Adsorption, a widely used separation technique, is essential for several industrial operations, environmental remediation, and resource recovery. Bioadsorbents are one of the most popular methods in this process since they are obtained from natural resources such as agricultural waste and biomass, providing a renewable alternative to traditional adsorbents. These materials have distinctive characteristics such as high surface areas, diverse functional groups, and biodegradability. Sugarcane, a versatile and abundant agricultural resource, has emerged as a promising adsorbent for wastewater treatment. The thermal and chemical treatment on sugarcane bagasse modified some of its functional groups to increase its oil adsorption capacity, making it very useful for treating petroleum hydrocarbon-contaminated wastewater. This study investigated how sorbent dosage, contact time, particle size, and pH level affected diesel sorption capacity. It was discovered that a dosage of 0.012270 g/g, a contact time of 15 min, a pH level of 6, and a size passing through a 1 mm sieve produced the highest sorption capacity in their respective categories. The two-way ANOVA showed significant effects of contact time, size, and pH on diesel sorption capacity (p = 0.00251, 0.03289, and 0.03959 < 0.05). Furthermore, the significant interaction between the parameters showed that the effect of contact time is proportional to the effect of size.