Partial Nitrification in a Sequencing Moving Bed Biofilm Reactor (SMBBR) with Zeolite as Biomass Carrier: Effect of Sulfide Pulses and Organic Matter Presence

Abstract

This work aimed to achieve partial nitrification (PN) in a Sequencing Moving Bed Biofilm Reactor SMBBR with zeolite as a biomass carrier by using sulfide pulses in the presence of organic matter as an inhibitor. Two conditions were evaluated: sulfide (HS−) = 5 mg S/L and vvm (air volume per liquid volume per minute, L of air L−1 of liquid min−1) = 0.1 (condition 1); and a HS− = 10 mg S/L and a vvm = 0.5 (condition 2). The simultaneous effect of organic matter and sulfide was evaluated at a Chemical Oxygen Demand (COD) = 350 mg/L and HS− = 5 mg S/L, with a vvm = 0.5. As a result, using the sulfide pulse improved the nitrite accumulation in both systems. However, Total Ammonia Nitrogen (TAN) oxidation in both processes decreased by up to 60%. The simultaneous presence of COD and sulfide significantly reduced the TAN and nitrite oxidation, with a COD removal yield of 80% and sulfide oxidation close to 20%. Thus, the use of a sulfide pulse enabled PN in a SMBBR with zeolite. Organic matter, together with the sulfide pulse, almost completely inhibited the nitrification process despite using zeolite.

Effect of Sulfide on the Processes of Transformation of Nitrogen Compounds and the Microbial Community Composition in the Anammox Bioreactor

“…The anammox process requires nitrite, which was produced in the bioreactor via ammonium oxidation by stage I nitrifiers of the genus Nitrosomonas. Our metatranscriptome data indicate decreased transcription of ammonium monooxygenase genes in the nitrifiers of the order Nitrosomonodales upon the addition of sulfide, which is in agreement with the previous data [4,5]. This resulted in the decreased production of nitrite, which the anammox bacteria require for ammonium oxidation.…”

“…The fact that the nitrifying bacteria may either decrease their growth rate at increasing sulfide concentrations (Otu2), increase it (Otu26 and Otu102), or be insensitive to this compound (Otu11) is both interesting and unexpected. Only inhibition of nitrifying bacteria in the presence of sulfide was reported in all previous studies [4,5,41].…”

“…They are usually associated either with sulfate reduction at the anaerobic stages of water treatment or in the sewage system or with sulfides of industrial wastewater [1,2]. The inhibitory effect of sulfide on the processes of biological water treatment, especially on nitrification, as well as their unpleasant odor and corrosive properties, resulted in elevated attention to sulfide in wastewater [3][4][5].…”

Removal of Ibuprofen and Diclofenac in Batch Nitrifying Reactors: Effect of Natural Zeolite on the Process

“…Nitrifying biomass was obtained from a continuous stirred-tank reactor (CSTR, 15 L liquid volume) with a settler, as previously described in our studies [23,24]. This CSTR with settler has been operated for three years.…”