Mestrado em Engenharia do Ambiente - Instituto Superior de AgronomiaOver the last decades, phytodepuration has been considered an efficient technology
to treat agricultural wastewaters.
Swine wastewater is rich in nutrients that can be used to grow biomass, producing a
treated wastewater that can be used for irrigation and a biomass that may be useful for
potential energy production by anaerobic digestion (AD). In this study a comparative
polishing treatment assays were developed, at a bench scale, through Lemna minor growth
in swine wastewater (4%) with similar concentration at a real scale last lagoon and Lemna
minor growth in synthetic medium. The highest observed growth rate obtained in swine
wastewater was 28.7 ± 2.3 g m-2 day-1 or 3.1 ± 0.3 gDM m-2 day-1. The highest nitrogen and
phosphorus uptake rates in swine wastewater system were 140 mg m-2 day-1 and 3.47 mg m-
2 day-1, respectively. The COD removal efficiency was 60.0 ± 1.0%.
Furthermore, an integrated approach was investigated assessing possible
valorisation of biomass by anaerobic co-digestion of swine wastewater with Lemna minor.
Results showed a clear improvement in gas production rate and methane specific production
in 40% and 44%, respectively, when compared to mono-substrate digestio
