Nitrogen and Phosphorus Treatment Can Be Sustainable During on-Site Wastewater Disposal.

Monitoring of a seasonal-use, on-site wastewater disposal system (septic system) in Canada, over a 33-year period from 1988 to 2021, showed that during recent sampling the groundwater plume had TIN (total inorganic nitrogen) averaging 12.2 mg/L that was not significantly different than early values, representing 80% removal, whereas SRP (soluble reactive phosphate), although higher than early values averaging 0.08 mg/L, was still 99% lower than the effluent concentration.

Nitrogen Attenuation in Septic System Plumes.

The persistence of inorganic nitrogen is assessed in a set of 21 septic system plumes located in Ontario, Canada, that were studied over a 31-year period from 1988 to 2019. In the plume zones underlying the drainfields, site mean NO values averaged 34 ± 27 mg N/L and exceeded the nitrate drinking water limit (DWL) of 10 mg N/L at 16 of 21 sites. In plume zones extending up to 30 m downgradient from the drainfields, site mean NO values averaged 24 ± 20 mg N/L and exceeded the DWL at 9 of 13 sites.

Use of mature willows (Salix nigra) for hydraulic control of landfill-impacted groundwater in a temperate climate.

Phreatophytic trees such as willows and poplars have a large capacity for extracting shallow groundwater, as evidenced by diurnal water table fluctuations corresponding to intensified transpiration during the day. As a result, they have been employed for phytoremediation of shallow contaminated groundwater. In this study, the water extraction (i.

Variable persistence of artificial sweeteners during wastewater treatment: Implications for future use as tracers.

For more than a decade the artificial sweeteners acesulfame (ACE) and sucralose (SUC) have been applied as tracers of the input of wastewater to environmental waters. Recently concerns have been raised that degradation of ACE during treatment may hinder or restrict its use as a wastewater tracer. In this study the value of ACE and SUC as tracers was reassessed based on samples of wastewater at 12 municipal wastewater treatment (MWWT) plants and from 7 septic systems and associated septic plumes in groundwater.

Environmental fluxes of perchlorate in rural catchments, Ontario, Canada.

Quantitative information about fluxes of perchlorate in the environment is lacking. This study reports analyses of perchlorate in various environmental waters sampled from rural headwater catchments in the Thames River basin in southern Ontario (Canada) that provide evidence about the fluxes and fate of perchlorate in the environment. Concentrations in streams (16 to 1047 ng/L) were used to estimate exports from these rural catchments (228-1843 mg/(ha·year)), atmospheric deposition (1480 ± 230 mg/(ha·year)), as well as variable rates of microbial degradation of perchlorate, which appeared to be enhanced in catchments with higher percentages of wetlands.