scholarly journals An Investigation on Zinc Biosorption with Agar Extraction Waste from Gracilaria tenuistipitata

KIMIKA ◽  
2020 ◽  
Vol 31 (2) ◽  
pp. 11-26
Author(s):  
Nikko Angelo S. Carisma ◽  
Reniza Yvonne E. Gonzales ◽  
Nancy Lazaro-Llanos

This study determined the biosorption capacity of algal waste, obtained through agar extraction from Gracilaria tenuistipitata, a common red seaweed in the Philippines and potential biosorbent, on Zn2+ ions. Agar was extracted from the seaweed and characterized through Fourier-transform infrared spectroscopy (FT-IR). The algal waste was then subjected to a biosorption study involving various Zn2+ standards. Atomic absorption spectroscopy (AAS) and FT-IR were employed to evaluate sorption processes. Biosorption data was analyzed using Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherms which yielded  values of 0.9680, 0.8103, and 0.5254, respectively. The Langmuir ( ), Freundlich ( ), and D-R ( ) constants garnered were 0.0231 L/mg, 0.9829 mg/g, and 2.159  10-6 mol2 J-2 respectively, qualifying the adsorption of Zn2+ ions onto the algal waste as a favorable and physical process. FT-IR spectra analysis suggests that carboxylic acid and amide groups are involved in biosorption, possibly an ion-exchange process taking place for the uptake of Zn2+ ions. It was concluded that G. tenuistipitata waste is a promising biosorbent for Zn2+ ions. Performing the biosorption procedure in triplicates and the inclusion of kinetic studies are recommended to improve and ensure the accuracy in determining biosorption capacity and optimization in future studies.

Author(s):  
Rahmiana Zein ◽  
Mutia Khuratul Aini ◽  
Hermansyah Aziz

Biosorpsi zat warna Rhodamine B menggunakan cangkang Pensi (Corbicula moltkiana) telah dikaji. Percobaan dilakukan dengan system batch guna memperoleh kondisi optimum biosorspi zat warna. Kapasitas biosorpsi zat warna pada pH 2 adalah 0.9958 mg/g, dengan konsentrasi larutan mula-mula 150 mg/L waktu kontak 105 menit, massa biosorben 0.1 g, ukuran partikel 32 µm dan temperature pengeringan biosorben pada 75oC. Model isotherm Langmuir menunjukkan bahwa proses penyerapan berlangsung secara kimia dan biosorpsi homogeny dari adsorbat (Rhodamine B) pada permukaan biosorben membentuk lapisan tunggal dengan nilai R2 0.9966. Analisis XRF menunjukkan bahwa penurunan kadar unsur logam pada cangkang Pensi membuktikan bahwa proses biosorpsi berlangsung dengan pertukaran kation. Hasil analisis spektrum FT-IR membuktikan adanya interaksi antaramolekul Rhodamin B dengan gugus fungsi pada cangkang Pensi. Analisis dengan SEM memperlihatkan bahwa pori-pori cangkang Pensi telah terisi penuh oleh molekul Rhodamin B. Kondisi optimum biosorpsi telah diaplikasikan pada limbah kerupuk merah dengan kapasitas penyerapan sebesar 0,2835 mg/g.   The biosorption of Rhodamine B dyes by Pensi (Corbicula moltkiana) shell has been investigated. The experiment was conducted in batch sistem in order to obtain the optimum conditions of dye biosorption. Biosorption capacity of dye was 0.9958 mg/g at pH 2, initial concentration 150 mg/L, contact time 105 minutes, biosorbent mass 0.1 gram, particle size 32 µ m and biosorbent drying temperature was at 75oC. The Langmuir Isotherm model showed chemisorption and homogeneous biosorption process of adsorbates onto the biosorbent surface formed monolayer dye molecules on the biosorbent surface with R2 value was 0.9966. XRF analysis showed that reduction of metals unsure quantity of pensi shell indicated biosorption process was occupied through cationic exchange. The result of FTIR spectra analysis indicated an interaction between Rhodamin B molecules and functional group of pensi shell. SEM analysis showed that the pensi shell pores were completely filled by Rhodamine B molecules. The optimum condition of biosorption has been aplicated in red chips wastewater industry with biosorption capacity was 0.2835 mg/g.


2020 ◽  
Vol 15 (1) ◽  
pp. 221-230 ◽  
Author(s):  
Sara Haoue ◽  
Hodhaifa Derdar ◽  
Mohammed Belbachir ◽  
Amine Harrane

In this paper we have explored a novel and green method to synthesis and polymerize ethylene glycol dimethacrylate (EGDM). This technique consists on using Maghnite (Algerian clay) as a green catalyst to replace toxic catalysts. The Algerian clay has been modified using two ion exchange process to obtain Maghnite-H+ (proton exchanged process) and Maghnite-Na+ (sodium exchanged process). Synthesis experiments of EGDM and Poly (EGDM) are performed in bulk respecting the principles of green chemistry. The structure of the obtained monomer and the obtained polymer was confirmed by FT-IR, 1H-NMR and 13C-NMR, where the methacrylate end groups are clearly visible. The presence of unsaturated end group in the structure of monomer was confirmed by UV-Visible analysis. Thermogravimetric analysis (TGA) was used to study the thermal stability of these obtained products. Copyright © 2020 BCREC Group. All rights reserved 


2016 ◽  
Vol 18 ◽  
pp. 39-51
Author(s):  
Dalila Smail ◽  
B. Djellouli ◽  
Ali Ourari

This paper presents preliminary results of modified Montmorillonite samples and the surface treatment with hydrochloric acid were investigated. The modification of this Montmorillonite surface, negatively charged and exchanged by organic cations such as alkylammoniums (Trimethylexadecyl C16 and Trimethyloctadecyl C18), yields a modified Montmorillonite (MMt). The resulting organo-mineral material acquires an organophilic character which could be used in several applications. The organically modified MMts were prepared by an ion exchange process in which sodium ions were replaced by alkylammonium ions. This material, used in the present work, is an Algerain montmorillonite obtained from MAGHNIA (West Algeria). Octadecyltrimethylammonium and hexadecyltrimethylammonium chlorides, utilized here as surfactants activators to organophilize the Montmorillonite. The microstructure of this modified Montmorillonite was characterized by XRD-diffraction with which the effects of the intercalation associated to the conformation of the long hydrocarbon chain were investigated. The results obtained showed that the amounts of hydrochloric acid added to these modified materials affect considerably the conformation of the intercalated surfactants. Their physical characteristics were determined by infrared spectrophotometer (FT-IR) and their chemical modification revealed that their thermal properties have been advantageously improved.


2020 ◽  
Vol 16 ◽  
Author(s):  
Reda M. El-Shishtawy ◽  
Abdullah M. Asiri ◽  
Nahed S. E. Ahmed

Background: Color effluents generated from the production industry of dyes and pigments and their use in different applications such as textile, paper, leather tanning, and food industries, are high in color and contaminants that damage the aquatic life. It is estimated that about 105 of various commercial dyes and pigments amounted to 7×105 tons are produced annually worldwide. Ultimately, about 10–15% is wasted into the effluents of the textile industry. Chitin is abundant in nature, and it is a linear biopolymer containing acetamido and hydroxyl groups amenable to render it atmospheric by introducing amino and carboxyl groups, hence able to remove different classes of toxic organic dyes from colored effluents. Methods: Chitin was chemically modified to render it amphoteric via the introduction of carboxyl and amino groups. The amphoteric chitin has been fully characterized by FTIR, TGA-DTG, elemental analysis, SEM, and point of zero charge. Adsorption optimization for both anionic and cationic dyes was made by batch adsorption method, and the conditions obtained were used for studying the kinetics and thermodynamics of adsorption. Results: The results of dye removal proved that the adsorbent was proven effective in removing both anionic and cationic dyes (Acid Red 1 and methylene blue (MB)), at their respective optimum pHs (2 for acid and 8 for cationic dye). The equilibrium isotherm at room temperature fitted the Freundlich model for MB, and the maximum adsorption capacity was 98.2 mg/g using 50 mg/l of MB, whereas the equilibrium isotherm fitted the Freundlich and Langmuir model for AR1 and the maximum adsorption capacity was 128.2 mg/g. Kinetic results indicate that the adsorption is a two-step diffusion process for both dyes as indicated by the values of the initial adsorption factor (Ri) and follows the pseudo-second-order kinetics. Also, thermodynamic calculations suggest that the adsorption of AR1 on the amphoteric chitin is an endothermic process from 294 to 303 K. The result indicated that the mechanism of adsorption is chemisorption via an ion-exchange process. Also, recycling of the adsorbent was easy, and its reuse for dye removal was effective. Conclusion: New amphoteric chitin has been successfully synthesized and characterized. This resin material, which contains amino and carboxyl groups, is novel as such chemical modification of chitin hasn’t been reported. The amphoteric chitin has proven effective in decolorizing aqueous solution from anionic and cationic dyes. The adsorption behavior of amphoteric chitin is believed to follow chemical adsorption with an ion-exchange process. The recycling process for few cycles indicated that the loaded adsorbent could be regenerated by simple treatment and retested for removing anionic and cationic dyes without any loss in the adsorbability. Therefore, the study introduces a new and easy approach for the development of amphoteric adsorbent for application in the removal of different dyes from aqueous solutions.


Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 102
Author(s):  
Ferenc Horkay

The objective of this article is to introduce the readers to the field of polyelectrolyte gels. These materials are common in living systems and have great importance in many biomedical and industrial applications. In the first part of this paper, we briefly review some characteristic properties of polymer gels with an emphasis on the unique features of this type of soft material. Unsolved problems and possible future research directions are highlighted. In the second part, we focus on the typical behavior of polyelectrolyte gels. Many biological materials (e.g., tissues) are charged (mainly anionic) polyelectrolyte gels. Examples are shown to illustrate the effect of counter-ions on the osmotic swelling behavior and the kinetics of the swelling of model polyelectrolyte gels. These systems exhibit a volume transition as the concentration of higher valence counter-ions is gradually increased in the equilibrium bath. A hierarchy is established in the interaction strength between the cations and charged polymer molecules according to the chemical group to which the ions belong. The swelling kinetics of sodium polyacrylate hydrogels is investigated in NaCl solutions and in solutions containing both NaCl and CaCl2. In the presence of higher valence counter-ions, the swelling/shrinking behavior of these gels is governed by the diffusion of free ions in the swollen network, the ion exchange process and the coexistence of swollen and collapsed states.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2741
Author(s):  
Pengcheng Lv ◽  
Ruihong Meng ◽  
Zhongyang Mao ◽  
Min Deng

In this study, the hydrated sodium aluminosilicate material was synthesized by one-step hydrothermal alkaline desilication using fly ash (FA) as raw material. The synthesized materials were characterized by XRD, XRF, FT-IR and SEM. The characterization results showed that the alkali-soluble desilication successfully had synthesized the sodium aluminosilicate crystalline (N-A-S-H) phase of sodalite-type (SOD), and the modified material had good ionic affinity and adsorption capacity. In order to figure out the suitability of SOD as an adsorbent for the removal of ammonium and phosphorus from wastewater, the effects of material dosing, contact time, ambient pH and initial solute concentration on the simultaneous removal of ammonium and phosphorus are investigated by intermittent adsorption tests. Under the optimal adsorption conditions, the removal rate of ammonium was 73.3%, the removal rate of phosphate was 85.8% and the unit adsorption capacity reached 9.15 mg/L and 2.14 mg/L, respectively. Adsorption kinetic studies showed that the adsorption of ammonium and phosphorus by SOD was consistent with a quasi-secondary kinetic model. The adsorption isotherm analysis showed that the equilibrium data were in good agreement with the Langmuir and Freundlich model. According to thermodynamic calculations, the adsorption of ammonium and phosphorus was found to be a heat-absorbing and spontaneous process. Therefore, the preparation of SOD by modified FA has good adsorption properties as adsorbent and has excellent potential for application in the removal of contaminants from wastewater.


1986 ◽  
Vol 20 (9) ◽  
pp. 1177-1184 ◽  
Author(s):  
Arup K. Sengupta ◽  
Dennis Clifford ◽  
Suresh Subramonian

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