Advancements in biofilm carriers and gas-permeable membranes: assessment of zeolite technologies for shortcut nitrogen removal applications in wastewater

Abstract

The partial nitrification-anammox (PNA) process and other shortcut nitrogen removal processes have been widely studied because of their potential to offer cost savings during wastewater treatment; nevertheless, sustainable examples of...

Stormwater applications of zeolite-coated biofilm carriers for ammonium removal with possible applications to PFAS biotransformation

“…This differs from what one might expect based on previous research that showed that zeolite was still capable of exchanging ammonium when covered by biofilm. 40 Nevertheless, those previous results were obtained under equilibrium conditions and not under conditions that were dominated by sorption kinetics. 40 As with the Z and C carrier-containing reactors, no nitrite was detected in the influent or the effluent.…”

“…40 Nevertheless, those previous results were obtained under equilibrium conditions and not under conditions that were dominated by sorption kinetics. 40 As with the Z and C carrier-containing reactors, no nitrite was detected in the influent or the effluent. Nitrate was detected in the influent to the reactors at 0.47 ± 0.40 mg N L −1 , and subsequently decreased in the effluent of both the ZP and CP carrier reactors (Fig.…”

“…Although it is difficult to determine whether anaerobic or aerobic ammonium oxidation was active on the carriers, based on previous observations of enhanced biological ammonium degradation under simulated mainstream wastewater conditions, it is likely that given time and the development of a more robust biofilm on the carriers, the biological component of ammonium removal in actual or simulated stormwater treatment systems would increase. 39,40…”

“…Experiments were performed with laboratory-scale flow-through reactors to monitor ammonium removal and the retention and/or enrichment of anammox bacteria and AOB during simulated storm events. The reactor configuration was identical to that of previous work 40 and is shown in Fig. 2.…”

“…35,36 Of particular importance is the fact that one feammox strain, A6, has been found to reductively defluorinate PFOS and PFOA, 37,38 which could have implications for treating PFOS and PFOA in situ , as defluorination is an important first step to further degradation and detoxification.2NH 4 + + 3O 2 → 2NO 2 − + 4H + + 2H 2 O2NH 4 + + 2NO 2 − → 2N 2 + 2H 2 O3Fe 2 O 3 ·0.5H 2 O + 10H + + NH 4 + → 6Fe 2+ + 8.5H 2 O + NO 2 − In previous work, novel biofilm carriers were developed for the retention of anammox bacteria in wastewater environments. 39,40 Polyethylene carriers with a porous structure (typical pore size of 10–25 μm) were loaded with zeolite to create carriers that we refer to as zeolite-coated. 41 The zeolite in/on these carriers sorbed ammonium at the surface of the carriers, resulting in the enrichment and retention of anammox bacteria with improved total nitrogen (TN) removal performance compared to carriers lacking zeolite.…”