On‐line monitoring of a BNR process using in situ ammonium and nitrate probes and biomass nitrification‐denitrification rates in an intermittently aerated and pulse fed bioreactor. Issue 10 (28th October 2013)

• Record Type: Journal Article
• Authors: Melidis, Paraschos; Ntougias, Spyridon; Sertis, Christos
• Is Part Of: Journal of chemical technology & biotechnology. Volume 89:Issue 10(2014:Oct.)
• Page Start: 1516
• Page End: 1522
• Publication Date: 2013-10-28
• Subjects: Biotechnology -- Periodicals; Chemistry, Technical -- Periodicals; Chemical engineering -- Periodicals; Industries -- Environmental aspects -- Periodicals; 660
• DOI: 10.1002/jctb.4230
• Languages: English
• ISSNs: 0268-2575

Abstract

<abstract abstract-type="main" id="jctb4230-abs-0001"> <title>Abstract</title> <sec id="jctb4230-sec-0001" sec-type="section"> <title>BACKGROUND</title> <p id="jctb4230-para-0001">The need to monitor and optimize biological nitrogen removal (BNR) processes has led to the use of on‐line instrumentation. <italic>In situ</italic> located sensors can monitor in a real‐time mode the dynamics of microbial processes, providing the opportunity to understand and optimize process performance.</p> </sec> <sec id="jctb4230-sec-0002" sec-type="section"> <title>RESULTS</title> <p id="jctb4230-para-0002">A nitrification–denitrification process was monitored on‐line for the first time in an intermittently aerated and pulse fed activated sludge system using <italic>in situ</italic> located sensors for ammonia and nitrate. Pulse feeding created a reduced C/N ratio gradient across the anoxic phase, resulting in complete denitrification within a period of 20 min. Two denitrification rates were determined, corresponding to nitrate reduction during utilization of the readily biodegradable (0.110–0.246 g g<sup>‐1</sup> d<sup>‐1</sup>) and the slowly (particulate) biodegradable (0.032–0.041 g g<sup>‐1</sup> d<sup>‐1</sup>) COD, respectively. Despite the fact that the initial C/N ratio at both Food/Microorganism ratio (F/M) 0.20 and 0.28 was decreased from 4.8 to 1.8 at the end of the anoxic phase, the C/N ratio decrease was twice as fast at the higher F/M ratio.</p> </sec> <sec id="jctb4230-sec-0003" sec-type="section"> <title>CONCLUSION</title> <p id="jctb4230-para-0003">Pulse‐feeding resulted in higher C/N ratios at the beginning of the anoxic phase, creating a reduced C/N ratio gradient during the denitrification period. Organic load was mostly consumed during the anoxic phase, resulting in high nitrification efficiency, low oxygen requirement and saving energy. © 2013 Society of Chemical Industry</p> </sec> </abstract>