Testing the ability of water hyacinth for wastewater treatment and methane biogas production

Abstract

This study aims to assess the potential of water hyacinth (WH) in treating wastewater and its viability for co-digestion with municipal solid waste to achieve zero waste treatment by generating methane biogas. A batch flow reactor treated wastewater, evaluating nine parameters (NO3, PO4, BOD5, Turbidity, Chromium, Cadmium, Lead, Calcium, and Magnesium). The highest removal efficiencies were observed for NO3 (94.13%), PO4 (75.85%), BOD5 (100%), Turbidity (93.86%), Chromium (94.3%), Cadmium (94.93%), Lead (91.33%), Calcium (41.42%), and Magnesium (43.13%). The pH ranged from 7.82 to 7.44. Methane biogas production was examined using anaerobic digesters with varying ratios of carbon-based waste and WH, along with pH, temperature, and total solid content variations. The optimal methane biogas production ratio was found to be 1:3 for WH and solid waste at 35°C, 10% total solids, and a pH of 7.5, resulting in the highest cumulative methane generation of 1039.80 mL/gm vs. The Gompertz model accurately described methane biogas generation with a yield of 1083.088 mL/gm vs., supported by a coefficient of determination (R2) of 0.999. The kinetics of the biodegradation process were evaluated using a first-order kinetic model. The negative value of k (-0.2364) suggests a rapid solid waste biodegradation, with a high correlation coefficient (R2) of 0.9971. Numerous correlations were employed to enhance the production of methane, yielding a correlation coefficient of 91.36%.