First demonstration of hydrophobic membrane contactors for removal of ammonia from condensate wastewater

Hydrophobic membrane contactors represent a promising solution to the problem of recovering ammoniacal nitrogen from wastewater. The process has been shown to work best with wastewater streams that present high ammonia concentrations, low buffering capacities and low total suspended solids. The removal of ammonia from rendering condensate, produced during heat treatment of waste animal tissue, was assessed in this research using a hydrophobic membrane contactor. The main objective was to test the ammonia stripping technology using two types of hydrophobic membrane materials, polypropylene and polytetrafluoroethylene, at pilot scale and carry out process modification for ammonia removal. The results demonstrate that polypropylene membranes are not compatible with the condensate waste as it caused wetting. The polytetrafluoroethylene membranes showed potential and had a longer lifetime than the polypropylene membranes, removing up to 64% of ammonia from the condensate waste. The product formed contained a 30% concentrated ammonium sulphate salt which has a potential application as a fertilizer. This is the first demonstration of hydrophobic membrane contactors for treatment of condensate wastewater

Pilot scale study: first demonstration of hydrophobic membranes for the removal of ammonia molecules from rendering condensate wastewater

Hydrophobic membrane contactors represent a promising solution to the problem of recycling ammoniacal nitrogen (N-NH4) molecules from waste, water or wastewater resources. The process has been shown to work best with wastewater streams that present high N-NH4 concentrations, low buffering capacities and low total suspended solids. The removal of N-NH4 from rendering condensate, produced during heat treatment of waste animal tissue, was assessed in this research using a hydrophobic membrane contactor. This study investigates how the molecular composition of rendering condensate wastewater undergo changes in its chemistry in order to achieve suitability to be treated using hydrophobic membranes and form a suitable product. The main objective was to test the ammonia stripping technology using two types of hydrophobic membrane materials, polypropylene (PP) and polytetrafluoroethylene (PTFE) at pilot scale and carry out: (i) Process modification for NH3 molecule removal and (ii) product characterization from the process. Theresults demonstrate that PP membranesarenotcompatiblewiththecondensate wasteasit caused wetting. The PTFE membranes showed potential and had a longer lifetime than the PP membranes and removed upto64%ofNH3 moleculesfromthecondensate waste. The product formed contained a 30%concentrated ammonium sulphate salt which has a potential application as a fertilizer. This is the first demonstration of hydrophobic membrane contactors for treatment of condensate wastewate

Oxygen transfer of microbubble clouds in aqueous solutions: application to wastewater

This study aims at improving the knowledge on the effects of gas injection, bubbles sizes and contaminants on oxygen transfer in microbubble clouds. First the effects of gas injection on oxygen transfer are studied and linked to several parameters that change together with changes in flow rate, namely bubble sizes and rise velocities. Oxygen transfer is then studied in the presence of contaminants that are shown to affect bubble size distribution, modify bubble dynamics and interfacial mass transfer. Oxygen transfer efficiencies are also measured in wastewater and compared with those obtained in aqueous solutions. The agreement between contaminated water in the lab (Triton X100) and wastewater experiments is emphasised as this offers the possibility to develop fundamental understanding relevant to wastewater under laboratory conditions. The role of the surfactants on the volumetric oxygen transfer coefficient is further analysed in terms of specific interfacial area and transfer coefficients, respectively. Interestingly, this shows that the increase in oxygen transfer efficiency as the concentration in Pentanol increases is due to the increase in interfacial area while the transfer coefficients decrease

First demonstration of hydrophobic membrane contactors for removal of ammonia from condensate wastewater

Hydrophobic membrane contactors represent a promising solution to the problem of recovering ammoniacal nitrogen from wastewater. The process has been shown to work best with wastewater streams that present high ammonia concentrations, low buffering capacities and low total suspended solids. The removal of ammonia from rendering condensate, produced during heat treatment of waste animal tissue, was assessed in this research using a hydrophobic membrane contactor. The main objective was to test the ammonia stripping technology using two types of hydrophobic membrane materials, polypropylene and polytetrafluoroethylene, at pilot scale and carry out process modification for ammonia removal. The results demonstrate that polypropylene membranes are not compatible with the condensate waste as it caused wetting. The polytetrafluoroethylene membranes showed potential and had a longer lifetime than the polypropylene membranes, removing up to 64% of ammonia from the condensate waste. The product formed contained a 30% concentrated ammonium sulphate salt which has a potential application as a fertilizer. This is the first demonstration of hydrophobic membrane contactors for treatment of condensate wastewater