Response surface optimization of Rhodamine B dye removal using paper industry waste as adsorbent

Int J Ind Chem DOI 10.1007/s40090-017-0113-4 RESEARCH Response surface optimization of Rhodamine B dye removal using paper industry waste as adsorbent Anita Thakur1 • Harpreet Kaur1 Received: 10 December 2015 / Accepted: 13 February 2017 Ó The Author(s) 2017. This article is published with open access at Springerlink.com Abstract The present investigation describes the conversion of waste product into effective adsorbent and its application for the treatment of wastewater, i.e., chemically modified solid waste from paper industry has been tested for its adsorption ability for the successful removal of Rhodamine B dye from its aqueous solution. The adsorption isotherm, kinetics and thermodynamic parameters of process have been determined by monitoring the different parameters, such as effect of pH, amount of adsorbent dose, concentration, contact time and temperature. The equilibrium data has been well described on the basis of various adsorption isotherms, namely Langmuir, Freundlich and Temkin adsorption isotherm. From Langmuir isotherm, the maximum monolayer adsorption capacity has been found to be 6.711 mg g-1 at 308 K temperature. The kinetics of adsorption has been studied using pseudo-first order, pseudo-second order and intra-particle diffusion model and the results show that kinetics has been well described by pseudo-second order. Thermodynamic parameters, such as free energy change (DG), enthalpy change (DH) and entropy change (DS), have been evaluated. The free energy has been obtained as -11.9452 kJ mol-1 for 75 mg L-1 concentration at 308 K temperature. Desorption and recycling efficiency of adsorbent has been studied and the adsorbent shows good recycling efficiency. Keywords Paper industry waste  Rhodamine B  Adsorption  Kinetics  Isotherms Abbreviations CMSW Chemically modified solid waste BET Brunauer–Emmett–Teller SEM Scanning electron microscope FTIR Fourier transformation infrared spectroscopy EDAX Energy dispersive X-ray spectroscopy List of symbols qe Adsorption capacity C0 Initial equilibrium concentration Ce Final equilibrium concentration V Volume of the solution W Weight of adsorbent qm Maximum adsorption capacity bL Energy of adsorption RL Dimensionless constant Kf Freundlich constant 1/n Heterogeneity factor R2 Regression coefficient B Intensity of adsorption KT Constant related to adsorption capacity K2 Pseudo-second order coefficient t Time Kipd Intra-particle diffusion rate constant DS Entropy change DH Enthalpy change DG Free energy change Introduction & Harpreet Kaur 1 Department of Chemistry, Punjabi University, Patiala 147002, India India ranks third among the leading textile-producing countries in the world behind China and European nations, and more than 95 million peoples got engaged in textile and related sectors in India [1]. But despites of 123 Int J Ind Chem significance, the textile industries are the main source of pollution due to discharge of hazardous effluent containing colours and organic chemicals used for bleaching, dyeing, printing and other finishing processes [2]. Globally, about 10–15% of total dyestuff (equivalent to 280,000 tonnes) is released annually into the environment during the manufacturing of textile products, which leads to the contamination of water reservoirs, and thereby affects human and animal health [3, 4]. One of the most commonly used dyes in industries is Rhodamine B dye. Rhodamine B is synthetically prepared xanthene cationic dye and widely used for paper printing and as a colourant in textile and food stuff [5]. It is harmful to both human beings and animals, because if this dye is swallowed it can cause irritation to skin, eyes and respiratory track [6]. It has been medically proven that drinking water contaminated with Rhodamine B dye is highly carcinogenic, neurotoxin and chronic [7, 8]. Thus, the wastewater contaminated with Rhodamine B dye must be treated carefully before discharged into water streams [9]. A number of conventional physical, chemical and biological methods, such as ion-exchange [10], coagulation/flocculation [11], reverse osmosis [12], membrane filtration [13], electrochemical oxidation [14], electrochemical degradation [15], photodegradation [16], and heterocatalytic Fenton oxidation [17], have been used for the removal of dyes. The serious drawbacks of these methods are low efficiency, disposal of waste, low sensitivity, etc. [18, 19]. Among all these, adsorption has been found to be very simple and innovative method for treating dye wastewater even at very low concentration of dyes [20]. In adsorption process, adsorbate adhered on the surface of adsorbent by physical, chemical or electrostatic forces [21]. Activated carbon has been the most widely used adsorbent for the wastewater treatment due to its high surface area and high adsorption capacity [22]. Though the removal of dyes through activated carbon is very effective, but sometimes its use is restricted due to its high cost and difficulties associated with regeneration [23]. The removal of hazardous dyes through adsorption technique using industrial waste materials, such as blast furnace dust, sludge, slag from steel plant and carbon slurry from fertilizer plant [24], chitosan [25], bottom ash [26], and agriculture wastes, such as date palm [27], coconut tree flowers [28] have been already reported. The paper industries produce a large amount of sludge every year, which can be used as an adsorbent for the removal of dyes. Thus, this study aimed to investigate the potential use of CMSW for the removal of hazardous dye Rhodamine B. 123 Experimental Materials and methods Preparation of dye solution Rhodamine is a basic dye having IUPAC name [9-(2-carboxyphenyl)-6-diethylamino-3-xanthenylidene]-diethylammonium chloride has been purchased from S.D. Fine chemicals, Mumbai, India. Stock solution of dye (500 mg L-1) has been prepared by dissolving 0.5 g of dye in 1000 mL of deionised water. Another solution of desired concentration has been prepared by successive dilutions of the stock solution. Concentration of the dye after adsorption has been determined using Shimadzu—1800 UV Visible Spectrophotometer at 553 nm wavelength. Preparation of adsorbent The waste material (sludge) from paper industry has been used as an adsorbent for the removal of dye. The sludge has been washed with deionised water and dried (under sunlight) and then kept in the oven at 100 °C for 3 days. The dried material has been grounded into fine powder. The finely powdered sludge has been mixed with sulphuric acid and kept overnight and then washed with deionised water to remove residue acid. The material has been dried at 100 °C for 24 h and then grounded, sieved and kept in air tight container for further uses. Adsorption studies Batch adsorption studies of removal of Rhodamine B dye onto CMSW has been carried out as a function of initial dye concentration, contact time, adsorbent dose and pH. All the adsorption experiments have b (...truncated)