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RISS 인기검색어
- 검색키워드
- 저자 : Makshoof Athar (검색결과 5 건)
- 무료
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A new approach to modification of an agro-based raw material for Pb(II) adsorption
Muhammad Salman,Makshoof Athar,Umar Farooq,Sadaf Rauf,Umy Habiba 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.3
This paper describes a relatively new and effective modification with thiourea of an agro-based raw material,sorghum biomass for adsorption of Pb(II) ions. The modification was done under microwave irradiation. Changes incharacteristics of modified material were determined by FT-IR and CHNS analysis. Effect of adsorbent dosage, contacttime, solution pH and temperature on equilibrium process was extensively studied. Famous equilibrium models (Langmuir,Freundlich, Temkin, Dubinin-Radushkevich) in non-linear fashion were applied to evaluate the equilibrium data usingdifferent initial concentrations of Pb(II) ranging from 20 mg/L to 300mg/L. The adsorption process followed the pseudosecond-order kinetics. This paper also discusses the thermodynamic parameters (free energy, enthalpy and entropy)and reveals that the adsorption process is spontaneous. An appreciable increase in adsorption capacity of the modifiedadsorbent was observed, depicting the advantages of thiourea modification of sorghum biomass under microwave irradiation.
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Microwave-assisted urea-modified sorghum biomass for Cr (III) elimination from aqueous solutions
Muhammad Salman,Makshoof Athar,Umar Farooq,Huma Nazir,Anam Noor,Saba Nazir 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.6
The present study concentrated on the use of an agro-waste biodegradable sorghum biomass in its simple and modified forms for the binding of Cr (III) ions. A relatively new method of modification was adopted using urea under microwave irradiation. FTIR analysis showed the presence of oxygen and nitrogen bearing functional groups in unmodified (UMS) and modified (MS) sorghum biomass. The appearance of new bands and shifts in the peaks confirmed the modification. The influence of different process parameters such as the adsorbent dose, solution pH, contact time, agitation speed and initial metal ion concentration was studied thoroughly to evaluate optimum conditions for adsorption. Maximum adsorption for Cr (III) ions occurred at pH 5.0-6.0 using UMS and MS. Langmuir, Freundlich,Temkin, and Dubinin-Radushkevich isotherm models in a non-linear fashion were used to explain the phenomenon. Maximum adsorption capacity was 7.03 and 16.36 mg of Cr (III) per gram of UMS and MS, respectively. Adsorption mechanism was explored by pseudo-first- and pseudo-second-order kinetic models, and it was found that the process followed pseudo-second-order kinetics. Thermodynamic study indicated the process favorability. The study concluded that urea modification under microwave irradiation produces a non-toxic and more effective adsorbent for Cr (III) remediation by inducing new nitrogen bearing functional groups to sorghum biomass.
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Madiha Tariq,Umar Farooq,Makshoof Athar,Muhammad Salman,Muqaddas Tariq 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.1
We investigated the adsorption potential of powdered branches from Ficus religiosa, an abundantly available plant, for the removal of Cu(II) from aqueous solution via column studies. Biomass was used as silica immobilized form and characterized using available techniques, including Fourier transformed infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Breakthrough curve approach was used to explain removal capacity of biomass in a continuous flow mode, using different operating parameters like bed height (5-30 cm), inlet metal concentration (100-300mg/L) and pH (3-5) of the solution, at a fixed flow rate of 2mL/min. Biosorption of Cu(II) favored with increased service time (breakthrough and exhaust time) of the column with an increase in pH of inlet solution. Maximum biosorption capacity (17.5mg/g) for Cu(II) was achieved at 5 cm bed height, pH 5 and 300 mg/L influent Cu(II) concentration. Findings suggested that Ficus religiosa branch powder takes less service time and thus triggers fast removal of metal ions. Bed depth service time (BDST), Thomas and Yoon-Nelson models were effectively applied to the breakthrough data. The study indicated that the immobilized powdered branches could be used for the effective removal of Cu(II) ions in a continuous flow mode.
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Basra, Muhammad Asim R,Saher, Manzoor,Athar, Muhammad Makshoof,Raza, Muhammad Hashim Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.7
Breast cancer (BC) is the most common malignancy of women worldwide. In the past it was considered as disease of older middle aged women, but the incidence of BC in young females is growing in recent years concordant with studies in Pakistan. In this paper, we reviewed the mutant functions of tumor suppressor genes (BRCA1, BRCA2, p53, ATM and PTEN), epigenetic transformation and involvement of estrogen receptors in development of breast cancer. We further reviewed the current situation of BC in Pakistan that depicts a higher incidence in young females. According to SKMCH and RC data, age group 45-49 years is more prone to BC with high rate of incidence 45.42%. A few studies explored the high expression of ER, PR and HER-2/neu in Pakistani females. Moreover, presence of BRCA1 (c.1961dupA) mutation in Pakistani shows concordance with data in different areas of world. But we are unable to find an authentic study that can explore epigenetic based transformation of breast tumors in Pakistan. This area of research needs more attention to explore the complete picture of BC in Pakistan.
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Use of wheat straw for effective binding of metal ions via a novel modification
Faiza Farooq,Umar Farooq,Madeeha Batool,Makshoof Athar,Muhammad Salman,Qaiser Ahmed,Ayesha Ashraf 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.9
An innovative biacetyl-modified Triticum aestivum (BMTA) was prepared and its biosorption efficiency was investigated for the removal of Pb(II) and Cr(III) ions from synthesized single and binary metal solutions. The characterization using infrared spectrum, surface area determination and potentiometric titrations indicated an increased acid content of the biomass, indicating BMTA as a potential choice for the binding of metal ions at a relatively low pH. The isoelectric point was found to be at pH 4.5. Various biosorption parameters were optimized. Langmuir model best fitted the experimental equilibrium data with qmax 27.39mg/g for Pb(II) ions and 24.69mg/g for Cr(III) ions in single metal system and 24.21mg/g for Pb(II) and 12.97mg/g for Cr(III) ions in binary system, respectively. The kinetics was described by pseudo-second-order model both in single and binary metal system. The studies indicated relatively selective biosorption of Pb(II) ions by BMTA compared to other metal ions.
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