Environmental Monitoring of Heavy Metals and Arsenic in Soils Adjacent to CCA-Treated Wood Structures in Gangwon Province, South Korea

Ahmed A. Abdelhafez,Yasser M. Awad,Min Su Kim,Kwang Joon Ham,Kyoung Jae Lim,Jin Ho Joo,Jae E Yang,Yong Sik Ok 韓國環境農學會 2009 한국환경농학회지 Vol.28 No.4

Chromated copper arsenate (CCA) is a chemical wood preservative that has been intensively used to protect wood from decay during the last few decades. CCA is widely used to build structures such as decks, fences, playgrounds and boardwalks. However, structures constructed of CCA-treated wood have caused adverse environmental effects due to leaching of Cr, Cu and As into surrounding soils. This research was conducted to monitor the vertical and horizontal distribution of Cr, Cu and As in soils adjacent to CCA-treated wood structures in Korea. Two structures constructed with CCA-treated wood were selected at Hongcheon and Chuncheon in Gangwon Province, South Korea. Eleven soil profile samples were collected at depths of 0 to 80 cm at each site, while 12 surface soil samples were collected at distances of 0 to 200 cm from each structure. The soil chemical properties, soil particle size distribution and total metal concentrations were then determined. The results revealed that soils near CCA-treated wood structures were generally contaminated with Cr, Cu and As when compared to the background concentration of each metal. In addition, the concentrations of Cr, Cu and As in soils decreased as the vertical and horizontal distance from the structure increased. Further studies should be conducted to evaluate the mobility and distribution of these metals in the environment as well as to develop novel technologies for remediation of CCA contaminated soils.

Phytotherapeutic effects of Echinacea purpurea in gamma-irradiated mice

Yasser E. Shahein,Amira M. K. Abouelella,Sameh S. Tawfik,Ahmed M. Zahran1 대한수의학회 2007 Journal of Veterinary Science Vol.8 No.4

Echinacea (E.) purpurea herb is commonly known as the purple coneflower, red sunflower and rudbeckia. In this paper, we report the curative efficacy of an Echinacea extract in γ-irradiated mice. E. purpurea was given to male mice that were divided into five groups (control, treated, irradiated, treated before irradiation & treated after irradiation) at a dose of 30 mg/kg body weight for 2 weeks before and after irradiation with 3 Gy of γ-rays. The results reflected the detrimental reduction effects of γ-rays on peripheral blood hemoglobin and the levels of red blood cells, differential white blood cells, and bone marrow cells. The thiobarbituric acid-reactive substances (TBARs) level, Superoxide dismutase (SOD) and glutathione peroxidase (GSPx) activities and DNA fragmentation were also investigated. FT-Raman spectroscopy was used to explore the structural changes in liver tissues. Significant changes were observed in the microenvironment of the major constituents, including tyrosine and protein secondary structures. E. purpurea administration significantly ameliorated all estimated parameters. The radio-protection effectiveness was similar to the radio-recovery curativeness in comparison to the control group in most of the tested parameters. The radio-protection efficiency was greater than the radio-recovery in hemoglobin level during the first two weeks, in lymphoid cell count and TBARs level at the fourth week and in SOD activity during the first two weeks, as compared to the levels of these parameters in the control group

Leaching of Chromium, Copper and Arsenic in Soils and Rapid Identification of CCA-Treated Woods Using Modified PAN Stain

Ahmed A. Abdelhafez,Yasser M. Awad,Samy A. M. Abd El-Azeem,Min-Su Kim(김민수),Kwang-Joon Ham(함광준),Kyoung-Jae Lim(임경재),Jae-E Yang(양재의),Yong-Sik Ok(옥용식) 한국토양비료학회 2010 한국토양비료학회지 Vol.43 No.1

목재방부제는 목재의 수명 연장을 위해 오랜 기간 사용되어 왔으나 이중 상당수는 환경에 유해한 금속을 다량 함유하고 있다. 특히 전세계적으로 목재방부시장을 점유하고 있는 크롬ㆍ구리ㆍ비소계열의 목재방부제 CCA (Chromated Copper Arsenate)는 환경에 유해한 독성 금속류로 구성되어 인체에 대한 피해와 환경오염에 대한 우려가 지적되고 있다. 미국의 경우 플로리다 주를 비롯하여 CCA 오염지역에 대한 복원사업을 추진하였으며 주별 CCA 오염도를 조사한 바 있다. 그러나 국내의 경우 목재방부제의 사용으로 인한 토양오염에 대한 연구는 극히 미비한 실정이므로 CCA에 대한 환경적 측면에서의 평가가 절실하다. 본 연구는 국내에서 가장 널리 사용된 목재방부제인 CCA를 선정하여 목재방부제 설치지역 토양의 깊이별 크롬ㆍ구리ㆍ비소 농도를 측정하였으며 국내에 널리 산재된 CCA 방무목 설치지역을 현장에서 효율적으로 검출할 수 있는 간이 PAN 지시약을 개발하고자 수행하였다. 토양 시료는 0~70㎝ 깊이에서 채취하였고 방부목은 목재 깊이별로 구분하여 채취한 후 산분해하였고 AAS를 이용하여 각 원소의 전함량을 측정하였다. 토양 중 비소와 구리는 0~1 ㎝에서 각각 34.38 ㎎/㎏, 33.65 ㎎/㎏ 였으나 70 ㎝에서는 1.72 ㎎/㎏, 7.84 ㎎/㎏로 토양 깊이에 따라 급격히 감소하였다. 원소별 이동성의 경우 비소가 타 원소(크롬, 구리)에 비해 상대적으로 이동성이 높은 것으로 평가되었다. 목재 시료의 경우 내부보다는 표면 (외부)의 농도가 높게 나타났으며 각 원소별로 1,000~5,000 ㎎/㎏의 수준으로 검출되었다. 현장에서 CCA 방부목을 효율적으로 판단하기 위한 지시약의 조성을 개발하고자 다양한 종류 및 농도의 용매와 PAN의 농도를 조절하며 발색 시간과 정도를 측정한 결과 100% 아세톤을 용매로 0.1% 수준의 PAN을 조제하는 경우 가장 잛은 시간에 발색하여 현장에서 방부목을 효율적으로 검출할 수 있을 것으로 평가되었다. Although several studies have reported that Cr, Cu and As can leach from CCA-treated woods, few studies have been conducted on this topic in Korea. Therefore, this study was conducted to monitor Cr, Cu and As leaching from CCA-treated wood products and to develop a rapid identification method for CCA-treated wood products by using indicators such as PAN stain. Soil samples were collected at depths of 0-70 ㎝ and wood samples were collected by thickness of wood layer. The soil and wood samples were then digested and analyzed for Cr, Cu and As concentrations using an atomic absorption spectrometer. The As and Cu concentrations decreased sharply with depth from 34.38 and 33.65 ㎎ ㎏?¹ at 0-1 ㎝ to 1.72 and 7.84 ㎎ ㎏?¹ at 70 ㎝, respectively. In general, As was more mobile than Cr and Cu in the soil. For wood samples, the Cr, Cu and As concentrations were higher in the outer layer (0-0.5㎝) than the inner layers (0.6-4.5㎝). Evaluation of rapid identification methods revealed that 100% acetone with 0.1% PAN indicator was the best combination for detection of CCA-treated wood in the field.

Synthesis of Nanoscale Zerovalent Iron Particle and Its Application to Cr(6) Removal from Aqueous Solutions

( Yasser M. Awad ),( Ahmed A. Abdelhafez ),( Mahtab Ahmad ),( Sang Soo Lee ),( Rog Young Kim ),( Jwa Kyung Sung ),( Yong Sik Ok ) 한국환경농학회 2010 한국환경농학회지 Vol.29 No.4

Zerovalent iron (ZVI) is one of the most commonly used metallic reducing agents for the treatment of toxic contaminants in wastewater. Traditional ZVIs are less effective than nanoscale ZVI (nZVI) due to prolonged reaction time. However, the reactivity can be significantly increased by reducing the size of ZVI particles to nanoscale. In this study, nZVI particles were synthesized under laboratory condition and their efficiency in removing hexavalent chromium (Cr(VI)) from aqueous solutions were compared with commercially available ZVI particles. The results showed that the synthesized nZVI particles (SnZVI) reduced >99% of Cr(VI) at the application rate of 0.2% (w/v), while commercial nZVI (CnZVI) particles resulted in 59.6% removal of Cr(VI) at the same application rate. Scanning electron micrographs (SEM) and energy dispersive spectra (EDS) of the nZVI particles revealed the formation of Fe-Cr hydroxide complex after reaction. Overall, the SnZVI particles can be used in treating chromium contaminated wastewater.

Synthesis of Nanoscale Zerovalent Iron Particle and Its Application to Cr(VI) Removal from Aqueous Solutions

Yasser M. Awad,Ahmed A. Abdelhafez,Mahtab Ahmad,이상수,김록영,옥용식,성좌경 한국환경농학회 2010 한국환경농학회지 Vol.29 No.4

Zerovalent iron (ZVI) is one of the most commonly used metallic reducing agents for the treatment of toxic contaminants in wastewater. Traditional ZVIs are less effective than nanoscale ZVI (nZVI) due to prolonged reaction time. However, the reactivity can be significantly increased by reducing the size of ZVI particles to nanoscale. In this study, nZVI particles were synthesized under laboratory condition and their efficiency in removing hexavalent chromium (Cr(VI)) from aqueous solutions were compared with commercially available ZVI particles. The results showed that the synthesized nZVI particles (SnZVI) reduced >99% of Cr(VI) at the application rate of 0.2% (w/v), while commercial nZVI (CnZVI) particles resulted in 59.6% removal of Cr(VI) at the same application rate. Scanning electron micrographs (SEM) and energy dispersive spectra (EDS) of the nZVI particles revealed the formation of Fe-Cr hydroxide complex after reaction. Overall, the SnZVI particles can be used in treating chromium contaminated wastewater.

Green gold@chitosan nanocomposite via solid-state synthesis; a separable catalyst for reduction of Cr(IV)

Ahmed Atia,Yasser K. Abdel-Monem,A.H. Salama,Salah M. El-kousy,Wael H. Eisa 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

A clean and high-throughput synthesis of gold@chitosan nanocomposite using nontoxic oxalic acid as areducing agent was developed. The synthetic route was carried out in completely dry conditions, i.e. solid-state reaction. The gold nanoparticles were bound with chitosan through the hydroxyl and aminogroups, as confirmed by Fourier transform infrared spectroscopic analysis. Scanning and transmissionelectron microscopy imaging confirmed the formation of semi-spherical gold particles with an averagesize of 8–15 nm. The catalytic performance of the synthesized gold nanoparticles for the reduction ofchromium(IV) in the presence of formic acid was evaluated. The film-forming ability of chitosan enabledthe design of separable/reusable heterogeneous catalyst which is convenient for real industrial applications. The proposed solid-state synthetic route could be adapted to produce a wide variety of nanostructuredmaterials that are characterized by high-yield, greenness, and low cost in very simple steps.

Functionalization of Electrospun Poly(Acrylonitrile-co-Styrene/Pyrrole) Copolymer Nanofibers for Using as a High-performance Carrier for Laccase Immobilization

M. R. El-Aassar,Mahmoud H. M. A. Shibraen,Yasser R Abdel-Fattah,Ahmed A. Elzain 한국섬유공학회 2019 Fibers and polymers Vol.20 No.11

Enzyme immobilization onto nanomaterials is a strategy to overcome the difficulties of the free enzymesapplications where the immobilization process affords excellent reusability and operational stability against temperature andpH, and high surface area for the catalytic reaction. In this work, poly(Acrylonitrile-co-Styrene/Pyrrole), (poly(AN-co-ST/Py)), copolymer nanofibers were successfully fabricated using the electrospinning technique. Laccase enzyme from Trametesversicolor was immobilized onto functionalized poly(AN-co-ST/Py) nanofibers by covalent attachment usingpolyethylenediamine (PEI) via physical adsorption and multipoint covalent attachment to the functional groups onto thepolymeric surface. Since the relative activity of the immobilized Laccase depends on the amount of the coupled PEI onto thepolymeric nanofibers, a colorimetric assay via copper ions complex formation was applied for the estimation of the processyield. Accordingly, the various factors affecting the PEI coupling process such as concentration, time, pH and temperaturewere investigated; Besides their influence on the morphology of the resultant nanofibers. Furthermore, thermal and pHstability, storage stability, and reusability were evaluated and compared. The optimum reaction temperature and pH for theimmobilized enzyme were 70 oC and 6.0, respectively. The scanning electron microscopy (SEM) images showed that themodified nanofibers with PEI have kept its nanofibers structure and uniform morphology with an average diameter ofapproximately 559.2 nm. Within 35 days, the immobilization process reduces the activity loss from 59 % to 29 %, whilethermal incubation at 50 oC for 2 hrs causes activity loss for the free and immobilized enzymes by 65 % and 30 %respectively. Therefore, the prepared copolymer nanofibers proposed in this work showed promising potential forapplications to enzyme immobilization.

Environmental Monitoring of Heavy Metals and Arsenic in Soils Adjacent to CCA-Treated Wood Structures in Gangwon Province, South Korea

Abdelhafez, Ahmed A.,Awad, Yasser M.,Kim, Min-Su,Ham, Kwang-Joon,Lim, Kyoung-Jae,Joo, Jin-Ho,Yang, Jae-E.,Ok, Yong-Sik The Korean Society of Environmental Agriculture 2009 한국환경농학회지 Vol.28 No.4

Chromated copper arsenate (CCA) is a chemical wood preservative that has been intensively used to protect wood from decay during the last few decades. CCA is widely used to build structures such as decks, fences, playgrounds and boardwalks. However, structures constructed of CCA-treated wood have caused adverse environmental effects due to leaching of Cr, Cu and As into surrounding soils. This research was conducted to monitor the vertical and horizontal distribution of Cr, Cu and As in soils adjacent to CCA-treated wood structures in Korea. Two structures constructed with CCA-treated wood were selected at Hongcheon and Chuncheon in Gangwon Province, South Korea. Eleven soil profile samples were collected at depths of 0 to 80 cm at each site, while 12 surface soil samples were collected at distances of 0 to 200 cm from each structure. The soil chemical properties, soil particle size distribution and total metal concentrations were then determined. The results revealed that soils near CCA-treated wood structures were generally contaminated with Cr, Cu and As when compared to the background concentration of each metal. In addition, the concentrations of Cr, Cu and As in soils decreased as the vertical and horizontal distance from the structure increased. Further studies should be conducted to evaluate the mobility and distribution of these metals in the environment as well as to develop novel technologies for remediation of CCA contaminated soils.

Synthesis of Nanoscale Zerovalent Iron Particle and Its Application to Cr(VI) Removal from Aqueous Solutions

Awad, Yasser M.,Abdelhafez, Ahmed A.,Ahmad, Mahtab,Lee, Sang-Soo,Kim, Rog-Young,Sung, Jwa-Kyung,Ok, Yong-Sik The Korean Society of Environmental Agriculture 2010 한국환경농학회지 Vol.29 No.4

Zerovalent iron (ZVI) is one of the most commonly used metallic reducing agents for the treatment of toxic contaminants in wastewater. Traditional ZVIs are less effective than nanoscale ZVI (nZVI) due to prolonged reaction time. However, the reactivity can be significantly increased by reducing the size of ZVI particles to nanoscale. In this study, nZVI particles were synthesized under laboratory condition and their efficiency in removing hexavalent chromium (Cr(VI)) from aqueous solutions were compared with commercially available ZVI particles. The results showed that the synthesized nZVI particles (SnZVI) reduced >99% of Cr(VI) at the application rate of 0.2% (w/v), while commercial nZVI (CnZVI) particles resulted in 59.6% removal of Cr(VI) at the same application rate. Scanning electron micrographs (SEM) and energy dispersive spectra (EDS) of the nZVI particles revealed the formation of Fe-Cr hydroxide complex after reaction. Overall, the SnZVI particles can be used in treating chromium contaminated wastewater.

Optimization, Purification, and Characterization of Haloalkaline Serine Protease from a Haloalkaliphilic Archaeon Natrialba hulunbeirensis Strain WNHS14

( Rania S Ahmed ),( Amira M Embaby ),( Mostafa Hassan ),( Nadia A Soliman ),( Yasser R Abdel-fattah ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 한국미생물·생명공학회지 Vol.49 No.2

The present study addresses isolation, optimization, partial purification, and characterization of a haloalkaline serine protease from a newly isolated haloarchaeal strain isolated from Wadi El Natrun in Egypt. We expected that a two-step sequential statistical approach (one variable at a time, followed by response surface methodology) might maximize the production of the haloalkaline serine protease. The enzyme was partially purified using Hiprep 16/60 sephacryl S-100 HR gel filtration column. Molecular identification revealed the newly isolated haloarchaeon to be Natrialba hulunbeirensis strain WNHS14. Among several tested physicochemical determinants, casamino acids, KCl, and NaCl showed the most significant effects on enzyme production as determined from results of the One-Variable-At-A-time (OVAT) study. The Box- Behnken design localized the optimal levels of the three key determinants; casamino acids, KCl, and NaCl to be 0.5% (w/v), 0.02% (w/v), and 15% (w/v), respectively, obtaining 62.9 U/ml as the maximal amount of protease produced after treatment at 40℃, and pH 9 for 9 days with 6-fold enhancement in yield. The enzyme was partially purified after size exclusion chromatography with specific activity, purification fold, and yield of 1282.63 U/mg, 8.9, and 23%, respectively. The enzyme showed its maximal activity at pH, temperature, and NaCl concentration optima of 10, 75℃, and 2 M, respectively. Phenylmethylsulfonyl fluoride (PMSF, 5 mM) completely inhibited enzyme activity.