Influences of mixed composition of chicken manure and water hyacinth (Eicchornia crassipes) and alkali pretreatment to enhance biogas production on anaerobic digester

Water hyacinth (Eichornia crassipes) is an aquatic plant species that considered as weeds, lead to accelerate eutrophication and sedimentation on the river. Water hyacinth has a potential to be used as a renewable energy source to produce biogas, because it has content of lignocellulose. Lignocellulose need to be pretreated to break down lignin to produce hemicellulose, cellulose and lignin. Chicken manure is added as a source of nutrients and microorganisms to degrade hemicellulose and cellulose to produced biogas.The purposes of this study were to determine the effect of pretreatment and composition of chicken manure and water hyacinth mixed to produce biogas volume. This study was used reactors with a capacity of 6 liters each. Research carried out by a batch process for 30 days. The research variables were the composition of water hyacinth and chicken manure, and pretreatment and without pretreatment of water hyacinth. The ratio of water hyacinth to chicken manure was 90:10; 70:30 and 50:50 (%w/w). The concentration of total solids of the mixture variation in this study was 10%. Pretreatment of water hyacinth was done by soaking NaOH 3% for 5 days at room temperature and then used as raw material. The results showed the highest production of biogas generated by a mixture of water hyacinth and chicken manure 70:30 (%w/w). The cumulative gas volume produced during 30 days was 439 mL. It is a slightly higher than the biogas produced in the same mixture without pretreatment which produced 366 ml biogas. A maximum methane concentration was 20% with pretreatment and 6% without pretreatment.