R. Lalremdika, Ran Bahadur Pradhan, Sengjrang Ch Momin, Jyotishma Nath, Ruthi Lalmuanzeli and Surya Kant Mehta
Abstract
Microcystis aeruginosa and Chlorella vulgaris was isolated from domestic sewage and grown in presence of sodium bicarbonate as carbon source at 0.5, 1.0 and 2.0 gl-1. Highest specific growth rate (0.665 õd-1) was obtained with 1 gl-1 bicarbonate on M. aeruginosa culture. The biomass productivity was in range of 0.281- 0.525 gl-1d-1on M. aeruginosa and 0.217-0.486 gl-1d-1 on C. vulgaris. At 1 gl-1 sodium bicarbonate concentration, maximum CO2 fixation (0.172 gl-1d-1) was found on M. aeruginosa culture. The present study also aimed to investigate the potential applications of Microcystis aeruginosa, Chlorella vulgaris and their consortium for bioremediation of domestic sewage with regard to their pollutant removal and improve water quality for reuse in irrigation. The results showed that both the monocultures and their consortium were quite effective and having capacity to reduce pH, conductivity, turbidity, total dissolved solids (TDS), biochemical oxygen demand (BOD), NO3-N, PO4-P, NH4-N, alkalinity, salinity and chlorides. The consortium cultures shows higher removal efficiency in pH (6.80 ñ 0.26%), conductivity (23.48 ñ 0.01%), BOD (82.35 ñ 0.10%), PO4-P (55 ñ 1.20%), salinity (40.52 ñ 0.03%) and chlorides (34.48 ñ 0.03%), C. vulgaris in turbidity (81.73 ñ0.07%), TDS (18.68 ñ 0.03%) and NO3-N (49.48 ñ 0.59%) while M. aeruginosa in NH4-N (42.10 ñ 1.82) and alkalinity (35.50 ñ 0.04). The concentration of all the parameters in effluent provided by all the treatment complied with different standards for irrigation and drinking water with the exception of M. aeruginosa in chlorides for irrigation water and all the treatment in conductivity, turbidity and NH4-N for drinking water.