Efficiency of Salicornia neei to treat aquaculture effluent from a hypersaline and artificial wetland

Abstract

AbstractIn this study we evaluated the potential of Salicornia neei, a halophyte plant native to South America, to treat saline effluents with simulated concentration of ammonium-N (Amm) and nitrate-N (Nit) similar to land-based marine aquaculture effluents. Plants were cultivated for 74 days in drainage lysimeters under three treatments of seawater fertilized with: 1) Nit+Amm, 2) Nit, or 3) without fertilizer (Control). Over 5 repetitions, nitrogen removal efficiency (RE) was high in both treatments (Nit + Amm = 89.6± 1,0 %; Nit 88.8 ± 0.9 %). While nitrogen removal rate (RR) was non linear and concentration-dependent (RRday 1-4: Nit+Amm= 2.9 ± 0.3 mg L−1 d−1, Nit = 2.4 ± 0.5mg L−1 d−1; RRday5-8: Nit + Amm = 0.8 ± 0.2mg L−1 d−1, Nit=1.0 ± 0.2mg L−1 d−1). Effluent salinity increased from 40.6 to 49.4 g L−1 during the experiment, with no observed detrimental effects on RE or RR. High nitrogen removal efficiency and significant biomass production observed, Nit+Amm = 11.3 ± 2.0 kg m−2; Nit = 10.0 ± 0.8 kg m−2; Control = 4.6 ± 0.6 kg m−2, demonstrate that artificial wetlands of S. neei can be used for wastewater treatment in saline aquaculture in South America.