Needlepunched banana and sisal fiber nonwovens: Design, response surface methodology optimization and performance as biodegradable marine oil sorbents

Marine oil spills pose a persistent treat to aquatic ecosystem and coastal livelihoods, yet commercially dominant synthetic sorbents such as polypropylene are non-biodegradable and generate secondary pollution after use. This study reports the fabrication and performance optimization of fully biodegradable needlepunched nonwoven mats manufactured from banana and sisal fibers as low-cost, sustainable sorbents for diesel-oil removal. Single-fiber webs were produced by carding and parallel-lay formation, then mechanically consolidated by needlepunching to yield cohesive mats with well-defined structural parameters: areal densities of 198.8 g/m ² (sisal) and 183.5 g/m ² (banana) and thickness of 2.7 and 2.38 mm respectively. Diesel-oil sorption was evaluated under dynamic conditions using an orbital shaker and central composite design with RSM was applied to model and optimize the effect of contact time and agitation speed on uptake capacity. Both materials exhibited statistically robust, reproducible behavior (ANOVA: p < 0.0001; R ² > 0.96). RSM optimization identified maximum predicted diesel uptake of 16.34% for banana mats (10 min, 100 rpm) and 13.59% for sisal mats (5 mi, 100 rpm). The higher uptake of banana mats is attributed to their finer fiber diameter (6.2 tex vs. 7.697 tex) and greater capillary driving force, whereas sisal mats achieved peak sorption at shorter contact times, reflecting their more open pore architecture. These findings demonstrate that agro-waste-derived banana and sisal mats are technically feasible, cost-effective alternatives to synthetic sorbents.