Advanced wastewater treatments have become an area of global focus for many communities, having in view the new, stricter discharge limits, imposed by the European Union Directives. The aim of this work is to evaluate conditions for a possible implementation of a Biological Nutrient Removal (BNR) process in the Wastewater Treatment Plant (WWTP) of Targoviste city (Romania). The problems initial...

This contribution deals with a novel anaerobic-anoxic reactor for biological nutrient removal (BNR) from wastewater, termed AnoxAn. In the AnoxAn reactor, the anaerobic and anoxic zones for phosphate removal and denitrification are integrated in a single continuous upflow sludge blanket reactor, aiming at high compactness and efficiency. Its application is envisaged in those cases where retrofi...

Real-time bioprocess monitoring is crucial for efficient operation and effective control. Aiming to develop an online strategy facilitating optimization, fault detection decision-making during wastewater treatment in a photo-biological nutrient removal (photo-BNR) process, this study investigated the application of Raman spectroscopy quantification total organic content (TOC), volatile fatty ac...

The effects of silver (Ag) nanoparticles (NPs) on activated sludge in a biological nitrogen removal (BNR) process were investigated under aerobic and anoxic conditions. We show that nitrification was more vulnerable to Ag NPs exposure than denitrification at the same Ag NPs concentration. In continuous operation of the BNR process, a higher inhibitory effect on nitrification was attributed to a...

Free ammonium in industries wastewater could be one of the worst toxic contaminants of aquatic life if diluted in water. Biological nitrogen removal (BNR) is the most common method for removing ammonium and nitrate from wastewater. Attached growth and suspended growth are the main BNR systems. The aim of the present work was to study the treatment of petrochemical wastewater (ammonium and nitra...

This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant was compared for a series of model assumptions. Three different model approaches describing BNR are...

In this paper the advantages and disadvantages of denitrifying PAOs (polyphosphate accumulating organisms) in conventional BNRAS (biological nutrient removal activated sludge) and external nitrification BNRAS (ENBNRAS) systems are evaluated, with experimental data exhibiting a range of anoxic P uptake from low (<10%) to very high (>60%). The results indicate that the specific denitrification ra...

Aerobic granular sludge is attractive for high-rate biological wastewater treatment. Biomass wash-out conditions stimulate the formation of aerobic granules. Deteriorated performances in biomass settling and nutrient removal during start-up have however often been reported. The effect of wash-out dynamics was investigated on bacterial selection, biomass settling behavior, and metabolic activiti...

In conventional wastewater treatment, biological nutrient removal (BNR) depends on bacterial assimilation for phosphorus removal and nitrification+denitrification for nitrogen removal, with the resulting loss of the fixed nitrogen resource. Alternatively, treatment by microalgae allows for assimilative removal of both phosphorus (P) and nitrogen (N) thereby avoiding the oxygen demand of nitrifi...

EXTENDED ABSTRACT Nowadays, biological nutrient removal (BNR) processes have been applied widely for wastewater treatment. However, one type of greenhouse gases, nitrous oxide (N2O), can be released from both nitrification and denitrification during BNR. In our previous study, we found that N2O emission during nitrification could be affected by heterotrophic activities significantly in a BNR sy...