Enhanced adsorption of nitrate from water by modified wheat straw: equilibrium, kinetic and thermodynamic studies

2019 ◽  
Vol 79 (2) ◽  
pp. 302-313 ◽  
Author(s):  
Behrouz Mehdinejadiani ◽  
Seyed Mojtaba Amininasab ◽  
Leila Manhooei
Keyword(s):  
Wheat Straw ◽  
Adsorption Process ◽  
Operating Conditions ◽  
Scanning Electron Micrographs ◽  
Solution Ph ◽  
Competing Anions ◽  
Adsorption Data ◽  
General Order ◽  
Nitrate Adsorption ◽  
Enhanced Adsorption

Abstract This study represents the first attempt to chemically modify wheat straw (WS) using 3-chloropropyltrimethoxysilane (CPTMS) and (1,4-diazabicyclo[2.2.2]octane) (DABCO). Field emission scanning electron micrographs (FESEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectra confirmed the successful morphological and structural modification of WS and the thermal stability of the modified WS (MWS). The MWS was used to remove nitrate from water. The optimum conditions of nitrate adsorption onto MWS were examined by conducting batch experiments. The results indicated that 85% of nitrate was removed under the conditions of initial nitrate concentration = 20 mg L−1, initial solution pH = 7, contact time = 10 min, MWS dosage = 2 g L−1 and temperature ≈ 25 °C. The kinetic adsorption data were best fitted to the general order model and the adsorption process occurred in three distinct stages. The equilibrium adsorption data were well described by the Langmuir isotherm. Additionally, separation factor values were smaller than 1, implying that the adsorption process was favorable. The presence of competing anions impeded the nitrate adsorption in the order of sulfate > chloride > bicarbonate> phosphate. Thermodynamic parameters suggested that the adsorption process was exothermic, feasible and spontaneous in nature. Overall, the MWS could achieve efficient removal of nitrate under the simplest operating conditions.

ETHANOL SEPARATION USING SEPABEADS207 ADSORBENT

2017 ◽  
Vol 79 (5) ◽  
Author(s):  
Mazin Abdulhusein Beden ◽  
Muhammad Abbas Ahmad Zaini ◽  
Tuan Amran Tuan Abdullah
Keyword(s):  
Ethanol Concentration ◽  
Fermentation Broth ◽  
Ethanol Solution ◽  
Operating Conditions ◽  
Solution Ph ◽  
Original Solution ◽  
Air Temperatures ◽  
Adsorption Data ◽  
Ethanol Adsorption ◽  
Ethanol Separation

This work was aimed at evaluating the ethanol separation using Sepabeads207 adsorbent. A 10 wt% of ethanol solution was used as a model fermentation broth. The separation of ethanol from the solution was performed in a tube containing Sepabeads207 at different operating conditions: temperatures, 20 to 40oC; solution pH, 4 to 7; and contact times, 5 to 25 minutes. Recovery of ethanol via stripping was studied between 15 and 35 minutes, and at different air temperatures of 80 to 95oC. The concentration of liquid ethanol was measured using gas chromatography and refractometer. A higher ethanol concentration by Sepabeads207 adsorption was obtained at 20oC and solution pH 4 for 5 minutes, while the recovery was performed better at 80oC for 15 minutes. By applying these conditions, 10 wt% of ethanol in the solution was concentrated to 46 wt%. The ethanol adsorption data are: i). capacity of 0.22 g ethanol/g adsorbent, ii). selectivity of 7.75 (g ethanol/g water (adsorbed)) / (g ethanol/g water (original solution)), and iii). efficiency of 100%. Sepabeads207 is a promising adsorbent for ethanol separation from the dilute ethanol solution.

The Research of Absorption on U(VI) by Nanometer α-Fe2O3 Microsphere

2014 ◽  
Vol 1010-1012 ◽  
pp. 817-820
Author(s):  
Qing Peng Wei ◽  
Shi You Li ◽  
Shui Bo Xie ◽  
Jian Biao Liao ◽  
Yin Li
Keyword(s):  
Adsorption Process ◽  
Removal Rate ◽  
Order Equation ◽  
Oxide Content ◽  
Solution Ph ◽  
Isothermal Adsorption ◽  
Adsorption Models ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
Pseudo Second Order

Adsorption of uranium(VI) ions by Sodium alginate (SA) immobilized nano-α-Fe2O3 particles beads were investigated in the batch experiments.The influences of the nano-ferric oxide content in beads，cross-linking time, solution pH, initial U(VI) concentration, temperature and contact time on U(VI) sorption were studied. The results indicated that the adsorption capacities are strongly affected by the solution pH, the best adsorption rate can be thought of to be at pH 3. The adsorption was rather fast in the initial 1.5 h, and the equilibrium was established in 9 h with the sorption capacity 2.64 mg/g. The kinetic adsorption data was simulated better by a pseudo-second-order equation. The removal rate increased slowly with temperature ascending . The adsorption process conformed to the Langmuir and Freundlich isothermal adsorption models, and the data fitted the latter better.

scholarly journals Kinetics Modeling and Isotherms for Adsorption of Nitrate from Aqueous Solution by Wheat Straw

2019 ◽  
Vol 25 ◽  
pp. 203
Author(s):  
Hedieh Ahmadpari ◽  
Mohsen Eskafi Noghany ◽  
Behnam Rigi Ladez ◽  
Babak Mehrparvar ◽  
Saeed Momeni
Keyword(s):  
Wheat Straw ◽  
Adsorption Process ◽  
Nitrate Removal ◽  
Freundlich Isotherm ◽  
Potassium Nitrate ◽  
The Body ◽  
World Health ◽  
Isotherm Models ◽  
Average Mass ◽  
Nitrate Adsorption

Nitrate is a colorless, odorless chemical substance with a chemical formulation of NO3- and average mass of 62.0049 gr/ Mol. According to an announcement of the world health organization (WHO), the standard amount of Nitrate in potable water is at most 50 ml/ lit (based on nitrate). Nitrate enters into the body and is transformed to nitrite by digestive system’s bacteria, then enters to the circulatory system and oxides the exiting iron in Hemoglobin of blood which converts the iron capacity from 2 to 3. As a result of this process Hemoglobin is converted to Methemoglobin which has far more less capacity in oxygen delivery. Therefore, the tissues cannot receive sufficient oxygen and it causes a disease called “Methemoglobinemia”. The objective of this study was to investigate the nitrate removal using wheat straw and determining the adsorption isotherms and kinetics. In this study, nitrate solutions were prepared from potassium nitrate salt. The pH values of the solutions were adjusted by NaOH and HCl at a concentration of 0.1 molar. The pH of the solution was adjusted to different values (4 to 13). Kinetics models of Ho et al and Lagergren were used to describe the data. Isotherm models of Langmuir and Freundlich were used to describe the data. The results showed that the maximum capacity of wheat straw in nitrate adsorption occurred at pH=6 and contact time 140 minutes. Equilibrium models (Langmuir and Freundlich) and non-equilibrium (Ho et al and Lagergren) were used to investigate the adsorption process. Comparing the determination coefficients between measured data and obtained value from Ho’s model (R2= 0.97) and Lagergren model (R2= 0.91) showed that the Ho’s model describes experimental data better. Also, comparing the Langmuir and Freundlich isotherm for nitrate adsorption by wheat straw showed that Freundlich isotherm (R2= 0.98) was more proper than Langmuir isotherm (R2= 0.83) in describing adsorption process.

scholarly journals Synthesis of Polymer-Based Magnetic Nanocomposite for Multi-Pollutants Removal from Water

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1742
Author(s):  
Fatimah Mohammed Alzahrani ◽  
Norah Salem Alsaiari ◽  
Khadijah Mohammedsaleh Katubi ◽  
Abdelfattah Amari ◽  
Faouzi Ben Rebah ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Magnetic Composite ◽  
Sample Treatment ◽  
Water Type ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Vibration Sample Magnetometer ◽  
Pollutants Removal ◽  
Co Precipitation ◽  
Red Dye

A magnetic polymer-based nanocomposite was fabricated by the modification of an Fe3O4/SiO2 magnetic composite with polypyrrole (PPy) via co-precipitation polymerization to form PPy/Fe3O4/SiO2 for the removal of Congo red dye (CR) and hexavalent chromium Cr(VI) ions from water. The nanocomposite was characterized using various techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), vibration sample magnetometer, and thermogravimetric analysis (TGA). The results confirm the successful fabrication of the nanocomposite in the size of nanometers. The effect of different conditions such as the contact time, adsorbent dosage, solution pH, and initial concentration on the adsorption process was investigated. The adsorption isotherm suggested monolayer adsorption of both contaminants over the PPy/Fe3O4/SiO2 nanocomposite following a Langmuir isotherm, with maximum adsorption of 361 and 298 mg.g−1 for CR dye and Cr(VI), respectively. Furthermore, the effect of water type on the adsorption process was examined, indicating the applicability of the PPy/Fe3O4/SiO2 nanocomposite for real sample treatment. Interestingly, the reusability of the nanocomposite for the removal of the studied contaminants was investigated with good results even after six successive cycles. All results make this nanocomposite a promising material for water treatment.

scholarly journals Facile Fabrication of Novel NiFe2O4@Carbon Composites for Enhanced Adsorption of Emergent Antibiotics

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6710
Author(s):  
Van Tan Lam ◽  
Thi Cam Quyen Ngo ◽  
Long Giang Bach
Keyword(s):  
Metal Organic Framework ◽  
Pharmaceutical Drugs ◽  
Optimum Conditions ◽  
Solution Ph ◽  
Antibiotic Drugs ◽  
Metal Organic ◽  
Facile Fabrication ◽  
Permissible Levels ◽  
Enhanced Adsorption ◽  
Quadratic Models

Water purification is becoming one of the most pertinent environmental issues throughout the world. Among common types of water pollution involving heavy metals, pharmaceutical drugs, textile dyes, personal care products, and other persistent organic pollutants, the pollution of antibiotic drugs is increasingly emerging due to their adverse effects on microorganisms, aquatic animals, and human health. Therefore, the treatment of such contaminants is very necessary to reduce the concentration of antibiotic pollutants to permissible levels prior to discharge. Herein, we report the use of NiFe2O4@C composites from a bimetallic-based metal-organic framework Ni-MIL-88B(Fe) for removal of ciprofloxacin (CFX) and tetracycline (TCC). The effect of production temperatures (600–900 °C), solution pH (2–10), NiFe2O4@C dose (0.05–0.2 g/L), concentration of antibiotics (10–60 mg/L), and uptake time (0–480 min) was investigated systematically. Response surface methodology and central composite design were applied for quadratic models to discover optimum conditions of antibiotic adsorption. With high coefficients of determination (R2 = 0.9640–0.9713), the proposed models were significant statistically. Under proposed optimum conditions, the adsorption capacity for CFX and TCC were found at 256.244, and 105.38 mg/g, respectively. Recyclability study was employed and found that NiFe2O4@C-900 could be reused for up to three cycles, offering the potential of this composite as a good adsorbent for removal of emergent antibiotics.

scholarly journals Evaluation of active sludge and aquatic ferns usage for removal of zinc in a biological wastewater treatment system

2019 ◽  
pp. 39-44
Author(s):  
Amir Hajiali ◽  
Lacramioara Diana Robescu
Keyword(s):  
Ph Value ◽  
Reaction Times ◽  
Treatment Method ◽  
Operating Conditions ◽  
Industrial Scale ◽  
Reactor Performance ◽  
Solution Ph ◽  
Active Sludge ◽  
Simple Method ◽  
Aquatic Fern

In this research capability of biological treatment method via active sludge and aquatic fern evaluated in different operating conditions and they were optimized in order to remove Zn (II). A simple reactor performance for treatment of model and real wastewater on laboratory and semi-industrial scale was investigated. This refining process proceeded with special attention to the effect of solution pH-value, pollutant concentration, absorbent concentration and reaction time. The batch semi-industrial scale reactor represented over 90 % removal efficiency under pH-value of 6 and 5-5.5 for aquatic ferns and active sludge, respectively. Effective reaction times represented various durations for aquatic ferns and active sludge with respect of 120 minutes and 90 minutes. The two biological masses had the best performances with 6 g/l for aquatic ferns and 5 g/l for active sludge. In the presence of 5 ppm of Zn (II) as the objective heavy metal, both absorbents had over 93.2 % removal efficiencies. While obviously laboratory-scale attempts introduced higher acceptable reduction efficiencies via this economic applicable treatment method. Additionally, economic considerations clarified feasibility of this recommended simple method.

scholarly journals Local wheat peel as a solid surface to remove Azure B dye from aqueous solution:Equilibrium isotherms and thermodynamic study

2016 ◽  
Vol 13 (2) ◽  
pp. 58-65
Author(s):  
Baghdad Science Journal
Keyword(s):  
Chloride Concentration ◽  
Effect Of Temperature ◽  
Order Kinetic ◽  
Solution Ph ◽  
Adsorption Phenomenon ◽  
Azure B ◽  
Adsorbent Surface ◽  
Experimental Parameters ◽  
Adsorption Data ◽  
Enthalpy And Entropy

In this research local wheat peel was used as an adsorbent surface for removal of Azure B (AB) dye from the aqueous solution. The adsorption process was performed at different experimental parameters, equilibrium time, temperature, ionic strength and solution pH. The isotherms of adsorption are of H-type as compared with Giles curves and the adsorption data were coincide with Freundlich equation. The adsorption kinetic data were analyzed using pseudo- first and second order kinetic models. The effect of temperature was studied and the amount of dye adsorbed was found to increase with the increasing of temperature from 25 to 50 oC. The values of thermodynamic functions like enthalpy and entropy have been estimated. The quantity of adsorbed dye on the wheat peel increase according to the sequence follows: pH 9.3? 8 ? 7 ?6 ?5.2.The adsorption phenomenon is influenced by the sodium chloride concentration of solution. The obtained data refer to a decrease in amount of Azure B adsorbed in the existence of electrolyte.

scholarly journals Adsorption of Hydrogen Sulphide on the Zeolite type A Synthezied from Iraqi Kaoline

2013 ◽  
Vol 10 (3) ◽  
pp. 1023-1033 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Adsorption Process ◽  
Adsorption Properties ◽  
Zeolite A ◽  
Exchange Method ◽  
Adsorption Data ◽  
H2s Adsorption ◽  
Zeolite Type ◽  
Ion Exchange Method ◽  
Isotherm Equations ◽  
Static Form

Three types of zeolite A were prepared from Iraqi kaoline which are 3A, 4A and 5A by ion exchange method .They were characterized by XRD and atomic absorption techniques .They were used as adsorbents to examine their applicability for H2S adsorption .The adsorption process was performed in a static form and constant volume system which constructed from stainless steel .The effect of zeolite type and temperature on the adsorption properties of H2S at -5 , 25 and 55 oC was studied .The zeolite type 5A has the highest adsorption value (79.384 µmol/g ) and the three types may be arranged in a sequence toward H2S adsorption as 5 A> 4A>3A .The amount of H2S adsorbed increased as temperature decreased from 55 to -5 for all samples. Langmuir , Frendlich and Toth isotherm equations model were applied for the adsorption data in order to determine the affinity and the heterogeneity of the three adsorbents. The heterogeneity parameters of the model equation applied indicated that 5A sample was more heterogeneous compared to other zeolite types.

Developing of Polypyrrole Coating on Rotating Steel Cylinder for Improving its Corrosion Resistance

2013 ◽  
Vol 685 ◽  
pp. 277-282
Author(s):  
Ahmed H. El-Shazly ◽  
H.A. Al-Turaif
Keyword(s):  
Corrosion Resistance ◽  
Rotational Speed ◽  
Saline Solution ◽  
Monomer Concentration ◽  
Operating Conditions ◽  
Solution Ph ◽  
Steel Cylinder ◽  
Sodium Tartrate ◽  
Rotating Speed ◽  
Pyrrole Monomer

This work investigates the possibility of using polypyrrole (PPy) coating for improving the corrosion resistance of rotating cylinder subjected to saline solution. Galvanostatic technique was used for layer formation under different conditions of current density, pyrrole monomer concentration, sodium tartrate concentration and solution pH. The potentiodynamic technique was used for examination of PPy coated steel in corrosive medium composed of 3.5%NaCl under different rotating speed ranging from 200 to 1000 rpm. The formed PPy layer was investigated for its corrosion resistance using 3.5% NaCl solution under different rotational speed using the potentiodynamic technique. The preliminary results showed that coating steel with polypyrrole layer under different rotational speed can improve its corrosion resistance by a factor ranging from 1.2 to 1.88 depending on the operating conditions

scholarly journals Adsorption Behaviors of Oxytetracycline onto Sediment in the Weihe River, Shaanxi, China

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Dong-Hui Cheng ◽  
Sheng-Ke Yang ◽  
Yue Zhao ◽  
Jing Chen
Keyword(s):  
Freundlich Isotherm ◽  
Entropy Change ◽  
Impact Factors ◽  
Isotherm Models ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Adsorption Data ◽  
Negative Effect ◽  
Weihe River ◽  
The Impact

Adsorption behaviors of oxytetracycline onto sediment in the Weihe River were described. The impact factors in the processes of adsorption, such as contact time, solution pH, temperature, and ionic strength, were determined by experiments. The experimental results were analyzed by kinetic and isotherm models. The adsorption kinetics was found to follow a pseudo-first-order model. The equilibrium adsorption data fitted well with the Langmuir and Freundlich isotherm models. However, the Langmuir isotherm was more suitable to describe the adsorption. Thermodynamics parameters such as Gibbs-free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) were calculated. Results showed that the adsorption was feasible, spontaneous, entropy increasing, and endothermic in nature, which reached equilibrium in about 24 hours. The adsorption capacity did not cause obvious change at solution pH 4.0–7.0, and both decreased in solution pH 7.0–10.0 and 4.0–2.0. The presence of electrolytes such as NaCl in aqueous solution had a significant negative effect on the adsorption. The mechanisms controlling the adsorption were supposed to be chemisorption.

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