Kinetic study of Cr(VI) Adsorption on Hydrotalcite Mg/Al with Molar Ratio 2:1

Abstract

Chromium(VI) is one of the metals that is harmful to biota and humans if large amount present in environments. One method for reducing metal contamination of Cr(VI) inaqueous is by adsorption using Mg/Al hydrotalcite with molar ratio 2:1. This study is determined the effect of contact time and adsorption models of Cr(VI) adsorption on Mg/Al hydrotalcite with molar ratio 2:1. Capacity of Cr(VI) adsorption on Mg/Al hydrotalciteoccursat the optimum contact time of 180 minutes with 93.81% percent adsorption. Adsorption kinetics model equations are analyzed with first order, second order, pseudo first order, pseudo second order, Elovich equation, the equation Dumwald-Wagner and Weber-Morris equation. Analysis model of adsorption kinetics of Cr(VI) followed pseudo second order models are characterized by the highest coefficient of determination, which is 0.998. Keywords: adsorption, Mg/Al hydrotalcite, Cr(VI), adsorption kinetic models ABSTRAKLogam Cr(VI) merupakan salah satu logam yang berbahaya bagi biota dan manusia jika paparannya besar di lingkungan. Salah satu metode untuk mengurangi cemaran logam Cr(VI) di perairan adalah dengan cara adsorpsi menggunakan hidrotalsit Mg/Al dengan ratio molar 2:1. Penelitian ini bertujuan mengetahui pengaruh waktu kontak dan model adsorpsi terhadap daya adsorpsi hidrotalsit Mg/Al dengan ratio molar 2:1 terhadap Cr(VI). Daya adsorpsi hidrotalsit Mg/Al terhadap Cr(VI) terjadi optimum pada waktu kontak 180 menit dengan persen adsorpsi 93,81%. Model kinetika adsorpsi dianalisis dengan persamaan orde satu, orde dua, pseudo orde satu, pseudo orde dua, persamaan Elovich, persamaan Dumwald-Wagner dan persamaan Weber-Morris. Analisis model kinetika adsorpsi Cr(VI) mengikuti model pseudo orde dua yang ditandai dengan koefisien determinasi yang paling tinggi, yaitu 0,998. Kata-kata

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