19/03/2018

Gianni Brundu & Anuta Chindris

Abstract

This study investigates the capability of Ulva lactuca to grow in an integrated system, aiming to optimise the needing of resources and to decrease the ecological impact of wastewater. The nutrients uptake and the growth of U. lactuca in Mugil cephalus wastewater (WW) were evaluated and compared with U. lactuca cultivated in estuarine water (EW). Fresh thalli of U. lactuca were cultivated for 10 days in 5 L cylindrical tanks, 3 replicates per treatment. The uptake of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorous (DIP), as well as the biomass yield and specific growth rate of U. lactuca, were assessed every two days. At the end of the experiment, U. lactuca resulted in a higher assimilation of DIN in EW (95.7 ± 0.3%, mean ± SE) than in wastewater (68.7 ± 1.0%) (p < .01). No significant differences were observed in DIP assimilation (>80%), as well as in the biomass yield and specific growth rate. This study demonstrates the efficiency of U. lactuca in the assimilation of DIN and DIP from M. cephalus WW, contributing to reduce the release of dissolved inorganic nutrients in the natural environment.

Chemistry and Ecology 34