Paul Johnston

TL;DR: Relatively high nitrogen loading was found on the septic tank sites discharging effluent into highly permeable subsoil that counteracted any significant denitrification, although a clear relationship to the soil mineralogy was determined.

TL;DR: An apparent increase in metal accumulation with time may be linked to the cumulative annual production and deposition of organic matter, indicating the importance of the vegetation as an integral part of the treatment process.

TL;DR: It is shown that CWs significantly influence NO3--N attenuation to reactive forms of N in the groundwater beneath them and that solely focusing on within wetland NO3-N attenuated can underestimate the environmental benefits of wetlands.

TL;DR: In this paper, the long-term performance of a constructed wetland treating highway runoff has been studied with respect to heavy metal removal in a temperate, maritime Irish climate, and the accumulation of heavy metals in both the sediment and the plants growing in the wetland have been quantified over a 6 year period of operation as well as the spatial distribution of the metals’ deposition.