Abstract:

Due to effects of high osmotic pressure and biological toxicity of inorganic salts, eubolism of activated sludge developing in fresh wastewater can not be carried out in highly saline wastewater.This difficulty could be solved by collecting, studying and culturing halophilic activated sludge from the estuary deposit at the mouth of the river.In this paper the effect of start-up, ammonium-nitrogen loading and salinity on nitrification performance of the halophilic nitrification culture in treating real saline domestic wastewater was studied.The results show that after 9 day adjustment stage, nitrification of ammonium-nitrogen is started.This halophilic system is sensitive to ammonium-nitrogen loading and its fluctuation.Salt tolerance of 10—60 g·L^-1as well as optimum salt of about 40 g·L^-1 was established.Comparing with fresh activated sludge and salt-acclimation activated sludge, this system is of advantages of high specific ammonium removal rate and tolerance of salt shocks, because the dominant population is composed by moderately halophilic and marine bacteria.〖JP2〗A noteworthy is that there is unusually high nitrite accumulation rate during experimental operation although all operation conditions are very preferable to nitrite oxidation.The research can provide an alternative way for application of the halophilic mixed culture in biological treatment of highly saline wastewater.