Water quality and nutrient dynamics of biofloc with different C/N ratios in inland saline water

Abstract

A study evaluating water quality and nutrient dynamics in inland saline water was carried out using biofloc technology with different C/N ratios employed to raise Litopenaeus vannamei juveniles. The study was carried out for 60 days in FRP with no water exchange. Salinity, temperature, Dissolved oxygen, pH, nutrients, Biofloc Volume and Total Suspended Solids were monitored. All biofloc units indicated reduction in alkalinity at 40th day except the treatment with highest (25:1) C/N ratio, pH and alkalinity was not significant different among various treatments. Dissolved Oxygen was found to be significantly decreasing with increasing C/N ratios. The least Dissolved Oxygen was recorded at higher C/N ratios of 20:1 and 25:1 at the end of experiment. The Total Ammonical Nitrogen (TAN) and NO2 –Nin C/N ratios 15:1 and 20:1 were found to have a significantly decreasing in trend after 20th and 18th day respectively. The NO3 –N, PO4 3-–P, BVF and TSS in biofloc were shown an increasing trend in all the experiments. The present study elucidates the suitability of optimum C/N ratios in biofloc for maintaining the water quality to raise L. vannamei in inland ground saline water. The finding could help in reducing the environmental concern saline waste water discharge from the shrimp pond to the land.