Fecha de publicación: 08/01/2025 Fuente: Asqueous Extraction Byproducts Abstract
Biogas production from Eichhornia-crassipes (Water-hyacinth, WH) and Pistia-stratiotes (Water-lettuce, WL) used in pot phytoremediation of textile wastewater was investigated. The macrophytes were used to remove pollutants from the wastewater for seven days, and changes in the target heavy metals (HMs) were monitored in the treated effluent. Harvested biomasses of WH and WL, and post-remediation biomasses PWH and PWL, were anaerobically digested for 50 and 40 days, respectively. Volume of biogas produced, and the methane content were evaluated. Water-hyacinth showed higher removal efficiencies for Pb (67.81%), Cu (63.16%), Cr (62.83%), and Cd (55.42%), while WL was more effective at removing Fe (91.83%), Ni (80.13%), and Zn (51.01%). Both plants achieved over 50% removal of HMs, except for Zn, where WH recorded 46.52%. Effluent-grown biomasses (PWH and PWL) had higher carbon and lower fat content than WH and WL, making them more suitable for biogas generation via anaerobic digestion. The recorded biogas yields were 24.85, 21.23, 12.42, and 10.28 L/kg for PWH, WH, PWL, and WL, with corresponding methane compositions of 67.5, 65.72, 72.43, and 68.03%, respectively. Higher biogas yield and quality was recorded by the heavy metal-ladened biomasses. The microbial activity in the biodigesters with PWH and PWL increased by 64 and 53% respectively over the controls (WH and WL), due to pollutants uptake during phytoremediation. Effect of the HMs on bioconversion of the biomasses favors the polynomial model of the first-order kinetics with strong positive correlations. Conclusively, biogas generation present a means to utilize post-remediation biomass.