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 Removal of hexavalent chromium from graphene oxide supported on a cellulose acetate and polyacrylic acid membrane

2021 ◽  
pp. 1-8
Author(s):  
Juan SÁNCHEZ-MÁRQUEZ ◽  
Rosalba FUENTES-RAMÍREZ ◽  
Zeferino GAMIÑO-ARROYO
Keyword(s):  
Graphene Oxide ◽  
Cellulose Acetate ◽  
Hexavalent Chromium ◽  
Polyacrylic Acid ◽  
Contact Time ◽  
Polymeric Membrane ◽  
Point Of Zero Charge ◽  
Inversion Method ◽  
Initial Concentration ◽  
Phase Inversion Method

This work focused on the study of the hexavalent chromium removal process from graphene oxide supported on a cross-linked cellulose acetate and polyacrylic acid polymeric membrane. The membranes were synthesized by the phase inversion method and Graphene oxide was added in proportions of 1% by weight to the polymeric material. Graphene oxide was obtained from crystalline graphite (Electron Microscope Science, No. 70230). The graphite was oxidized using the improved method of Hummers. The characterization of polymer and graphene oxide was made by Raman spectroscopy. The surface charge and point of zero charge of the materials were evaluated using a potentiometric titration method proposed by Loskutov and Kuzin. The removal of Cr (VI) was studied as a function of contact time and of initial concentration of Cr (VI). The removal of Cr (VI) (~90%) mainly occurs in a contact time from 32 to 64 h when the initial concentration of Cr (VI) is 1 mg/L.

Response Surface Methodology Approach for Optimization of Biosorption Process for Removal of Binary Metals by Immobilized Saccharomyces cerevisiae

2014 ◽  
Vol 661 ◽  
pp. 51-57
Author(s):  
Mohd Zawawi Mohamad Zulhelmi ◽  
Alrozi Rasyidah ◽  
Senusi Faraziehan ◽  
Mohamad Anuar Kamaruddin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Aqueous Solution ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Contact Time ◽  
Optimization Procedure ◽  
Effective Parameters ◽  
Solution Ph ◽  
Initial Concentration ◽  
Biosorption Process

Biosorption process is considered as economical treatment to remove metal from the aqueous solution compared to other established methods. In this study, Saccharomyces cerevisiae was used as biosorbent and subject to immobilization process which consists of ethanol treatment for the removal of binary metals, lead (II) and nickel (II) from aqueous solution. Response surface methodology (RSM) was used to optimize effective parameters condition and the interaction of two or more parameters in order to obtain high removal of the binary metals. The parameters that have been studied were initial concentration of binary metals solution (10 - 60 mg/L), biosorbent dosage (0.2 - 1.0 g), pH (pH 2 - pH 6) and contact time (30 - 360 minutes) towards lead (II) and nickel (II) ions removal. Based on analysis of variance (ANOVA), biosorbent dosage, solution pH and contact time factor were found significant for both responses. Through optimization procedure, the optimum condition for lead (II) and nickel (II) ions removal were obtained at initial concentration of 10.0 mg/L, biosorbent dosage of 1.0 g, solution pH of pH 6, and contact time of 360.00 minutes, which resulted in 95.08 % and 21.09 % removal of lead (II) and nickel (II) ions respectively.

Removal of Fluoride on Chitosan Coated Alumina (CAL) from Aqueous Solution

2012 ◽  
Vol 518-523 ◽  
pp. 797-800 ◽  
Author(s):  
Xuan Lin Tang ◽  
Huan Zhen Zhang ◽  
Shuang Zhao ◽  
Shu Fen Gong
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Rate ◽  
Fluoride Removal ◽  
Batch Experiments ◽  
Solution Ph ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Naoh Solution

CAL beads were made by dropping wise mixture of chitosan and alumina into NaOH solution. Effects of contact time, adsorbent dosage, initial concentration and pH on fluoride removal were carried out by batch experiments. Results show that adsorption rate was relatively rapid in the first 6 h, thereafter distinctly decreased until adsorption reached the equilibrium within 48 h, at this time, adsorption capacity was up to 0.67 mg/g, which was much higher than raw chitosan (0.052 mg/g). Fluoride removal increased significantly with an increase of adsorbent dosage, however, it rose slowly when the adsorbent dosage was above 16 g/L. Adsorption capacity reduced from 0.75 mg/g to 0.64mg/g when solution pH rose from 4 to 7, nevertheless, adsorption was relatively independent on solution pH between 7 and 10.

scholarly journals Adsorptive removal of cationic and anionic dyes using graphene oxide

2018 ◽  
Vol 78 (4) ◽  
pp. 732-742 ◽  
Author(s):  
V. Sabna ◽  
Santosh G. Thampi ◽  
S. Chandrakaran
Keyword(s):  
Graphene Oxide ◽  
Contact Time ◽  
Uv Spectroscopy ◽  
Point Of Zero Charge ◽  
Order Kinetic ◽  
Dye Molecules ◽  
Anionic Dyes ◽  
Batch Mode ◽  
Initial Concentration ◽  
Adsorptive Removal

Abstract This paper presents the results of comparative study on the application of graphene oxide (GO) for the adsorptive removal of crystal violet (CV) and methyl orange (MO) in batch mode. GO, synthesised from graphite, was characterised by field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, point of zero charge (pHPZC) and ultra violet (UV) spectroscopy. Dispersion of GO in water revealed the conversion of hydrophobic graphite into hydrophilic. Performance with regard to adsorption of CV and MO on GO was evaluated at different values of the operational parameters such as contact time between GO and the dye molecules, dosage of GO, and initial concentration and pH of the dye solution. Uptake and percentage removal of the dyes increased with increase in contact time and adsorbent dosage, but declined with increase in initial concentration of the dye. Experimental data on the uptake of dye molecules by GO showed good fit with the Freundlich isotherm model and the pseudo second order kinetic model. The maximum uptake by GO was higher for CV (207.4 mg/g) than that for MO (37.2 mg/g). Results indicate that GO is an effective adsorbent for the removal of CV but not for MO.

scholarly journals Mechanisms of halosulfuron methyl pesticide biosorption onto neem seeds powder

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Atta ul Haq ◽  
Muhammad Saeed ◽  
Muhammad Usman ◽  
Ameer Fawad Zahoor ◽  
Muhammad Naveed Anjum ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Sorption Kinetics ◽  
Point Of Zero Charge ◽  
Neem Seed ◽  
Solution Ph ◽  
Chemical Surface ◽  
Operation Conditions ◽  
Zero Charge ◽  
Pseudo Second Order ◽  
Kinetics Of

AbstractThe current investigation was designed to remove halosulfuron methyl from aqueous media by means of neem seed powder (NSP) in batch modes. Characterizations of NSP were carried out by using EDX, SEM, FTIR, point of zero charge and surface analysis. Optimum operation conditions were scrutinized by studying the influence of different factors like solution pH, dose of NSP, contact time, initial halosulfuron methyl concentration and temperature. Result indicates the dependency of the removal of halosulfuron methyl on solution pH and maximal removal (54%) was achieved in acidic medium (i.e. pH 3.0). To identify the chemical surface of NSP, point of zero charge of NSP was determined and was found to be 6.5 which imply that the surface of NSP is positively charged below pH 6.6 and favored the anionic sorption. Kinetics of halosulfuron methyl were demonstrated well by pseudo second order due to highest R2 (0.99) owing to the nearness between experimental and calculated sorption capacities. Isotherm results imply that Langmuir was found to the principal model to explain the removal of halosulfuron methyl and maximum monolayer sorption capacity was determined to be 200 mg g−1. Thermodynamic parameters like ΔH°, ΔG° and ΔS° were calculated from van’t Hoff plot and were found negative which suggest that removal of halosulfuron methyl is exothermic and spontaneous at low temperature. These outcomes insinuate that neem seed power may be a valuable, inexpensive and ecofriendly biosorbent for the removal of pesticides.

scholarly journals Synthesis of Modified Spent Tea for Aspirin Adsorption in Aqueous Solution

2019 ◽  
Vol 8 (3) ◽  
pp. 531-534
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Acid Treatment ◽  
Agricultural Waste ◽  
Point Of Zero Charge ◽  
Solution Temperature ◽  
Batch Adsorption ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Adsorption Mechanisms

This present study focuses on the synthesis of a new modified eco-friendly adsorbent, spent tea (ST, discarded Camellia sinensis leaves), and its application in the adsorption of Aspirin from aqueous solution by batch adsorption technique. This is an effort in shifting towards new substitutes that are both inexpensive and highly efficient, such as agricultural waste materials as an alternative of the commonly used adsorbent material, activated carbon. The ST will first undergo an acid treatment using phosphoric acid, and subsequently modified with Polyethyleneimine (PEI) using Glutaraldehyde (GA) as the cross-linker. Aspirin removal efficiency was compared between the untreated spent tea (ST) and new PEI modified acid treated spent tea (TA-PEI). Effects of ratio of acid treated spent tea (TA) and PEI (1:1, 1:2,1:3, 2:1,3:1), and GA concentration (0,0.5,1.0,2.0,3.0, and 4.0 v/v%) were investigated. The optimal conditions for the synthesis of the modified adsorbent, TA-PEI are TA: PEI ratio of 1:2, and 0.5(v/v %) of GA. Afterwards, the untreated ST and TA-PEI were tested to determine the effect of contact time on Aspirin adsorption. It was found that TA-PEI shows great removal effectiveness - up to 64.70% before reaching equilibrium after 30min of contact time. Nevertheless, ST only shows removal of 1% and after 15min, there is no appreciable adsorption. These results suggested that TA-PEI has high potential to be used as an effective adsorbent for Aspirin removal. In the future, TA-PEI will undergo further research to investigate the effects of different adsorbent dosage, solution pH, initial concentration, solution temperature, and contact time. Several analysis (FTIR, SEM, CHNS, BET and point of zero charge) has to be done as well to get a better understanding of its properties and the adsorption mechanisms

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.

scholarly journals Functionalization of Synthesized Nanoporous Silica and Its Application in Malachite Green Removal from Contaminated Water

2021 ◽  
Author(s):  
Bahman Hassan-Zadeh ◽  
Reza Rahmanian ◽  
Mohammad Hossein Salmani ◽  
Mohammad Javad Salmani
Keyword(s):  
Adsorption Capacity ◽  
Malachite Green ◽  
Contact Time ◽  
Pollutant Removal ◽  
Nanoporous Silica ◽  
Maximum Adsorption Capacity ◽  
Effective Parameters ◽  
Solution Ph ◽  
Average Pore ◽  
Initial Concentration

Introduction: Nanoporous silica has received growing interest for its unique application potential in pollutant removal. Therefore, the development of a simple technique is required to synthesize and functionalize the nanoporous materials for industrial application. Materials and Methods: The synthesis of nanoporous silica was investigated by the template sol-gel method, and it functionalized as an adsorbent for adsorption of malachite green. The morphology and structure of the prepared and functionalized nanoporous silica were studied using X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption-desorption technique. Subsequently, the effective parameters such as solution pH, contact time, and initial concentration on the adsorption process were optimized by adsorption tests. Results: The results showed that high-order nanoporous silica had been produced with an average diameter of 20.12 nm and average pore volume of 1.04 cm3.g−1. It was found that the optimum parameters of pH, initial concentration and contact time for malachite green adsorption on nanoporous silica were 6.5, 10 mg.l-1, and 60 min, respectively. The experimental data confirmed the Freundlich model (R2 = 0.995) and the obtained kinetic data followed the pseudo-first-order equation. The maximum adsorption capacity calculated by Langmuir isotherm was found to be 116.3 mg.g-1. Conclusion: The high adsorption capacity showed that the acid-functionalized nanoporous silica adsorbent can be used as an adequate adsorbent to remove malachite green from aquatic environments. The large surface area can be suggested that the silica nanoporous will have potential application prospects as the adsorbent.

scholarly journals Sorption of Pb(II) from Aqueous Solutions by Acid-Modified Clinoptilolite-Rich Tuffs with Different Si/Al Ratios

2019 ◽  
Vol 9 (12) ◽  
pp. 2415 ◽  
Author(s):  
Mohamed Abatal ◽  
Atl V. Córdova Quiroz ◽  
María T. Olguín ◽  
América R. Vázquez-Olmos ◽  
Joel Vargas ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Batch Studies ◽  
X Ray ◽  
Pseudo Second Order ◽  
Modified Clinoptilolite ◽  
Adsorbent Dose

The removal of Pb(II) from aqueous solutions by acid-modified clinoptilolite-rich tuff was investigated in this work. Clinoptilolite-rich tuff samples were treated using H2SO4 at different concentrations. Prior to and following acid treatment, the samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR). The pH of the point of zero charge (pHPZC) was also determined as part of this characterization. Batch studies were studied to investigate Pb(II) removal as a function of contact time, initial Pb(II) concentration, adsorbent dosage, and solution pH. The results of the XRD and SEM techniques showed that clinoptilolite is the main mineral of the non- and acid-treated natural zeolite samples. However, EDS analysis indicated that the Si/Al ratio increases as the exchangeable ions decrease with increasing acid concentrations. The optimum conditions for Pb(II) removal for samples with 4.37 ≤ Si/Al ≤ 7.9 were found to be as follows: Contact time of 60–360 min, pH: 6–8, and adsorbent dose of 6 mg g−1; whereas for acid-modified clinoptilolite-rich tuffs with 9.01 ≤ Si/Al ≤ 9.52, these conditions were as follows: Contact time of 1440 min, pH: 8–10, and adsorbent dose of 10 mg g−1. The experimental data were analyzed by kinetic and isotherms models. The results showed that the sorption of Pb(II) on samples with Si/Al ratios of 4.37, 5.31, and 7.91 were in agreement with the pseudo-second order and Langmuir isotherm with qm = 48.54, 37.04, and 14.99 mg g−1, respectively, while the kinetic data and isotherm for samples with 9.01 ≤ Si/Al ≤ 9.52 were found to fit the pseudo-first order and Freundlich model.

scholarly journals Polystyrene Magnetic Nanocomposites as Antibiotic Adsorbents

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1313 ◽  
Author(s):  
Leili Mohammadi ◽  
Abbas Rahdar ◽  
Razieh Khaksefidi ◽  
Aliyeh Ghamkhari ◽  
Georgios Fytianos ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Diblock Copolymer ◽  
Contact Time ◽  
Wastewater Treatment Plants ◽  
Treated Wastewater ◽  
Order Kinetic ◽  
Operational Parameters ◽  
Solution Ph ◽  
Initial Concentration ◽  
Antibiotic Drug

There are different ways for antibiotics to enter the aquatic environment, with wastewater treatment plants (WWTP) considered to be one of the main points of entrance. Even treated wastewater effluent can contain antibiotics, since WWTP cannot eliminate the presence of antibiotics. Therefore, adsorption can be a sustainable option, compared to other tertiary treatments. In this direction, a versatile synthesis of poly(styrene-block-acrylic acid) diblock copolymer/Fe3O4 magnetic nanocomposite (abbreviated as P(St-b-AAc)/Fe3O4)) was achieved for environmental applications, and particularly for the removal of antibiotic compounds. For this reason, the synthesis of the P(St-b-AAc) diblock copolymer was conducted with a reversible addition fragmentation transfer (RAFT) method. Monodisperse superparamagnetic nanocomposite with carboxylic acid groups of acrylic acid was adsorbed on the surface of Fe3O4 nanoparticles. The nanocomposites were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) analysis. Then, the nanoparticles were applied to remove ciprofloxacin (antibiotic drug compound) from aqueous solutions. The effects of various parameters, such as initial drug concentration, solution pH, adsorbent dosage, and contact time on the process were extensively studied. Operational parameters and their efficacy in the removal of Ciprofloxacin were studied. Kinetic and adsorption isothermal studies were also carried out. The maximum removal efficiency of ciprofloxacin (97.5%) was found at an initial concentration of 5 mg/L, pH 7, adsorbent’s dosage 2 mg/L, contact time equal to 37.5 min. The initial concentration of antibiotic and the dose of the adsorbent presented the highest impact on efficiency. The adsorption of ciprofloxacin was better fitted to Langmuir isotherm (R2 = 0.9995), while the kinetics were better fitted to second-order kinetic equation (R2 = 0.9973).

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