Studi Ekstraksi Pelarut Emas (III) dalam Larutan Konsentrat Tembaga PT Freeport dengan 8-metylxantin

Solvent extraction of Au (III) in Cu-concentrate solution at PT Freeport Indonesia by using 8-Methylxanthine had been carried out. Three steps of research consisted of Synthesis of 8-Methylxanthine as an extractant, Selectivity and Ability Test of gold extraction, and its application for the sample of Cu-concentrate. The result of synthesis showed that the extractant 8-Methylxanthine was a yellowish white crystal with m.p. 366 – 368 0C. The selectivity of Au (III) extraction on to Cu as well as Fe metal ions was very high. The extractant 8-Methylxanthine was able to isolate Au(III) in the Cu-concentrate and the structure of compound obtained was predicted to be two nuclei complex compound

Kinetika Adsorpsi Ion Emas(iii) Oleh Hibrida Merkapto Silika

: Adsorption kinetics study has been done of gold(III) ions by mercapto silica hybrid (MSH) adsorben. MSH was synthesized by sol-gel process with sodium silicate (Na2SiO3) from rice husk ash as a precursor. MSH made by adding hydrochloric acid to 3-(trimetoksilil)-1-propantiol (TMSP) compounds and Na2SiO3 solution. Adsorption kinetics are determined by adsorption static system (batch) with variation of time. The amount of the adsorbed gold ions is quantified by the difference in metal concentration before and after adsorption analyzed by atomic absorption spectroscopy (AAS). The data showed, MSH interaction with gold ion tends to follow the pattern of reaction kinetics pseudo-second-order with rate constant (k) =1x10-2 g mg-1min-1. Based on the value of the standard Gibbs free energy for adsorption (-ΔG°= 34,63-37,99 kJ/mol) showed that the adsorption takes place chemically (chemisorption)

Aplikasi Limbah Kulit Buah Kakao Sebagai Media Fermentasi Asam Laktat Untuk Bahan Baku Bioplastik

Penelitian ini bertujuan untuk mempelajari kondisi optimum proses delignifikasi, hidrolisis asam dan enzimatis kulit buah kakao serta pemanfaatannya sebagai media fermentasi asam laktat. Karakterisasi kulit buah kakao dilakukan dengan metode X-Ray Diffraction (XRD), Spektrometri Infra Red(IR) dan Scanning Electron Microscopy(SEM). Konsentrasi glukosa ditentukan secara kuantitatif dengan metode UV-Sulfat, sedangkan total asam laktat dengan metode titrasi asam basa. Hasil penelitian menunjukkan bahwa konsentrasi optimum NaOH pada delignifikasi kulit buah kakao adalah 6%, sedangkan kondisi optimum hidrolisis asam adalah konsentrasi H2SO4 2,0%, suhu 120°C dan waktu 30 menit. Hasil karakterisasi menunjukkan bahwa proses ini hanya dapat menghidrolisis hemiselulosa dan selulosa amorf. Glukosa hasil hidrolisis asam dapat digunakan sebagai media fermentasi dan menghasilkan asam laktat sebesar 13,27 g/L