Continuous-flow biological denitrification with zeolite as support for bacterial growth

Abstract

A B S T R A C TZeolite particles with bacterial culture (Bio-NPC) were used for nitrate removal from surface water (SW) and effects of Bio-NPC, and the methanol amount and the pH value of SW were investigated in the batch reactor and the process was then monitored in the continuous-flow stirred reactor. The application of Bio-NPC particles (10% w/w) in the batch reactor was efficient for the removal of 100 mg NO 3 -N/L from the SW, and the addition of methanol was optimal at CH 3 OH/N ratio of 2.5:1. The process was stable in the pH range of 5.85-8.03, but the highest denitrification rate was obtained at the pH value of 7.13. In the continuous-flow stirred reactor, nitrate removal was investigated at different hydraulic retention times (HRTs) (37.04, 23.26, 10.53, 2.33 and 1.32 h) and the efficient nitrate removal was achieved even at HRT of 1.32 h with nitrate and organic removal higher than 99 and 79%, respectively. The volumetric denitrification rates during the first eight days of continuous flow were in the range of 39.2-51.28 mg NO 3 -N/L h and then it fluctuated within the range of 63.47-79.90 mg NO 3 -N/L h. The use of Bio-NPC was demonstrated as an efficient method for complete nitrate removal from the surface water.

Anammox-zeolite system acting as buffer to achieve stable effluent nitrogen values

“…Recent practices with zeolite demonstrate that it could also be used as a carrier material for biofilter systems to enhance biodegradation in different environments (Foglar and Gasparac 2013;Qiu et al 2010;Weatherley and Miladinovic 2004). Foglar and Gasparac (2013) used zeolite as a biomass support for nitrate removal from surface water in a CSTR reactor.…”

“…Foglar and Gasparac (2013) used zeolite as a biomass support for nitrate removal from surface water in a CSTR reactor. Qiu et al (2010) compared the organic carbon and ammonia removal efficiencies of three biologically aerated filters (BAF) with ceramic, zeolite and carbonate media and observed that ammonia nitrogen removal efficiency in zeolite and carbonate BAF was not only higher but also steadier than that of ceramic particle BAF in the case of shock ammonia nitrogen load.…”

Use of Ion Exchange Beads as a Bacterial Carrier for Biodenitrification

“…It could be assumed that phosphate present in the surface water (Table 1) was sufficient for bacterial growth. However, in a study by Foglar & Gašparac (2013) performed under similar conditions with zeolites as carriers of the bacterial cells, the use of raw water for continuous‐flow denitrification was seen to significantly increase pH values in the effluent stream. A comparison of that study's findings with the current results could support the assumption that the application of the bio‐IER beads affected the stabilization of effluent pH values.…”

Insights into biofilm carriers for biological wastewater treatment processes: Current state-of-the-art, challenges, and opportunities

“…To date, it has been reported that inorganic materials-based biofilm carriers appear to be effective in treatment of nutrients and organic pollutants (Lameiras et al, 2008 Among inorganic materials-based biofilm carriers, zeolite has been frequently used to eliminate ammonia-nitrogen containing wastewater/water since this carrier shows high selectivity to NH4 + (Eldyasti et al, 2012;Tarjányi-Szikora et al, 2013), since natural zeolites have extremely negative charge surface. In earlier studies, it was observed that the adsorptive removal efficiencies of NH4-N in water were greater than 90% or even up to 99% using zeolite as carriers (Foglar and Gašparac, 2013;Huang et al, 2013). Zeolite was proven to have better adsorptive removal efficiency than other inorganic carriers (i.e.…”