title: Biosorption of Cd(II) on jatropha fruit coat and seed coat.
abstract: Jatropha (Jatropha curcas L.) seed coat (JSC) and fruit coat (JFC) were investigated for adsorption of Cd(II) from aqueous solutions. JFC and JSC fine powders were characterized using FTIR and SEM which indicated that both the adsorbents have high surface area, pore space on their surface, and anionic sites for metal ion binding. Batch adsorption study was conducted to study the effect of adsorption time, agitation speed, and initial concentration of Cd(II) ion, pH, and temperature on the adsorption of Cd(II) by adsorbents. The equilibrium isotherm, kinetics, and thermodynamics of the adsorption process were studied. Adsorption equilibrium followed both Langmuir and Freundlich isotherm. The adsorption capacity (Q m ) of Cd(II) on JSC and JFC were 22.83 and 21.97 mg g(-1), respectively. The adsorption of Cd(II) on JSC and JFC is endothermic in nature. The change of free energy (∆G) of the biosorption of Cd(II) on JSC ranged from -37.05 to -40.54 kJ mol(-1) and for JFC -34.50 to -37.35 kJ mol(-1). The enthalpy change (∆H) and entropy change (∆S) was 15.84 kJ mol(-1) and -0.17 kJ mol(-1) K(-1) for JSC and 8.77 kJ mol(-1) and -0.14 kJ mol(-1) K(-1) for JFC. Elovich model provided a better correlation of the experimental data in comparison with pseudo-first-order and pseudo-second-order kinetic models. The study indicated that JFC and JSC have good adsorption capacity for Cd(II).
authors.affiliation: Centre for Environment Science and Climate Resilient Agriculture, Indian Agricultural Research Institute, New Delhi, 110 012, India, nivetajain@gmail.com.
authors.forename: Niveta
authors.initials: N
authors.lastname: Jain
authors.forename: Thomas Anish
authors.initials: TA
authors.lastname: Johnson
authors.forename: Thoma Anish
authors.initials: TA
authors.lastname: Johnson
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.forename: ShahiVind
authors.initials: S
authors.lastname: Mishra
authors.forename: Navindu
authors.initials: N
authors.lastname: Gupta
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D031286:Jatropha; D007700:Kinetics; D028321:Plant Preparations / Q000737:chemistry; D016062:Porosity; D011208:Powders; D012639:Seeds / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D028321:Plant Preparations; D011208:Powders; D014874:Water Pollutants, Chemical; D002104:Cadmium