scholarly journals Removal of cadmium (II) from aqueous effluents by sorption on Romanian silver fir tree bark (Abies alba Mill.) wastes

2017 ◽  
Vol 19 (1) ◽  
pp. 107-114 ◽  

<p>In last decades the search for new low cost sorbents that have heavy metal ions binding capabilities is a hot topic in the field of clean-up technologies. In this study,&nbsp; wastes of&nbsp; Romanian silver tree (<em>Abies alba)</em> bark&nbsp; were explored for first time as green and economical sorbent for the removal of Cd(II) ions from aqueous solutions.&nbsp; The effect of various experimental parameters such as initial solution pH, sorbent dose, initial Cd(II) concentration, temperature and contact time has been investigated under batch conditions.&nbsp;</p> <p>The Langmuir and Freundlich models were used to describe the equilibrium isotherms and both models have been fitted very well. According to the evaluation using the Langmuir equation, the maximum sorption capacity of Cd (II) ions on <em>Abies alba</em> bark waste was found to be 11.98<br /> mg g<sup>-1</sup> at 293 K. The thermodynamic parameters showed that the process of Cd(II) sorption on silver fir tree bark was feasible, spontaneous and endothermic. Kinetic data were properly fitted with the pseudo–second order model. The obtained results strongly suggest that Romanian silver tree (<em>Abies alba)</em> bark is eligible as an efficient sorbent for the decontamination of toxic metals from wastewaters.</p>

2016 ◽  
Vol 74 (10) ◽  
pp. 2314-2324 ◽  
Author(s):  
Lavinia Tofan ◽  
Carmen Paduraru ◽  
Roxana Laura Mihailescu Amalinei ◽  
Ion Bunia ◽  
Anca Miron

Considering recycling as the first option in the hierarchy of sustainable waste management, and also the demand for efficient processes for wastewater treatment with reduced costs, the potential applicability of Romanian Abies alba bark, the main waste from the industrial processing of the wood of mature silver fir trees, as sorbent for Cu(II) has been studied in batch conditions. It was observed that the extent of Cu(II) sorption is strongly dependent on initial solution pH, sorbent dose, initial Cu(II) ion concentration, temperature and contact time. Equilibrium data fitted very well with both Langmuir and Freundlich isotherm models. The Langmuir maximum sorption capacity of Cu(II) ions on Abies alba bark waste was found to be 7.80 mg/g at 293 K. Kinetic studies showed a high affinity of the sorption experimental data to the pseudo-second order model. Gibbs free energy was spontaneous for all interactions and the sorption process exhibited endothermic enthalpy value. The waste of Abies alba bark was successfully used for the sorption removal of Cu(II) ions from industrial electroplating wastewaters.


2020 ◽  
Vol 16 ◽  
Author(s):  
Vedat Tolga Özdemir ◽  
Himmet Mert Tuğaç ◽  
Özgür Arar

Background: Cellulose is one of the most abundant, non-toxic, and renewable natural biopolymers. The presence of hydroxyl groups in cellulose leads to further modification of it. Preparation and modification of cellulose-based sorbents and their applications on water treatment gained traction in recent years. Objective: A low-cost and eco-friendly biosorbent was designed and fabricated by introducing the acetate functional groups into cellulose for removing Beryllium (Be2+) from an aqueous solution. The so rption of Be2+ on acetate containing cellulose was evaluated for varying sorbent doses and initial solution pH values. Method: The sorbent was prepared by a two-step oxidation process. In the initial step, cellulose reacted with NaIO4 and aldehyde groups were introduced to cellulose. In the second step, newly obtained aldehyde groups were oxidized to create acetate groups. Results: The kinetics of the sorption process showed that Be2+ uptake reached equilibrium in 3 minutes. The sorption isotherm was well fitted in the Langmuir model, and maximum sorption capacity was 4.54 mg/g. Moreover, the thermodynamic studies demonstrated that Be2+ sorption is spontaneous and exothermic. Furthermore, the prepared sorbent can be regenerated by using 0.1 M HCl or H2SO4 solutions. Conclusion: Removal of Be2+ is pH dependent and it is favorable at high solution pH. The kinetics of the prepared sorbent is rapid and equilibrium attained in 3 minutes. The prepared sorbent can be regenerated with 0.1 M acid solution with > 99% efficiency.


2014 ◽  
Vol 804 ◽  
pp. 59-62
Author(s):  
Lian Ai ◽  
Xue Gang Luo ◽  
Xiao Yan Lin

Low cost agricultural by-products are potential materials for water pollution treatment such as removal of radionuclide. This paper deals with removal of strontium ions from aqueous solution using sunflower stem (SFS) and leaf (SFL). Batch sorption experiments were performed as a function of initial solution pH, adsorbent dosage and initial strontium (II) concentration. The removal efficiency of strontium (II) increased with initial pH and achieved maximum values at a pH range of 4.0-7.0 both for SFS and SFL. The isotherm adsorption data was modeled best by the nonlinear Langmuir-Freundlich equation. The maximum sorption capacity of SFS and SFL were observed to be 17.87 and 22.31 mg/g under optimal conditions, respectively.


2019 ◽  
Vol 26 (4) ◽  
pp. 743-757
Author(s):  
Michaela Tokarčíková ◽  
Jana Seidlerová ◽  
Oldřich Motyka ◽  
Mirka Šafaříková

Abstract Biochar produced from fermentation residue of maize hybrid was used in untreated form as a sorbent for the removal of Cd(II), Pb(II) and Zn(II) from aqueous solution. The capability of biochar to immobilized ions was investigated by leaching test. Equilibrium between biochar sample and studied elements in solution was reached at a contact time 30 min for Zn(II) and 90 min for Pb(II) and Cd(II). The experimental data were described by pseudofirst-order and pseudo-second-order kinetic model, two- and three-parameter isotherms in non-linear form. The maximum sorption capacity achieved was 30.07 mg·g−1 in the case of Cd(II) ions, 99.44 mg·g−1 in the case of Pb(II) and 40.18 in the case of Zn(II). Biochar developed for this study is comparable to conventional biochar, low cost, non-toxic and experimental results show that is a suitable and efficient sorbent for Cd(II), Pb(II) and Zn(II) removal from aqueous solutions.


Author(s):  
Mazen K. Nazal ◽  
Durga Rao ◽  
Nabeel Abuzaid

Abstract Emerging contaminants such as pharmaceutical compounds have potential hazards to the aquatic environment and human health. In this paper, the adsorptive removal of the drug Nitrazepam from water was investigated for the first time using biochar prepared from Sargassum macroalgae. The removal efficiency of Nitrazepam using 1 g/L of Sargassum macroalgae-derived biochar was 98% with a maximum adsorption capacity of 143.12 mg/g. Effects of solution pH, adsorbent mass, adsorbate concentration, contact time and temperature on the removal of Nitrazepam were investigated. Different adsorption isotherms and kinetics were also tested. It was found that the solution pH slightly influenced the removal efficiency. The adsorption data fit the Freundlich isotherm model and the adsorption process of Nitrazepam onto Sargassum macroalgae-derived biochar is spontaneous, endothermic and followed the pseudo-second-order kinetics. Based on this work, it was determined that the low-cost Sargassum macroalgae-derived biochar adsorbent could be a promising adsorbent to remove Nitrazepam from water effectively.


2015 ◽  
Vol 16 (1) ◽  
pp. 115-127 ◽  
Author(s):  
P. Dhanasekaran ◽  
P. M. Satya Sai ◽  
C. Anand Babu ◽  
R. Krishna Prabhu ◽  
K. K. Rajan

Arsenic is a toxic element found naturally in groundwater. Due to its carcinogenicity, risk for heart diseases and diabetes, arsenic needs to be removed from groundwater for potable application. ‘Anjili’ tree sawdust was chemically modified with ferric hydroxide and activated alumina (SFAA) and used as an adsorbent for the removal of arsenic from groundwater. The adsorbent was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) to study the pore structure and surface functional groups. Effect of contact time, initial concentration, pH, particle size and temperature was studied. Arsenic adsorbed by SFAA followed Freundlich adsorption isotherm. Maximum sorption of arsenic by SFAA adsorbent occurred at pH 6.5. Arsenic sorption kinetics followed a pseudo-second-order model. The maximum sorption capacity at 303 K was found to be 54.32 mg/g for As(III) and 77.60 mg/g for As(V). Interference of other ions on the adsorption was in the order of PO43− &gt; SO42− &gt; HCO3− &gt; NO3−.


2012 ◽  
Vol 573-574 ◽  
pp. 150-154
Author(s):  
Yun Bo Zang ◽  
Nai Ying Wu

In this study, removal of copper ions from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, EDTA and addition sequences at room temperature. It is found that HTlc could reduced copper ions concentration effectively. The kinetics closely fit pseudo-second order kinetics with necessary time 9 h to reach equilibrium. The sorption process followed langmuir model. The maximum sorption capacity calculated was found to be 39.4 mg/g. The presence of EDTA and addition sequences could affect sorption of Cu(II) onto HTlc.


2020 ◽  
Vol 13 (2) ◽  
pp. 080-090
Author(s):  
Daniel Eneji Sani ◽  
John O. Idoko ◽  
Enyojo Samson Okwute ◽  
Matthew Chijioke Apeh

Unactivated adsorbent was prepared from Moringa oleifera seed shells precursor, characterized and evaluated for aqueous phase removal of phenol. The effects of operational parameters such as initial phenolic solution pH and adsorbent dosage on equilibrium sorption were studied. Adsorption isotherms and kinetic experiments performed at (25 oC) furnished some equilibrium and kinetic parameters, respectively. UAMSS shows favorable attributes on (pH, bulk density, attrition, iodine number/surface area, surface charge/functional groups and Fourier transform infrared FTIR). Phenol uptake decreases with increase in solution pH for the adsorbent. Maximum adsorption capacity Qmax (mg/g) was (6.95). The optimal pH for phenol adsorption was attained at pH 3, adsorption kinetics obeyed closely pseudo-second-order model. Adsorption of phenol was well described by Langmuir isotherm. The adsorbent shows a promise of applicability in dephenolation of aqueous effluents/wastewater.


2021 ◽  
pp. 1-12
Author(s):  
Raafia Najam ◽  
Syed Muzaffar Ali Andrabi

Sawdust of willow has been investigated as an adsorbent for the removal of Ni(II), and Cd(II) ions from aqueous solution. Since willow tree is widely grown in almost all parts of Kashmir, it can be a common most easily available, sustainable, low cost adsorbent for the treatment of wastewaters in this part of the world where growing industrialization is affecting water quality like elsewhere in the world. Therefore, it is worthwhile to investigate the potential of sawdust of willow tree as an adsorbent for the removal of Ni(II) and Cd(II) ions from aqueous solution as a first step. Batch experiments were conducted to study the effect of some parameters such as contact time, initial concentration of metal ions, solution pH and temperature. Langmuir and Freundlich models were employed for the mechanistic analysis of experimental data obtained. Results reveal that in our system adsorption follows the Langmuir isotherm. The maximum adsorption capacity of Ni(II) and Cd(II) were found to be 7.98 and 7.11 mg/g respectively at optimum conditions. The pseudo-first-order and pseudo-second-order models were employed for kinetic analysis of adsorption process. The adsorption process follows pseudo-second-order kinetics. The efficacy of the adsorbent in the treatment of effluent from fertilizer factory has been investigated and the results have been found encouraging.


2018 ◽  
Vol 7 (3) ◽  
pp. 204-216
Author(s):  
Lamya Kadiri ◽  
Abdelkarim Ouass ◽  
Youness Essaadaoui ◽  
El Housseine Rifi ◽  
Ahmed Lebkiri

Coriandrum sativum seeds (CSS) were investigated as a new eco-friendly and economic biosorbent for the removal of methylene blue (MB) dye from synthetic solutions. First, the spectroscopic analyses were effectuated using FTIR and SEM to confirm the possibility of CSS to remove MB dye from aqueous solutions. The study of the influence of different parameters, such as contact time, CSS mass, solution pH, MB concentration, and temperature was realized and proved the rapid and efficient power adopted by CSS as a removal of the studied dye. Also, the regeneration study was effectuated for four cycles with excellent adsorption rates. The modeling studies revealed that the studied process obeys the pseudo-second-order model and Langmuir isotherm model. The adsorption amount was found to be 107.53 mg/g. Finally, the determination of thermodynamic parameters indicated the exothermic and spontaneous type of the removal process of MB onto CSS.


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