Linear and Non-linear Regression Analysis for the Sorption Kinetics of Rhodamine Dye from Aqueous Solution using Chitosan-Jackfruit nanocomposite

This paper presents experimental results such as the adsorbate-adsorbent chemical properties and chemical interaction as well as adsorption conditions. The experimental results were fitted to batch kinetic studies to obtain the characteristic parameters of each model. According to the evaluation using the Kinetic equation, the maximum sorption capacity at dye concentration was 19.6 (mg g), pH 11.6 (mg g) and temperature 24.2 (mg g) Rhodamine dye were investigated. For all of the systems studied, the pseudo-first-order and pseudo-second-order model provided the best correlation of the kinetic experimental data. The results revealed that with increasing temperature and decreasing pH, ionic strength, and adsorbate concentration, dye removal efficiency has increased. Chitosan-Jackfruit nanocomposite could remove 90.2% dye from the solution containing 40 mg/L dye at 100 min. The results indicated that dye removal followed pseudo-second-order kinetic (R>0.99). According to the findings, Chitosan-Jackfruit nanocomposites an effective adsorbent for direct dye removal from wastewater. DOI: https://dx.doi.org/10.4314/jasem.v26i1.15 Open Access Article: (https://pkp.sfu.ca/ojs/) This an open access article distributed under the Creative Commons Attribution License (CCL), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Impact factor: http://sjifactor.com/passport.php?id=21082 Google Analytics: https://www.ajol.info/stats/bdf07303d34706088ffffbc8a92c9c1491b12470 Copyright: Copyright © 2022 John-Britto et al. Dates: Received: 23 August 2021; Revised: 21 December 2021; Accepted: 06 January 2022

The current world is facing the problem of a shortage of pure drinking water because of limited sources of clean and pure water. Due to rapid growth in industries, a wide range of wastes is generated from the industries and is ultimately discharging into water resources, thereby affecting the quality and aesthetic of water Mahanta et al., (2009) ;Ahmad and Kumar, 2010;Mittal et al., (2010); Ansari et al., (2011);Janaki et al., (2012); Sajid et al., (2016); Sajid et al., (2018); Nidheesh et al., (2018);Fang et al., (2018); Siddiqui et al., (2018); Nusrat Tara et al., (2019). This is a very serious concern for developing countries. Among various wastes generated from the industries, color substances, particularly, dyes are the most dischargeable pollutants. Dyes are utilized in textile, paper printing, carpet, plastic, food, and cosmetic industries (Hussaini and Halbus, 2012); Subramanian et al., (2018). Fabric and textile industries use dyes as a colorant on a large scale and commercially about 0.1 million dyes are available and approximately 7.0 × 10 5 ton dyes are produced annually Sen et al., (2011); (Christie, 2017). The total dye consumption in textile industries is more than 10,000 tonnes per year, and about 10-15% of dyes are released into water from textile industries Dod et al., (2012); Geetha et al., (2015); (Akanksha and Sanjeev, 2018); Yao et al., (2018); Yunhong et al., (2018). Dyes can be mutagenic, carcinogenic, and allergenic to the human body, therefore, the contamination of dyes in water can be hazardous for aquatic organisms as well as humans Lin et al., (2008); Ozdemir et al., (2009); Gupta et al., (2015). Dye wastewater that ends up in freshwater bodies causes havoc to aquatic species by increasing toxicity chemical oxygen demand (COD). It also affects the photosynthetic activities of aquatic plants through the reduction of light penetration Oliveira et al., (2008). It has been reported that high COD, biological oxygen demand (BOD5) values, particulate matter (PM), and sediments, grease, and oil in effluents lead to the depletion of dissolved oxygen creating serious consequences on aquatic species Wang et al., (2011). These activities generate highly colored effluents and should be treated before discharge in order to avoid negative environmental impacts. Unfortunately, most dyes are poorly biodegradable and cannot be effectively removed by conventional waste treatments Moran et al., (1997); Sepulveda et al., (2015). As tougher environmental legislation is enforced in most countries, there is a greater need for cost-effective treatment systems. In recent years, alternative wastewater treatment options for dye removal have been assessed including highperformance biological treatment (Sani and Banerjee, 1999), adsorption on activated carbon Allen et al., Linear and Non-linear , chemical coagulation, or physical retention by membranes Vandevivere et al., (1998). However, most of these methods involve high operational costs in order to achieve the effectiveness required to meet strict environmental standards. On the other hand, the use of low-cost adsorbents offers an interesting option for the industrial implementation of adsorption-based removal of dyes. The adsorption process is one of the best water treatment techniques among various available methods. Adsorbent efficiently removes different pollutants and economical and eco-friendly. Among these, adsorption currently appears to offer the best potential for overall treatment, and it can be expected to be useful for a wide range of compounds. In this study, pomegranate peel activated carbon (PPAC) was evaluated as a new adsorbent for removal of a synthetic dye from an aqueous solution. We examined the effects of solution pH, Temperature, Dosages, and initial dye concentration on Rhodamine dye adsorption process onto Chitosan-Jackfruit nanocomposite from aqueous solution. Kinetic data were analyzed by different types of models were evaluated by pseudo-first-order; pseudo-second-order were also determined to understand the spontaneity of the adsorption process.

MATERIALS AND METHODS
Materials: All the necessary chemicals used in the study were of analytical grade. Rhodamine dye, Chitosan. Sodium tripolyphosphate was provided by Hi-media Private Ltd, Mumbai.
Preparation of Jackfruit sorbent: Jackfruit peel was obtained from a local fruit market in Alwarkurichi. The peels were first washed (more than 5 times) to remove any adhering dirt or moisture. They were then dried at room temperature (40°C) for 48 h, before being ball-milled from smaller particles of Jackfruit Sorbent Powder. The Jackfruit Peel powder was heated to 50°C in a water bath for about 2 days to remove color and pigments. The dried and ground Jackfruit peel powder (25g) was defatted by extraction with chloroform and methanol, and then placed at a ratio of 2:1, in soxhlet for 12 hrs to completely remove the color. The defatted Jackfruit peel was mixed with 350 ml of 0.2M Na3PO4 to bring the pH to 7.9 and to remove inactivates the pectic enzymes. After incubation overnight at 65 °C, the sample was filtered. The deproteinated Jackfruit peel powder was mixed with 100 ml of 0.50% ammonium oxalate (pH: 4.5). This mixture was shaken at 65°C in a water bath for 180 min then filtered. 10% of NaOH (25ml) was added to the depectinated Jackfruit peel powder. The mixture was shaken at 65°C in a water bath for 2 days, then filtered and washed in distilled water to remove the base. The hemicellulose-free Jackfruit peel powder was mixed with 100 ml of distilled water, 5 ml of 20% acetic acid, and 2.0g of NaCl. This mixture was shaken at 60°C in a water bath for 120 min and then filtered. The residue was washed with distilled water and ethanol to remove the acid and then dried at 50 °C in an oven for 16 hrs, finally producing smaller particles of Jackfruit Sorbent Powder.
Preparation of chitosan Nanoparticle: 3g of chitosan was weighed out and dissolved in 4% of the acidic acid solution followed by continuous stirring at room temperature for about 1 hour by using a magnetic stirrer and then 2g of sodium tripolyphosphate was dissolved in 200ml of distilled water and then added dropwise and freeze this solution (Chitosan Solutions) stand by 24 hrs and then precipitate was settled at the bottom and collected the precipitate and dried hot air oven 50 0 C at 24 hrs. Finally prepared the chitosan nanoparticle was prepared.
Preparation of chitosan with Jackfruit Sorbent Powder: Chitosan-Jackfruit Nanocomposite was prepared in a 1:1 ratio. Firstly, 1g of chitosan nanoparticle and then 1g of Jackfruit sorbent powder was mixed within 100ml distilled water. And then this solution was shacked in shaken in 3 days. Next, the solution was filtered by using Whatman No. 1 filter paper. Finally, the particle was settled and then the particle was dried in Hot air oven for 24 hours, and then finally Chitosan-Jackfruit Nanocomposite was prepared.
Kinetic Studies: A 100 ml dye solution concentration (Rhodamine dye) 40 mg/L was treated with 1 g of the adsorbent material (Chitosan-Jackfruit nanocomposite) over some time with constant stirring. The following parameters were studied to elucidate the kinetics of adsorption.
(iii) Effect of pH: 5.8, 6.8, and 9.4 at constant temperature (30 0 C) and Adsorbent dosages (Chitosan-Jackfruit nanocomposite) (1g/L) with 40mg/L Rhodamine dye concentration. The amount of dye adsorbed onto the adsorbent, qe (mg/g), was calculated by a mass balance relationship: Mass balance equation: Throughout the experiment the mass balance equation was used, to find the amount of protein adsorbed in each flask which was determined by the equation (1), Where Q -Adsorption capacity (mg/g), Co -Initial concentration of Rhodamine dye (mg/L), Ct -Final concentration of Rhodamine dye (mg/L), V -Solution volume of Rhodamine dye (L), and W -Mass of adsorbent (g) Hence, using this equation the amount of Rhodamine dye being adsorbed by the adsorbent was determined. All the experiments were conducted in duplicate and the results were presented as the average.

Adsorption Kinetics:
The kinetics of adsorption was studied for its possible importance in the treatment of  dye-containing industrial effluents (Cheremisinoff, 1995); Vandevivere et al., (1998); Lin and Lin (1993). Numerous kinetic models have been proposed to elucidate the mechanism by which pollutants are adsorbed. To investigate the mechanism of the dye adsorption kinetic models were considered as follows.
The kinetics of adsorption is important from the point of view that it controls the process efficiency Garg et al., (2004);Mittal et al., (2010). Various kinetic models have been used by various workers and different systems conform to different models but the Langergrens rate equations for the sorption of a solute from a liquid solution. To examine the controlling mechanism of adsorption processes such as mass transfer and chemical reaction; several kinetic models are used to test experimental data. Type 5: Pseudo 2 nd order

Effect of Dosages:
The initial concentration of the adsorbate in solution supplies an important driving force to overcome the mass transfer resistance between the solution and the solid adsorbent Almeida et al., (2009). It has been demonstrated that enough contact time gives a chance to the interaction between the adsorbate and the adsorbent Hebeish et al., (2011). To decide the impact of contact time on dye removal by Chitosan-Jackfruit nanocomposite at different dosages (1.0, 2.0, and 3.0 g/L) and the initial dye concentration of 40 mg/L, as per pertest, different time intervals (0 to 200 min) were investigated. The effect of adsorbent was the different weight of dosages on sorption of Rhodamine dye as shown in Figure. 1. It can be observed that as the dosages increases, the adsorption of dye increases. The result shows that there is a gradual increase in adsorption with increasing dosages. This figure shows that with increasing contact time, dye removal effectiveness increases, and the most elevated dye removal productivity and adsorption limit were gotten after 100 to 200 min for adsorbent dosages of 1.0, 2.0, and 3.0g/L, separately. As it is obvious from the outcomes, dye removal is fast in the underlying phases of sorption and afterward turns out to be moderate, and in the end contingent upon the adsorbent, portion accomplishes to balance at a particular time Hassan et al., (2014); Amir Hossein Mahvi and Arash Dalvand (2020). By expanding the adsorbent portion from 1.0 to 3.0 g/L, the required time to reach equilibrium decreases. In the first stage of adsorption, many vacant sites are available and adsorption is fast Weber et al., (2014), but later due to occupying and decreasing vacant sites, driving force decreases that lead to a decrease in the rate of adsorption. These results are in agreement with the results reported by Hebeish et al., (2011); Amir Hossein Mahvi, and Arash Dalvand (2020).
The Effect of pH: The initial pH of the aqueous solution is an important parameter that influences the adsorption process Almeida et al., (2009) by controlling the surface charge of the adsorbent, the adsorption availability of the dyes, and the degree of ionization of the atoms or molecules in the solution Errais et al., (2011). The effect of pH on the adsorption process was studied at different pH values, namely, 5.8, 6.8, and 9.4 The results are represented in Figure. 2. This may be due to the number of positive charges on the sorbent surface which leads to the no rejection of the negatively charged dye molecule, and thereby increasing the adsorption Low and Lee (1997); Namasivayam et al., (1996); Jumasiah et al., (2005). In general, the uptakes are much higher in acidic solutions than those in neutral and alkaline conditions. The maximum values of the adsorption capacity ratio between acidic and alkaline conditions reach 5.5 to GANDHIMATHI, S; ANNADURAI, G 6.8 Rhodamine dye on chitosan sorbent. The dye absorption may also derive support from the ion exchange reaction. According to Ho and McKay (1999) at lower pH more protons will be available to protonate amine groups of chitosan molecules to form groups -NH3 + , thereby increasing electrostatic attractions between negatively charged dye anions and positively charged adsorption sites and causing an increase in dye adsorption. This explanation agrees with our data on the pH effect. It can be seen that the pH of aqueous solution plays an important role in the adsorption of Rhodamine dye onto Chitosan-Jackfruit Nanocomposite. All amino groups of the Chitosan-Jackfruit Nanocomposite are cationized and the dye anion pulled in strongly by electrostatic attraction Wang et al., (2005); Nagarethinam and Mariappan, (2001). Higher dye removal efficiency at pH 6.8 can be attributed to the protonation of active groups on the surface of the adsorbent, which improves the electrostatic attraction of negatively charged dye molecules each dye molecule contains two anionic sulfonate groups toward positively charged adsorbent Mohanty et al., (2006). With increasing pH, due to the deprotonation mechanism, the number of positively charged sites on the adsorbent decreases and as a result, the dye removal efficiency decreases Chiou and Li, (2002). Moreover, lower dye adsorption at higher pH is because of the presence of negatively charged hydroxyl ions which compete with the anionic dye molecules. For the adsorption sites Ho et al., (2005). Effect of Temperature: The adsorption decreases with an increase in temperature because the adsorption is an exothermic process. Figure. 3. Adsorption isotherms for the Rhodamine dye at 30 0 C to 60 0 C, may also be explained on the basis that the solubility of the dyes is increased at higher temperature and adsorbate-adsorbent interactions decreased resulting in decreased adsorption. This also indicated that desorption steps increase at a higher temperature than the adsorption. This type of adsorption is likely to be classified as reversible adsorption. A behavior similar to this has also been observed by Robinson et al., (2002) on studies of adsorption of orange (IV) and orange G on biopolymer chitin. The adsorption of malachite green also decreases with the temperature in activated carbon (Aksu, 2001). The increase in temperature would increase the mobility of the large dye ion and also produces a swelling effect within the internal structure of the Chitosan-Jackfruit Nanocomposite Johann et al., (2007); Batzias and Sidiras (2007). thus, enabling the large dye molecule to penetrate further. Therefore, the adsorption capacity should largely depend on the chemical interaction between the functional groups on the adsorbent surface and the adsorbate and should increase with a temperature rising Zeynep Eren and Filiz Nuran Acar (2007); Gopal et al., (2014). The experimental rate curves of the Rhodamine dye on Chitosan-Jackfruit Nanocomposite at different Dosages, pH, and temperatures are shown in Figure. 1-3. In the beginning, the dyes molecules are adsorbed by the exterior surface of Chitosan-Jackfruit Nanocomposite. The adsorption rate is fast, and the adsorption of the exterior surface reaches saturation in a short time. At the same time, the dye enters into the Chitosan-Jackfruit Nanocomposite particle by the pore within the particle and is adsorbed by the interior surface of the particle. To have well known of the dye transient behavior onto Chitosan-Jackfruit Nanocomposite, the kinetic experimental results are analyzed by using the first-order kinetic model, second-order kinetic model, and various type of second-order kinetic model, respectively  G al., (2008). The models are given by the following equations. From a system design viewpoint, a lumped analysis of adsorption rates is thus sufficient for practical operation. A simple kinetic analysis of adsorption is the pseudo-first-order equation; After definite integration by applying the initial conditions qt=0 at t=0 and qt=qt at t=t, equation (2) becomes; Where qeq and qt are amounts of dye adsorbed at equilibrium and at the time, in mg g-1 respectively, and the k1 (mg g -1 min -1 ) and qe (mg g -1 min -1 ), was applied to the present studies of dye adsorption. As such the values of log (qe-qt) vs t were calculated from the kinetic data of ( Figure. 4 -6) and plotted against time (Ho and McKay, 1998).
The first-order rate constant calculated from the plots is shown in (Table. 1).  This lower R 2 1 value confirms the applicability of this model but not an appropriate one. Adsorption kinetics for some systems can also be described by a pseudo-second-order reaction Franke et al., (1987); Bolan, et al., (1991). The pseudo-second-order equation based on adsorption equilibrium capacity may be expressed in the form; Where k2 is the rate constant of pseudo-second-order adsorption. Integrating equation (4)  The equilibrium adsorption capacity (qeq), and the second-order constants k2 (g/mg min) can be determined experimentally from the slope and intercept of plot t/qt versus t. The applicability of the pseudo-second-order models can be examined by the linear plot as shown in ( Figure. 7-9). The correlation coefficient R 2 shows that the pseudo-second-order model an indication of chemisorption's mechanism that fits the experimental data slightly better than the pseudo-first-order model. Therefore, the adsorption of Rhodamine dye can be approximated more favorably by the pseudo-secondorder model Ho and McKay (2000); Hasnain Isa et al., (2007); Longhinotti et al., (1998);Muhammad and Muhammad (2007). This model has been successfully applied to describe the kinetics of many adsorption systems. Calculated correlations are closer to unity for the second-order kinetics model; therefore, the adsorption kinetics could well be approximated more favorably by the second-order kinetic model for dye adsorption. The k2 (mg g -1 min -1 ) and qe (mg g -1 min -1 ) values as calculated are listed in (Table 2).  Fig. 7-9 shows the pseudo-second-order plot for Rhodamine dye onto Chitosan-Selenium nanoparticle. The pseudo-second-order rate constant K2, the calculated qe value, and the corresponding linear regression correlation coefficient values R 2 , K2 is given in Table 3. At all different dosages, pH, and temperature, the linear regression correlation coefficient R 2 , K2 values were higher and ranged from 0.9646 to 0.9908. The higher R 2 , K2 values confirm that the sorption data are well represented by pseudo-second-order kinetics and supports the assumption behind the model that the sorption is due to chemisorption Robinson et al., (2002); Sajid et al., ; Schierz and Zanker (2009). The average R 2 , K2 value of 0.98354, which even better than that of R 2 , K1 values. This observation made clear that the sorption data tend to follow a pseudo-second-order kinetic model. The initial sorption rate h was calculated using and the calculated values are shown in Table 3. From the Table, it was observed that the pseudo-second-order rate constant K2 gets decreased with an increase in different dosages, pH, and temperature, and the initial sorption rate h was found to increase with the increase in different dosages and temperature Si et al., (2015); Webber and Chakraborty (1974); Yan et al., (2013). The relation for the predicted qe, h calculated based on predicted qe and second-order rate constant K2 with different dosages and temperature were respectively. The relation between qe, h, and K2 with a higher correlation coefficient confirms that all these parameters depend on the initial solute concentration  Linear regression of second-order kinetics-Rhodamine dye-Chitosan-Jackfruit nanocomposite: The Pseudo 2 nd order equation may be written in four linearized types, the pseudo-2 nd order constants qe and K2 values can be calculated utilizing plotting among Type 1: t/q versus t, Type 2: 1/q as opposed 1/(qe-qt) vs t as opposed to t, Pseudo 2nd order isotherm, respectively as shown in Figure. 10 -21.
Similarly, the pseudo-first-order isotherm constants K1 can be calculated from the plot of log (qe-q) as opposed to t, and the R 2 value is used to locate the first-rate becoming isotherm. The linear approach does no longer checks whether the experimental information is linear Low and Lee, (1997); Lin and Lin (1993). It assumes the experimental facts were linear and predicts the slope and intercept that makes an instant line that predicts the first-class-fit of experimental equilibrium statistics Ho and McKay (2000); Ho et al., (2005); Hasnain Isa M et al., (2007).
The linear method assumes that the scatter of points around the road follows a Gaussian distribution and the mistake distribution is equal at every price of X.
The linear technique simply predicts the Y for the corresponding X.
It considers best the mistake distribution along the Y-axis irrespective of the corresponding Xaxis ensuing within the extraordinarily determined parameters. Pseudo-second-order model and there are good-fit straight lines for all of the experimental data at different dosages (1.0, 2.0, and 3.0g/L), pH (5.8, 6.8 and 9.4), and 20 0 C. 45 0 C and 60 0 C.
It means that the pseudo-secondorder equation (Type 4-7) can well predict the rate behavior of the Rhodamine dye onto Chitosan-Jackfruit Nanocomposite over the whole range, which strongly supports the validity of chemisorption probably involves in the adsorption of Rhodamine dye onto Chitosan-Jackfruit nanocomposite.
Conclusions: The removal of Rhodamine dye from aqueous solution using Chitosan-Jackfruit nanocomposite has been investigated under experimental conditions in batch mode. The adsorption of Rhodamine dye was found to be dependent on the adsorbent surface characteristics, adsorbent dosages and Temperature, pH, and initial dye concentration. Kinetics for the removal of Rhodamine dye were obtained and fitted to different kinetics model.