Title:
Growth, Productivity and Biomass Quality of Kenaf Irrigated with Wastewaters - the Effect of Nitrate Ion
Author(s):
Fernando, A.L., Ferreira, M., Boléo, S., Mendes, B., Alexopoulou, E.
Document(s):
Paper
Abstract:
The aim of this work was to evaluate growth responses, as well as the quality and biomass productivity of the G4 variety of kenaf, irrigated with treated wastewaters (TWW) presenting different nitrate ion concentrations: 0, 50 e 100 mg.L-1 (NO3). Wastewater was obtained at Campo de Tiro de Alcochete wastewater treatment plant, after secondary treatment. Essays were conducted in small pots, and for each treatment, in triplicate. NPK fertilization effect was also studied. A Control essay was also performed, with tap water and NPK fertilization. Throughout the experiment, in pots, percolated waters were analyzed in terms of nitrites and nitrates. Results show that irrigation with wastewater enriched with nitrate ion does not affect the growth and productivity of kenaf, within the levels of nitrate studied (maximum concentration 100 mg.L-1 NO3). Results show that the application of TWW (0 mg.L-1 NO3 + 15 mg/L of NH4) led to the highest yields in the G4 variety, with low ash and low nitrogen content. It was found that the system biomass-soil contributes to the removal of nitrates from the wastewaters – circa 90-100% at the stages of plants major development. However, it is important to balance the quantity of nitrogen added along the growing period with the plant needs, in order to prevent the degradation of the surface and groundwater quality due to excess nitrogen. In terms of the biomass quality, the increment of nitrate ion in the irrigation led to increased accumulation of nitrogen in the biomass, and this can compromise its use for combustion purposes. But no effect was observed for the remaining parameters evaluated namely ash, phosphorus and potassium content. Heat of combustion and fiber content were also not affected by the nitrate increment in the wastewater. Kenaf can assume a high importance on projects by merging the treatment of water bodies containing nitrate ion up to 100 mg.L-1 (NO3), with the production of highly valuable biomass, in a short time period and with low production costs.
Keywords:
biomass composition, kenaf, wastewater treatment, biomass yields
Topic:
Biomass Resources
Subtopic:
Energy crops and energy grasses
Event:
20th European Biomass Conference and Exhibition
Session:
1CO.3.4
Pages:
179 - 182
ISBN:
978-88-89407-54-7
Paper DOI:
10.5071/20thEUBCE2012-1CO.3.4
Price:
FREE
