http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Abdul Rahman Abdul Rahim,Khairiraihanna Johari,Nurul Ekmi Rabat,Murid Hussain,Nasir Shezad,Young-Kwon Park 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.127 No.-
In this study, charred–desiccated coconut waste was treated with several chemicals, such as NaOH,NaOCl, H2O2, and HNO3, to prepare chemically modified adsorbents. Fourier transform infrared spectroscopyrevealed that chemical modification enhanced the surface chemistry of the adsorbent by introducingnew functional groups and increasing their concentration. The chemically modified adsorbentshad lower surface areas of 0.13–17.36 m2/g, which were substantially lower than that of the pristineadsorbent. Regardless of the surface area, all modified adsorbents exhibited higher Pb(II) adsorptioncapacities, wherein that of desiccated coconut-waste char (DCWC)-NaOH was the highest, with a removalefficiency of 96% (Q = 29.854 mg/g) for an adsorption time of 1 min. The equilibrium and kinetic data forthe DCWC-NaOH adsorbent best fit the Freundlich isotherm and pseudo-second-order kinetic models,respectively, with a maximum monolayer adsorption capacity of 1666.67 mg/g. The adsorption of Pb(II) ions was an exothermic process, with an optimum temperature of 40 C. Compared to existing commercialadsorbents, the proposed adsorbent was highly regenerable and considerably low-cost, showingpromising potential for commercial applications.
Norasikin Saman,Helen Kong,Safia Syazana Mohtar,Khairiraihanna Johari,Azmi Fadziyana Mansor,Onn Hassan,Noorhalieza Ali,Hanapi Mat 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.7
The adsorption dynamics of inorganic mercury, Hg(II) and organic methylmercury, MeHg(II) removal by low-cost reactive agrowaste adsorbents namely CP-Pure, CP-MPTES and CP-RR was investigated in a fixed-bed adsorber. The results show that the breakthrough and saturation times were delayed with decreasing flow rate (F) and initial concentration (Co), and increasing bed height (Z). The Hg(II) possessed better adsorption performance than MeHg(II). The isotherm and kinetic model analyses of adsorption data followed the Temkin isotherm and the pseudosecond order kinetic models, respectively. The breakthrough curve was simulated well by the Thomas and Yoon-Nelson models, and then was further used for scale-up studies. The empty bed contact time (EBCT) concept was successfully demonstrated for the adsorber design and scale-up studies. The regeneration studies showed that the regenerated CP-Pure and CP-MPTES have a high regeneration efficiency up to third adsorption cycle
Abdul Rahman Abdul Rahim,Iswarya,Khairiraihanna Johari,Nasir Shehzad,Norasikin Saman,Hanapi Mat 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.4
Desiccated coconut waste (DCW) is an agricultural waste that originates from the coconut milk processing industry. In this study, it was utilized for the removal of copper (Cu(II)) and nickel (Ni(II)) via adsorption process. The physicochemical characterization of the DCW adsorbent shows that the adsorbent have a surface area of 6.63 ㎡/g, have high elemental carbon content and existences of important functional groups on its surface. The adsorptive capability of DCW adsorbent in removing the heavy metal were conducted in batch studies. DCW adsorbent performed highest Ni(II) and Cu(II) adsorption capacity at pH 6, where equilibrium is achieved at 450 minutes. The kinetic analysis showed the adsorption agreed with pseudo-second order kinetic model, indicating the Cu(II) and Ni(II) adsorption were a chemical adsorption, limited by the film diffusion. The DCW adsorbent still retained its effective adsorption capacity after 2 adsorption-desorption cycles, which is one of the excellent criteria of a good adsorbent for an adsorption process.
Norasikin Saman,Gamal Abdulaziz Mohammed Alaghbari,Safia Syazana Mohtar,Helen Kong,Khairiraihanna Johari,Noorhalieza Ali,Hanapi Mat 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.4
Pure silica nanocapsules (SiNC-P) and elemental sulfur-encapsulated silica nanocapsules (SiNC-ES) as Ag(I) adsorbents were successfully synthesized by a one-step water-in-oil microemulsion polymerization process. The characterization of the synthesized materials, such as surface morphology, surface area, porosity, functional groups and thermal characteristics, was carried out using various analytical techniques. The SiNC-P and SiNC-ES have nearly similar morphology, but the surface area and pore size of the SiNC-ES are higher than SiNC-P. The Ag(I) adsorption study showed that it increased with increasing elemental sulfur (ES) amount in the SiNC-ES. The SiNC-ES shows high adsorption capacity, independent of pH, and higher adsorption rate as compared to SiNC-P. The maximum Ag(I) adsorption capacity of SiNC-P and SiNC-ES was 50.49mg g1 and 98.51mg g1, respectively. The adsorption isotherm data were best described by the Langmuir model. The diffusion modeling analysis of the kinetic data indicated that film diffusion is the controlling step, while chemical reaction modeling obeys the pseudo-second-order kinetic model. The SiNC-ES was reusable and good adsorption performance up to four adsorption cycles was observed. The practical capability of the SiNC-ES to adsorb Ag(I) was successfully demonstrated using an industrial waste solution in which a high removal efficiency was observed (>90%). This demonstrates that the SiNC-ES can be a potential adsorbent for Ag(I) recovery from industrial wastes.