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Journal : Communications in Science and Technology

Removal of Cr(VI) from aqueous solution by biochar derived from rice husk Mohadi, Risfidian; Palapa, Neza Rahayu; Taher, Tarmizi; Siregar, Patimah Mega Syah Bahar Nur; Normah; Juleanti, Novie; Wijaya, Alfan; Lesbani, Aldes
Communications in Science and Technology Vol 6 No 1 (2021)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.6.1.2021.293

Abstract

In this work, biochar produced from Indonesian rice husks. Then used as adsorbent of Cr(VI) in aqueous solution. The XRD pattern of biochar showed the characterization pattern at 23º (002) reflection, appearance of silicate oxide, and the carbon vibrations. The surface area and SEM morphologies confirmed that after pyrolysis treatment the surface of rice husk has changed. The surface area of biochar increased after thermal treatment. The adsorption study of Cr(VI) by biochar demonstrate 2nd-order reaction, and Langmuir isotherm models. The maximum adsorption capacity of biochar derived rice husk to adsorb Cr(VI) is 161.290 mg/g, and biochar showed the good potential as reuseable adsorbent to remove heavy metal in aqueous solution.
Mg/Al-CH, Ni/Al-CH and Zn/Al-CH, as adsorbents for Congo Red removal in aqueous solution Siregar, Patimah Mega Syah Bahar Nur; Normah; Juleanti, Novie; Wijaya, Alfan; Palapa, Neza Rahayu; Mohadi, Risfidian; Lesbani, Aldes
Communications in Science and Technology Vol 6 No 2 (2021)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.6.2.2021.547

Abstract

In this study, chitosan was extracted from shrimp shells by demineralization and deproteination processes. The extracted chitosan was used to modify the layered double hydroxide and used as an adsorbent for the removal of congo red from aqueous solutions. Composites were successfully synthesized using M2+/Al (M2+ = Zn, Mg, Ni) and chitosan (CH) and the samples obtained were characterized using XRD and FTIR. The X-ray diffraction (XRD) pattern appeared at the layered double hydroxide peak of 2? = 11.63°; 23.00°; 35.16°; and 61.59° and chitosan at 2? = 7.93° and 19.35. The composite appearing in the layered double hydroxide and chitosan indicated that the composite material has been successfully synthesized. The XRD diffraction patterns of Zn/Al-CH, Ni/Al-CH, and Mg/Al-CH showed low crystallinity. The Fourier Transform Infrared (FTIR) spectra verifying absorption spectrum showed the presence of two bands at 3448 cm-1, 1382cm-1 characteristic to both chitosan and LDH. Adsorption of Congo Red (CR) followed the pseudo-second-order and Langmuir isotherm models. The adsorption capacities of Zn/Al-CH, Ni/Al-CH, and Mg/Al-CH were 181.818 mg/g, 227.273 mg/g, and 344.828 mg/g, respectively. The layered double hydroxide-chitosan composite adsorption was endothermically characterized by positive enthalpy and entropy values. On the other hand, the adsorption spontaneously was characterized by a negative Gibbs free energy value. The composites in this study were formed from LDH modified from chitosan extracted from shrimp shells to form Zn/Al-CH, Ni/Al-CH, and Mg/Al-CH. The results of the characterization showed a number of characteristics that resembled the constituent materials in the form of LDH and chitosan. After being applied as an adsorbent to absorb Congo red dye, it then showed the most effective results using Mg/Al-CH adsorbent with an adsorption capacity of 344.828 mg/g.
Mg/Cr-(COO)22- layered double hydroxide for malachite green removal Palapa, Neza Rahayu; Badri, Arini Fousty; Mardiyanto; Mohadi, Risfidian; Taher, Tarmizi; Lesbani, Aldes
Communications in Science and Technology Vol 7 No 1 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.1.2022.851

Abstract

Mg/Cr layered double hydroxide (LDH) was prepared and modified using an intercalation of oxalate anions ((COO)22-) to form Mg/Cr-(COO)22. The materials were then investigated to malachite green removal to determine the adsorption ability. Furthermore, the desorption process and regeneration of adsorbent were systematically conducted. The adsorption of green malachite on Mg/Cr- LDH and Mg/Cr-(COO)22- materials fitted to the pseudo-second-order (PSO) kinetic model and Freundlich isotherm model with an adsorption capacity of 33.784 mg/g (333K) for Mg/Cr LDH and 64.516 mg/g (333K) for Mg/Cr-(COO)22-. Thermodynamic data showed that the adsorption process was spontaneous and endothermic. Also, the appropriate reagent desorption study was found as hydrochloric acid and material regeneration studies exhibited a good recycling performance after 3 times cycles and, the Mg/Cr-oxalate showed a good performance for malachite green adsorption. It can be concluded that Mg/Cr--(COO)22- can adsorb the dye stuffs effectively.
Modification of pristine layered double hydroxide to form metal oxide composites as an anionic dye photodegradation catalysts Yuliasari, Nova; Amri; Mohadi, Risfidian; Elfita; Lesbani, Aldes
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.1009

Abstract

Pristine layered double hydroxide (LDH) in the form of clay Mg/Al LDH was enhanced its catalytic ability by impregnating metal oxides to form Mg/Al-metal oxide composites in congo red (CR) degradation. The composite was calcined at a not high temperature of 300 oC and characterized using SEM and DRUV. In this report, the photodegradation of CR as anionic dye was optimized based on the variables of pH, catalyst weight and time radiation. The stability of the catalyst was studied from the percent degradation in the recycling test. The characterization of the catalyst that has undergone 5th regeneration cycles was carried out using XRD and FTIR. The results of this study revealed that catalysis by Mg/Al-metal oxide composites resulted in a better percent degradation, rate constant and materials stability than pristine Mg/Al LDH. Mg/Al LDH, Mg/Al-TiO2 and Mg/Al-ZnO catalyzed the photodegradation of CR by 65.97%, 73.06 % and 86.86%, respectively.
Palm oil mill effluent (POME) precipitation using ammonium-intercalated clay coagulant Priatna, Satria Jaya; Hakim, Yusuf Mathiinul; Alfarizi, Muhammad Afif; Sailah, Siti; Mohadi, Risfidian
Communications in Science and Technology Vol 8 No 1 (2023)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.8.1.2023.1034

Abstract

Clay intercalation has been completed to improve coagulation ability using ammonium ions intercalant via multi-step intercalation. The intercalated clay was confirmed by Scanning Electron Microscope-Energy Dispersive Spectroscopy analysis of expanded lamellar and reduction impurities. Fourier Transform Infra-Red analysis confirmed the sharp and strong peak adsorption at 1448 cm-1 as ammonium (NH4+) bendingvibration, and X-Ray Diffraction analysis confirmed the peak shifting to smaller 2? at 10.08° as increasing basal spacing because of ammonium ion intercalated. The Palm Oil Mill Effluent (POME) coagulation was carried out using contact time and coagulant dose variations to determine the optimum conditions, reaching 45 minutes of coagulation and 0.4 g coagulant was used. Furthermore, the turbidity, free fatty acid, and total suspended solids were measured to reach the reduction values of 93%, 49.7%, and 73.7%, respectively. The reusable study of ammoniumintercalated clay confirmed the stability of the three cycles of coagulation used.
Photocatalytic of anionic dyes on Congo red with M2+/Al (M2+=Ni, Mg, and Zn) layered double hydroxide intercalated polyoxometalate Hanifah, Yulizah; Mohadi, Risfidian; Mardianto; Nur Ahmad; Suheryanto; Lesbani, Aldes
Communications in Science and Technology Vol 8 No 1 (2023)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.8.1.2023.1170

Abstract

The modification catalysts of layered double hydroxide (LDH) with polyoxometalate based on Keggin type were prepared and characterized using X-Ray, FTIR, and SEM to confirm the layered double hydroxide structure. Intercalation was successfully synthesized and showed a heterogeneous aggregate resulted from SEM analysis. The degradation parameters of LDH pristine and LDH composite were determined by observing a number of factors such as pH, catalyst weight, and degradation time. The modification material resulted by preparation material LDH and polyoxometalate (POM) successfully resulted in the lower band gap value compared to material pristine LDH allowing LDH polyoxometalate as photocatalysts to show good photocatalytic activities. The NiAl-SiW12O40 material had the highest percentage of degradation removing Congo Red up to 86% degradation when compared to another composite material, yet it was still significantly better than LDH pristine. The result showed that the LDH composite presented excellent photocatalytic activity in reducing Congo Red.