Journal article

Monitoring of ammonia in marine waters using a passive sampler with biofouling resistance and neural network-based calibration

Lenka O'Connor Sraj, Maria Ines GS Almeida, Simon M Sharp, Ian D McKelvie, Richard Morrison, Spas D Kolev



A biofouling resistant passive sampler for ammonia, where the semi-permeable barrier is a microporous hydrophobic gas-diffusion membrane, has been developed for the first time and successfully applied to determine the time-weighted average concentration of ammonia in estuarine and coastal waters for 7 days. Strategies to control biofouling of the membrane were investigated by covering it with either a copper mesh or a silver nanoparticle functionalised cotton mesh, with the former approach showing better performance. The effects of temperature, pH and salinity on the accumulation of ammonia in the newly developed passive sampler were studied and the first two parameters were found to influen..

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Funding Acknowledgements

The authors would like to thank EPA Victoria and CAPIM, for the loan of field equipment and assistance from EPA staff, namely, Chris Garland, Adele McKenzie and Mick Ernest, also Professor Vincent Pettigrove (RMIT University, former CEO of CAPIM), and Mr. Andrew Longmore for assistance with field work and sampling guidance. The authors would also like to thank Mr. Roger Eastham and the Royal Yacht Club of Victoria for allowing field work in the marina, Parks Victoria for permitting field work in the coastal waters of Nerm (PPB) and Werribee River estuary, and Melbourne Ports for allowing field work in the Birrarung (Yarra River) estuary. Mr. Marcus Hammarstedt assisted with the graphic design of Fig. 1, and Lenka O'Connor Sraj is grateful to the University of Melbourne for the award of a postgraduate scholarship.