Climate resilient products development through valorization of Eichhornia crassipes to biofuel and biochar

In the context of climate change-induced nutrient enrichment, followed by rigorous spread of water hyacinth (Eichhornia crassipes), a mitigation strategy was envisaged to convert the substrate into biochar and biofuel. Lignocellulosic compositional analyses were performed, and the pretreatment of the substrate was done with a concentration of 0.1% of hydrogen peroxide at two varying pH (4 and 11.5). Acid hydrolysis was carried out on raw and pretreated substrates, followed by estimation of reducing sugar yield. It was found that pretreatment at pH 4 increases the reducing sugar content and was selected for further fermentation process. Fermentation was carried out with the yeast Saccharomyces cerevisiae for 48 h at 30 °C in a rotary shaker at 120 rpm. Presence of bioethanol was further detected by high-performance liquid chromatography. Biochar production from water hyacinth was attained by pyrolysis technique in a muffle furnace under the pre-optimized conditions of 300 °C after 30 min. The produced biochar was experimented for heavy metal (Zinc) remediation under laboratory conditions. The heavy metal (Zinc) analysis indicated efficacy of water hyacinth biochar in heavy metal removal from 2 ppm to 1.0265 ppm by 3 days, which implies the possibility to use the derived biochar as a remedial means of contaminated aquaculture sites.