Corncob, an agricultural bio-waste, was used as adsorbent to remove organic and inorganic contaminants in waste lubricating oil (WLO) from diesel engine. To improve its adsorption capacity, corncob was modified with mixed solution of nitric acid, Hexadecyl trimethyl ammonium bromide and ethanol. Characterization results showed the crystallinity index of corncob enhanced 12%, which would be ascribed to the disruption of the dense lignin-carbohydrates structure in lignocellulose biomass by modification. The surface of modified corncob became smoother and porous. The adsorption results showed modified corncob had better removal rates to contaminants than raw corncob. For WLO with 80,000 km mileage, the removal rates to Fe, Al, Cu were enhanced from 19%, 6.4%, 48–27%, 27%, 53%, while that for oxide, sulphate, aromates, soot and insoluble resins were enhanced 1.7, 1.2, 3.0, 1.7 and 1.7 times. The reduction rate of total acid number to WLO with 40,000, 60,000, 80,000 km were enhanced 16%, 9%, 12% by modified corncob, respectively. The optimal adsorption condition was explored as adsorbing 60 min at 90 °C with 2% adsorbent. Corncob, with the advantages of low cost, good biodegradability and high adsorption capacity, could be used as alternative to conventional adsorbent for WLO.

玉米芯，一种农业生物废料，被用作吸附剂，以去除柴油机废润滑油（WLO）中的有机和无机污染物。为了提高其吸附能力，玉米芯用硝酸，十六烷基三甲基溴化铵和乙醇的混合溶液进行了改性。表征结果表明，玉米芯的结晶度指数提高了12％，这归因于改性对木质纤维素生物质中致密木质素-碳水化合物结构的破坏。改性玉米芯的表面变得更光滑和多孔。吸附结果表明，改性玉米芯比原始玉米芯对污染物的去除率更高。对于里程数为80,000 km的WLO，铁，铝，铜的去除率分别从19％，6.4％，48-27％，27％，53％提高，而氧化物，硫酸盐，芳香剂的去除率则提高了。烟灰和不溶性树脂分别提高了1.7、1.2、3.0、1.7和1.7倍。改性玉米芯分别使40,000、60,000、80,000 km的总酸值对WLO的降低率分别提高了16％，9％和12％。探索了最佳的吸附条件，即在90°C下用2％的吸附剂吸附60分钟。玉米芯具有低成本，良好的生物降解性和高吸附能力的优点，可以替代传统的WLO吸附剂。