scholarly journals Sorption of Cd2+ and Pb2+ on Aragonite Synthesized from Eggshell

2020 ◽  
Vol 12 (3) ◽  
pp. 1174 ◽  
Author(s):  
Lulit Habte ◽  
Natnael Shiferaw ◽  
Mohd Danish Khan ◽  
Thenepalli Thriveni ◽  
Ji Whan Ahn
Keyword(s):  
Experimental Data ◽  
Synthetic Wastewater ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Solution Ph ◽  
Surface Precipitation ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
High Sorption ◽  
Pseudo Second Order

In the present work, waste eggshells were used as a precursor for the synthesis of aragonite crystals through the wet carbonation method. Cadmium (Cd2+) and lead (Pb2+) were removed by the synthesized aragonite from synthetic wastewater. The influence of initial solution pH, contact time, Cd2+ and Pb2+ concentration, and sorbent dosage were evaluated. The major sorption was observed in the first 100 mins and 360 mins for Pb2+and Cd2+ respectively reaching sorption equilibrium at 720 mins (12 hr). The sorption capacity toward Pb2+ was much higher than toward Cd2+. Both heavy metals displayed high sorption capacities at initial pH 6. The pseudo-second-order kinetic model fits well with the experimental data with a higher correlation coefficient R2. Two isotherm models were also evaluated for the best fit with the experimental data obtained. Langmuir isotherm best fits the sorption of the metals on aragonite synthesized from eggshells. X-ray diffraction (XRD) and Scanning electron microscopy (SEM) results of sorbent after sorption showed that the mechanism of sorption was dominated by surface precipitation. Therefore, aragonite crystals synthesized from waste eggshells can be a potential substitute source for the removal of Cd2+ and Pb2+ from contaminated water.

scholarly journals Effectiveness of beetroot seeds and H3PO4 activated beetroot seeds for the removal of dyes from aqueous solutions

2017 ◽  
Vol 8 (4) ◽  
pp. 522-531
Author(s):  
A. Machrouhi ◽  
M. Farnane ◽  
A. Elhalil ◽  
R. Elmoubarki ◽  
M. Abdennouri ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Solution Ph ◽  
Experimental Isotherm ◽  
Adsorbent Dosage ◽  
Adsorption Capacities ◽  
Monolayer Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Raw beetroot seeds (BS) and H3PO4 activated beetroot seeds (H3PO4-BS) were evaluate for their effectiveness in removing methylene blue (MB) and malachite green (MG) from aqueous solution. BS were carbonized at 500°C for 2 h, and then impregnated with phosphoric acid (phosphoric acid to BS ratio of 1.5 g/g). The impregnated BS were activated in a tubular vertical furnace at 450°C for 2 h. Batch sorption experiments were carried out under various parameters, such as solution pH, adsorbent dosage, contact time, initial dyes concentration and temperature. The experimental results show that the dye sorption was influenced by solution pH and it was greater in the basic range. The sorption yield increases with an increase in the adsorbent dosage. The equilibrium uptake was increased with an increase in the initial dye concentration in solution. Adsorption kinetic data conformed more to the pseudo-second-order kinetic model. The experimental isotherm data were evaluated by Langmuir, Freundlich, Toth and Dubinin–Radushkevich isotherm models. The Langmuir maximum monolayer adsorption capacities were 61.11 and 74.37 mg/g for MB, 51.31 and 213.01 mg/g for MG, respectively in the case of BS and H3PO4-BS. The thermodynamic parameters are also evaluated and discussed.

scholarly journals Comparative Study of Ni-Zn LHS and Mg-Al LDH Adsorbents of Navy Blue and Yellow F3G Dye

2018 ◽  
Vol 16 (1) ◽  
pp. 36 ◽  
Author(s):  
Idha Yulia Ikhsani ◽  
Sri Juari Santosa ◽  
Bambang Rusdiarso
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Disperse Dyes ◽  
Order Kinetic ◽  
Initial Ph ◽  
Isotherm Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Adsorption of disperse dyes from wastewater onto Ni-Zn LHS (layered hydroxide salts) and Mg-Al LDH (layered double hydroxides) has been compared in this study. Effects of initial pH solution, contact time and initial dye concentration were investigated. The ability of the adsorbent to be reused was also studied. The results showed that acidic condition was favorable for the adsorption of each dyes onto both adsorbent. The adsorption kinetics was studied using pseudo-first-order, pseudo-second-order and Santosa’s kinetics models. The experimental data fits well with the pseudo-second order kinetic model. The equilibrium adsorption data were analyzed using Langmuir and Freundlich isotherm models. The results showed that adsorption of navy blue onto both adsorbent followed Freundlich isotherm adsorption, while yellow F3G followed Langmuir isotherm adsorption. In the application for the adsorption the wastewater containing dyes, Ni-Zn LHS has a better adsorption capacity of 52.33 mg/g than that of Mg-Al LDH that 30.54 mg/g. Calcination of the adsorbent which has already been used increased the adsorption capacity of Mg-Al LDH to 84.75 mg/g, but decreased the adsorption capacity of the Ni-Zn LHS to 42.65 mg/g.

scholarly journals Isotherm and selectivity studies of Ni(II) removal using natural and acid-activated nanobentonites

2021 ◽  
Author(s):  
Zahra Ashouri Mehranjani ◽  
Majid Hayati-Ashtiani ◽  
Mehran Rezaei
Keyword(s):  
Experimental Data ◽  
Sulfuric Acid ◽  
Adsorption Capacity ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Isotherm Models ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Selectivity Studies ◽  
Working Out

Abstract In this research, natural bentonite and its acid-activated forms were employed as adsorbents for the adsorption of Ni2+ ions from wastewater. Natural bentonite was activated with 2M sulfuric acid, 4.5 h and 95 °C (the beast acid-activated sample with the highest adsorption capacity) and the other 6M sulfuric acid, 7.5 h and 95 °C (the worst acid-activated sample with the lowest adsorption capacity). The adsorption of Ni2+ was studied through experiments including equilibrium contact time and selectivity. The equilibrium time of contact for bentonite was obtained at 180 min. The Ni2+ separation process along with Zn2+ selectivity studies was considered through adsorption experiments. The results showed that there was a maximum amount of Ni2+ adsorption in the absence of Zn2+ for all samples. The results showed the best fit is obtained with the pseudo-second-order kinetic model. Working out different bentonite types to determine the best kinetic models, we explored the Langmuir and Florry–Huggins models provided a good fit with experimental data for acid-activated bentonites and the best results from linear forms of the adsorption isotherm models for fitting the experimental data of natural bentonite are obtained Langmuir, Temkin and Freundlich models.

Adsorption Characteristics of Phenol in Aqueous Solution by Pinus massoniana Biochar

2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Pinus Massoniana ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Salt Ions ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The objective of this paper is to investigate the feasibility of phenol adsorption from aqueous solution by Pinus massoniana biochar. Adsorption conditions, including contact time, initial phenol concentration, adsorbent dosage, strength of salt ions and pH, have been investigated by batch experiments. Equilibrium can be reached in 24 h for phenol from 50 to 250 mg• L-1. The optimum pH value for this kind of biochar is 5.0. The amount of phenol adsorbed per unit decreases with the increase in adsorbent dosage. The existence of salt ions makes negligible influence on the equilibrium adsorption capacity. The experimental data is analyzed by the Freundlich and Langmuir isotherm models. Equilibrium data fits well to the Freundlich model. Adsorption kinetics models are deduced and the pseudo-second-order kinetic model provides a good correlation for the adsorbent process. The results show that the Pinus massoniana biochar can be utilized as an effective adsorption material for the removal of phenol from aqueous solution.

scholarly journals The sorption of inorganic arsenic on modified sepiolite: Effect of hydrated iron(III)-oxide

2014 ◽  
Vol 79 (7) ◽  
pp. 815-828 ◽  
Author(s):  
Nikola Ilic ◽  
Slavica Lazarevic ◽  
Vladana Rajakovic-Ognjanovic ◽  
Ljubinka Rajakovic ◽  
Djordje Janackovic ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Arsenic Removal ◽  
Ph Value ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Deionized Water ◽  
Order Kinetic ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of inorganic arsenic species, As(III) and As(V), from water by sepiolite modified with hydrated iron(III) oxide was investigated at 25 ?C through batch studies. The influence of the initial pH value, the initial As concentrations, the contact time and types of water on the sorption capacity was investigated. Two types of water were used, deionized and groundwater. The maximal sorption capacity for As(III) from deionized water was observed at initial and final pH value 7.0, while the bonding of As(V) was observed to be almost pH independent for pH value in the range from 2.0 to 7.0, and the significant decrease in the sorption capacity was observed at pH values above 7.0. The sorption capacity at initial pH 7.0 was about 10 mg g?1 for As(III) and 4.2 mg g?1 for As(V) in deionized water. The capacity in groundwater was decreased by 40 % for As(III) and by 20 % for As(V). The Langmuir model and pseudo-second order kinetic model revealed good agreement with the experimental results. The results show that Fe(III)-modified sepiolite exhibits significant affinity for arsenic removal and it has a potential for the application in water purification processes.

Phosphorus removal from aqueous solution using a novel granular material developed from building waste

2017 ◽  
Vol 75 (6) ◽  
pp. 1500-1511 ◽  
Author(s):  
Shengjiong Yang ◽  
Pengkang Jin ◽  
Xiaochang C. Wang ◽  
Qionghua Zhang ◽  
Xiaotian Chen
Keyword(s):  
Granular Material ◽  
Chemical Precipitation ◽  
Phosphate Removal ◽  
Precipitation Process ◽  
Order Kinetic ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Removal Capacity ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, a granular material (GM) developed from building waste was used for phosphate removal from phosphorus-containing wastewater. Batch experiments were executed to investigate the phosphate removal capacity of this material. The mechanism of removal proved to be a chemical precipitation process. The characteristics of the material and resulting precipitates, the kinetics of the precipitation and Ca2+ liberation processes, and the effects of dosage and pH were investigated. The phosphate precipitation and Ca2+ liberation processes were both well described by a pseudo-second-order kinetic model. A maximum precipitation capacity of 0.51 ± 0.06 mg g−1 and a liberation capacity of 6.79 ± 0.77 mg g−1 were measured under the experimental conditions. The processes reached equilibrium in 60 min. The initial solution pH strongly affected phosphate removal under extreme conditions (pH <4 and pH >10). The precipitates comprised hydroxyapatite and brushite. This novel GM can be considered a promising material for phosphate removal from wastewater.

Adsorption of Chromium (VI) from Aqueous Solution by Agricultural Waste Derived Activated Carbon

2013 ◽  
Vol 726-731 ◽  
pp. 2100-2106 ◽  
Author(s):  
Hua Zhang ◽  
Xue Hong Zhang ◽  
Yi Nian Zhu ◽  
Shou Rui Yuan
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Agricultural Waste ◽  
Order Kinetic ◽  
Chromium Vi ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Grapefruit Peel ◽  
Pseudo Second Order ◽  
C 30

Activated carbon prepared from grapefruit peel, an agricultural solid waste by-product, has been used for the adsorption of Cr(VI) from aqueous solution. The effects of adsorbent dosage, pH and temperature on adsorption of Cr(VI) were investigated. The maximum adsorption yield was obtained at the initial pH of 3. The dynamical data fit very well with the pseudo-second-order kinetic model and the calculated adsorption capacities (23.98, 24.33 and 24.81 mg/g) were in good agreement with experiment results at 20°C, 30°C and 40 °C for the 100 mg/L Cr(VI) solution. The Freundlich model (R2 values were 0.9198-0.9871) fitted adsorption data better than the Langmuir model. The calculated parameters confirmed the favorable adsorption of Cr(VI) on the activated carbon prepared from grapefruit peel.

scholarly journals Preparation of bio-absorbents by modifying licorice residue via chemical methods and removal of copper ions from wastewater

2021 ◽  
Author(s):  
Xiaochun Yin ◽  
Nadi Zhang ◽  
Meixia Du ◽  
Hai Zhu ◽  
Ting Ke
Keyword(s):  
Adsorption Capacity ◽  
Copper Ions ◽  
Order Kinetic ◽  
Solution Ph ◽  
Chemical Methods ◽  
Simple Strategy ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Surface Active ◽  
Adsorption Desorption

Abstract In this paper, a series of bio-adsorbents (LR-NaOH, LR-Na2CO3 and LR-CA) were successfully prepared by modifying Licorice Residue with NaOH, Na2CO3 and citric acid, which were used as the adsorbents to remove Cu2+ from wastewater. The morphology and structure of bio-adsorbents were characterized by Fourier Transform Infrared, SEM, TG and XRD. Using static adsorption experiments, the effects of the adsorbent dosage, the solution pH, the adsorption time, and the initial Cu2+ concentration on the adsorption performance of the adsorbents were investigated. The results showed that the adsorption process of Cu2+ by the bio-adsorbents can be described by pseudo-second order kinetic model and the Langmuir model. The surface structure of the LR-NaOH, LR-Na2CO3 and LR-CA changed obviously, and the surface-active groups increased. The adsorption capacity of raw LR was 21.56 mg/g, LR-NaOH, LR- Na2CO3 significantly enhanced this value up to 43.65 mg/g, 43.55 mg/g, respectively. After four adsorption-desorption processes, the adsorption capacity of LR-NaOH also maintained about 73%. Therefore, LR-NaOH would be a promising adsorbent for removing Cu2+ from wastewater, and the simple strategy towards preparation of adsorbent from the waste residue can be as a potential approach using in the water treatment.

Equilibrium and Kinetic Studies for the Biosorption of Aqueous Nickel(II) Ions onto the Pseudomonas alcaligenes Biomass

2010 ◽  
Vol 171-172 ◽  
pp. 41-44
Author(s):  
Xiao Cun Xiao ◽  
Gai Xia Fang ◽  
Er Li Zhao ◽  
Lv Bin Zhai ◽  
Jun Shuai Shi
Keyword(s):  
Industrial Wastewater ◽  
Chemical Interaction ◽  
Kinetic Studies ◽  
Synthetic Wastewater ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Pseudomonas Alcaligenes ◽  
Batch Biosorption

The objective of this study is to assess the environmentaly friendly Ni(II) adsorption from synthetic wastewater using Pseudomonas alcaligenes biomass (PA-2). The ability of PA-2 to remove the Ni(II) ions was investigated by using batch biosorption procedure. The effects such as pH, dosage of biosorbent, Ni(II) initial concentration and sorbate–sorbent contact time and agitating speed on the adsorption capacities of PA-2 were studied. Biosorption equilibriums were rapidly established in about 60 min and the adsorption kinetics followed the pseudo-second order kinetic model. The maximum Ni(II) adsorption capacity determined from Langmuir isotherm were 82.23 mg/g PA-2 at pH 5.0, at 25±2°C and shaker speed 150 rpm, respectively. The carboxyl , hydroxyl and amino groups of the PA-2 were involved in chemical interaction with the Ni(II) ions depicted by Fourier transform infrared spectroscopic (FTIR) results. The study points to the potential of new use of Pseudomonas alcaligenes biomass as an effective biosorbent for the removal of Ni(II) and from environmental and industrial wastewater.

scholarly journals The Removal of Uranium and Thorium from Their Aqueous Solutions by 8-Hydroxyquinoline Immobilized Bentonite

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Langmuir Isotherm ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.

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