scholarly journals Determination of the point of zero charge of pineapple (Ananas comosus L.) peel and its application as copper adsorbent

2021 ◽  
Author(s):  
Cintya Valerio Cárdenas ◽  
Jorge Martínez-Herrera ◽  
Diana Laura Velázquez-Vargas ◽  
Patricia De la Cruz-Burelo
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Ananas Comosus ◽  
Point Of Zero Charge ◽  
Copper Adsorption ◽  
Zero Charge ◽  
Pineapple Peel ◽  
Reliable Parameter ◽  
Initial Ph ◽  
Ph Range

Objective: To determine the optimum pH at which the pineapple peel can adsorb the greatest amount of copper. Design/methodology/approach: Sorbent material. The size of the pineapple peel was reduced to 0.250 mm; it was chemically modified with 0.2 M NaOH and 0.2 M CaCl2. Point of zero charge (PZC). Six solutions were prepared with 0.5 g of sorbent in an aqueous medium (with a 3-8 pH range), they were stirred at 225 rpm for 48 h. The derivative method was used to plot the initial pH versus final pH, in order to determine the PZC. Copper adsorption. CuSO4 solutions were prepared in 2, 4, 6, 8 10 mg/L concentrations; 0.1 g of pineapple biomass was added adjusting the pH to 5. The solutions had a contact time of 0 to 24 h. Results: The pineapple peel had a 5.0 point of zero charge (PZC) value, which indicates that pH values higher than the PZC are required to obtain an adsorbent with a negatively charged surface and favor the copper adsorption. A 50% copper removal was obtained in all concentrations after a 1 h contact time. Limitations on study/implications: This research had no limitations. Findings/conclusions: The point of zero charge is a reliable parameter that allows the adsorption process to take place and provides a greater certainty to the metal adsorption process. Meanwhile, pineapple peel can be used as an adsorbent material, consequently reducing its accumulation in open dumps.

Removal of Methyl Red from Aqueous Solution by Adsorption onto Mg-Al HTLc

2013 ◽  
Vol 750-752 ◽  
pp. 1426-1429
Author(s):  
Yun Bo Zang
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Adsorption Process ◽  
Bulk Solution ◽  
Methyl Red ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Percent Removal

In this study, removal of Methyl Red from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, pH and temperature. It is found that HTlc could reduced Methyl Red concentration effectively. The kinetic process which reached equilibrium at about 2h can be fitted by pseudo-second order kinetics. The percent removal of MR by the HTlc was dependent on the initial pH of bulk solution. There was no much changes in amount of adsorption in the initial pH range of 6-8, while it reached maxium at about of 9. The adsorption process was endothermic.

scholarly journals Use of sweet ‘Pêra’ peel as an adsorbent in the treatment of textile effluents

2019 ◽  
Vol 23 (9) ◽  
pp. 716-722
Author(s):  
Ketyla K. R. do Nascimento ◽  
Fernando F. Vieira ◽  
Marcello M. de Almeida ◽  
Josué da S. Buriti ◽  
Aldre J. M. Barros ◽  
...  
Keyword(s):  
Contact Time ◽  
Exponential Model ◽  
Point Of Zero Charge ◽  
Infrared Analysis ◽  
Hydroxyl Groups ◽  
Solution Ph ◽  
Initial Concentration ◽  
Zero Charge ◽  
Adsorbed Quantity ◽  
Air Circulation

ABSTRACT The disposal of industrial wastewater into aquatic bodies without proper treatment can cause severe damage to the environment and human health. The objective of this study was to perform the drying of the sweet orange (Citrus sinensis L. Osbeck) peel cultivar Pêra and evaluate the viability of its use as biosorbent in the removal of a direct dye. Drying was carried out in an oven with air circulation at temperatures of 60 and 80 ºC. The mathematical models of Page, Henderson and Pabis, Logarithmic, Midilli and Two-term exponential were fitted to the moisture data as a function of time. The material was characterized by scanning electron microscopy, point of zero charge, and infrared spectroscopy. In the adsorption study, a complete 24 factorial design was used to analyze the influence of mass, initial concentration, solution pH and contact time on adsorbed quantity (qt) and removal percentage of the dye (R%). In the drying, the two-term exponential model fitted best to the experimental data. The characterization of the material indicated that the adsorbent has zero charge point of 3.5 and porous structure, and the infrared analysis indicated the presence of carboxylic and hydroxyl groups. In the adsorption, the adsorbed quantity of the dye increased under conditions of lower pH and biosorbent mass and higher initial concentration and contact time. The removal percentage of dye increases with higher biosorbent mass. The biosorbent used is a promising waste for the adsorption of the burgundy-16 dye.

scholarly journals Effect of Hydrogen Ion Presence in Adsorbent and Solution to Enhance Phosphate Adsorption

2021 ◽  
Vol 11 (6) ◽  
pp. 2777
Author(s):  
Taehoon Kim ◽  
Byungryul An
Keyword(s):  
Hydrochloric Acid ◽  
Adsorption Mechanism ◽  
Ph Effect ◽  
Total Surface Area ◽  
Point Of Zero Charge ◽  
Phosphate Adsorption ◽  
Hydrogen Ions ◽  
Solution Ph ◽  
Initial Ph ◽  
Ph Range

In this paper, the effect of hydrogen ions on the adsorption onto granular activated carbon (GAC) with the inorganic contaminant phosphate, which exists as a form of four species depending on the solution pH, is investigated. Various batch isotherm and kinetic experiments were conducted in an initial pH 4 as an acid, a pH 7 as neutral, and a pH 9 solution as a base for the GAC conditioned with deionized water and hydrochloric acid, referred to as GAC and GACA, respectively. The physical properties, such as the total surface area, pore volume, pore size distribution, and weight of the element, obtained from Brunauer–Emmett–Teller (BET) and scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM–EDX) represent no significant differences. However, the hydrochloric acid (HCl) condition results in an alteration of the pH of the point of zero charge from 4.5 to 6.0. The optimized initial pH was determined as being acid for the GAC and as being neutral for the GACA. According to the Langmuir isotherm, the relatively high Qm was obtained as being acid for the GAC and clearly distinguishes the pH effect as being the base for the GACA. An attempt was made to assess the adsorption mechanism using the pseudo-first-order (PFO), the pseudo-second-order (PSO), and the intraparticle diffusion models. The higher R2 for the PSO in the entire pH range indicated that chemisorption was predominant for phosphate adsorption, and the pH did not change the adsorption mechanism. A prolonged Bed Volume (BV) for the GACA demonstrated that the hydrogen ions on the surface of the GAC enhanced phosphate adsorption.

scholarly journals Adsorption of Chromium(VI) on Radiation Grafted N,N-dimethylaminoethylmethacrylate onto Polypropylene, from Aqueous Solutions

2017 ◽  
Vol 57 (2) ◽  
Author(s):  
Guillermina Burillo ◽  
Juan Serrano-Gómez ◽  
Juan Bonifacio-Martínez
Keyword(s):  
Contact Time ◽  
Metal Ion ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Ion Adsorption ◽  
Initial Concentration ◽  
Chromium Vi ◽  
Adsorption Data ◽  
Initial Ph ◽  
Chromium Adsorption

Polypropylene (PP) grafted with dimethylaminoethylmethacrylate (DMAEMA), was prepared by irradiation with a <sup>60</sup>Co γ source. The obtained PP-<em>g</em>-DMAEMA was used to study the Cr(VI) ion adsorption as a function of contact time, initial pH, initial concentration of metal ion and temperature. Chromium adsorption data on PP-<em>g</em>-DMAEMA at various initial concentration fit well the Freundlich and Langmuir isotherms. The maximum adsorption capacity (a<sub>max</sub>) was found to be 0.3103 × 0<sup>-4</sup> mol g<sup>-1</sup>. The thermodynamic parameters ΔH<sup>0</sup>, ΔG<sup>0</sup> and ΔS<sup>0</sup> were estimated showing the adsorption process to be exothermic and spontaneous.

scholarly journals Al (III) removal from wastewaters by natural clay and coconut shell

2019 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Acid Treatment ◽  
Adsorption Process ◽  
Coconut Shell ◽  
Maximum Adsorption Capacity ◽  
Agitation Rate ◽  
Batch Experiments ◽  
Natural Clay ◽  
Initial Ph

<p>This paper describes the adsorption of Al3+ ions from aqueous solutions, by natural clay (from Sakarya's Yenigün district) and coconut shell modified by means of acid treatment. Batch experiments were carried out to determine the effect of various factors such as initial pH (4-9), temperature (20, 40, 70 oC), initial concentration (10 to 200 mg L-1) and contact time (1-120 minute) on the adsorption process. The adsorption experiments were performed at a temperature of 20 ±2 oC), at 200 rpm agitation rate, with an adsorbent level of 1 g L-1, produced 98.95% (at pH 6) and 92.83% (at pH 7) maximum Al3+ removal efficiency for clay and coconut shell based adsorbents respectively. Furthermore, the process was found to be exothermic for clay and endothermic for coconut. XRF and XRD analyses of the clay variety used in adsorption analyses revealed it to be saponite clay, within the larger group of smectite clay minerals. The application of Langmuir revealed maximum adsorption capacity of 149.25 mg g-1 for natural clay adsorbent (NCA), and 120.482 mg g-1 for coconut shell adsorbent (CSA). Moreover, adsorption kinetics were found to be consistent with the second order kinetics (R2 &gt; 0.95). The result shows that, natural clay and coconut shell adsorbents are effective adsorbents to remove Al3+ from aqueous solutions with good adsorption rate (&gt;92.8%).</p>

scholarly journals Reductive Adsorption of Chromium(VI) with Activated Carbon

2021 ◽  
Vol 333 ◽  
pp. 04004
Author(s):  
Anh Viet Hoang ◽  
Ya Wen Chen ◽  
Ya-Fen Wang ◽  
Syouhei Nishihama ◽  
Kazuharu Yoshizuka
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Contact Time ◽  
Adsorption Process ◽  
Acidic Ph ◽  
High Adsorption ◽  
Varying Parameters ◽  
High Ph ◽  
Chromium Vi ◽  
Ph Range

Reductive adsorption of chromium (Cr) has been investigated, employing coal-based activated carbon with batchwise study. The adsorption was carried out by varying parameters such as pH of the aqueous solution and contact time. Cr(III) was hardly adsorbed on activated carbon, and it was precipitated at high pH region. High adsorption amounts of Cr(VI) was obtained at pH range 4.5 – 5.5. In the adsorption process, reduction of Cr(VI) to Cr(III) was occurred at especially acidic pH region, and thus most of Cr remained in the aqueous solution in this pH region was Cr(III).

Removal of sunset yellow FCF from aqueous solution using polyethyleneimine-modified MWCNTs

2015 ◽  
Vol 73 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
Hejun Gao ◽  
Luanluan Zhang ◽  
Yunwen Liao
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Order Model ◽  
Sunset Yellow ◽  
Multi Wall Carbon Nanotubes ◽  
Initial Ph ◽  
Pseudo Second Order

A novel adsorbent consisting of polyethyleneimine-modified multi-wall carbon nanotubes (PEI-MWCNTs) was synthesized by grafting PEI on the carboxyl MWCNTs. The surface properties of the PEI-MWCNTs were measured by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared, and zeta potential. The adsorption behavior of the PEI-MWCNTs was investigated using sunset yellow FCF as adsorbate. The effects of dosage of adsorbent, the initial pH of solution, contact time and temperature on the adsorption capacity were studied. Then, the kinetics and thermodynamics of the adsorption process were further investigated. Experimental results showed that the adsorption kinetics fitted a pseudo-second-order model and the adsorption isotherms agreed well with the Langmuir model. The adsorption process occurred very fast and the adsorption capacity of PEI-MWCNTs was much higher than that of many of the previously reported adsorbents. Additionally, the plausible adsorption mechanism was discussed.

Use of Fly Ash in the Removal of Copper, Nickel and Zinc from Wastewater

1993 ◽  
Vol 28 (2) ◽  
pp. 369-384 ◽  
Author(s):  
T. Viraraghavan ◽  
Murali M. Dronamraju
Keyword(s):  
Fly Ash ◽  
Thermodynamic Parameters ◽  
Contact Time ◽  
Adsorption Process ◽  
Initial Concentration ◽  
Copper Nickel ◽  
Adsorption Data ◽  
Ph Range ◽  
Langmuir And Freundlich Models

Abstract The effectiveness of fly ash in adsorbing copper, nickel and zinc was studied by conducting batch kinetic and isotherm studies. The effect of contact time, pH, initial concentration of the adsorbate, and temperature on the adsorption process was studied. Fly ash was found to be an effective adsorbent. The contact time necessary to attain equilibrium was found to be two hours. Maximum adsorption occurred in the pH range of 3.0 to 3.5. The Langmuir and Freundlich models were found to be applicable to the adsorption data of copper, nickel and zinc. Thermodynamic parameters suggested the exothermic nature of the adsorption process.

scholarly journals Sorption of Sr-85 and Am-241 from liquid radioactive wastes by alginate beads

Nukleonika ◽  
2015 ◽  
Vol 60 (4) ◽  
pp. 927-931 ◽  
Author(s):  
Agata Oszczak ◽  
Leon Fuks
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Decontamination Factor ◽  
Alginate Beads ◽  
Radioactive Wastes ◽  
Batch Experiments ◽  
Optimum Conditions ◽  
Liquid Radioactive Wastes ◽  
Initial Aqueous Solution ◽  
Initial Ph

Abstract The paper reports the adsorption of strontium(II) and americium(III) from aqueous solutions onto calcium alginate (CaA), barium alginate (BaA) and strontium alginate (SrA) beads. Adsorption process was studied in batch experiments as a function of the initial pH of the solution and the contact time. All sorbents were examined by the termogravimetric analysis (TG). Laboratory obtained spherical beads of CaA, BaA and SrA seem to be good metal sorbents from liquid radioactive wastes. A contact time of about 4 h and neutral pH of the initial aqueous solution have been proposed to be optimum conditions for Sr-85 and Am-241 removal from the contaminated solutions using alginate sorbents. Laboratory obtained beads of CaA, BaA and SrA are characterized by the decontamination factor (DF) equal to 85% for Sr(II) and 90% for Am(III).

Cu2+ Removal by Hydroxyapatite Nanorods Prepared by Surfactant-Templated Method

2013 ◽  
Vol 807-809 ◽  
pp. 1258-1261
Author(s):  
Shao Hong Wang ◽  
Jian Guo Xia ◽  
Mei Han Wang ◽  
Zhao Xia Hou ◽  
Xiao Dan Hu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Contact Time ◽  
Adsorption Process ◽  
Adsorption Property ◽  
Copper Ion ◽  
Ion Concentration ◽  
Batch Adsorption ◽  
Copper Adsorption ◽  
Initial Adsorption ◽  
Templated Method

Nanohydroxyapatite (HA) with rod-like shape was synthesized by a cationic surfactant-templated method. Batch adsorption experiments were conducted to investigate its copper adsorption property from aqueous solution. The effect of initial copper ion concentration and contact time were studied. Results showed that HA adsorption capacity increased from 25.6 mg/g to 81.4 mg/g with the increase of initial copper ion concentration from 20 mg/L to 200 mg/L. Meanwhile, the removal efficiency decreased from 64.1% to 20.3%. Moreover, it also revealed that the removal efficiency of Cu2+increased with the increasing contact time and the initial adsorption process is rapidly increased within 15 min and the equilibrium was attained after 15 min.

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