Equilibrium, Kinetics and Mechanism of Removal of Methylene Blue from Aqueous Solution by Adsorption onto Pine Cone Biomass of Pinus radiata

Abstract

The kinetics and mechanism of methylene blue adsorption onto raw pine cone biomass (Pinus radiata) was investigated under various physicochemical parameters. The extent of the methylene blue dye adsorption increased with increases in initial dye concentration, contact time and solution pH but decreases with the amount of adsorbent, salt concentration and temperature of the system. Overall the kinetic studies showed that the methylene blue adsorption process followed pseudo-second-order kinetics among various kinetic models tested. The different kinetic parameters including rate constant, half-adsorption time and diffusion coefficient are determined at different physicochemical conditions. Equilibrium data were best represented by Langmuir isotherm among Langmuir and Freundlich adsorption isotherm. The maximum monolayer adsorption capacity of pine cone biomass was 109.89 mg/g at 30°C. The value of separation factor, R L , from Langmuir equation and Freundlich constant, n, both give an indication of favourable adsorption. Thermodynamic parameters such as standard Gibbs free energy (ΔG 0 ), standard enthalpy (ΔH 0 ), standard entropy (ΔS 0 ) and the activation energy (A) were calculated. A single-stage batch absorber design for the methylene blue adsorption onto pine cone biomass has been presented based on the Langmuir isotherm model equation. Nomenclature AActivation energy of adsorption (kJ/mol) C f Final metal ion concentration, ppm (mg/l) C 0 Initial metal ion concentration, ppm (mg/l) C t Metal ion concentration at time t, ppm (mg/l) D Diffusion coefficient (cm 2 /s) ΔG 0 Gibbs free energy change (kJ/mole) ΔH 0 Enthalpy change (kJ/mole) ΔS 0 Entropy change (J/k mole) k 1 Pseudo-first-order rate constant (min −1 ) k 2 Pseudo-second-order rate constant (mg/g min) K f Freundlich adsorption constant (mg/g) K idIntra-particle rate constant [(mg/g) min 0.5 ] MMass of adsorbent per unit volume (g l −1 ) m Amount of adsorbent added (g) n Freundlich constant q Amount of adsorbate per gram of adsorbent (mg/g) q e Amount of adsorbate per gram of adsorbent at equilibrium, (mg/g) q tAmount of adsorbate per gram of adsorbent at any time, t q m Equilibrium adsorption capacity using model q max Maximum adsorption capacity (mg/g) R 2Linear correlation coefficient Water Air Soil Pollut (2011) 218:499-515

Review on Dye Removal from Its Aqueous Solution into Alternative Cost Effective and Non-Conventional Adsorbents

“…[20]. Adsorption process is a very effective separation technique and it is considered to be superior compared to other available techniques for wastewater treatment in terms of initial cost, simplicity of design, ease of operation and insensitive to toxic substances [4,21]. The efficiency of adsorption process depends on the physical and chemical properties of the adsorbents and adsorbate.…”

“…All of these methods have their own advantages and disadvantages. However, adsorption process is considered to be a very effective physical separation technique in wastewater treatment in terms of simplicity of design, ease of operation and insensitivity to toxic substances provided adsorbents are locally available with little or no value [4][5][6][7]. The current research seeks various cost effective sustainable alternative to commercial activated carbon adsorbents therefore, research has been grown into this direction since last decades.…”

Adsorption Kinetics of Malachite Green and Methylene Blue from Aqueous Solutions Using Surfactant-modified Organoclays

“…4,5 It has been estimated that annually 7 × 10 5 metric ton of different commercial dyes and pigments are being produced globally, and of which 5-10% are being lost and discharged into the wastewater in the form of industrial effluents. 6,7 Among them azo dyes are the one most widely used and accounts 65-70% of the total dyes produced. 8 A great deal of dyes exists and exhibit structural variations and can be classified in several ways.…”

“…12 Beside their greater use, they have now turned into an exceedingly questionable compounds because of the risks it (MG) postures to the consumers of treated fish including its effects on the immune and reproductive system, 13,14 similarly, intense exposure to MB can bring about numerous health risks such as fast pulse, skin disease, jaundice, and tetraplegia and tissue necrosis. 6 In response to concerns regarding the health risks associated with the utilization of dyes, adsorption is prob-Ullah et al: Adsorption Kinetics of Malachite Green ... ably the most adaptable and versatile approach for the expulsion of dyes from aqueous solutions. 15 Sometimes, it is conceivable to recoup the adsorbed dye through desorption and also to reuse the huge amount of water utilized by textile sector.…”

Adsorption of methylene blue from aqueous solution using untreated and treated (Metroxylon spp.) waste adsorbent: equilibrium and kinetics studies

“…Various physical, chemical and biological methods, including adsorption, biosorption coagulation and flocculation, advanced oxidation, ozonation, membrane filtration and liquid-liquid extraction, have been widely used for the treatment of dye-bearing wastewater [2,[6][7][8]. Adsorption is a very effective separation technique and is considered to be superior to other techniques for water treatment in terms of initial cost, simplicity of design, ease of operation and resilience to toxic substances [9,10]. Although adsorption technologies are well established, a significant limitation is the cost of adsorbent materials.…”