A Study on Acclimation and Culture of Salt Tolerant Sludge

The inoculated sludge in this experimental system is from the end of aeration tank of the wastewater treatment plant. Under stable operation, the system’s treatments of COD and NH4+-N are all in line with Level One Urban Sewage Discharge stipulated by Pollutant Discharge Standards for Urban Sewage Treatment Plants (GB 18918-2002). The removal rates of COD and NH4+-N are 94.27% and 91.03%. By gradually improving the method of salinity acclimation, the salt tolerant sludge with outstanding performance can be successfully acclimated, and each gradual increase in salinity scope is controlled at around 4 g/L. When the salinity is 1%, the removal rates of COD and NH4+-N reach to 92.09% and 70.13%. The salinity has significant impacts on microbial activity. With the increase in salinity, the dehydrogenase activity gradually decreases. Salinity has significant effects on protozoa. Paramecia and nematodes can be taken as the biological indicator of outflow water quality of brine waste.