TY - JOUR T1 - Reclamation of Oil-Polluted Soils with Modified Humic Preparations A1 - Ainash Nauanova A1 - Zhanar Kassenova A1 - Maira Kazankapova A1 - Bolat Yermagambet A1 - Nurgul Kazangapova A1 - Ainagul Malgazhdarova A1 - Gulnar Nurgazina JF - World Journal of Environmental Biosciences JO - World J Environ Biosci SN - 2277-8047 Y1 - 2026 VL - 15 IS - 1 DO - 10.51847/ebdOngEMzN SP - 132 EP - 144 N2 - Soil contamination with oil products remains a pressing environmental issue, particularly in regions with extensive oil production. Promising approaches to remediating such soils include the use of humic substances, which bind pollutants and promote microbiological degradation. This study aimed to evaluate the effectiveness of oil-contaminated soil remediation using basic potassium humate and its modified forms at concentrations of 1% and 10% over a 60-day experimental period. Oil-contaminated soil collected at the "Zhetybai" oil field (Mangistau region, Kazakhstan) was used as the study object. The following humate formulations were used in the experiments: humic acid (1% and 10%), basic potassium humate (1% and 10%), potassium humate modified with silicon (Si), calcium (Ca), magnesium (Mg), and a macronutrient complex (NPK) in the same concentrations. A total of 12 test samples and a control without additives were studied. Oil product concentrations were determined on days 5, 10, 20, 30, and 60. Structural changes were assessed using Fourier transform infrared spectroscopy. The highest purification rates by day 60 were demonstrated by basic potassium humate 10% (77.12%), potassium humate + NPK 10% (74.69%), and potassium humate + Si 10% (68.68%). The modified forms were found to enhance both sorption and biological mechanisms of hydrocarbon degradation. IR spectra confirmed the destruction of oil components and the restoration of humus structures. Humic preparations, especially in combination with nutrient and structure-forming components, are an effective means for accelerated bioremediation of oil-contaminated soils. These findings demonstrate strong potential for field-scale application in the remediation of petroleum-contaminated arid soils. UR - https://environmentaljournals.org/article/reclamation-of-oil-polluted-soils-with-modified-humic-preparations-91sl5ujaztfypaq ER -