The Effects of Contact Time and pH on the Adsorption of Ag(I) Ion in the Solution by Volcanic Ash

AMALIA BUDIASTUTI, Prof. Dr. Endang Tri Wahyuni, M.S.; Dr. Suherman, M.Sc.

2018 | Skripsi | S1 KIMIA

PENGARUH WAKTU KONTAK DAN pH PADA PENYERAPAN ION Ag(I) DALAM LARUTAN DENGAN ABU VULKANIK Amalia Budiastuti 13/344146/PA/15138 INTISARI Sebuah studi tentang penggunaan abu vulkanik sebagai adsorben untuk penghilangan ion Ag(I) telah dilakukan. Abu vulkanik dari letusan gunung berapi dianalisis dengan XRD untuk menentukan komponen mineral. Kemudian, abu vulkanik dicuci dengan larutan HCl 1,2 M untuk menghilangkan oksida logam yang menutupi permukaan abu vulkanik. Langkah selanjutnya adalah proses adsorpsi ion Ag(I) ke abu vulkanik dimana waktu kontak dan pH bervariasi. Kristalinitas dan morfologi permukaan abu vulkanik yang dicuci dan tidak dicuci dianalisis dengan XRD, SEM dan TEM secara bergantian. Jumlah ion Ag(I) dalam larutan ditentukan oleh AAS. Hasil penelitian menunjukkan bahwa abu vulkanik mengandung kristal kuarsa, mullite dan feldspar yang sebagian besar tersusun oleh atom Si dan Al. Perlakuan pencucian abu vulkanik dengan larutan HCl 1.2 M dapat meningkatkan kemampuan abu vulkanik dalam proses adsorpsi terhadap ion Ag(I) dalam larutan. Adsorpsi ion Ag(I) ke abu vulkanik dipengaruhi oleh waktu kontak. Waktu optimum ditemukan pada menit ke 60 dan adsorpsi sesuai dengan model kinetika orde dua semu dengan kapasitas adsorpsi sebanyak 37.45 mg g-1. Interaksi antara ion Ag(I) dan abu vulkanik dipengaruhi oleh pH dan pH optimum ditemukan pada pH 7 dengan jumlah ion Ag(I) yang teradsorbsi oleh abu vulkanik sebanyak 27.70 mg g-1.

THE EFFECTS OF CONTACT TIME AND pH ON THE ADSORPTION OF Ag(I) ION IN THE SOLUTION BY VOLCANIC ASH Amalia Budiastuti 13/344146/PA/15138 ABSTRACT A study on the use of volcanic ash as an adsorbent for Ag(I) ion removal has been conducted. Volcanic ash from volcanic eruptions was analyzed by using XRD to determine the mineral component. Then, the volcanic ash was washed with 1.2 M HCl solution to remove the metal oxides that covering the surface of volcanic ash. The next step was adsorption process of Ag(I) ion onto volcanic ash in which the contact time and pH were varied. The crystallinities and the surface morphology of the washed and unwashed volcanic ash were analyzed by using XRD, SEM and TEM, respectively. The amount of Ag(I) ion in the solution was determined by AAS. The research result showed that the volcanic ash contained of quartz, mullite and feldspar crystals that give high content of Si and Al in volcanic ash. The washing treatment of the volcanic ash with 1.2 M HCl solution can increase the ability of the volcanic ash in the adsorption of Ag(I) ion in the solution. The adsorption of Ag(I) ion onto volcanic ash was effected by contact time. The optimum time was found at 60 min and the adsorption fits to the kinetic model of pseudo-second order reaction with adsorption capacity as much as 37.45 mg g-1. The interaction between Ag(I) ion and volcanic ash was effected by pH solution and the optimum pH was observed at pH 7 with the amount of the adsorbed Ag(I) ion by volcanic ash as much as 27.70 mg g-1.

Kata Kunci : Silver properties, low-cost adsorbent, removal methods, activation process