Efficiency of Salicornia neei in removing nitrogen and producing biomass from a hypersaline and artificial wetland to treat aquaculture effluent
In 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.