effective concentration (EC) values indicated SMZ, SMX, and their mixture (11:1) showed varying toxicity levels, with the mixture being better predicted by concentration addition rather than independent action.
  • Despite the toxicity levels being high, S. obliquus showed some ability to remove these contaminants, with significant enhancement in SMZ removal when combined with SMX, and the formation of multiple metabolites was identified through mass spectrometry analysis.
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Microalgal biomass has received much attention as feedstock for biofuel production due to its capacity to accumulate a substantial amount of biocomponents (including lipid, carbohydrate, and protein), high growth rate, and environmental benefit. However, commercial realization of microalgal biofuel is a challenge due to its low biomass production and insufficient technology for complete utilization of biomass. Recently, advanced strategies have been explored to overcome the challenges of conventional approaches and to achieve maximum possible outcomes in terms of growth.

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  • Pyrite and other iron sulfides can oxidize when exposed to dissolved oxygen in water, leading to environmental issues like increased acidity and Fe(2+) levels.
  • A study at a Boeun site in South Korea tested the effectiveness of surface coatings (Na2SiO3 and KH2PO4) to prevent this oxidation over 449 days, finding that the rock sample had a high potential for acid production.
  • Results showed that Na2SiO3 significantly reduced pyrite oxidation, keeping pH levels between 5-6 and decreasing oxidation rates by almost 100%, indicating its potential for field application in combating iron sulfide oxidation.
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Subsurface geochemical behavior of As(V) with Fe(II) was studied under strict anoxic conditions. Abiotic reduction of As(V) (0.1 mM) to As(III) by aqueous Fe(II) and sorbed Fe(II) in pH range 5.

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This research was undertaken to evaluate the feasibility of granular ferric hydroxide (GFH) for fluoride removal from aqueous solutions. Batch experiments were performed to study the influence of various experimental parameters such as contact time (1 min-24h), initial fluoride concentration (1-100 mgL(-1)), temperature (10 and 25 degrees C), pH (3-12) and the presence of competing anions on the adsorption of fluoride on GFH. Kinetic data revealed that the uptake rate of fluoride was rapid in the beginning and 95% adsorption was completed within 10 min and equilibrium was achieved within 60 min.

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