Modified Sidoarjo Volcanic Mud as Adsorbent for The Decolourisation of Textile Wastewater

The Sidoarjo mudflow disaster has persisted for 19 years in Gempol Sari Village, Sidoarjo, East Java, Indonesia. It has resulted in mudflows that have engulfed thousands of hectares of land and affected dozens of villages. Therefore, it is important to explore the positive aspects of this mud disaster, particularly the potential for utilizing the mud. This study investigates the activation of Sidoarjo volcanic mud using sulfuric acid and its application as an adsorbent for decolorizing wastewater from small-scale Batik textile production. The research examines the effects of various operational parameters such as contact time, dosage, pH, and dye concentration. The adsorption process is conducted in a batch system utilizing an orbital shaker. Characterization of the modified Sidoarjo volcanic mud as an adsorbent is performed using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and Fourier Transform Infrared Spectroscopy (FTIR). Meanwhile, dye concentration is measured spectrophotometrically. Elemental analysis through EDX indicates that acid modification removes certain elements such as chlorine (Cl), potassium (K), calcium (Ca), and titanium (Ti), while increasing the surface area of Sidoarjo volcanic mud from 25.405 m2/m3 to 69.734 m2/m3. The study achieved a decolorization rate of 95% within 120 minutes of adsorption at an initial color concentration of 880 Platinum-Cobalt (Pt-Co), with an adsorbent dosage of 3 g/L and a pH of 3. The reusability tests showed modest removal efficiency, likely due to pore blockages. The reusability assessment highlighted challenges with the adsorbent's long-term performance, especially regarding irreversible dye deposition.