TAYLOR & FRANCIS

 Journal

 Long-term Trends Of Atmospheric SO2 In Seoul, Korea From 1987-2013

 Khan, A., Brown, R., Jeon, E., Oh, J., Shin, Y., Adelodun, A.A., Kim, K-H

 2017

Atmospheric concentration of sulfur dioxide (SO2) was intermittently measured at an air quality monitoring (AQM) station in the Yong-san district of Seoul, Korea between 1987 and 2013. The SO2 level was compared with other important pollutants concurrently measured including methane (CH4), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), ozone (O3), and particulate matter (PM10). If split into three different periods (period 1 (1987-1988), period 2 (1999-2000), and period 3 (2004-2013)), the respective mean [SO2] values (6.57±4.29, 6.30±2.44, and 5.29±0.63 ppb) showed a slight reduction across the entire study period. The concentrations of SO2 are found to be strongly correlated with other pollutants such as CO (r = 0.614, p = 0.02) which tracked reductions in reported emissions due to tighter emissions standards enacted by the S Korean government. There was also a clear seasonal trend in the SO2 level, especially in periods 2 and 3, reflecting the combined effects of domestic heating by coal briquettes and meteorological conditions. Although only a 16% concentration reduction was achieved during the 27-year study duration, this is significant if one considers rapid urbanization, an 83.2% increase in population, and rapid industrialization that took place during that period. Implication Statement Since 1970, a network of air quality monitoring (AQM) stations has been operated by the Korean Ministry of Environment (KMOE) for routine nationwide monitoring of air pollutant concentrations in urban/suburban areas. To date, the information obtained from these stations has provided a platform for analyzing long-term trends of major pollutant species. In this study, we examined the long-term trends of SO2 levels and relevant environmental parameters monitored continuously in the Yong-san district of Seoul between 1987 and 2013. The data was analyzed over various timescales (i.e., monthly, seasonal, and annual). The results obtained from this study will allow us to assess the effectiveness of abatement strategy while allowing predictions of future concentrations trends when considering future abatement strategies and technologies

 

 Elsevier

 Journal

 Air Ionization As A Control Technology For Off-gas Emissions Of Volatile Organic Compounds

 3. Kim, K-H., Szulejko, J.E., Kumar, P., Kwon, E.E., Adelodun, A.A., Police, A

 2017

High energy electron-impact ionizers have found applications mainly in industry to reduce off-gas emissions from waste gas streams at low cost and high efficiency because of their ability to oxidize many airborne organic pollutants (e.g., volatile organic compounds (VOCs)) to CO2 and H2O. Applications of air ionizers in indoor air quality management are limited due to poor removal efficiency and production of noxious side products, e.g., ozone (O3). In this paper, we provide a critical evaluation of the pollutant removal performance of air ionizing system through comprehensive review of the literature. In particular, we focus on removal of VOCs and odorants. We also discuss the generation of unwanted air ionization byproducts such as O3, NOx, and VOC oxidation intermediates that limit the use of air-ionizers in indoor air quality management.

 

 Asian Journal Of Atmospheric Environment

 Journal

 A Test Of Sorptive Removal Properties Of Odors By Zeolite.

 4. Adelodun, A.A., Vellingiri, K., Jeon, V., Oh, J.M., Kim, K-H

 2017

The adsorptive removal properties of synthetic A4zeolite were investigated against a total of 16 offensiveodors consisting of reduced sulfur compounds(RSCs), nitrogenous compounds (NCs), volatile fattyacids (VFAs), and phenols/indoles (PnI). Removal ofthese odors was measured using a laboratory-scaleimpinger-based adsorption setup containing 25 g ofthe zeolite bed (flow rate of 100 mL min-1). The highest and lowest breakthrough (%) values were shownfor PnIs and RSCs, respectively, and the maximumand minimum adsorption capacity (μg g-1) of the zeolitewas observed for the RSCs (range of 0.77-3.4)and PnIs (0.06-0.104), respectively. As a result ofsorptive removal by zeolite, a reduction in odorstrength, measured as odor intensity (OI), was recordedfrom the minimum of approximately 0.7 OIunits (indole [from 2.4 to 1.6]), skatole [2.2 to 1.4],and p-cresol [5.1 to 4.4]) to the maximum of approximately4 OI units (methanethiol [11.4 to 7.5],n-valeric acid [10.4 to 6.5], i-butyric acid [7.9 to4.4], and propionic acid [7.2 to 3.7]). Likewise, whenremoval was examined in terms of odor activity value(OAV), the extent of reduction was significant (i.e.,1000-fold) in the increasing order of amy acetate, ibutyricacid, phenol, propionic acid, and ammonia. 

 Asian Journal Of Atmospheric Environment

 Journal

 Performance Of Air Freshener System For The Removal Of Various Odorants Released From Foodstuffs.

 5. Kim, K-H., Adelodun, A.A., Deep, A., Kwon, E.E., Jeon E-C., Kim, Y-H

 2017

The effectiveness of four air fresher (AF) systemswas evaluated with respect to their removal efficienciesagainst offensive odorants. For this purpose,malodorous species were generated by exposingfreshly cooked foods emitting odorants with levelsmoderately above their respective threshold valuesin a confined room. The deodorization efficiency ofthe four AF systems was then tested for a period of30 min by estimating the extent of reduction in odorantlevels after the operation of each AF. The removalefficiency of the four AF units against each odorantwas evaluated as follows: (1) between AF productsfrom different manufacturers, (2) between odorantsand ultrafine particulate matter (PM2.5), and (3) betweenoperation and natural degassing. The averagesorptive removal of odorants was generally <80%and considered less effective or non-effective relativeto PM2.5. Further examination of odor reduction,if evaluated in terms of odor indices like odor intensity(OI) and odor activity value (OAV), recorded amean of 33% and 87%, respectively. The overallresults of this study confirmed that all tested AF unitswere not effective to resolve odor problems createdunder our testing conditions. 

 Elsevier

 Journal

 Synthesis And Photocatalytic Application Of TiO2 Nanoparticles Immobilized On Polyacrylonitrile Nanofibers Using EDTA Chelating Agents.

 Chauque, E.F.C., Adelodun, A.A., Dlamini, L.N., Greyling, C.J., Ray, S.C., Ngila, J.C.

 2017

The photocatalytic properties of TiO2 nanoparticles (TNPs) have been widely demonstrated in theliterature. Here, we report the chemical attachment of TNPs to the surface of polyacrylonitrile nanofibers(PNFs) using the ethylenediaminetetraacetic acid (EDTA) and ethylenediamine (EDA) as the chelatingagents. The composite nanofibers were prepared through the chelation of Ti4þ ions with surface carboxylicand amine groups followed by self-growth of TiO2 nanoparticles on the surface of modified PNFsduring the incubation process. The fabricated composite nanofibers were stabilized at 240 C in a tubefurnace under N2 gas. The heat treatment served to simultaneously crystallize the TNPs and enhancerobustness of PNFs as cyclization reactions and the cross-linking of adjacent nitrile groups (eC]NeC]Ne) usually takes place at temperatures above 200 C. Characterization techniques included X-rayphotoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fouriertransform infrared (FT-IR), Raman spectroscopy and Brunauer-Emmett-Teller (BET) technique. Thechemical impregnation of EDTA-EDA on the surface of PNFs resulted in slight increase in the averagenanofibers diameter. The anatase TiO2 nanoparticles with average 9.4 nm particle size prepared in situwere immobilized on the surface of pre-functionalized PNFs. The fabricated composite nanofibers were applied in the photocatalytic degradation of methyl orange (MO) in synthetic aqueous solutions. The asprepared composite nanofibers were reused for five (5) cycles without considerable decline in the MOremoval efficiency (i.e. >98% of initial performance). 

 Elsevier

 Journal

 Engineered Nanoparticles: Nature, Behavior And Effect On The Environment.

 7. Goswami, L., Kim, K-H., Deep, A., Das, P., Bhattacharya, S., Kumar, S., Adelodun, A.A.

 2017

Increased application of engineered nano particles (ENPs) in production of various appliances andconsumer items is increasing their presence in the natural environment. Although a wide variety ofnano particles (NPs) are ubiquitously dispersed in ecosystems, risk assessment guidelines to describetheir ageing, direct exposure, and long-term accumulation characteristics are poorly developed. In thisreview, we describe what is known about the life cycle of ENPs and their impact on natural systemsand examine if there is a cohesive relationship between their transformation processes and bioaccessibilityin various food chains. Different environmental stressors influence the fate of theseparticles in the environment. Composition of solid media, pore size, solution chemistry, mineralcomposition, presence of natural organic matter, and fluid velocity are some environmental stressorsthat influence the transformation, transport, and mobility of nano particles. Transformed nano particlescan reduce cell viability, growth and morphology, enhance oxidative stress, and damage DNA inliving organisms. 

 Springer

 Journal

 Recovery Of Ammonium Ion As Struvite From Flue Gas Scrubbing Wastewater

 8. Thapa, S., Ha, T-Y., Adelodun, A.A., Lee, H-S., Jo, Y.M

 2017

Direct disposal of flue gas scrubbing-derived waste water with a high level (9000–10,000 mg/L) of ammonium ion (NH 4+) into aquatic systems has contributed to environmental depreciation. Here, we report a feasibility study on NH 4+ recovery and conversion to struvite (NH 4MgPO 4·6H 2O), which is a slow-release fertilizer. Such conversion also aids in compliance with the discharge limits for nitrogen-based compounds. Lab-scale experiments were performed to determine the optimum pH and molar ratio (Mg 2+:NH 4+:PO 43−) for struvite formation. A chemical equilibrium model (Visual Minteq) was also employed to corroborate the experimental results. The optimum pH for struvite precipitation was found to be pH 9 with a molar ratio of Mg 2+:NH 4+:PO 4³ − = 1:1:1. At this pH, more than 93, 92.3 and 100% of the NH 4+, Mg 2+ and PO 43−, respectively, were removed from the scrubbing waste water Visual Minteq simulation also demonstrated optimum struvite formation at pH 9–10. Both X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) analysis revealed that the synthesized struvite was comparable to that of a commercial struvite. Thus, our findings confirmed the possibility of synthesizing struvite from de-NOx scrubbing wastewater utilizing the residual ammonium ions (NH 4+).

 

 Elsevier

 Journal

 Toward A Better Understanding Of The Impact Of Mass Transit Air Pollutants On Human Health

 Kim, K.H., Kumar, P., Szulejko, J.E., Adelodun, A.A., Junaid, M.F

 2017

Globally, modern mass transport systems whether by road, rail, water, or air generate airborne pollutantsin both developing and developed nations. Air pollution is the primary human health concern originatingfrom modern transportation, particularly in densely-populated urban areas. This review will specificallyfocus on the origin and the health impacts of carbonaceous traffic-related air pollutants (TRAP), includingparticulate matter (PM), volatile organic compounds (VOCs), and elemental carbon (EC). We concludethat the greatest current challenge regarding urban TRAP is understanding and evaluating the humanhealth impacts well enough to set appropriate pollution control measures. Furthermore, we provide adetailed discussion regarding the effects of TRAP on local environments and pedestrian health in low andhigh traffic-density environments. 

 Renewable & Sustainable Energy Reviews ; Elsevier

 Journal

 Solar Energy: Potential And Future Prospects.

 Kabir, E., Kumar, P., Kumar, S., Pawan, Adelodun, A.A., Kim, K-H.

 2017

The development of novel solar power technologies is considered to be one of many key solutions toward fulfilling a worldwide increasing demand for energy. Rapid growth within the field of solar technologies is nonetheless facing various technical barriers, such as low solar cell efficiencies, low performing balance-of-systems (BOS), economic hindrances (e.g., high upfront costs and a lack of financing mechanisms), and institutional obstacles (e.g., inadequate infrastructure and a shortage of skilled manpower). The merits and demerits of solar energy technologies are both discussed in this article. A number of technical problems affecting renewable energy research are also highlighted, along with beneficial interactions between regulation policy frameworks and their future prospects. In order to help open novel routes with regard to solar energy research and practices, a future roadmap for the field of solar research is discussed.

 

 WILEY, Journal Of Applied Polymer Science

 Journal

 Evaluation Of CO2 Adsorption Capacity Of Electrospun Carbon Fibers With Thermal And Chemical Activation.

 Kim, D.W., Jung, D.W., Adelodun, A.A., Jo, Y.M

 2017

The use of urea was investigated as an alternative to the poisonous and expensive NH3 gas, commonly used for amination of adsorbents. First, we fabricated activated carbon nanofibers (AnFs) by electrospinning of urea-doped polyacrylonitrile solution (N-AnF). By increasing the activation temperature, the average specific surface area (SBET) and micropore volume (Vmicro) of pristine nFs improved from 27.3 to 300 m2/g and 0.004 to 0.13 cm3/g, respectively. Upon urea doping, both properties were further enhanced to 542 m2/g and 0.22 cm3/g, respectively. However, with chemical investigation via X-ray photoelectron spectroscopy, we observed that the urea-doping incorporated more of less desired quaternary-N, along with other more basic and desirable N-functionalities (i.e., nitrile, pyridinic, pyrrolic N) tethered. Based on the eventual CO2adsorption results, we realized that average pore diameter (davg) is a limiting factor with regard to CO2 adsorption by AnFs; the lower the davg, the better the adsorption. Further examination via adsorption isotherm model fitting showed that CO2 molecules were homogenously collected in a monolayer pattern. However, three-parameter model Redlich–Peterson model best fits the experimental data, suggesting that the adsorption is concentration-driven and that it tends toward Langmuir rather than Freundlich at elevated concentration of CO2