Inorganic nitrogen dynamics in the River Seine downstream from Paris (France)

Abstract

Abstract. The River Seine, below Paris, receives the effluents from a large sewage treatment plant, increasing the ammonium concentration up to 6 mgN.1-in late summer. Careful measurement of ammonium, nitrate and organic nitrogen during the downriver travel of the water masses over 100 km below the ouffall, along with direct determination of nitrification and benthic fluxes, allowed to establish a budget of nitrogen transport and transformations in this reach of the river. Nitrification is shown to start after a distinct period of several days required for the growth of a significant nitrifying bacterial population. Denitrification is active in the upper layer of bottom sediments but absent from the water colunm. Comparison of our data with those published for the period [1973][1974][1975][1976] shows that the nitrate load carried by the river has increased not only because of higher runoff of agricultural nitrate in the upstream part of the watershed, but also as a result of the severe reduction in the rate of denitrification processes, owing to the restoration of better oxygen conditions.

Nitrogen Behaviour and Nitrous Oxide Emission in the Tidal Seine River Estuary (France) as Influenced by Human Activities in the Upstream Watershed

“…Indeed, benthic denitrification, as it is controlled by the nonfractionating process of nitrate diffusion into the anoxic sediment layers, does not cause any significant change in the natural isotopic composition of nitrate . Some direct measurements of the benthic nitrate flux through the water sediment interface allowed Chesterikoff et al (1992) to estimate a benthic denitrification of at least 3 · 10 3 kg N d À1 in the riverine sector downstream of the Ache`res WWTP outlet.…”

Effects of high ammonia concentrations on three cyprinid fish: Acute and whole-ecosystem chronic tests

“…Thus, the toxicity of total ammonia increases as pH or temperature increases (USEPA, 2013), and pH is increasing with phytoplankton production, which, in turn, may be stimulated by higher loading of ammonia (Moss et al, 2013). However, aquatic ecosystems possess mechanisms reducing accumulation of ammonia: (1) uptake by aquatic algae and macrophytes as their nitrogen source (Mulholland et al, 2000;Peterson et al, 2001;Dodds et al, 2002), (2) transfer to sediments by adsorption on particulates (Rosenfeld, 1979;Mackin and Aller, 1984;Peterson et al, 2001), (3) emission to the atmosphere in the form of N 2 via nitrification-denitrification (Admiraal and Botermans, 1989;Chesterikoff et al, 1992;Mulholland et al, 2000;Peterson et al, 2001), and (4) NH 3 volatilization at the airwater interface (Young and Huryn, 1999;Jha et al, 2001;Hall and Tank, 2003;Passell et al, 2007). Accordingly, the organisms in natural lake ecosystems are often exposed lower ammonia concentrations than would be expected from the loading.…”

The response of river nitrification to changes in wastewater treatment (The case of the lower Seine River downstream from Paris)

“…In the 1970s, a significant fraction of Paris wastewater was still discharged without treatment, causing a major drop in oxygen concentration in a 100 km river stretch immediately downstream the largest wastewater treatment plant (WWTP) of Paris conurbation, called Seine Aval (SAV) at 65 km (Chesterikoff et al, 1992). Better organic matter elimination from sewage improved the oxygenation level in this sector.…”