Işık, Mustafa13.07.20192019-07-1613.07.20192019-07-1620081383-5866https://doi.org/10.1016/j.seppur.2008.02.002https://hdl.handle.net/20.500.12451/4535The respirometric assessment of the inhibitory impact of Ni(II) on substrate utilization and microbial carbonate precipitation (MCP) by ureolytic mixed microorganisms was investigated with a glucose containing mineral medium under batch conditions over an incubation period of 134 h. The IC25 was determined as 224 mg Ni(II) L-1 from the BOD values of samples. The interpretation of kinetic data showed that the substrate removal rate fitted a zero-order at the beginning of the incubation period and first-order during the last period, for a range of Ni(II) concentrations between 0 and 512 mg L-1. Increasing Ni(II) concentrations from 0 to 512 mg L-1 reduced the substrate degradation rate constant from 10.8 to 5.3 mg L-1 h(-1) for zero-order rate constant (k(0)), and from 0.015 to 0.002 h(-1) for first-order rate constant (k(1)). The zero- and first-order reaction rates during incubation period were equalized to the reaction rate of the Monod equation in order to determine the kinetic constants, half saturation concentration (K-S) and maximum substrate removal rate (R-max). BOD removal rate was inhibited accordingly to mixed inhibition model with increasing Ni(II) concentrations during the calcification process. Also, the inhibition of calcium precipitation was observed at a higher Ni(II) concentration because of inhibition of ammonium production in these samples. (C) 2008 Elsevier B.V. All rights reserved.eninfo:eu-repo/semantics/closedAccessUreolyticCalciumİnhibitionNi(II)MixedArticle62233734110.1016/j.seppur.2008.02.002Q1WOS:000258363600010N/A