Utilization of Sludge from Sidoarjo Mudflow for Zeolite Synthesis

Abstract

Sidoarjo mudflow occurred in 2006 has been causing major environmental problems in a wide area surrounding the region. The utilization of the sludge from this mudflow as useful materials is a potential solution to this problem. In this study, we proposed a hydrothermal treatment method to convert the silica-rich sludge into zeolites useful as adsorbent for inorganic pollutants such as heavy metals. Prior to the hydrothermal treatment, the sludge was contacted with NaOH solution in a teflon vessel. During the hydrothermal treatment, the mixture was subjected to increasing temperature for a certain period of time. After hydrothermal treatment, the solid phase was filtered, washed thoroughly until neutral pH and dried. In this study, we evaluated the effect of NaOH concentration and hydrothermal treatment temperature on the type of zeolite formed. The surface morphology and composition of prepared zeolite was characterized by SEM-EDS while the type of zeolite was determined by XRD analysis. Preliminary study of the adsorption ability of the zeolites towards metal ions was carried out by CEC measurement using sodium acetate method.