Utilization of corncob as adsorbent to remove oil and grease from produced water

The hazardous composition of produced water (PW) places it as a dangerous contamination agent, which must be treated to meet environmental and operational requirements before disposal, reuse, or reinjection. The current work evaluated an adsorption treatment using raw and pretreated corncob samples to remove total oil and grease (TOG) from PW. The influence of adsorbent dosage (1.0, 2.5, and 5.0 g), particle size (0.5, 1.0, and 2.0 mm), and contact time (60, 120, and 240 min) were tested in a batch system, showing that the lowest oil concentration was achieved with the smallest particle size (0.5 mm) and highest contact time (240 min) and adsorbent dosage (5.0 g). Using a 20 cm secondary partition in the fixed-bed column system was more efficient for TOG removal than a 10 cm one: the raw corncob removed 85.23% of TOG against 17.41% pretreated biomass. Comparative studies showed that the adsorption performance of untreated corncob was superior to that observed for walnut shells (69%), a widely used commercial absorbent. Results indicated corncob's environmental and economic potential as a natural and cost-effective adsorbent.