Publications by authors named "Andrew N Shilton"

Waste stabilization ponds (WSP) are one of the most common forms of wastewater treatment for smaller communities globally, but have poor phosphorus removal. It is known that WSP algae can accumulate polyphosphate within their cells in excess of that needed for cell function. If polyphosphate accumulation could be triggered at the higher range of WSP cell concentrations, phosphorus removal from domestic wastewater could be significantly improved.

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The New Zealand Greenhouse Gas Inventory (the NZ Inventory) uses country-specific data to quantify CH emissions from anaerobic ponds treating dairy farm effluent (315 Gg CO equivalent [CO-e] in 2009). In this study, we used literature data to: (i) evaluate the accuracy of the NZ Inventory's parameters used to quantify these CH emissions; and (ii) determine whether the NZ Inventory's scope is capturing the full spectrum of sources with bio-CH potential entering anaerobic ponds. The research indicated that the current NZ Inventory methodology is underestimating CH emissions from anaerobic ponds across New Zealand by 264 to 603 Gg CO-e annually.

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At present, resource recovery by irrigation of wastewater to plants is usually driven by the value of the water resource rather than phosphorus recovery. Expanded irrigation for increased phosphorus recovery may be expected as the scarcity and price of phosphorus increases, but providing the necessary treatment, storage and conveyance comes at significant expense. An alternative to taking the wastewater to the plants is instead to take the plants to the wastewater.

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Phosphorus removal in waste stabilization ponds (WSP) is highly variable, but the reasons for this are not well understood. Luxury uptake of phosphorus by microalgae has been studied in natural systems such as lakes but not under the conditions found in WSP. This work reports on the effects of phosphate concentration, light intensity, and temperature on luxury uptake of phosphorus by WSP microalgae in continuous culture bioreactors.

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