V. M. Saraiva1, A. L. C. Araújo1,2*, M. A. Camargo-Valero3,4
1 Department of Natural Resources, Federal Institute for Education, Science and Technology of Rio Grande do Norte. Natal-RN, Brazil. 2 Post-Graduation Program of Sanitary Engineering, Federal University of Rio Grande do Norte. Natal-RN, Brazil. 3 School of Civil Engineering, University of Leeds, Leeds LS2 9JT, UK. 4 Departamento de Ingeniería Química, Universidad Nacional de Colombia, Sede Manizales.(free)
Due to its high yield potential and calorific power, purple elephant grass (Pennisetum purpureum) can be used as biomass for energy generation in the form of briquettes for cooking stoves. Grass irrigation was conducted in a 1 ha crop, adjacent to a WSPS located in Pendencias-RN, in Northeast Brazil, and crop productivity was assessed. Plots of 144 m2 were irrigated under two regimes (five and three times per week) and grass was harvested in sub plots of 9 m2, after 160 days of planting. Final effluent presented high salinity, low risk for sodium saturation, and thermotolerant coliform content below 104/100 ml. The productivity of grass reached 40 ton/ha (dry mass) and briquettes presented a mean calorific power of 4,170 Kcal/kg superior than that for firewood. By the end of the experiments, the soil showed saline-sodic characteristics, however, without affecting crop productivity.