Biogas production by the fermentation of water hyacinth enhanced by solid bases

A solid base has been used for water hyacinth pretreatment and sludge acclimation,by addition to a water hyacinth fermentation system for anaerobic fermentation. The effects of solid base addition on activated sludge acclimation,water hyacinth microstructure,gas production rate and the methane content of fermentation gas were investigated. The results showed that: adding solid base during the initial fermentation with a dosage of 60% of the substrate gave the maximum average gas production rate by the water hyacinth(16. 88 mL/(g·d)) with a methane content of 80. 06%; compared with the fermentation system in the absence of solid base,these values represent increases of 72. 77% and 64. 73% respectively. The solid base can acclimate sludge,destroy the dense fibrous structure of the water hyacinth,adjust the pH value of the fermentation system in order to prevent organic acid feedback inhibition of bacteria,create a more suitable enabling environment for Methanogenus growth,and improve the efficiency and rate of water hyacinth methanation.