Comparison ability of algae and nanoparticles on nitrate and phosphate removal from aquaculture wastewater

Background: Aquaculture wastewater contains high levels of phosphate and nitrate. The reuse of this water requires standards beyond the secondary standards to eliminate more organic pollutants from aquaculture effluents. In this research, the removal of these pollutants from wastewater using Chlorella vulgaris and Fe3O4 nanoparticles in the reactor space was investigated. Methods: This study was conducted on fish farms effluent in the laboratory system. For this purpose, a 5-L semi-industrial reactor with a mixer blade, porous plate, and a compressor was designed. Chlorella vulgaris samples were collected from the natural environment and cultured in the laboratory environment. Also, Fe3O4 nanoparticles were prepared from Iranian Nano Pishgaman Company to make the desired solution. During the experiment (3 weeks), samples were taken weekly (in one phase) from the effluent. Dissolved oxygen (DO), pH, nitrate (NO3), and phosphate (PO4) factors from the influent and effluent of the farms were measured. The statistical data were analyzed using SPSS version 21 and Excel 2013. Results: The amounts of nitrate and phosphate were decreased by about 80.76 and 80.55% in the biological reactor, whereas these amounts were 70.52 and 70.48% in the nanoparticle reactor, respectively. Also, there were significant differences in the amounts of NO3 and PO4 between the control treatment and weekly treatment (P < 0.05). Conclusion: Based on the results, both reactors were able to reduce nitrate and phosphate from aquaculture wastewater, but the efficiency of the biological reactor was higher than that of the nanoparticle reactor. Keywords: Nitrate, Phosphate, Fe3O4 nanoparticle, Chlorella vulgaris, Biological refinemen

Effects of physicochemical factors on seasonal variations of phytoplankton in the Mond River Estuary of Bushehr Province, Persian Gulf, Iran

Abstract. Pouladi M, Qadermarzi A, Baharvand F, VazirizadehA, Hedayati A. 2017. Effects of physicochemical factors on seasonal variations of phytoplankton in the Mond River Estuary of Bushehr Province, Persian Gulf, Iran. Biodiversitas 18: 229-237. The main purpose of present study was to investigate the abundance and biodiversity of phytoplankton from Mond estuary, Bushehr, Persian Gulf during different seasons and its relationships with environmental parameters and nutrients. Samples were taken in mid-season from spring 2012 to winter 2013 for oneyear period. The phytoplankton were contributed by the phyla Bacillariophyta, Dinophyta, Haptophyta, and Chlorophyta. The class Coscinodiscophyceae and Bacillariophyceae belonging to Bacillariophyta were the most diverse and dominant with 22 and 16 genera, respectively. The mean phytoplankton abundance were recorded in spring (12706.7±3586.9 cells L-1), in summer (10173.3±2560.08 cells L-1), in autumn (10600±2758.2 cells L-1) and in winter (7000±2401.6 cells L-1), respectively. Simpson and Shannon-Wiener biodiversity indices obtained showed in spring (0.93±0.007 and 3.8±0.2), in summer (0.92±0.008 and 3.64±0.2), in autumn (0.92±0.006 and 3.63±0.15) and in winter (0.89±0.013 and 3.07±0.24), respectively. The phytoplankton assemblages were most diverse and abundant at station-5 in all seasons. In addition, there were significant correlation (P<0.01) between phytoplankton abundance and diversity with pH, salinity, NO3, PO4 and temperature. Based on Principle Component Analysis (PCA), the most important factors that could describe most changes of abundance and diversity of phytoplankton in the Mond River estuary system were salinity, NO3, pH, PO4 and temperature, respectively. Results demonstrated that diatoms were the dominant population and salinity factor was more effective factor that affected the diversity and abundance of phytoplankton during study period in Mond River estuary. Keywords: Abundance, Bushehr, diversity, Mond River Estuary, phytoplankton, Persian Gul