The coupling between nitrification and denitrification and the regulation of these processes by oxygen were studied in freshwater sediment microcosms with O(2) and NO(3) microsensors. Depth profiles of nitrification (indicated as NO(3) production), denitrification (indicated as NO(3) consumption), and O(2) consumption activities within the sediment were calculated from the measured concentratio...

The aim of the study was to determine how soil contamination with diesel oil affected biochemical properties of soil and to determine whether the application of compost, bentonite or lime could recover the biochemical equilibrium of soil. The experiments were carried out in a greenhouse. Typical Eutric Cambisols soil formed from sandy loam was polluted with the following amounts of diesel oil: ...

Research so far has provided little evidence that benthic biogeochemical cycling is affected by ocean acidification under realistic climate change scenarios. We measured nutrient exchange and sediment community oxygen consumption (SCOC) rates to estimate nitrification in natural coastal permeable and fine sandy sediments under pre-phytoplankton bloom and bloom conditions. Ocean acidification, a...

In wastewater treatment plants, nitrifying systems are usually operated with elevated levels of aeration to avoid nitrification failures. This approach contributes significantly to operational costs and the carbon footprint of nitrifying wastewater treatment processes. In this study, we tested the effect of aeration rate on nitrification by correlating ammonia oxidation rates with the structure...

BACKGROUND Chemoautotrophic ammonia oxidizing bacteria (AOB) have the metabolic ability to oxidize ammonia to nitrite aerobically. This metabolic feature has been widely used, in combination with denitrification, to remove nitrogen from wastewater in wastewater treatment plants (WWTPs). However, the relative influence of specific deterministic environmental factors to AOB community dynamics in ...

Sun, Zhe. M.S.E., Purdue University, May 2014. Attached-Growth System for Nitrification at Low Temperature. Major Professor: Ernest R. Blatchley III. Lagoon systems are commonly used in small communities for domestic wastewater treatment. These systems are simple and economical to operate, and are often appropriate for use in areas where land costs are low. Lagoons are effective in removing con...

A perfusion technique was used to study the effects of l) simulated acid rain on the mineralization and nitrification of glycine (NH 2-N) or ammonium sulfate (NH4-N) by adjusting the pH of the perfusates to 3.0, 2.5, or 2.0 with H 2S0 4 ; and 2) 0, 50, I 00, 500, and I ,000 1-1-g Cd!g dry weight of soil on the mineralization and nitrification of NH 2-N, both in soil adjusted with H 2S04 to pH 3...

The spatial distribution and diversity of archaeal and bacterial ammonia oxidizers (AOA and AOB) were evaluated targeting amoA genes in the gradient of a littoral buffer zone which has been identified as a hot spot for N cycling. Here we found high spatial heterogeneity in the nitrification rate and abundance of ammonia oxidizers in the five sampling sites. The bacterial amoA gene was numerical...

In the external nitrification (EN) biological nutrient removal (BNR) activated sludge (AS) system, the nitrification process is removed from the BNR activated sludge system and performed ‘externally’ on an integrated nitrifying trickling filter (NTF). As such, optimum design and operation of the NTF is essential for reliable performance of the ENBNRAS system. Although information on the design ...

Removal of ammonia nitrogen and nitrate nitrogen by an heterotrophic nitrification-aerobic denitrification strain is an economical and effective method. In this article, a kind of heterotrophic nitrification-aerobic denitrification strain which has aerobic denitrification and heterotrophic nitrification ability was selected, and then was identified as rhodococcus sp. by 16S rRNA sequencing anal...