Study of the Effects of Bandar Abbas Urban Sewage Pollution entering Gursouzan Embayment on the Growth and Chemical Composition of Microalgae Tetraselmis chuii

Abstract

Urban sewage contain high amounts of nutrients such as nitrogen and phosphorus compounds. Microalgae can be utilized in removal and treatment of excessive nutrients from the sewage. The present study investigated the effect of different concentrations of urban sewage entering Gursuzan embayment in Bandar Abbas on the growth and chemical components of microalgae Tetraselmis chuii during a 14 days rearing period. The growth of T.chuii in 6 treatments (with 3 replicates) had an increasing trend and the maximum growth (Optical density: 1.4), was observed on day 14 in treatment 5 (consisting %60 F2 culture medium + %40 urban sewage). Moreover the maximum amounts of nitrate and phosphate (0.013±0.0007 and 0.003±0.00001 µg/l), chlorophyll a and b (0.19±0.002 and 0.16±0.003 mg/g), protein (1.3±0.04 mg/g) and fatty acids EPA and DHA (3.36±0.09% and 3.76±0.12%) were also observed in treatment 5. The results indicated that microalgae T. chuii is capable of efficiently removing organic compounds from urban sewage, and due to the more effective role of treatment 5 culture medium (%60 F2 culture medium + %40 urban sewage), in rapid propagation and production of more algal biomass rich in unsaturated fatty acids, it can be recommended to be utiulized as a proper alternative, for the secondary treatment and rehabilitation of urban sewage.

Keywords

• nitrate
• phosphate
• pollution
• tetraselmis chuii
• wastewater treatment