WATER HYACINTH

The escalating ecological threats posed by invasive aquatic plants and the pressing need for sustainable bioenergy sources have driven the investigation of viable lignocellulosic feedstocks. This research centers on the thermochemical pretreatment of water hyacinth (Eichhornia crassipes) to improve biodegradability and biogas production. Water hyacinth, recognized for its high lignin content that prolongs microbial digestion periods (30–60 days), was treated with sodium hydroxide (NaOH) under varying conditions of temperature, dosage and reaction. Response Surface Methodology (RSM) via Design-Expert software was utilized to optimize the pretreatment variables and assess their impact on degradation efficiency. The compositional analysis of raw water hyacinth indicated a moisture content of 70.17%, ash content of 19.94%, crude fiber of 0.4932%, and volatile solids of 9.88%, underscoring its suitability as a biogas substrate. The thermochemical pretreatment markedly boosted organic matter solubilization, evidenced by soluble chemical oxygen demand (sCOD) range of 36,600 mg/L and degree of degradation (%DD) reaching up to 91.05%, though RSM analysis showed no significant factor influences (mean %DD = 88.55%), implying a recalcitrance-induced plateau. The optimal conditions for the pretreatment were identified at temperatures of 80°C, 30ml NaOH dosage, and 30 minutes reaction time, yielding consistent improvements in solubilization. These results illustrate that thermochemical pretreatment effectively overcomes biomass recalcitrance in water hyacinth, enhancing digestibility and prospective biogas output.