A Comparative Study Of Linear And Non-Linear Methods of Isotherm Parameters For Biosorption Of Sodium Diclofenac Onto Calcined Cow Leather (CCL)

21 In the current work, the activated biosorbent prepared from Calcined Cow Leather (CCL) was 22 used to study the biosorption potential on anti-inflammatory, namely Sodium Diclofenac and 23 derived from phenylacetic acid from the group of arylcarboxylic acids. Thus, it has been 24 selected because they are widely used and potential associated toxicological effects and also 25 apparently detected in aqueous environments. The biosorption study was carried out to examine 26 the biosorption mechanism by applying the five isotherms models represented by the 27 Langmuir, Freundlich, Elovich, Temkin and Dubinin-Radushkevich. The comparison of linear 28 the squares of the errors (SSE) , Hybrid fractional error function (HYBRID), Average relative error (ARE) , Sum of the absolute errors (SAE) and Marquardt’s percent standard deviation (MPSD). Whereas, the comparison between different models shows that the nonlinear form of 35 Langmuir model was the best fitted to describe the equilibrium data which was confirmed by 36 the five error functions and the smallest ‘sum of the normalized errors (SNE)’ parameter. 37 Therefore, the kinetics data was evaluated by various models. It was found that the biosorption 38 process was conducted by the pseudo-second-order model which predicted best the 39 experimental data. 40


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Water is a vital resource for all living creatures. Unfortunately, It is threatened by pollution 44 that is becoming increasingly important, linked to the release of dangerous chemical 45 compounds by different industries: chemicals, textiles, tanneries, agribusiness, 46 pharmaceuticals … etc. 47 Among these pollutants, many molecules come from pharmaceutical industries. Medicated 48 residues, rejected by industries, but also by hospitals, industrial farms (large consumers of 49 antibiotics) or domestic urine and stool. These residues are detected today at very low 50 concentrations (ng.L -1 or μg.L -1 ) in aquatic environment thanks to analytical devices 51 performing. The revelation of the omnipresence of pharmaceutical chemicals (ketoprofen, 52 naproxen, ketotifen and diclofenac…) into the environment has given rise to a new concern, 53 due to their intrinsic biological activity, photodegradation sensitivity and inherent toxicological 54 effects [1]. In addition, Sodium Diclofenac (SD) contains several structural motifs, which are 55 photochemically active and also reactive toward photochemically generated oxidizing agents, 56 such as the hydroxyl radical and singlet oxygen.
Many water treatment techniques have been developed in recent years. These techniques 58 include chemical precipitation processes, flocculation, ion exchange, electrolysis, membrane 59 processes; however present dissatisfactory results because of the formation of residual toxic 60 by-products in addition to high treatment cost. Hence, many researchers shifted their interest 61 to adsorption technique due to their efficiency and cheaper cost and also the low cost of . 65 In the current work, the used biosorbent is the Calcined Cow Leather (CCL) which presents an 66 abundant slaughterhouse waste especially at Eid al-Adha holiday. Thus, the CCL biosorbent 67 was used to study the adsorption potential of pharmaceutical products. On the other hand, as to 68 describe well the equilibrium adsorption, the linear and nonlinear forms of two-parameter 69 isotherm models are frequently conducted to give the right description and characterization to 70 adsorption mechanism. However, the primary aim of this work is to shed more light on the 71 comparison of these two methods by taking into consideration mathematical and statistical 72 properties of these two methods and compare different statistical criteria to determine the best 73 model fitted to experimental data and isotherm parameters. The synthetic stock solution (1 g.L -1 ) used in these studies was prepared by dissolving 100 mg 88 of powdered sodium diclofenac (SD) (99% purity) in 100 mL deionized water. All desired test  Table 1.  The biosorption efficiency of the activated biosorbent (CCL) is highly influenced by the

2.4.Adsorption procedure 114
The biosorption experiments were performed in batch system to study the effectiveness of SD Where Ci is the initial concentration of SD (mg/L) and Cf is the final concentration (mg/L).

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The metal uptake q (mg/g) was estimated following the equation [14]: Where m is the quantity of biosorbent (g) and V is the volume of the suspension (L). Radushkevich (two-parameter) isotherm equations (Table 2).
146 The biosorption kinetics provides the rate of biosorbate uptake onto the activated biosorbent 150 within the equilibrium contact time. In this study, two models were implemented to evaluate 151 the rate constant of the biosorption process: The pseudo-first-order and pseudo-second-order 152 kinetic models gathered in Table 3. 153

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(e) Sum all these normalized errors for each parameter set.

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The smallest sum normalized error (SNE) is considered to be optimal for that isotherm   determined from the intercept and the slope when t=0. However, Figure 3 shows the plot of     The XRD analysis was carried out to determine the structure of the prepared activated carbon.

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The absence of a sharp peak reveals a predominantly amorphous structure for CCL, which  The specific surface area of CCL was determined by Brunauer-Emmett-Teller (BET) 295 multipoint technique by adsorption-desorption isotherms of nitrogen at its liquid temperature 296 (77K) and was found Sp = 15 m 2 /g. The specific surface area (BET) is outstanding by 297 comparing it with that of other biosorbents derived from a natural origin.

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In this work, the prime objective is the valorization of the slaughterhouse wastes and the use 300 of those raw natural materials for the preparation of low cost biosorbents with good textural 301 and structural properties. Therefore, it was crucial for this study to identify informations 302 concerning the steps of adsorbent preparation, the textural and structural characteristics of the prepared biosorbent as well as those relating to their adsorption capacities of various inorganic 304 pollutants. For this purpose, the biosorbent was prepared from calcined cow leather (CCL) and 305 have been used successfully as an adsorbing agent for the removal of active pharmaceutical 306 ingredient (Sodium Diclofenac) from aqueous solutions. After activation, we carried out 307 characterization tests by physico-chemical methods (FX, DRX, IRTF and SEM) and we found 308 that CCL is essentially composed of oxygen and carbon which gives it a structure of calcite 309 (CaCO3) and silicate (SiO2). With the increase of concentration from 10mg/L to 50mg/L, the   Linearized plots for Pseudo-rst-order kinetics for biosorption of sodium diclofenac (SD) onto CCL biosorbent.

Figure 3
Linearized plots for Pseudo-second-order kinetics for biosorption of sodium diclofenac (SD) onto CCL biosorbent.