No abstract

The transformation of kaolin to amorphous mesoporous aluminosilicate was investigated in this study. We demonstrated the use of koalin as silica and alumina sources without prior pretreatment. Two steps synthesis method were carried out; hydrothermal reaction at 80°C, followed by addition of mesoporogen cetyltrimethylammonium bromide (CTABr) surfactant. We observed that prolonging the synthesis period improves the surface area of the aluminosilicate with enhances mesopore volume and surface acidity.

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

Abstract. This study aimed to determine the total of anthocyanin content in ethanol extract from super red dragon fruit rind. The extraction was affected by temperature and light conditions. The determination of anthocyanin's total content was performed with a variation of pH and analyzed by UV-Visible spectrophotometer. The results showed that the average contained total anthocyanins obtained at room temperature, 40 and 60 ºC were 4.6757, 5.6108, 21

The CaOZnO nanoparticle catalysts with Ca to Zn atomic ratios of 0.08 and 0.25 have been successfully synthesized by co-precipitation method. The catalyst was characterized by X-ray Diffraction (XRD) analysis provided with Rietica and Maud software, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared spectroscopy (FT-IR), and its properties was compared with bare CaO and ZnO catalysts. The phase composition estimated by Rietica software revealed that the CaO catalyst consists of CaO and CaCO3 phases. The estimation of the particle size by Maud software, showed that the particle size of all catalysts increased by the following order: ZnO