Influence of pH over nitrifying biofilm activity in submerged biofilters

Removal of Carbon and Nitrogen Compounds in Hybrid Bioreactors

“…The rise in pH value versus the rise of nitrogen compounds removal rate, what was observed by other authors [52]. The lime addition resulted in some changes in biomass, e.g.…”

Nitrification in fixed-bed reactors treating saline wastewater

“…Mechanisms of pH inhibition of nitrification might be an activationdeactivation of nitrifying bacteria, nutritional effects connected with alkalinity or inhibition through free ammonia and free nitrous acid, as summarized by Villaverde et al (1997). In this study deactivation of nitrifiers might likely be caused by the pH inhibition mechanism.…”

“…-Influence of pH, alkalinity and ammonia loading Villaverde et al (1997) (Table 3.1) or by addition of NaHCO 3 as pH buffer (Table 3 The use of NaHCO 3 was chosen as a pH buffer system and also as a source of carbon for bacteria growth. When the concentration of ammonia in wastewater increased, more NaHCO 3 must be added to stabilize the pH.…”

Origin, causes and effects of increased nitrite concentrations in aquatic environments

“…Whatever the temperature, Mauret et al (1996) observed a transient nitrite build-up of roughly 50% of the initial ammonia concentration for threshold concentrations of FA of 8.91 mg N L −1 . Villaverde et al (2000) and Rols et al (1994) remark that the inhibition phenomenon is specific and depends both upon the concentration of nitrifying organisms Villaverde et al (1997) as upon the threshold concentration (on volume basis) of FA causing inhibition. In doing so, Rols et al (1994) established the threshold of inhibition of NOB between 0.5 and 3 mg NH 3 -N mg −1 viable NOB biomass.…”

“…The inhibiting effect of FA on NOB may be the result of a combination of several factors such as initial NH + 4 concentration, pH and temperature (Balmelle et al 1992). It is further said that the inhibition by FA is such that the effect of temperature, alkalinity and ammonium load is masked when the concentration of free ammonia is above certain values (Fdz-Polanco et al 1994, 1996Villaverde et al 1997). A comparison between FA threshold concentrations, i.e.…”