Nitritating-anammox biomass tolerant to high dissolved oxygen concentration and C/N ratio in treatment of yeast factory wastewater

Abstract

Maintaining stability of low concentration (< 1 g L(-1)) floccular biomass in the nitritation-anaerobic ammonium oxidation (anammox) process in the sequencing batch reactor (SBR) system for the treatment of high COD (> 15,000 mg O2 L(-1)) to N (1680 mg N L(-1)) ratio real wastewater streams coming from the food industry is challenging. The anammox process was suitable for the treatment of yeast factory wastewater containing relatively high and abruptly increased organic C/N ratio and dissolved oxygen (DO) concentrations. Maximum specific total inorganic nitrogen (TIN) loading and removal rates applied were 600 and 280 mg N g(-1) VSS d(-1), respectively. Average TIN removal efficiency over the operation period of 270 days was 70%. Prior to simultaneous reduction of high organics (total organic carbon > 600mg L(-1)) and N concentrations > 400 mg L(-1), hydraulic retention time of 15 h and DO concentrations of 3.18 (+/- 1.73) mg O2 L(-1) were applied. Surprisingly, higher DO concentrations did not inhibit the anammox process efficiency demonstrating a wider application of cultivated anammox biomass. The SBR was fed rapidly over 5% of the cycle time at 50% volumetric exchange ratio. It maintained high free ammonia concentration, suppressing growth of nitrite-oxidizing bacteria. Partial least squares and response surface modelling revealed two periods of SBR operation and the SBR performances change at different periods with different total nitrogen (TN) loadings. Anammox activity tests showed yeast factory-specific organic N compound-betaine and inorganic N simultaneous biodegradation. Among other microorganisms determined by pyrosequencing, anammox microorganism (uncultured Planctomycetales bacterium clone P4) was determined by polymerase chain reaction also after applying high TN loading rates.

High efficacy on diclofenac removal by activated carbon produced from potato peel waste

“…Although there has been an effort to improve biological treatments in WWTPs for nitrogen and organic carbon compounds (Zekker et al 2012c(Zekker et al , 2014(Zekker et al , 2015(Zekker et al , 2016, the removal percentages of DCF in WWTPs are usually low, 21-40 %, (Zhang et al 2008) due to its poor biodegradation during biological treatment.…”

Photo-oxygenation for nitritation and the effect of dissolved oxygen concentrations on anaerobic ammonium oxidation

“…It was also shown that 0.8 mg O 2 /L oxygen inhibited the efficiency of anammox bacteria in a reversible manner, but that at 1.4 mg O 2 /L the inhibition became irreversible (Egli et al, 2001). However, Zekker et al (2014) found that a high oxygen concentration in the bulk liquid of 3.2 ± 1.7 mg O 2 /L did not inhibit anammox bacteria that were growing in aggregates (flocculent biomass). The ammonium oxidizing organisms (AOO) also present in the aggregates, probably caused steep oxygen gradients within the aggregates.…”

“…The activity of anammox bacteria under dark conditions does not prove anammox activity for the light phase in the reactor. However, the low DO (b0.2) is unlikely to be inhibitory for anammox (Zekker et al (2014), although locally higher oxygen concentrations could prevail in algae-aggregates. A mass balance for nitrogen species over the light phase (Fig.…”

“…Apart from the changes in conversion rates, the lack of nitrite removal during the dark period is the strongest indication of anammox bacteria inhibition. Inhibition of anammox bacteria by oxygen may be reversible (Egli et al, 2001;Zekker et al, 2014) and therefore the nitrogen conversions were also monitored during the days following the cycle in which the DO was temporarily increased. System recovery could most clearly be seen from the nitrite concentrations at the end of the dark period (Table 2).…”

Photocatalytic treatment of oil and grease spills in wastewater using coated N-doped TiO2 polyscales under sunlight as an alternative driving energy

“…Due to drastic modernization and urbanizations, the use of petroleum oil and grease products for its energy need at industrial and anthropogenic activities has been increased drastically which led oil and grease pollution in water bodies (Hassan 1989;Rosario et al 2003;Agota et al 2012;Olumide et al 2011;Zekker et al 2012Zekker et al , 2014. Oil and grease is pollution caused by many sources such as accidental oil spills, leaks, industrial discharges, automobile discharge, and sewage, during chronic and careless usage of oil and oil products (Hassan 1989;Rosario et al 2003).…”