Recovering biomethane and nutrients from anaerobic digestion of water hyacinth (Eichhornia crassipes) and its co-digestion with fruit and vegetable waste

• Published in: Water science and technology 2016-01, Vol.73 (2), p.355-361
• Main Authors: Hernández-Shek, M A, Cadavid-Rodríguez, L S, Bolaños, I V, Agudelo-Henao, A C
• Format: Article
• Language: English
• Subjects: Alternative energy sources; Ammonia - analysis; Anaerobic digestion; Anaerobic treatment; Anaerobiosis; Aquatic plants; Bacteria, Anaerobic - metabolism; Biofuels; Biogas; Biological Oxygen Demand Analysis; Bioreactors; Bone morphogenetic proteins; Continuously stirred tank reactors; Digestion; Eichhornia - metabolism; Eichhornia crassipes; Fatty Acids, Volatile - analysis; Feasibility studies; Fertilizers; Floating plants; Freshwater; Freshwater plants; Fruit - metabolism; Fruits; Garbage; Greenhouse gases; Hydraulic retention time; Laboratories; Liquid fertilizers; Load distribution; Loading rate; Methane; Methane - isolation & purification; Methane - metabolism; Mineral nutrients; Municipal solid waste; Nitrogen - isolation & purification; Nutrients; Organic loading; Reactors; Recovering; Renewable energy; Retention time; Stability; Vegetables; Vegetables - metabolism; Volatile solids; Water hyacinths; Weeds; Yields
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2015.501

The potential to recover bioenergy from anaerobic digestion of water hyacinth (WH) and from its co-digestion with fruit and vegetable waste (FVW) was investigated. Initially, biogas and methane production were studied using the biochemical methane potential (BMP) test at 2 g volatile solids (VS) L(-1) of substrate concentration, both in the digestion of WH alone and in its co-digestion with FVW (WH-FVW ratio of 70:30). Subsequently, the biogas production was optimized in terms of total solids (TS) concentration, testing 4 and 6% of TS. The BMP test showed a biogas yield of 0.114 m(3) biogas kg(-1) VSadded for WH alone. On the other hand, the biogas potential from the WH-FVW co-digestion was 0.141 m(3) biogas kg(-1) VSadded, showing an increase of 23% compared to that of WH alone. Maximum biogas production of 0.230 m(3) biogas kg(-1) VSadded was obtained at 4% of TS in the co-digestion of WH-FVW. Using semi-continuously stirred tank reactors, 1.3 m(3) biogas yield kg(-1) VSadded was produced using an organic loading rate of 2 kg VS m(-3) d(-1) and hydraulic retention time of 15 days. It was also found that a WH-FVW ratio of 80:20 improved the process in terms of pH stability. Additionally, it was found that nitrogen can be recovered in the liquid effluent with a potential for use as a liquid fertilizer.