Publications by authors named "Chul-Woong Cho"

To effectively characterize natural zeolite powder (ZP) and faujasite zeolite (FAU) as adsorbents to remove a wide variety of organic micropollutants, quantitative structure-activity relationship (QSAR) models for the adsorption of zeolites were developed. For this purpose, batch isotherms were performed to measure the adsorption affinity (K) between zeolite and organic micropollutants, and the measured K values were used as a dependent variable in the QSAR modeling. In the modeling, the concept of a linear free energy relationship (LFER) was employed and used either empirically measured or in silico calculated descriptors.

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Seaweed, one of the most abundant biomaterials, can be used as a biosorbent to remove organic micropollutants. In order to effectively use seaweed to remove a variety of micropollutants, it is vital to rapidly estimate the adsorption affinity according to the types of micropollutants. Thus, the isothermal adsorption affinities of 31 organic micropollutants in neutral or ionic form on seaweed were measured, and a predictive model using quantitative structure-adsorption relationship (QSAR) modeling was developed.

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Article Synopsis
  • The production of fruit waste and organic micropollutants poses significant environmental challenges, but fruit peels like those from oranges, mandarins, and bananas can be used as effective biosorbents to help remove these pollutants.
  • Evaluating the adsorption affinity of these biosorbents for various micropollutants is complicated and resource-intensive, leading researchers to develop quantitative structure-adsorption relationship (QSAR) models that simplify this process.
  • The study found that the fruit peels effectively adsorbed cationic and neutral micropollutants, while having less affinity for anionic ones, and the developed models showed high accuracy in predicting adsorption outcomes, suggesting they can be used for other micropollutants as well
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Yeast is ubiquitous and may act as a solid phase in natural aquatic systems, which may affect the distribution of organic micropollutants (OMs). Therefore, it is important to understand the adsorption of OMs on yeast. Therefore, in this study, a predictive model for the adsorption values of OMs on the yeast was developed.

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Activated carbon fiber (ACF) has received increasing attention as an adsorbent due to its excellent surface properties. However, the adsorption mechanism of ACF for micropollutants, especially those in ionic forms, has not been sufficiently characterized to date. Therefore, the adsorption property of ACF was characterized using isotherm experiments and linear free energy relationship (LFER).

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Cellulose can be considered as a raw material for the production of filters and adsorbents for the removal of micropollutants, particularly in pharmaceutical-based products. To study its applications, it is important to estimate the adsorptive interaction of cellulose with the targeted chemicals, and develop predictive models for the expandable estimation into various types of micropollutants. Therefore, the adsorption affinity between cellulose and micropollutants was measured through isotherm experiments, and a quantitative structure-adsorption relationship model was developed using the linear free energy relationship (LFER) equation.

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Water-soluble organic acids (e.g., acetic acid, acrylic acid, and ascorbic acid), as green leachants, have been applied to leach strategic metals (Ni, Li, Mn, and Co) from spent lithium-ion batteries (LIBs).

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Article Synopsis
  • The study focuses on the biodegradation of polystyrene (PS), a major plastic waste that is notoriously hard to break down, using specific bacterial cultures found in soil.
  • Two bacterial strains, Pseudomonas lini JNU01 and Acinetobacter johnsonii JNU01, were identified as effective in growing and degrading PS when cultivated in a nutrient medium with PS as the sole carbon source.
  • Various analytical techniques, including spectroscopy and microscopy, confirmed the biodegradation process and identified the alkane-1-monooxygenase enzyme (AlkB) in A. johnsonii JNU01 as key in facilitating PS breakdown, highlighting the potential of these microbes in managing
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Interest in ionic liquids (ILs), called green or designer solvents, has been increasing because of their excellent properties such as thermal stability and low vapor pressure; thus, they can replace harmful organic chemicals and help several industrial fields e.g., energy-storage materials production and biomaterial pretreatment.

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It is of great importance to predict the adsorption of micropollutants onto CNTs, which is not only useful for exploring their potential adsorbent applications, but also helpful for better understanding their fate and risks in aquatic environments. This study experimentally examined the adsorption affinities of thirty-one micropollutants on four multi-walled CNTs (MWCNTs) with different functional groups (non-functionalized, -COOH, -OH, and -NH). The properties of each adsorbent were predicted based on the linear free energy relationship (LFER) model.

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In this study, Zr-based metal-organic frameworks (MOFs) of UiO-66 and UiO-66-NH were synthesized and applied to removal of mercury from aqueous solution. The characterizations of UiO-66 and UiO-66-NH were examined by X-ray diffraction (XRD), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). To investigate the adsorption properties of UiO-66-NH for mercury, the experiments of kinetics, isotherm, pH, temperature, and salt concentration were conducted, and the results were compared with those by UiO-66.

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The disposal of bio-waste (e.g., Corynebacterium glutamicum) produced by the fermentation industry is a serious problem and has a negative impact on economic returns.

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In this study, banana peel (BP) and its derivatives after sequential extraction of biochemical components were evaluated for selective recovery of gold. In-depth instrumental characterizations including XPS, FTIR, XRD and HR-TEM were performed to understand the adsorption mechanisms. The biomass after lipid extraction, BP-L, demonstrated very good affinity and selectivity towards gold.

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The adsorptive removal possibility of persistent pharmaceuticals with different charges by activated carbon fiber (ACF) was examined. The pharmaceuticals tested included carbamazepine (CBZ), propranolol (PRO), and diclofenac (DCF), in neutral, cationic, and anionic forms, respectively, which were frequently detected in sewage. The adsorption characteristics of ACF were identified according to the kinetics, isotherm, pH, and ionic strength experiments.

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Article Synopsis
  • The study focused on selecting an effective cation-exchange resin (CER) to remove positively charged tricyclic antidepressants (TCAs) like amitriptyline from wastewater, finding Dowex 50WX4-200 to be the best option due to its high uptake of the drug.
  • Dowex 50WX4-200 showed maximum adsorption capacities for TCAs ranging from 2.53 to 3.76 mmol/g, outperforming previously used materials thanks to its unique interaction properties.
  • The removal efficiency of desipramine (a type of TCA) varied based on water conditions, achieving 95.68% in distilled water but only 56.66
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Dyes are colored compounds which are visible even at trace concentrations. Due to their recalcitrance and esthetic persistence, certain methods are unable to effectively eliminate them. So far, adsorptive treatment using activated carbons (ACs) is one of the most successful methods.

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Modeling for the toxicity of ionic liquids (ILs) is necessary to fill data gaps for untested chemicals and to understand the relevant mechanisms at the molecular level. In order for many researchers to easily predict toxicity and/or develop some prediction model, simple method(s) based on a single parameter should be proposed. Therefore, previously our group developed a comprehensive toxicity prediction model with unified linear free-energy relationship descriptors to address the single parameter for predicting the toxicities, as follows (Cho et al.

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After consumption of the inner fleshy fruit, the banana peel like many other fruit peels is usually disposed of unprocessed. For sustainable development, agro-wastes including banana peels need to be converted into valuable products that will be beneficial to human and the environment. In this study, biochemical components including lipids, proteins and structural polysaccharides were sequentially extracted from banana peel, and the residuals were characterized by FE-SEM/EDX, FTIR, XRD, TGA/DSC, XPS and elemental analysis.

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Ionic liquids provide challenges and opportunities for sustainable industrial developments. However, the toxic impacts of ionic liquids reported by many researchers cannot be overlooked. Therefore, in this chapter, we introduce the antimicrobial activities of ionic liquids in bioprocesses and, in greater detail, we discuss their environmental impacts, including the toxicity, biodegradability, bioaccumulation, and mobility of ionic liquids.

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Environmental fate or transport of pharmaceutical waste depends on the adsorptive interactions of pharmaceuticals with various environmental phases e.g. soil, sediment, microalgae, and bacteria etc.

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Adsorptive interactions, namely adsorption capacity (q) and affinity (b), between nonsteroidal anti-inflammatory drugs (NSAIDs) in anionic forms and commercial activated charcoal (AC), were estimated by isotherm experiment in a batch, and the properties were modeled based on the concept of quantitative structure-activity relationship (QSAR). Experimental results showed that AC had a high q (0.38-0.

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Due to high mobility and specific toxic actions of the ionizable pharmaceuticals in surface water with a normal range of pH, the pharmaceuticals should be removed before being discharged. Therefore, this study investigated the adsorptive interactions between cationic pharmaceuticals and a popular adsorbent (i.e.

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Bisphenol A (BPA), diethyl phthalate (DEP), and carbamazepine (CBZ) have been widely used in chemical and pharmaceutical fields, and their residues are detected in various environments. Therefore, to find a suitable method for removing the compounds from an aqueous solution, an adsorption method by granular activated charcoal (AC) was studied. To investigate the adsorption properties of AC, its kinetics, equilibrium, pH effects, and regeneration of AC were examined.

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TCAs are known to be toxicants and endocrine disrupting agents. Generally, after being used, TCAs are passed through wastewater treatment plants (WWTPs) to be treated. However, still trace amounts (ng/L to μg/L) of TCAs have been founded even in the treated water.

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Since estimating the octanol-water partitioning coefficients (log P) of numerous ionic liquids (ILs) is tedious, time & material consuming and labor intensive, predicting by quantitative structure-activity relationship (QSAR) approach is necessary. Although several researchers presented the QSAR models for the property, validation assessment of the models were not sufficiently performed due to lack of log P dataset. In this study, the log P values of external ILs were measured by a shaking-flask method or collected from literatures.

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