Abstract
<title>Abstract</title> <p>Effect of increased salinity levels (0 to 30 g/L of NaCl dose) on a symbiotic reactor was evaluated during the assimilation of pollutants in a synthetic agricultural wastewater. Removals of urea (99% to 11%), COD (88% to 9%), potassium (98% to 5%), and ammonia-N (81% to 29%) decreased with increase in salinity. Removal of phosphorous was only hampered after 25 g/L of salt. Decrease in the overall reactor performance was due to the reduction in the ability of the reactor biomass at hypersaline condition. Overall reactor biomass decreased (9.21 g/L to 7.49 g/L) with increase in influent NaCl. Biomass yield rate and biomass productivity decreased with increase in salinity. Formation of nitrate-N and nitrite-N were reduced as ammonia-N oxidation was hampered. Overall elemental C, H, N, and S increased with increase in the dead biomass settlement on the soil. SVI and MDD increased, suggesting the increase in the puffy nature of the reactor soil. Dominant reactor microbes were hampered by high salinity.</p>