Determination of optimum conditions for the synthesis of activated carbon from the pineapple peels to be used to remove toxic elements

Usage of biowastes in activated carbon synthesis including pineapple leaves has been published in previous studies. However, optimization of H2SO4 concentration, mixing time and pyrolysis temperature as a chemical activation tool in the synthesis step has not been investigated, up to now. In this study, pineapple peels were transformed into activated carbon thermally in an inert gas media In optimization studies, the active carbons synthesized by treatment with H2SO4 in the ranges of concentration from 25% to 70%, mixing time between 5-15 hours, and temperatures between 500-600 oC were evaluated. The adsorbents obtained were characterized by methods such as conductivity measurement, FTIR, SEM and BET. In the preconcentration step, conditions including pH, stirring time and initial volume were changed for optimization of analytical parameters. The adsorbent synthesized using optimum parameters (modified with 25% sulfuric acid, mixed for 9 hours and obtained at 600 oC) were used for determination of toxic elements in natural waters at the optimized preconcentration pH conditions (pH 3 for Pb and pH 4.5 for Ni) and 45 minutes of stirring time as optimum for both Pb and Ni. In the measurements, the ICP - MS method, in which multiple elements can be determined simultaneously, was used. By applying preconcentration processes under optimum conditions, Pb and Ni concentrations in natural waters were observed in the range of 1.8-8.0 and 0.6-22.0 ppb (ng / mL), respectively. The concentrations found were below the limit values permitted by the World Health Organization for all the elements studied.