A comparison of figure of merit (FOM) for various materials in adsorptive removal of benzene under ambient temperature and pressure

Khan, Azmatullah,Szulejko, Jan E.,Kim, Ki-Hyun,Sammadar, Pallabi,Lee, Sang Soo,Yang, Xiao,Ok, Yong Sik Elsevier 2019 Environmental research Vol.168 No.-

<P><B>Abstract</B></P> <P>To effectively remove gaseous pollutants from air using sorbents, a thorough knowledge of the actual sorption performance is needed at ambient conditions rather than at unrealistically high-pressure conditions, as is commonly presented in the literature. To this end, the sorbent capacities of gaseous benzene were evaluated at a constant sorbent bed inlet pressure (50 ppm or ~5 Pa) in 1 atm of N<SUB>2</SUB>, room temperature (298 K), a fixed flow rate (50 mL min<SUP>−1</SUP>), and equal outlet sampling intervals (5 min). The benzene adsorption patterns were investigated against six sorbent types in a total of 17 different forms: 1- zeolite in five forms: beads (ZB), ground to 212 µm (ZG212), beads ground to 300 µm (ZG300), coarsely ground/washed zeolite (ZWc), and coarsely ground/washed/thermally treated zeolite (ZTc), 2- activated carbon in two forms: 212 µm (ACd212) and granular (ACdg), 3- Carbopack-X (CX), 4- Tenax TA (TA), 5- used black tea leaves of 150 or 300 µm in three forms: dry (TD150/TD300), wet (TW150/TW300), and wet dust (TWd), and 6- used ground coffee in either dry (CD) or wet forms (CW). Accordingly, the largest adsorption capacities at 5 Pa (e.g., >10 mg g<SUP>−1</SUP>) were observed for ACd212 (79.1) and ACdg (73.6). Moderate values (e.g., 5 < < 10 mg g<SUP>−1</SUP>) were obtained for ZG212 (7.98), CX (6.79), ZG300 (5.70), and ZB (5.58), while the remainder were far lower at < 5 mg g<SUP>−1</SUP> (e.g., tea leaves, ground coffee, TA, ZWc, and ZTc). The experimental benzene capacities of the tested sorbents were further assessed by the Langmuir, Henry's law, Freundlich, Dubinin-Radushkevich, and Elovich isotherm models. The linearized Langmuir adsorption isotherms of ACd212, ACdg, and CX showed the presence of more than one adsorption site (i.e., retrograde at the lowest pressures and two others at higher pressures). However, TA, zeolite, tea leaves, and ground coffee exhibited a type-V isotherm, wherein the sorption capacity continued to increase with loaded volume (i.e., multilayer adsorption). Thus, ACd212 has the best figure-of-merit based on a high 10% breakthrough volume (BTV) and low cost for real-world applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Activated carbon (ACd212) has retrograde isotherm. </LI> <LI> The ground sorbent has higher BTV compare to granular sorbent. </LI> <LI> The Langmuir adsorption isotherms identified more than one adsorption site. </LI> <LI> Tea leaves and ground coffee followed multilayer adsorption isotherm. </LI> <LI> The practicality of different sorbents is finally evaluated in terms of FOM. </LI> </UL> </P>

Airborne volatile aromatic hydrocarbons at an urban monitoring station in Korea from 2013 to 2015

Khan, Azmatullah,Szulejko, Jan E.,Kim, Ki-Hyun,Brown, Richard J.C. Elsevier 2018 Journal of environmental management Vol.209 No.-

<P><B>Abstract</B></P> <P>The concentrations of C<SUB>6</SUB>-C<SUB>10</SUB> volatile aromatic hydrocarbons (AHCs) in air were measured at an urban air quality monitoring station in Jong-Ro, Seoul, Korea, between 2013 and 2015. Their temporal patterns (e.g., diurnal, intraweek, daily) were assessed individually and collectively as groups of benzene, toluene, ethylbenzene, styrene, and xylene (BTESX); total aliphatic hydrocarbon (TALHC: C<SUB>2</SUB>-C<SUB>12</SUB>); total aromatic hydrocarbon (TARHC: C<SUB>6</SUB>-C<SUB>10</SUB>); and total hydrocarbon (THC: C<SUB>2</SUB>-C<SUB>12</SUB>). The highest mean AHC concentrations over the 3-year study (in ppb (v/v)) were observed for toluene (6.0 ± 4.3), followed by the xylenes (1.5 ± 1.3), ethylbenzene (0.85 ± 0.93), benzene (0.73 ± 0.77), and styrene (0.16 ± 0.30) nL/L. The mean ppbC ((v/v), nL∙atm∙C/nL∙atm) values for BTESX, TALHC, TARHC, and THC were 65.8, 113, 77.7, and 191 ppbC, respectively. For most AHC species (e.g., toluene, styrene, and BTESX), only weak seasonal trends were observed in contrast to temporally varying species like nitric oxide (NO) (e.g., 26.3 ppb (January–February) vs. 8.5 ppb (July–August) during weekdays in 2013). Furthermore, toluene and NO concentrations were much higher (up to a factor 3) on weekdays than on Sunday for most weeks. This might reflect reduced anthropogenic activities on Sunday.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Toluene was the major BTESX. </LI> <LI> Propane was major hydrocarbon in all 56 hydrocarbons. </LI> <LI> Toluene and NO has strong correlation. </LI> <LI> Both toluene and NO showed much higher working day levels compare to Sunday. </LI> </UL> </P>

The effect of diverse metal oxides in graphene composites on the adsorption isotherm of gaseous benzene

Khan, Azmatullah,Szulejko, Jan E.,Samaddar, Pallabi,Kim, Ki-Hyun,Eom, Wonsik,Ambade, Swapnil B.,Han, Tae Hee Elsevier 2019 Environmental research Vol.172 No.-

<P><B>Abstract</B></P> <P>The effective removal technique is necessary for the real world treatment of a hazardous pollutant (e.g., gaseous benzene). In an effort to develop such technique, the adsorption efficiency of benzene in a nitrogen stream (5 Pa (50 ppm) at 50 mL atm min<SUP>−1</SUP> flow rate and 298 K) was assessed against 10 different metal oxide/GO composite materials (i.e., 1: graphene oxide Co (GO-Co (OH)<SUB>2</SUB>), 2: graphene oxide Cu (GO-Cu(OH)<SUB>2</SUB>), 3: graphene oxide Mn (GO-MnO), 4: graphene oxide Ni (GO-Ni(OH)<SUB>2</SUB>), 5: graphene oxide Sn (GO-SnO<SUB>2</SUB>), 6: reduced graphene oxide Co (rGO-Co(OH)<SUB>2</SUB>), 7: reduced graphene oxide Cu (rGO-Cu(OH)<SUB>2</SUB>), 8: reduced graphene oxide Mn (rGO-MnO), 9: reduced graphene oxide Ni (rGO-Ni(OH)<SUB>2</SUB>), and 10: reduced graphene oxide Sn (rGO-SnO<SUB>2</SUB>)) in reference to their pristine forms of graphene oxide (GO) and reduced graphene oxide (rGO). The highest adsorption capacities (at 100% breakthrough) were observed as ~23 mg g<SUP>−1</SUP> for both GO-Ni(OH)<SUB>2</SUB> and rGO-SnO<SUB>2</SUB>, followed by GO (~19.1 mg g<SUP>−1</SUP>) and GO-Co(OH)<SUB>2</SUB> (~18.8 mg g<SUP>−1</SUP>). Therefore, the GO-Ni(OH)<SUB>2</SUB> and rGO-SnO<SUB>2</SUB> composites exhibited considerably high capacities to treat streams containing >5 Pa of benzene. However, the lowest adsorption capacity was found for GO-MnO (0.05 mg g<SUP>−1</SUP>). Alternately, if expressed in terms of the 10% breakthrough volume (BTV), the five aforementioned materials showed values of 0.50, 0.46, 0.40, 0.44, and 0.39 L g<SUP>−1</SUP>, respectively. The experimental data of target sorbents were fitted to linearized Langmuir, Freundlich, Elovich, and Dubinin-Radushkevich isotherm models. Accordingly, the non-linear Langmuir isotherm model revealed the presence of two or more distinct sorption profiles for several of the tested sorbents. Most of the sorbents showed type-III isotherm profiles where the sorption capacity proportional to the loaded volume.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The diverse forms of graphene-based composite with metal oxides were synthesized. </LI> <LI> The adsorption performance of these composites has been evaluated against benzene. </LI> <LI> Empirical isotherm models were employed to interpret the role of metal oxides in the adsorption. </LI> <LI> The possible mechanisms were explained by performance metrics over varying pressure regions. </LI> </UL> </P>

Experimental Pathogenesis of Pullorum Disease with the Local Isolate of Salmonella enterica serovar. enterica subspecies Pullorum in Pullets in Bangladesh

Haider, M.G.,Chowdhury, E.H.,Khan, M.A.H.N.A.,Hossain, M.T.,Rahman, M.S.,Song, H.J.,Hossain, M.M. The Korean Society of Poultry Science 2009 韓國家禽學會誌 Vol.35 No.4

이 실험은 추백리의 병원성을 연구하고자 2006년 2월부터 12월까지 Salmonella enterica serovar. enterica subspecies (S.) Pullorum 야외주를 분리한 후, 이를 건강한 닭에 실험적으로 감염시킨 다음 임상증상, 여러 기관의 육안 및 조직병리학적 검색과 아울러 공격주의 재분리와 동정을 시도하였다. S. Pullorum에 혈청학적으로 음성인 12주령의 100수의 암탉을 $A{\sim}E$까지 20수씩 5그룹으로 구분하였다. $A{\sim}DS$. Pullorum을 $10^6\;CFU$, $10^7\;CFU$, $2{\times}10^7\;CFU$, $10^8\;CFU$로 각각 경구 감염시켰고, E는 비감염 대조군으로 삼았다. 실험 방법으로는 부검, 조직병리학적 검사, Salmonella에 대한 세균 배양, 염색, 생화학적 특성을 조사하고 그 결과를 기술하였다. The research work was carried out to study the pathogenesis covering the clinical signs, gross and histopathological lesions in different organs, and reisolation and identification of the organisms after experimental infection with the local isolate of Salmonella enterica serovar. enterica subspecies (S.) Pullorum at different time interval of the experiment during the period February 2006 to December 2006. One hundred pullets (seronegative to S. Pullorum of 12 weeks age were purchased and divided into 5 (A, B, C, D and E) groups and each group consisted of 20 birds. Four groups (A, B, C and D) were infected orally with a dose of $10^6\;CFU$, $10^7\;CFU$, $2{\times}10^7\;CFU$, $10^8\;CFU$ of S. Pullorum, respectively, and one group (E) was treated as uninfected control. The used methods were necropsy and histopathology, culture of bacteria, staining and biochemical test of Salmonella. Five birds from each group were randomly selected and sacrificed $1^{st}$ week, $2^{nd}$, $3^{rd}$ and $4^{th}$ weeks of post infection (PI). From all the groups, the bacteriological samples (crop, liver, lung, heart, spleen, bile duodenum, ceca and blood) were collected with pre enriched in buffered peptone water in sterile poly bags. Liver, lungs, heart, spleen, intestine, etc. were collected in 10% buffered-formalin for histopathological examination. No clinical signs, gross and histopathological lesions were found in control group and no S. Pullorum was reisolated. Clinical sign of experimentally infected with S. Pullorum in pullets were loss of appetite (100%), slight depression (75%), ruffled feathers (85%), diarrhea (60%) and loss of weight (100%) in chickens. The feed intake and body weight at different weeks after PI differed significantly (p<0.01) among the groups. Grossly, the highest recorded lesion was button-like ulcer in the ceca (80%) and the lowest was white nodules in lungs (1.25%). S. Pullorum were reisolated from crop (91.25%), liver (91.25%), lung (83.75%), heart (71.25%), spleen (87.75%), bile (33.25%), duodenum (92.50%), ceca (97.50%) and from different group of infection (61.25%). The highest microscopic findings were intestinal and cecal mucosa and submucosa exhibited infiltration of mononuclear cells and congestion (96.25%), and the lowest finding was nodule formation in the lungs (3.75%). The pattern of the disease production by local isolate of S. Pullorum in Bangladesh is almost similar with other isolates in different countries.

Long-term trend analysis of CO in the Yongsan district of Seoul, Korea, between the years 1987 and 2013

Khan, Azmatullah,Szulejko, Jan E.,Bae, M.-S.,Shon, Zang Ho,Sohn, Jong-Ryeul,Seo, J.W.,Jeon, E.-C.,Kim, Ki-Hyun Elsevier 2017 Atmospheric pollution research Vol.8 No.5

Genetic Parameters of Milk Yield and Adjustment for Age at Calving in Nili-Ravi Buffaloes

Khan, M.S.,Shook, G.E.,Asghar, A.A.,Chaudhary, M.A.,Mcdowell, R.E. Asian Australasian Association of Animal Productio 1997 Animal Bioscience Vol.10 No.5

Data were from four institutional herds and four field data collection centers involved in a progeny testing program for Nili-Ravi buffaloes in Pakistan. The REML with a single trait animal model, employed on 2,353 lactations, from 901 daughters of 66 sires, gave a heritability estimate of 0.18 for milk yield with repeatability (between lactations) of 0.43. Estimated milk yield was highest at 65 months of age for the first parity and 81 months for later parities. Correction factors for age at calving, standardized to 60 months in the second and later parities, were developed.

CdS-graphene Nanocomposite for Efficient Visible-light-driven Photocatalytic and Photoelectrochemical Applications

Khan, M.E.,Khan, M.M.,Cho, M.H. Academic Press 2016 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.482 No.-

This paper reports cadmium sulphide nanoparticles-(CdS NPs)-graphene nanocomposite (CdS-Graphene), prepared by a simple method, in which CdS NPs were anchored/decorated successfully onto graphene sheets. The as-synthesized nanocomposite was characterized using standard characterization techniques. A combination of CdS NPs with the optimal amount of two-dimensional graphene sheets had a profound influence on the properties of the resulting hybrid nanocomposite, such as enhanced optical, photocatalytic, and photo-electronic properties. The photocatalytic degradation ability of the CdS-Graphene nanocomposite was evaluated by degrading different types of dyes in the dark and under visible light irradiation. Furthermore, the photoelectrode performance of the nanocomposite was evaluated by different electrochemical techniques. The results showed that the CdS-Graphene nanocomposite can serve as an efficient visible-light-driven photocatalyst as well as photoelectrochemical performance for optoelectronic applications. The significantly enhanced photocatalytic and photoelectrochemical performance of the CdS-Graphene nanocomposite was attributed to the synergistic effects of the enhanced light absorption behaviour and high electron conductivity of the CdS NPs and graphene sheets, which facilitates charge separation and lengthens the lifetime of photogenerated electron-hole pairs by reducing the recombination rate. The as-synthesized narrow band gap CdS-Graphene nanocomposite can be used for wide range of visible light-induced photocatalytic and photoelectrochemical based applications.

An Efficient Re-keying Scheme for Cluster Based Wireless Sensor Networks

Khan, F. I.,Jameel, H.,Raazi, S. M. K.,Khan, A. M.,Huh, E. N. SPRINGER-VERLAG 2007 Lecture Notes in Computer Science Vol.- No.4706

Lithium ameliorates lipopolysaccharide-induced neurotoxicity in the cortex and hippocampus of the adult rat brain

Khan, M.S.,Ali, T.,Abid, M.N.,Jo, M.H.,Khan, A.,Kim, M.W.,Yoon, G.H.,Cheon, E.W.,Rehman, S.U.,Kim, M.O. Pergamon Press 2017 Neurochemistry International Vol.108 No.-

Lithium an effective mood stabilizer, primary used in the treatment of bipolar disorders, has been reported as a protective agent in various neurological disorders. In this study, we examined the neuroprotective role of lithium chloride (LiCl) against lipopolysaccharide (LPS) in the cortex and hippocampus of the adult rat brain. We determined that LiCl -attenuated LPS-induced activated toll-like receptor 4 (TLR4) signalling and significantly reduced the nuclear factor-<SUB>k</SUB>B (NF-<SUB>K</SUB>B) translation factor and various other inflammatory mediators such as interleukin-1 beta (IL-1β) and tumour necrosis factor alpha (TNF-α). We also analyzed that LiCl significantly abrogated activated gliosis via attenuation of specific markers for activated microglia, ionized calcium-binding adaptor molecule (Iba-1) and astrocytes, glial fibrillary acidic protein (GFAP) in both the cortex and hippocampus of the adult rat brain. Furthermore, we also observed that LiCl treatment significantly ameliorated the increase expression level of apoptotic neurodegeneration protein markers Bax/Bcl2, activated caspase-3 and poly (ADP-ribose) polymerase-1 (PARP-1) in the cortex and hippocampus regions of the LPS-treated adult rat brain. In addition, the morphological results of the fluoro-jade B (FJB) and Nissl staining showed that LiCl attenuated the neuronal degeneration in the cortex and hippocampus regions of the LPS-treated adult rat brain. Taken together, our Western blot and morphological results indicated that LiCl significantly prevents the LPS-induced neurotoxicity via attenuation of neuroinflammation and apoptotic neurodegeneration in the cortex and hippocampus of the adult rat brain.

Host plant growth promotion and cadmium detoxification in Solanum nigrum, mediated by endophytic fungi

Khan, A.R.,Ullah, I.,Waqas, M.,Park, G.S.,Khan, A.L.,Hong, S.J.,Ullah, R.,Jung, B.K.,Park, C.E.,Ur-Rehman, S.,Lee, I.J.,Shin, J.H. Academic Press 2017 Ecotoxicology and environmental safety Vol.136 No.-

<P>Current investigation conducted to evaluate the associated fungal endophyte interactions of a Cd hyper accumulator Solanum nigrum Korean ecotype under varying concentrations of Cd. Two indole-3-acetic acid (IAA) producing fungal strains, RSF-4L and RSF-6L, isolated from the leaves of S. nigrum, were initially screened for Cd tolerance and accumulation potential. In terms of dry biomass production, the strain RSF-6L showed higher tolerance and accumulation capacity for Cd toxicity in comparison to RSF-4L. Therefore, RSF-6L was applied in vivo to S. nigrum and grown for six weeks under Cd concentrations of 0, 10, and 30 mg Kg(-1) of dry sand. The effect of fungal inoculation assessed by plant physiological responses, endogenous biochemical regulations, and Cd profile in different tissues. Significant increase were observed in plant growth attributes such as shoot length, root length, dry biomass, leaf area, and chlorophyll contents in inoculated RSF-6L plants in comparison to non-inoculated plants with or without Cd contamination. RSF-6L inoculation decreased uptake of Cd in roots and above ground parts, as evidenced by a low bio-concentration factor (BCF) and improved tolerance index (TI). However, Cd concentration in the leaves remained the same for inoculated and non-inoculated plants under Cd spiking. Fungal inoculation protected the host plants, as evidenced by low peroxidase (POD) and polyphenol peroxidase (PPO) activities and high catalase (CAT) activity. Application of appropriate fungal inoculation that can improve tolerance mechanisms of hyper-accumulators and reduce Cd uptake can be recommended for phyto-stabilisation/immobilisation of heavy metals in crop fields. (C) 2016 Elsevier Inc. All rights reserved.</P>