scholarly journals Impact of NaOH- surface treatment on emerging pollutant biosorption performance using marine algua, Posidonia Oceanica

2021 ◽  

<p>In the present investigation, marine biomass (Posidonia Oceanica) (PO), in both its unmodified PO and basic-modified (Na-PO) forms, was studied for its possible utilisation as a cheap biosorbent for the retention of amoxicillin (AMX). Biosorption studies were carried out in a batch system and the effects of solution pH, biosorbent dose, initial AMX concentration, contact time and temperature were studied in detail. Characterization of the biosorbent was performed using Fourier transforms infra-red spectroscopy (FTIR) and pHPZC. The biosorption of AMX was adjusted by Langmuir and Freundlich isotherm models, equilibrium isotherms were applicable with maximum monolayer biosorption capacity of 51.33 mg g-1 and 75.33 mg g-1 for PO and Na-PO, respectively. Kinetics investigations showed that both biosorbents followed the pseudo-second order. Thermodynamics studies indicated that the biosorption of AMX onto PO and Na-PO was spontaneous and endothermic in nature. These results proved that chemical modification of Posidonia Oceanica surface improved the biosorption properties of AMX.</p>

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Hizkeal Tsade Kara ◽  
Sisay Tadesse Anshebo ◽  
Fedlu Kedir Sabir ◽  
Getachew Adam Workineh

The study was focused on the preparation and characterizations of sodium periodate-modified nanocellulose (NaIO4-NC) prepared from Eichhornia crassipes for the removal of cationic methylene blue (MB) dye from wastewater (WW). A chemical method was used for the preparation of NaIO4-NC. The prepared NaIO4-NC adsorbent was characterized by using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and Brunauer–Emmett–Teller (BET) instruments. Next, it was tested to the adsorption of MB dye from WW using batch experiments. The adsorption process was performed using Langmuir and Freundlich isotherm models with maximum adsorption efficiency (qmax) of 90.91 mg·g−1 and percent color removal of 78.1% at optimum 30 mg·L−1, 60 min., 1 g, and 8 values of initial concentration, contact time, adsorbent dose, and solution pH, respectively. Pseudo-second-order (PSO) kinetic model was well fitted for the adsorption of MB dye through the chemisorption process. The adsorption process was spontaneous and feasible from the thermodynamic study because the Gibbs free energy value was negative. After adsorption, the decreased values for physicochemical parameters of WW were observed in addition to the color removal. From the regeneration study, it is possible to conclude that NaIO4-NC adsorbent was recyclable and reused as MB dye adsorption for 13 successive cycles without significant efficient loss.


2014 ◽  
Vol 16 (2) ◽  
pp. 87-94 ◽  
Author(s):  
Wojciech Konicki ◽  
Iwona Pełech ◽  
Ewa Mijowska

Abstract The removal of Ni2+ from aqueous solution by magnetic multiwalled carbon nanotube nanocomposite (MMWCNTs-C) was investigated. MMWCNTs-C was characterized by X-ray Diffraction method (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), surface area (BET), and Fourier Transform-Infrared Spectroscopy (FTIR). The effects of initial concentration, contact time, solution pH, and temperature on the Ni2+ adsorption onto MMWCNTs-C were studied. The Langmuir and Freundlich isotherm models were applied to fit the adsorption data. The results showed that the adsorption isotherm data were fitted well to the Langmuir isotherm model with the maximum monolayer adsorption capacity of 2.11 mg g–1. The adsorption kinetics was best described by the pseudo-second-order model. The thermodynamic parameters, such as ΔHo, ΔGo and ΔSo, were also determined and evaluated. The adsorption of Ni2+ is generally spontaneous and thermodynamically favorable. The values of ΔHo and ΔGo indicate that the adsorption of Ni2+ onto MMWCNTs-C was a physisorption process.


2016 ◽  
Vol 7 (3) ◽  
pp. 307-318 ◽  
Author(s):  
F. Z. Mahjoubi ◽  
A. Khalidi ◽  
O. Cherkaoui ◽  
R. Elmoubarki ◽  
M. Abdennouri ◽  
...  

This work involved the preparation, characterization and dyes removal ability of Zn-Al, Mg-Al and Ni-Al layered double hydroxide (LDH) minerals intercalated by chloride ions. The materials were synthetized by the co-precipitation method. X-ray diffraction, Fourier transform infrared, thermogravimetric-differential thermal analysis and transmission electron microscopy characterization exhibited a typical hydrotalcite structure for all the samples. Adsorption experiments for methyl orange were performed in terms of solution pH, contact time and initial dye concentration. Experimental results indicate that the capacity of dye uptake augmented rapidly within the first 60 min and then stayed practically the same regardless of the concentration. Maximum adsorption occurred with acidic pH medium. Kinetic data were studied using pseudo-first-order and pseudo-second-order kinetic models. Suitable correlation was acquired with the pseudo-second-order kinetic model. Equilibrium data were fitted to Langmuir and Freundlich isotherm models. The maximum Langmuir monolayer adsorption capacities were 2,758, 1,622 and 800 mg/g, respectively, for Zn-Al-Cl, Mg-Al-Cl and Ni-Al-Cl. The materials were later examined for the elimination of color and chemical oxygen demand (COD) from a real textile effluent wastewater. The results indicated that the suitable conditions for color and COD removal were acquired at pH of 5. The maximum COD removal efficiency from the effluent was noted as 92.84% for Zn-Al-Cl LDH.


Author(s):  
Khawla Ben Jeddou ◽  
Fatma Bouaziz ◽  
Fadia Ben Taheur ◽  
Oumèma Nouri-Ellouz ◽  
Raoudha Ellouz-Ghorbel ◽  
...  

Abstract Adsorption of direct red 80 (DR 80) and methylene blue (MB) from aqueous solutions on potato peels (PP) has been compared. The use of peels in decontamination technology is very promising given the near zero-cost for the synthesis of those adsorbents. The selected potato peels were first analyzed by scanning using electron microscopy (SEM) and Fourier transforms infra red spectroscopy (FTIR). Then the adsorption behavior was studied in a batch system. The adsorption process is affected by various parameters such as the solution pH (2–11), the initial concentration of the dye (20, 50, 100, 150 and 200 mg L−1), the adsorbent dose (0.1%–3%), the temperature (303.16 K, 313.16 K, and 323.16 K), agitation (up to 250 rpm), as well as the contact time. Adsorption isotherms of the studied dye on the adsorbent were determined and compared with the Langmiur, Freundlich and Temkin adsorption models. The results show that the data was most similar to the Freundlich isotherm (R2 = 0.99). The maximum adsorption capacities (Qmax) of MB and DR 80 by the PP at temperatures 303.16 K, 313.16 K and 323.16 K were found to be approximately 97.08 mg g−1; 45.87 mg g−1; 61.35 mg g−1 and 27.778 mg g−1; 45.45 mg g−1; and 32.258 mg g−1. The kinetic data was compared to the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. This revealed that adsorption of methylene blue onto PP abided mostly to the pseudo-second-order kinetic model. Calculations of various thermodynamic parameters such as enthalpy change (ΔH), entropy change (ΔS), and free energy change (ΔG) display the endothermic and spontaneous nature of the adsorption process.


2019 ◽  
Vol 20 (2) ◽  
pp. 23-32
Author(s):  
Marah Waleed Khalid ◽  
Sami D. Salman

Due to the broad range uses of chromium for industrial purposes, besides its carcinogenic effect, an efficient, cost effective removal method should be obtained. In this study, cow bones as a cheap raw material were utilized to produce active carbon (CBAC) by physiochemical activation, which was characterized using: SEM to investigate surface morphology and BET to estimate the specific surface area. The best surface area of CBAC was 595.9 m2/gm which was prepared at 600 ᵒC activation temperature and impregnation ratio of 1:1.5. CBAC was used in aqueous chromium ions adsorption. The investigated factors and their ranges are: initial concentration (10-50 mg/L), adsorption time (30-300 min), temperature (20-50 ᵒC) and solution pH (2-11). Isotherm of adsorption and its kinetics were studied. The adsorption process was modeled statistically and was represented by an empirical model. Equilibrium data were fitted to the Langmuir and Freundlich isotherm models and the data best represented by Freundlich isotherm. Pseudo- first order and pseudo- second order kinetic equations were utilized to study adsorption kinetics, where chromium adsorption on CBAC fitted pseudo- second order fitted the data more adequately. The best removal efficiency was found to be 94.32%.


2016 ◽  
Vol 74 (11) ◽  
pp. 2560-2568 ◽  
Author(s):  
Qiulai He ◽  
Hongyu Wang ◽  
Jing Zhang ◽  
Zhuocheng Zou ◽  
Jun Zhou ◽  
...  

The adsorption of methylene blue (MB) by low cost biomass lotus seedpod (LSP) was optimized by a central composite design combined with response surface methodology in aqueous solution. Solution pH, initial dye concentration and adsorbent dosage were studied as independent variables at five levels each, respectively. Analysis of variance suggested the validity of the regression model. LSP was characterized by Fourier transform infrared spectra and energy dispersive spectroscopy. The kinetics revealed that the adsorption behavior followed the pseudo-second-order model. Langmuir and Freundlich isotherm models were used to evaluate the adsorption, and the experimental data were better fitted by the Langmuir isotherm than the Freundlich isotherm. The maximum monolayer adsorption capacity of the LSP was 157.98 mg g−1 at 30 °C for MB adsorption. In addition, 0.2 M HCl solution could be used for reusability of LSP via desorption tests. LSP was proven to be an available and effective biosorbent for MB removal from aqueous solution.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Klaiani B. Fontana ◽  
Giane Gonçalves Lenzi ◽  
Erica R. L. R. Watanabe ◽  
Ervin Kaminski Lenzi ◽  
Juliana A. M. T. Pietrobelli ◽  
...  

The removal of Pb(II) from water by biosorption processes onto malt bagasse was investigated and the kinetic and thermodynamic parameters were obtained; additionally a diffusion modeling was proposed. The characterization of malt bagasse was performed by FTIR and SEM/EDS. The experiments were conducted in batch system and an experimental design based response surface methodology was applied for agitation speed and pH optimization. The kinetics of biosorption followed pseudo-second-order model and the temperature of the process affected the biosorption capacity. Isotherm models of Langmuir, Freundlich, and Elovich were applied and the Langmuir model showed better fit and the estimated biosorption capacity was 29.1 mg g−1. The negative values obtained for ΔG° and positive values of ΔH° confirm, respectively, the spontaneous and endothermic nature of the process. The diffusion modeling was performed based on experiments in the absence of agitation to investigate the influence of the biosorbent on the sorption process of Pb(II) ions.


2001 ◽  
Vol 19 (3) ◽  
pp. 197-210 ◽  
Author(s):  
A. Hashem ◽  
Reda M. El-Shishtawy

The factors influencing the cationization of microcrystalline cellulose with 3-chloro-2-hydroxypropyl triethylammonium chloride in the presence of NaOH were investigated. The course of the reaction was followed by estimating the nitrogen content of the cationized product while its structural features were confirmed by IR analysis. The ability of cationized cellulose to adsorb anionic dyes, viz. Acid Orange 7, Direct Blue 75 and Direct Violet 31, was investigated at 25°C and 50°C. The equilibrium data obtained were fitted by the Langmuir and Freundlich isotherm models, allowing the corresponding adsorption parameters to be determined. The results showed that the adsorption capacity was dependent on the adsorbent, temperature, the nature of the dye and (to some extent) on van der Waals and hydrogen bonding. Cationized cellulose exhibited a much better adsorption capacity towards anionic dyes than cellulose.


2021 ◽  
Vol 19 (9) ◽  
pp. 46-54
Author(s):  
Makarim A. Mahdi ◽  
Aymen A.R. Jawad ◽  
Aseel M. Aljeboree ◽  
Layth S. Jasim ◽  
Ayad F. Alkaim

The AAc/GO nanocomposite hydrogel was successfully employed as a polymeric Nano sorbent of the removal efficiency of M G dye from the model. The complication of the mechanism of the adsorption system was completely exposed by examining how solution pH affects adsorption, Ionic strength isotherm models, kinetic models, and thermodynamics. The adsorption of the MG dye was greatly dependent on the solution pH. The Freundlich model has been demonstrated to be the most accurate in describing the MG dye sorption, whilst the Langmuir model was shown to be the least accurate. Additionally, these integrated mechanisms fit nicely within the framework of a pseudo-second-order model. Additionally, the contact time at equilibrium short (ten minutes) required to MG removes demonstrates the AAc/GO nanocomposite hydrogel can be considered an efficient and potentially useful adsorbent for MG removal from industrial effluents.


2021 ◽  
Vol 348 ◽  
pp. 01016
Author(s):  
Rajaa Bassam ◽  
Marouane El Alouani ◽  
Nabila Jarmouni ◽  
Jabrane Maissara ◽  
Mohammed El Mahi Chbihi ◽  
...  

Heavy metals are the most dangerous inorganic pollutants Due to their bioaccumulation and their nonbiodegradability, for this, several studies have focused on the recovery of these metals from water using different techniques. In this context, our study consists of evaluating an efficient and eco-friendly pathway of competitive recovery of heavy metals (Cd, Cr and As) from aqueous solutions by adsorption using raw rock. This adsorbent was characterized before and after the adsorption process by several techniques. The multi-metals adsorption process in the batch mode was undertaken to evaluate the effect of adsorbent mass, contact time, pH, Temperature, and initial heavy metals concentration. The kinetic data were analyzed using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic models. According to the modeling of the experimental results, the adsorption kinetics of heavy metals were adapted to the pseudo-second-order model. The adsorption isotherms were evaluated by the Langmuir and Freundlich isotherm models. The experimental isotherm data of heavy metals were better fitted with the Langmuir model rather than Freundlich isotherm models. The maximum experimental adsorption capacities (Qmax) predicted by the Langmuir model are 15.23 mg/g for Cd (II), 17.54 mg/g for Cr (VI) and 16.36 mg/g for As (III). The values of thermodynamic parameters revealed that the heavy metals adsorption was exothermic, favorable, and spontaneous in nature. The desorption process of heavy metals showed that this raw rock had excellent recycling capacity. Based on the results, these untreated clays can be used as inexpensive and environmentally friendly adsorbents to treat water contaminated by heavy metals.


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