Seoul National University · 環境科学
Professor Nag-Choul Choi's research lab specializes in environmental biotechnology and materials science, focusing on the development of sustainable solutions for water and soil remediation. Key research directions include microbial transport and adhesion in porous media, biosurfactant-enhanced contaminant removal, and the design of functional biochar and hybrid membrane systems for heavy metal and arsenic removal. The lab also investigates bioleaching processes using indigenous acidophilic microorganisms and applies advanced modeling techniques such as artificial neural networks to predict complex environmental processes.
Figures are computed from collected data and may differ slightly.
The objective of this study was to investigate the bacterial adhesion to iron (hydr)oxide-coated sand (IHCS) and aluminum oxidecoated sand (AOCS) in the presence of Tween 20 (nonionic surfactant) and lipopeptide biosurfactant (anionic surfactant) through column experiments. Results show that in the presence of Tween 20, bacterial adhesion to the coated sands was slightly decreased compared to the condition of deionized water; the mass recovery (Mr) increased from 0.491 to 0.550 in IHCS and from
In this study, we quantified the attachment and detachment of bacteria during transport in order to elucidate the contributions of reversible attachment on bacterial breakthrough curves. The first set of breakthrough experiment was performed for a laboratory sand column using leaching solutions of deionized water and mineral salt medium (MSM) of 200 mM with reference to KCl solution by employing Pseudomonas putida as a model bacterium. In the second set of experiment, the ionic strengths of leac
가축 매몰지내 침출수의 누출은 인간과 다른 가축들에게 쉽게 질병을 확산시킬 수 있는 중요한 문제이다. 본 연구에서는 매몰된지 5개월 이내의 초기 16개 가축매몰지에 대한 침출수의 물리화학적 특성과 분자미생물학적 방법을 이용하여 침출수내 존재하는 호기성 미생물을 분석하였다. 총대장균군, 총유기탄소, 암모니아이온 및 질산성질소가 관련된 참고문헌자료에 비하여 높게 나타났다. 또한 암모니아 이온과 질산성질소는 국내 먹는물 기준치를 초과하여 나타났다. 16S rNA 서열 분석법을 사용하여 호기성 조건에서 침출수의 미생물 분포를 분석한 결과, 높은 빈도의 Bacillus pumilus, Lysinibacillus sphaericus 및 Bacillus sphaericus이 관찰되었지만, Bucillus cereus와 Salmonella와 같은 식중독 미생물은 발견되지 않았다. 본 연구는 가축매몰지로부터 형성되는 침출수에 대한 지질 매체 내에서의 거동특성, 처리 및 위해성 평가에 대한 기초자료로
In this study, indigenous acidophilic bacteria living in mine drainage and hot acidic spring were collected and used for bioleaching experiments. The incubated indigenous acidophilic bacteria were inoculated on various minerals. The changes in pH, Eh, and heavy metal concentrations were examined with uninoculated controls to study bioleaching over time. As a result, the aspects of bioleaching varied greatly depending on the origin of microorganisms, the type of minerals, the temperature conditio
Ceramic membranes and ion exchangers are effective at removing turbidity and ionic contaminants from water, respectively. In this study, we demonstrate the performance of a hybrid ion-exchange fabric/ceramic membrane system to treat metal ions and turbidity at the same time in synthetic wastewater. The removal rate of As(V) and Zn(II) by the ceramic membrane increased with solution pH, while turbidity was completely removed regardless of the solution pH. The main reaction of As(V) removal was ad
• Fe-modified spirulina platensis (SP)-derived biochar showed excellent arsenic removal in solution. • After Fe modification, the formed Fe species and N-containing components of SP were used to introduce pyridinic N, which can be coordinated with Fe to form Fe-N. • The formed Fe species (Fe 0 , Fe 2+ and Fe 3+ ) and defective structures in FeSP600 act as active sites for catalytic surface reactions. • The effect of pH not only promoted the release of dissolved Fe from FeSP600, but also affected
The high affinity of iron-based byproducts for anion removal can facilitate wastewater treatment using membranes functionalized with such byproducts. In this study, a low-cost functional ceramic membrane (LFCM) based on waste cast iron (WCI) was fabricated and applied to remove selenium from aqueous solutions. The effect of roasting (1250 °C) on the raw material properties was analyzed by X-ray diffraction and specific surface area measurements. Upon roasting, zero-valent iron (Fe0) present in W
본 연구에서는 매몰경과시간에 따라 4지점의 가축매몰지 침출수에 대하여 물리화학적 특성과 분자미생물학적 방법을 이용하여 침출수내 미생물을 분석하였다. 침출수에 대한 물리화학적 분석 결과, 매몰중기 (매몰경과 20개월)에서 매몰초기 (매몰경과 5개월) 자료에 비하여 EC, DO, <TEX>$HCO_3{^-}$</TEX>, TOC, T-N 과 <TEX>$SO_4{^{2-}}$</TEX> 의 함량이 높게 나타났다. 16S rRNA방법을 이용한 침출수의 미생물을 동정한 결과, 매몰초기에 Lysinibacillus sphaericus, Bacillus pumilus, Pseudoclavibacter helvolus, Pseudochrobactrum saccharolyticum 과 Corynebacterium callunae 이 동정되었으며, 매몰중기에는 Bacillus cereus, Lysinibacillus sphaericus, Bacillus circulans 과 Corynebacteriu
The aim of this study was to investigate the effect of a simple and economical salt-roasting method on the gold recovery of a conventional lead fire assay. An enhanced gold recovery of 30.99 g/ton (16.82%) was obtained by roasting a gold concentrate at 750°C, but this was further enhanced to 40.44 g/ton (21.95%) at the same temperature with the addition of 20% salt. The fact that the maximum recovery was obtained at a roasting temperature of 750°C was attributed to the fact that pyrites within t
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