Modification of Diatomite Mineral Sorbent for the Cleanup of Petroleum Spills on Water Surfaces

Abstract

The study investigates the structural, thermal, and adsorption properties of natural diatomite and its modified forms (thermally and acid-treated) for oil spill remediation. X-ray diffraction analysis revealed amorphous silica alongside crystalline phases. Thermogravimetric analysis showed mass losses at 80–300 °C (removal of adsorbed water) and 430–700 °C (dehydroxylation), with an 8.63% total mass loss. Acid treatment with 0.5N H2SO4 significantly altered the chemical composition, increasing the SiO2 content to 88.8% while dissolving CaO, Na2O, and MnO2. Infrared spectroscopy confirmed the removal of hydroxyl groups and structural changes following treatment. Nitrogen adsorption analysis revealed enhanced porosity in the acid-modified diatomite (D-H2SO4-400), showing a BET surface area of 80.0 m2/g and a uniform pore size distribution of 19.0 nm. Scanning electron microscopy revealed preserved skeletal structures with improved porosity. Oil sorption tests showed that D-H2SO4-400 exhibited the highest adsorption capacity (optimal at 4 g, 30 µm particle size), achieving maximum uptake within 2 minutes. Overall, these findings confirm that thermal and acid treatments enhance the sorption efficiency of diatomite, making it a promising low-cost and environmentally friendly material for oil spill remediation.