Study on inorganic nitrogen removal abilities of some microalgal strains from wastewater of shrimp pond at laboratory scale

Abstract

The study was to evaluate the inorganic nitrogen removal capacity of some microalgal strain in wastewater from whiteleg shrimp ponds. In this study, there were three separated treatments searching on three popular microalgal strains in aquaculture in Vietnam including Chlorella sp. NTU-201, Tetraselmis chuii NTU-202, and Oscillatoria sp. NTU-301. The wastewater characteristics, microalgal population growth, and removal effi ciency of inorganic nitrogen were tested. The research results showed a high salinity (28.6-32.3 mg.L^-1), mediated-potential of pH (7.7-8.0) and alkalinity (69.3-145.6 mgCaCO₃.^L-1) for microalgal growth, inorganic nitrogen and phosphate concentration were little low. The green microalgal Chlorella sp. Appeared the highest acclimated and growth at maximum cell density of 5.6±1.1×10⁶ (cells.mL1) exponential growth rate of 0.57±0.08, and doubling time of 1.24±0.16 (days). The blue-green microalgal, Oscillatoria sp. showed the best inorganic nitrogen removal capacity, in which 100% nitrate concentration was removed from water after 2 days incubation.

DOI: https://doi.org/10.53818/jfst.03.2022.65