A Test of Relative Removal Properties of Various Offensive Odors by Zeolite

Adedeji A. Adelodun,Kowsalya Vellingiri,전병훈,오종민,Sandeep Kumar,김기현 한국대기환경학회 2017 Asian Journal of Atmospheric Environment (AJAE) Vol.11 No.1

The adsorptive removal properties of synthetic A4 zeolite were investigated against a total of 16 offensive odors consisting of reduced sulfur compounds (RSCs), nitrogenous compounds (NCs), volatile fatty acids (VFAs), and phenols/indoles (PnI). Removal of these odors was measured using a laboratory-scale impinger-based adsorption setup containing 25 g of the zeolite bed (flow rate of 100 mL min-1). The high est and lowest breakthrough (%) values were shown for PnIs and RSCs, respectively, and the maximum and minimum adsorption capacity (μg g-1) of the zeolite was observed for the RSCs (range of 0.77-3.4) and PnIs (0.06-0.104), respectively. As a result of sorptive removal by zeolite, a reduction in odor strength, measured as odor intensity (OI), was recorded from the minimum of approximately 0.7 OI units (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 approximately 4 OI units (methanethiol [11.4 to 7.5], n-valeric acid [10.4 to 6.5], i-butyric acid [7.9 to 4.4], and propionic acid [7.2 to 3.7]). Likewise, when removal 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, ibutyric acid, phenol, propionic acid, and ammonia.

Surface oxidation of activated carbon pellets by hydrogen peroxide for preparation of CO2 adsorbent

Adedeji A. Adelodun,임윤희,조영민 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

This work attempted to use H2O2 as an oxidant for the incorporation of surface oxygen functionalities (SOFs) on activated carbon in the preparation of a CO2 adsorbent. Experimental results showed that oxidation at lowered temperature improved both structural and chemical properties more than those at ambient temperature, although oxidation at this temperature with 30% H2O2 incorporated the highest amount of useful SOFs for amination purpose. pHpzc value was most significantly reduced by altering the temperature either way while dilution seemed to have positive impact regarding this property. Pretreatment ultimately enhanced the selectivity for CO2 adsorption as well as its capacity.

Synthesis and characterization of a new energy material: Pyridinium dinitramide (Py-DN)

김우람,권윤자,Adedeji A. Adelodun,조영민 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-

A solid oxidizer pyridinium dinitramide (Py-DN) has been newly synthesized as a low toxic chlorine-free energetic oxidizer. The reaction yield increased by 10% higher than the other dinitramide such as ADN because Py-DN was directly converted without sequential precipitation of intermediates. A thermal analyzer, a UV–visible spectrometer and a Fourier transform-infra-red spectrometer were used to characterize the physical and chemical properties of the synthesized Py-DN, and the results were compared with previously prepared salts of ammonium dinitramide (ADN, NH4N(NO2)2) and guanidine dinitramide [GDN, NH2C(NH2)NH2N(NO2)2]. The characteristic endothermic and exothermic decomposition temperatures of Py-DN were 77.4 C and 144.7 C, respectively, and the material had a combustion caloric value of 1,739 J/g. These low values indicate that Py-DN is more thermally sensitive than the conventional dinitramides. Furthermore, it enables to decrease the decomposition temperature, which can reduce preheating temperature required for thruster operation.

Influence of Operation Conditions on the Performance of Non-thermal Plasma Technology for VOC Pollution Control

Adedeji A. Adelodun 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.92 No.-

The viability of non-thermal plasma (NTP) systems for the treatment of various VOC types was assessed. Also evaluated were the individual and collective influences of selected process parameters on the NTP-VOC systems’ performances. To this end, the process and performance evaluations of the reported NTP-VOC pairs, based on the established (VOC molecular weight, input voltage, specific input energy (SIE),flow rate, and degradation efficiency) and calculated (processing rate, system efficiency, cumulativeenergy density (e), and space-time yield) parameters were reported. With a catalyst, an increase in thegasflow rate enhanced the processing rate of the system by approximately 50%. At the same time, theinfluence of a on the byproducts remains unpredictable. Also, the correlation values of the processing rateagainst the system efficiency were significantly high and positive (0.9423). About 87% of the calculatedattributes correlated with the double-barrier discharge reactor. Theflow rate and input voltage evincedas the most influential parameters for all NTP-VOC systems. Moreover, the estimated e (J/L) is morereliable than the SIE for performance comparison. Conclusively, the processing rate, space-time yield, andenergy density are the derived attributes that should be considered before any NTP-VOC process design.

Performance of Air Fresher System for the Removal of Various Odorants Released from Foodstuffs

김기현,Adedeji A. Adelodun,Akash Deep,권일한,전의찬,김용현,조상희,이민희,조성백,황옥화 한국대기환경학회 2017 Asian Journal of Atmospheric Environment (AJAE) Vol.11 No.1

The effectiveness of four air fresher (AF) systems was evaluated with respect to their removal efficiencies against offensive odorants. For this purpose, malodorous species were generated by exposing freshly cooked foods emitting odorants with levels moderately above their respective threshold values in a confined room. The deodorization efficiency of the four AF systems was then tested for a period of 30 min by estimating the extent of reduction in odorant levels after the operation of each AF. The removal efficiency of the four AF units against each odorant was evaluated as follows: (1) between AF products from different manufacturers, (2) between odorants and ultrafine particulate matter (PM2.5), and (3) between operation and natural degassing. The average sorptive removal of odorants was generally <80% and considered less effective or non-effective relative to PM2.5. Further examination of odor reduction, if evaluated in terms of odor indices like odor intensity (OI) and odor activity value (OAV), recorded a mean of 33% and 87%, respectively. The overall results of this study confirmed that all tested AF units were not effective to resolve odor problems created under our testing conditions.

Toward a better understanding of the impact of mass transit air pollutants on human health

Kim, Ki-Hyun,Kumar, Pawan,Szulejko, Jan E.,Adelodun, Adedeji A.,Junaid, Muhammad Faisal,Uchimiya, Minori,Chambers, Scott Pergamon Press 2017 Chemosphere Vol.174 No.-

<P><B>Abstract</B></P> <P>Globally, modern mass transport systems whether by road, rail, water, or air generate airborne pollutants in both developing and developed nations. Air pollution is the primary human health concern originating from modern transportation, particularly in densely-populated urban areas. This review will specifically focus on the origin and the health impacts of carbonaceous traffic-related air pollutants (TRAP), including particulate matter (PM), volatile organic compounds (VOCs), and elemental carbon (EC). We conclude that the greatest current challenge regarding urban TRAP is understanding and evaluating the human health impacts well enough to set appropriate pollution control measures. Furthermore, we provide a detailed discussion regarding the effects of TRAP on local environments and pedestrian health in low and high traffic-density environments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Efficient transport system is an essential step toward sustainable urban development. </LI> <LI> The effect of traffic-related air pollutants (TRAP) on human health is significant. </LI> <LI> The overall health conditions of pedestrians in a localized area were assessed. </LI> </UL> </P>

Air ionization as a control technology for off-gas emissions of volatile organic compounds

Kim, Ki-Hyun,Szulejko, Jan E.,Kumar, Pawan,Kwon, Eilhann E.,Adelodun, Adedeji A.,Reddy, Police Anil Kumar Elsevier Applied Science Publishers 2017 Environmental pollution Vol.225 No.-

<P><B>Abstract</B></P> <P>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 (<I>e.g</I>., volatile organic compounds (VOCs)) to CO<SUB>2</SUB> and H<SUB>2</SUB>O. 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 (O<SUB>3</SUB>). 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 O<SUB>3</SUB>, NOx, and VOC oxidation intermediates that limit the use of air-ionizers in indoor air quality management.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Much research effort has been put to eliminate or reduce airborne pollutants. </LI> <LI> Destructive methods of VOCs commonly involve thermal oxidation with or without a catalyst. </LI> <LI> In this review, we provide insights into effective strategy for air quality remediation. </LI> <LI> To this end, we assessed the role of air ionization methods for the control of IAQ. </LI> <LI> We discuss future opportunities for air ionization techniques as reliable tools for controlling VOCs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Electrospun melamine‐blended activated carbon nanofibers for enhanced control of indoor CO₂

Jeong, Dongwon,Jie, Wang,Adelodun, Adedeji A.,Kim, Sangbum,Jo, Youngmin John Wiley Sons, Inc. 2019 Journal of applied polymer science Vol.136 No.28

<P><B>ABSTRACT</B></P><P>Electrospun carbon nanofibers were activated with melamine–polyacrylonitrile [melamine‐blended carbon nanofibers (MACNFs)] for use as a fibrous adsorbent for indoor CO<SUB>2</SUB> removal. Although, melamine doping was intended solely to incorporate basic nitrogen functionalities on the nanofibers, it also shortened fabrication time, conserving time, and energy cost. The specific surface area and microporosity of the fibers were enhanced from 412 m<SUP>2</SUP> g<SUP>−1</SUP> and 0.1646 cm<SUP>3</SUP> g<SUP>−1</SUP> to 547 m<SUP>2</SUP> g<SUP>−1</SUP> and 0.220 cm<SUP>3</SUP> g<SUP>−1</SUP>, respectively, upon final CO<SUB>2</SUB> activation of the nanofibers. With the chemical properties, we observed significant tethering of pyridine functionality. The sample, MACNF‐7 (10 mL of polymer solution doped with 0.7 g of melamine), provided the optimum melamine doping condition to achieve the highest CO<SUB>2</SUB> adsorption capacity of 3.15 mmol g<SUP>−1</SUP>. The adsorption performance was based on simultaneous improvement in microporosity (physical) and surface basicity (chemical) properties of the adsorbent. However, in a binary mixture with nitrogen, the selective adsorption of CO<SUB>2</SUB> showed the predominance of the improved surface basicity over microporosity. The highest CO<SUB>2</SUB> selective capture (1.22 mmol g<SUP>−1</SUP>) was occurred for a CO<SUB>2</SUB>:N<SUB>2</SUB> ratio of 0.15:0.85, with a selectivity of 58.19 at 273 K. In a regeneration test, stable and robust performance was achieved more than five cycles. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. <B>2019</B>, <I>136</I>, 47747.</P>

Solar energy: Potential and future prospects

Kabir, Ehsanul,Kumar, Pawan,Kumar, Sandeep,Adelodun, Adedeji A.,Kim, Ki-Hyun Elsevier 2018 RENEWABLE & SUSTAINABLE ENERGY REVIEWS Vol.82 No.1

<P><B>Abstract</B></P> <P>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.</P>

Preparation of Ag–Cu/Al2O3 Composite Catalyst for Ammonia Decomposition

이주열,임윤희,박병현,Adedeji A. Adelodun,조영민 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.1

A catalyst of Ag with alumina has been widely used for the decomposition of odorous ammonia. In order to meet cost effectiveness, copper was added with five different doping ratios of Ag/Cu in this work, and NH3 decomposition was examined at 150–400 C. Experimental results show that the catalyst doped with only Cu shows very weak potential to oxidize NH3 despite its excellent selectivity for nitrogen molecules than NO or N2Oat temperatures over 300 C. Analysis by X-ray photoelectron spectroscopy indicates thatAg0 is the major chemical functionality that determines the decomposition rate of NH3 at low temperature, e.g., 200 C, while Ag+ and Ag2+ are efficient at higher temperatures. Among the five segregated copper functionalities, only Cu 2pa/2 appeared to be favorable for the activity of Ag particles. It was found from the experimental results that Ag/Cu = 1:9 could provide a cost-effective combination for the low temperature regime.