Potential Low-Cost Biosorbent for Copper Removal: Pineapple Leaf Powder

The present study investigates the adsorption characteristics of Cu(II) onto a low-cost biosorbent, pineapple leaf powder (PLP). Results of batch adsorption experiments showed that PLP could effectively remove Cu(II) from aqueous solution. Functional groups of PLP responsible for binding the Cu2+ were identified. The uptake of Cu2+ by PLP was very rapid, and 90% of Cu could be removed within the first 20 min. A pseudo-second-order equation could describe the kinetic data well. Copper adsorption was highly dependent on solution pH, and the removal efficiency was greater at a higher pH and low ionic strength. The apparent activation energy was calculated to be 6.99 kJ mol(-1). The adsorption increased with temperature, suggesting an endothermic reaction. The maximum adsorption capacities calculated from Langmuir isotherms was 9.28 mg g(-1) at pH 5.0. From the perspective of waste utilization, high copper adsorption capacity, and freely abundant availability of this low-cost adsorbent, PLP is potentially useful for future practical applications. DOI: 10.1061/(ASCE)EE.1943-7870.0000424. (C) 2012 American Society of Civil Engineers.