Adsorptive and Coagulative Removal of Trace Metals from Water Using Surface Modified Sawdust-Based Cellulose Nanocrystals

The presence of toxic metals in surface and natural waters, even at trace levels, poses a great danger to humans and the ecosystem. Although the combination of adsorption and coagulation techniques has the potential to eradicate this problem, the use of inappropriate media remains a major drawback. This study reports on the application of NaNO2/NaHCO3 modified sawdust-based cellulose nanocrystals (MCNC) as both coagulant and adsorbent for the removal of Cu, Fe and Pb from aqueous solution. The surface modified coagulants, prepared by electrostatic interactions, were characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS). The amount of coagulated/adsorbed trace metals was then analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). SEM analysis revealed the patchy and distributed floccules on Fe-flocs, which was an indication of multiple mechanisms responsible for Fe removal onto MCNC. A shift in the peak position attributed to C2H192N64O16 from 2θ = 30 to 24.5° occurred in the XRD pattern of both Pb- and Cu-flocs. Different process variables, including initial metal ions concentration (10–200 mg/L), solution pH (2–10), and temperature (25–45 °C) were studied in order to investigate how they affect the reaction process. Both Cu and Pb adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 111.1 and 2.82 mg/g, respectively, whereas the adsorption of Fe was suggestive of a multilayer adsorption process; however, Fe Langmuir maximum adsorption capacity was found to be 81.96 mg/g. The sequence of trace metals removal followed the order: Cu > Fe > Pb. The utilization of this product in different water matrices is an effective way to establish their robustness.

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Removal of Chromium(III) and Cadmium(II) Heavy Metal Ions from Aqueous Solutions Using Treated Date Seeds: An Eco-Friendly Method

Molecules ◽

10.3390/molecules26123718 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3718

Author(s):

Mohammad Azam ◽

Saikh Mohammad Wabaidur ◽

Mohammad Rizwan Khan ◽

Saud I. Al-Resayes ◽

Mohammad Shahidul Islam

Keyword(s):

Metal Ions ◽

Adsorption Capacity ◽

Low Cost ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Surface Analysis Techniques ◽

Adsorption Processes ◽

Ft Ir ◽

Metal Elution ◽

Date Pits

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3–88.2% and 81.8–86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.

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Dysprosium Removal from Water Using Active Carbons Obtained from Spent Coffee Ground

10.20944/preprints201908.0076.v1 ◽

2019 ◽

Author(s):

Lorena Alcaraz ◽

María Esther Escudero ◽

Francisco J. Alguacil ◽

Irene Llorente ◽

Ana Urbieta ◽

...

Keyword(s):

Adsorption Capacity ◽

Activated Carbons ◽

Chemical Study ◽

Bet Surface Area ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Microporous Material ◽

Physico Chemical ◽

Spent Coffee Ground ◽

Coffee Ground

This paper describes the physico-chemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. KOH activated carbon is a microporous material with a specific BET surface area of 2330 m2·g-1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g-1. A significant dependence of the adsorption capacity on the solution pH was found, while it does not depend significantly neither on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g-1 and 33.52 mg·g-1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better fit to a Langmuir model and a pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous and favorable process.

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Removal of Cu(II) from Aqueous Solutions Using Amine-Doped Polyacrylonitrile Fibers

Applied Sciences ◽

10.3390/app10051738 ◽

2020 ◽

Vol 10 (5) ◽

pp. 1738

Author(s):

Kay Thwe Aung ◽

Seung-Hee Hong ◽

Seong-Jik Park ◽

Chang-Gu Lee

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Equilibrium Studies ◽

Naoh Solution ◽

Surface Modified ◽

Pan Fibers

Polyacrylonitrile (PAN) fibers were prepared via electrospinning and were modified with diethylenetriamine (DETA) to fabricate surface-modified PAN fibers. The surface-modified PAN fibers were used to evaluate their adsorption capacity for the removal of Cu(II) from aqueous solutions. Batch adsorption experiments were performed to examine the effects of the modification process, initial concentration, initial pH, and adsorbent dose on the adsorption of Cu(II). Kinetic analysis revealed that the experimental data fitted the pseudo-second-order kinetic model better than the pseudo-first-order model. Adsorption equilibrium studies were conducted using the Freundlich and Langmuir isotherm models, and the findings indicated that the PAN fibers modified with 85% DETA presented the highest adsorption capacity for Cu(II) of all analyzed samples. Moreover, the results revealed that the Freundlich model was more appropriate than the Langmuir one for describing the adsorption of Cu(II) onto the modified fibers at various initial Cu(II) concentrations. The maximum adsorption capacity was determined to be 87.77 mg/g at pH 4, and the percent removal of Cu(II) increased as the amount of adsorbent increased. Furthermore, the surface-modified PAN fibers could be easily regenerated using NaOH solution. Therefore, surface-modified PAN fibers could be used as adsorbents for the removal of Cu(II) from aqueous solutions.

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Efficient Removal of Diclofenac from Aqueous Solution by Potassium Ferrate-Activated Porous Graphitic Biochar: Ambient Condition Influences and Adsorption Mechanism

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17010291 ◽

2019 ◽

Vol 17 (1) ◽

pp. 291 ◽

Cited By ~ 6

Author(s):

Nguyen Thi Minh Tam ◽

Yunguo Liu ◽

Hassan Bashir ◽

Zhihong Yin ◽

Yuan He ◽

...

Keyword(s):

Aqueous Solution ◽

Adsorption Capacity ◽

Diclofenac Sodium ◽

Maximum Adsorption Capacity ◽

Potassium Ferrate ◽

Solution Ph ◽

Modified Biochar ◽

Prepared Material ◽

Endothermic Process ◽

One Step

Porous graphitic biochar was synthesized by one-step treatment biomass using potassium ferrate (K2FeO4) as activator for both carbonization and graphitization processes. The modified biochar (Fe@BC) was applied for the removal of diclofenac sodium (DCF) in an aqueous solution. The as-prepared material possesses a well-developed micro/mesoporous and graphitic structure, which can strengthen its adsorption capacity towards DCF. The experimental results indicated that the maximum adsorption capacity (qmax) of Fe@BC for DCF obtained from Langmuir isotherm simulation was 123.45 mg·L−1 and it was a remarkable value of DCF adsorption in comparison with that of other biomass-based adsorbents previously reported. Thermodynamic quality and effect of ionic strength studies demonstrated that the adsorption was a endothermic process, and higher environmental temperatures may be more favorable for the uptake of DCF onto Fe@BC surface; however, the presence of NaCl in the solution slightly obstructed DCF adsorption. Adsorption capacity was found to be decreased with the increase of solution pH. Additionally, the possible mechanism of the DCF adsorption process on Fe@BC may involve chemical adsorption with the presence of H-bonding and π–π interaction. With high adsorption capacity and reusability, Fe@BC was found to be a promising absorbent for DCF removal from water as well as for water purification applications.

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Application of Carbonaceous Materials to Phenol Removal from Aqueous Solution by Adsorption

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.164.297 ◽

2012 ◽

Vol 164 ◽

pp. 297-301 ◽

Cited By ~ 1

Author(s):

Wei Fang Dong ◽

Li Hua Zang ◽

Qing Chao Gong ◽

Cun Cun Chen ◽

Cai Hong Zheng ◽

...

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Petroleum Coke ◽

Granular Activated Carbon ◽

Powdered Activated Carbon ◽

Maximum Adsorption Capacity ◽

Phenol Removal ◽

Carbonaceous Materials ◽

Solution Ph ◽

Equilibrium Studies

Low cost carbonaceous materials were evaluated for their ability to remove phenol from wastewater. The effects of adsorbents dosage, contact time and maximum adsorption capacity were investigated for granular activated carbon, powdered activated carbon, petroleum coke and multi-walled carbon nanotube (MWNT). Equilibrium studies were conducted in 50mg/L initial phenol concentration, solution pH of 5 and at temperature of 23°C. The results showed the adsorption process was fast and it reached equilibrium in 3 h. Petroleum coke and MWNT had poor adsorption which could reach the removal efficiency of phenol with 43.18% and 36.64% respectively. The granular activated carbon possessed good adsorption ability to phenol with 96.40% at the optimum dosage 5g and optimum time 90min.The powdered activated carbon was an effective adsorbent with a maximum adsorption capacity of 42.32 mg/g.

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Selenate Adsorption from Water Using the Hydrous Iron Oxide-Impregnated Hybrid Polymer

Metals ◽

10.3390/met10121630 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1630

Author(s):

Vesna Marjanovic ◽

Aleksandra Peric-Grujic ◽

Mirjana Ristic ◽

Aleksandar Marinkovic ◽

Radmila Markovic ◽

...

Keyword(s):

Iron Oxide ◽

Adsorption Capacity ◽

Ph Value ◽

Xrd Analysis ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Adsorbent Regeneration ◽

Desorption Efficiency ◽

Hydrous Iron Oxide ◽

The Cross

Hybrid adsorbent, based on the cross-linked copolymer impregnated with hydrous iron oxide, was applied for the first time for Se(VI) adsorption from water. The influence of the initial solution pH, selenate concentration and contact time to adsorption capacity was investigated. Adsorbent regeneration was explored using a full factorial experimental design in order to optimize the volume, initial pH value and concentration of the applied NaCl solution as a reagent. Equilibrium state was described using the Langmuir model, while kinetics fitted the pseudo-first order. The maximum adsorption capacity was found to be 28.8 mg/g. Desorption efficiency increased up to 70%, and became statistically significant with the reagent concentration and pH increase, while the applied solution volume was found to be insignificant in the investigated range. Based on the results obtained, pH influence to the adsorption capacity, desorption efficiency, Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analysis of loaded adsorbent, it was concluded that the outer- and inner-sphere complexation are mechanisms responsible for Se(VI) separation from water. In addition to the experiments with synthetic solutions, the adsorbent performances in drinking water samples were explored, showing the purification efficiency up to 25%, depending on the initial Se(VI) concentration and water pH. Determined sorption capacity of the cross-linked copolymer impregnated with hydrous iron oxide and its ability for regeneration, candidate this material for further research, as a promising anionic species sorbent.

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Dysprosium Removal from Water Using Active Carbons Obtained from Spent Coffee Ground

Nanomaterials ◽

10.3390/nano9101372 ◽

2019 ◽

Vol 9 (10) ◽

pp. 1372 ◽

Cited By ~ 9

Author(s):

Lorena Alcaraz ◽

María Esther Escudero ◽

Francisco José Alguacil ◽

Irene Llorente ◽

Ana Urbieta ◽

...

Keyword(s):

Adsorption Capacity ◽

Potassium Hydroxide ◽

Activated Carbons ◽

Bet Surface Area ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Microporous Material ◽

Spent Coffee Ground ◽

Coffee Ground ◽

Pseudo Second Order

This paper describes the physicochemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. Potassium hydroxide (KOH)-activated carbon is a microporous material with a specific Brunauer–Emmett–Teller (BET) surface area of 2330 m2·g−1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g−1. A significant dependence of the adsorption capacity on the solution pH was found, but it does not significantly depend on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g−1 and 33.52 mg·g−1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better a fit to the Langmuir model and pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous, and favorable process.

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Adsorption of cadmium(II) from aqueous solution onto activated carbon

Water Science & Technology ◽

10.2166/wst.1997.0278 ◽

1997 ◽

Vol 35 (7) ◽

pp. 205-211 ◽

Cited By ~ 51

Author(s):

R. Leyva-Ramos ◽

J. R. Rangel-Mendez ◽

J. Mendoza-Barron ◽

L. Fuentes-Rubio ◽

R. M. Guerrero-Coronado

Keyword(s):

Activated Carbon ◽

Adsorption Isotherm ◽

Adsorption Capacity ◽

Freundlich Isotherm ◽

Carbon Surface ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Ph Values ◽

Average Percent Deviation ◽

Initial Ph

The adsorption isotherm of cadmium on activated carbon was measured in a batch adsorber. Effects of temperature and solution pH on the adsorption isotherm were investigated by determining the adsorption isotherm at temperatures of 10, 25, and 40°C and at initial pH values from 2 to 8. Langmuir isotherm better fitted the experimental data since the average percent deviation was lower than with the Freundlich isotherm It was noticed that the amount of Cd2+ adsorbed was reduced about 3 times by increasing the temperature from 10 to 40°C. It was found that Cd2+ was not adsorbed on activated carbon at pH of 2 or lower and that Cd2+ was precipitated out as Cd(OH)2 at pH values above 9. Maximum adsorption capacity was observed at pH of 8 and the adsorption capacity was decreased about 12 times by reducing the initial pH from 8 to 3. According to the cadmium speciation diagram the predominant species below pH of 8 is Cd2+. Thus, cadmium was adsorbed on the activated carbon surface as Cd2+. It was concluded that the adsorption capacity is a strong function of pH and temperature.

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Core-Shell Structured Magnetic Carboxymethyl Cellulose-Based Hydrogel Nanosorbents for Effective Adsorption of Methylene Blue from Aqueous Solution

Polymers ◽

10.3390/polym13183054 ◽

2021 ◽

Vol 13 (18) ◽

pp. 3054

Author(s):

Yiming Zhou ◽

Te Li ◽

Juanli Shen ◽

Yu Meng ◽

Shuhua Tong ◽

...

Keyword(s):

Methylene Blue ◽

Aqueous Solutions ◽

Adsorption Capacity ◽

Carboxymethyl Cellulose ◽

Chemical Properties ◽

Polymer Nanocomposite ◽

Core Shell ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Solution Ph

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.

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Removal and Regeneration of Iron (III) from Water Using New Treated Fluorapatite Extracted from Natural Phosphate as Adsorbent

Biointerface Research in Applied Chemistry ◽

10.33263/briac115.1313013140 ◽

2021 ◽

Vol 11 (5) ◽

pp. 13130-13140

Keyword(s):

Adsorption Capacity ◽

Maximum Adsorption Capacity ◽

X Ray Diffraction ◽

Solution Ph ◽

Natural Phosphate ◽

Dissolved Iron ◽

Naturally Occurring ◽

Ft Ir ◽

Adsorption Desorption ◽

Ft Ir Spectroscopy

Our study aims to evaluate the efficiency of dissolved iron (III) retention in synthetic solutions by adsorption on treated natural phosphate collected in the Khouribga region. This research focused on the valorization of phosphate, a naturally occurring resource that is abundant in Morocco. The resulting products were analyzed by various methods, including FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). In this work, we studied the effect of several parameters such as adsorbent amount, contact time, solution pH, and initial concentration of iron (III) on the adsorption process. The results of the adsorption of iron (III) indicate that the efficiency was achieved after 5 minutes, and the maximum adsorption capacity calculated from the Langmuir model was 26.18 mg g-1. The regeneration and reuse of synthesized adsorbent are effective for five cycles of adsorption-desorption cycles without reducing adsorption capacity.

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