The current paper describes a novel passive aeration simultaneous nitrification and denitrification (PASND) zeolite amended biofilm reactor that removes organic carbon and nitrogen from wastewater with low-energy consumption. Next to the ammonium oxidizing bacteria (AOB), this reactor contained naturally enriched glycogen accumulating organisms (GAOs) and zeolite powder to initially adsorb BOD (acetate) and ammonium (NH4+-N) from synthetic wastewater under anaerobic conditions. Draining of the treated wastewater exposed the biofilm directly to air enabling low-energy oxygen supply by passive aeration. This allowed the adsorbed ammonium to be oxidized by the AOB and the produced nitrite and nitrate to be reduced simultaneously by the GAOs using the adsorbed BOD (stored as PHAs) as carbon source. Overall, with an operation mode of 1 h anaerobic and 4 h aerobic phase, the nutrient removal efficiency after single treatment was about 94.3% for BOD and 72.2% for nitrogen (NH4+-N). As high-energy aeration of the bulk solution for oxygen supply is completely avoided, the energy requirement of the proposed PASND biofilm reactor can be theoretically cut down to more than 50% compared to the traditional activated sludge process.

ABSTRACT:In wastewater, biological phosphate removal can fail because of the presence of glycogen accumulating organism (GAO), therefore measuring glycogen stored in microbial cultures provides information on the bacterial population type. Once glycogen is hydrolysed to glucose it was accurately measured using a human glucose meter. The standard curves demonstrate linearity regardless of the pre-treatment of the glucose solution at neutral pH.Keywords: Novel Method, PHA, Glucose, Glycogen Accumulating Organisms, Diabetic Glucose MeterEnhanced biological phosphate removal (EBPR) sludge uses phosphate accumulating organisms (PAO) to store poly-phosphate under anaerobic conditions. In aerobic conditions poly-phosphate is lysed, resulting in an ATP source for soluble carbon uptake in the form of poly-hydroxy-alkanoate (PHA)1 . However PAO can be outcompeted by glycogen accumulating organisms (GAO) resulting in poor phosphate removal in wastewater treatment plants 2 . GAO use glycogen anaerobically as an ATP source to store organic carbon, producing PHA 3 . Measuring glycogen in microbial cultures reveals the presence of the GAO.Measuring glycogen requires it to be split into two glucose molecules. This paper

Flavigny, R.M.G. and Cord-Ruwisch, R. (2015) OrganicThis is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The principal reason for the high energy costs for biological wastewater treatment is the poor transfer efficiency of oxygen to the bulk water phase. The current paper describes a biofilm reactor in which oxygen transfer to the bulk solution is avoided by alternating anaerobic submersed (2h) and drained (1 h) operation of the biofilm. During the submersed phase the biofilm enriched for glycogen accumulating organism (GAO) stored the organic carbon (acetate) as poly-hydroxy-alkanoate (PHA). After draining the reactor, this carbon stored as PHA was biologically oxidised, using oxygen directly from the atmosphere. The 12 Cmmol/L (384 mg/L BOD) of acetate was completely removed during long term automated operation of the reactor for 9 months with a cycle length of 3.3 hours. As the process specifically removes dissolved organic carbon but not N or P it could possibly be coupled with novel processes such as Anammox or nutrient recovery.

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