Acute and chronic toxicity of nickel to nitrifiers at different temperatures
Xiaoguang Liu , Mohammad M.I. Chowdhury , Masuduz Zaman , Mingu Kim , George Nakhla
DOI:10.1016/j.jes.2019.03.009
Received February 07, 2019,Revised , Accepted March 13, 2019, Available online March 21, 2019
Volume 31,2019,Pages 169-178
This study investigated the acute nickel toxicity on nitrification of low ammonia synthetic wastewater at 10, 23, and 35°C. The nickel inhibition half-velocity constants (KI,Ni) for ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) based on Ni/MLSS ratio at 10, 23, and 35°C were 5.4 and 5.6 mg Ni/g MLSS, 4.6 and 3.5 mg Ni/g MLSS, and 9.1 and 2.7 mg Ni/g MLSS, respectively. In addition, chronic toxicity of nickel to nitrification of low ammonia synthetic wastewater was investigated at 10°C in two sequencing batch reactors (SBRs). Long-term SBRs operation and short-term batch tests were comparable with respect to the extent of inhibition and corresponding Ni/MLSS ratio. The μmax, b, and Ko of AOB were 0.16 day-1, 0.098 day-1 and 2.08 mg O2/L after long-term acclimatization to nickel of 1 mg/L at 10°C, high dissolved oxygen (DO) (7 mg/L) and long solids retention time (SRT) of 63–70 days. Acute nickel toxicity of nitrifying bacteria was completely reversible.
