title: Preparation and characterization of poly(ethyl hydrazide)-grafted oil palm empty fruit bunch fibre for the removal of Cu(II) ions from an aqueous environment.
abstract: Poly(ethyl hydrazide)-grafted oil palm empty fruit bunch fibre (peh-g-opefb) was successfully prepared by heating poly(methyl acrylate)-grafted opefb (pma-g-opefb) at 60 °C for 4 h with a solution of hydrazine hydrate (15% v/v) in ethanol. The Fourier transform infrared spectrum of the product shows a secondary amine peak at 3267 cm⁻¹, with amide carbonyl peaks at 1729 cm⁻¹ and 1643 cm⁻¹. The chelating ability of peh-g-opefb was tested with copper ion in aqueous solution. A batch adsorption study revealed that maximum adsorption of copper ion was achieved at pH 5. An isotherm study showed the adsorption follows a Langmuir model, with a maximum adsorption capacity of 43.48 mg g-1 at 25 °C. A kinetic study showed that the adsorption of copper ion rapidly reaches equilibrium and follows a pseudo-second-order kinetic model, with a constant rate of 7.02 × 10⁻⁴ g mg⁻¹ min⁻¹ at 25 °C. The Gibbs free energy, ∆G⁰, value is negative, indicating a spontaneous sorption process. Entropy, ∆S⁰, gives a positive value, indicating that the system is becoming increasingly disordered after the adsorption of copper ion. A positive enthalpy value, ∆H⁰, shows that the endothermic process takes place during the adsorption and is more favourable at high temperatures.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
authors.forename: Ili Syazana
authors.initials: IS
authors.lastname: Johari
authors.forename: Nor Azah
authors.initials: NA
authors.lastname: Yusof
authors.forename: Md Jelas
authors.initials: MJ
authors.lastname: Haron
authors.forename: Siti Mariam Mohd
authors.initials: SM
authors.lastname: Nor
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D007477:Ions / Q000737:chemistry*; D007700:Kinetics; D008962:Models, Theoretical; D000073878:Palm Oil; D010938:Plant Oils / Q000737:chemistry; D012996:Solutions; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D007477:Ions; D010938:Plant Oils; D012996:Solutions; D014867:Water; D000073878:Palm Oil; D003300:Copper