Salt inhibition of nitrification and denitrification in saline wastewater

Biological processes used for nitrification and denitrification of saline w astewater results in low treatment efficiencies because of plasmolysis or l oss of activity of organisms in the presence of salt. However, adverse effe cts of salt on performance of nitrifcation/denitrification processes has no t been systematically investigated and mathematically formulated. Biologica l nitrification and denitrification of synthetic wastewater containing diff erent concentrations of salt were investigated in this study. Effect of sal t concentration on the system performance was investigated. Salt concentrat ions above 2% resulted in significant reductions in performances of both ni trification and denitrification. Denitrification was more sensitive to salt compared to nitrification. A mathematical model was developed and the salt inhibition constants were determined using the experimental data.