nitrification rate of biofilters is influenced by ammonia concentration and levels of ammonia vary in response to feeding time. on the other hand, existence and activity of different groups of bacteria can be expected in the biofilters. hence in this research, nitrification dynamic of biofilters during day hours and also rules of different biofilteration process (nitrification, denitrification ...

Understanding nitrification rates and their regulation continues as a key area of research for assessing human's increasing impact on the terrestrial N cycle. We review the organisms and processes responsible for nitrification in terrestrial systems. The control of nitrification by substrate availability is discussed with particular attention to the factors affecting ammonia/ammonium availabili...

Thiosphaera pantotropha is capable of simultaneous heterotrophic nitrification and aerobic denitrification. Consequently, its nitrification potential could not be judged from nitrite accumulation, but was estimated from complete nitrogen balances. The maximum rate of nitrification obtained during these experiments was 93.9 nmol min mg of protein. The nitrification rate could be reduced by the p...

Previous studies have shown that Lamto savannah exhibits two different types of nitrogen cycle with high and low nitrification sites and suggested that the perennial grass Hyparrhenia diplandra is responsible for this duality at a subpopulation level, with one ecotype being thought to be able to inhibit nitrification. The present work aimed to investigate the relationships between nitrification...

no on-site sanitation system treats both urine and faecal matter in one process. a laboratory scale biological filter was fed with high concentration of urea (4 g n/l) and 17.1 g cod/l to determine if it will be possible to treat liquid that leach from a ventilated improved pit latrine. the hlr in the proposed biological filter system was calculated to be ca 36 l/m2/d, significantly lower than ...

The goal of this study was to compare the microbial ecology, gene expression, biokinetics, and N2O emissions from a lab-scale bioreactor operated sequentially in full-nitrification and partial-nitrification modes. Based on sequencing of 16S rRNA and ammonia monooxygenase subunit A (amoA) genes, ammonia oxidizing bacteria (AOB) populations during full- and partial-nitrification modes were distin...

This study aimed to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A 15N tracer experiment with (15NH4)2SO4 was conducted to determine the nitrification rates of four acidic agricultural soils with pH 4.03–6.02 in Yunnan Province, Southern China. The accumulation of 15N-NO3− and nitrification rates decreased with the addition of biochar at the end of incubat...

Batch nitrification tests were conducted with sludge and wastewater streams obtained from field implementations to evaluate nitrification inhibition and efficiency of a nitrifiers bioaugmentation technology at full-scale municipal wastewater treatment plants (WWTPs). The results showed that the substrate organic carbon and pH of wastewater streams were inhibitory factors to nitrification and th...

A six-point primary sere developed on sand dunes and a four-point secondary sere developed on old fields were studied to examine the regulation of nitrification in succession. Soils from sites along the seres were incubated in funnel-microlysimeters leached weekly with NH4CI and other nutrient solutions. Nitrate output in soils from the five youngest sites along the primary sere was rapidly sti...