Affiliations: School of Environmental Engineering and Science,
Qingdao University, Qingdao 266071, China | School of Environment and Energy Engineering, Beijing
Polytechnic University, Beijing 100022, China | Pingdingshan Institute of Technology, Pingdingshan
467001, China
Abstract: The effect of seawater salinity on nitrite accumulation in
short-range nitrification to nitrite as the end product was studied by using a
SBR. Experimental results indicated that the growth of nitrobacteria was
inhibited and veryhigh levels of nitrite accumulation at different salinities
were achieved under the conditions of 25–28°C, pH 7.5–8.0, and the influent
ammonia nitrogen of 40–70 mg/L when seawater flow used to flush toilet was less
than 35% (salinity 12393 mg/L, Cl^- 6778 mg/L) of total
domestic wastewater flow, which is mainly ascribed to much high chlorine
concentration of seawater. Results showed that high seawater salinity is
available for short-range nitrification to nitrite as the end product. When the
seawater flow used to flush toilet accounting for above 70% of the total
domestic wastewater flow, the removal efficiency of ammonia was still above 80%
despite the removal of organics declined obviously (less than 60%). It was
found that the effect of seawater salinity on the removal of organics was
negative rather than positive one as shown for ammonia removal.
Keywords: seawater salinity, short range nitrification-denitrification to nitrite as the end
product, nitrite accumulation, organics removal efficiency, ammonia removal efficiency
