The Modification of Silica Surfaceseparated from Overflowing Mud in Lapindo Indonesia as Cation Exchange Adsorbent

Abstract

          The mud overflowing in Lapindo Indonesia was a major disaster for lots of people. In fact, the mud contains silica that is very potential as adsorbents. This research studied the preparation of cation exchange adsorbent from the Lapindo mud-separated silica and the measurement of cation exchange capacity of the adsorbent. The preparation was done by reacting the silica with 3-(Trimethoxysilyl)-1-propanethiol, and the result was oxidized to produce silica whose surface was saturated by sulfonate functional groups. Each step of the preparation was accomplished by spectroscopic analysis of FTIR, and some of them were completed by XRD and SEM-EDX. The cation exchange capacity of the adsorbent was determined by titration, in which the adsorbent was saturated by Na+ ions, and the H + ions released were then titrated by OH ¯ ions. This research succeeded to prepare well cation exchange adsorbent. The cation exchange capacity of the mud, of gel silica, of 3-(Trimethoxysilyl)-1-propanethiol-saturated silica, and of sulfonate-saturated silica were 0, 0.32, 0.84, and 4.15 meq/gram of sorbent, respectively. It can be concluded that the preparation of sulfonate-saturated silica can increase significantly the cation exchange capacity, became 13 times larger than that of silica.