HighlightsDenitrifying woodchip bioreactors treat nitrate-N in a variety of applications and geographies.This review focuses on subsurface drainage bioreactors and bed-style designs (including in-ditch).Monitoring and reporting recommendations are provided to advance bioreactor science and engineering.Abstract. Denitrifying bioreactors enhance the natural process of denitrification in a practical way to treat nitrate-nitrogen (N) in a variety of N-laden water matrices. The design and construction of bioreactors for treatment of subsurface drainage in the U.S. is guided by USDA-NRCS Conservation Practice Standard 605. This review consolidates the state of the science for denitrifying bioreactors using case studies from across the globe with an emphasis on full-size bioreactor nitrate-N removal and cost-effectiveness. The focus is on bed-style bioreactors (including in-ditch modifications), although there is mention of denitrifying walls, which broaden the applicability of bioreactor technology in some areas. Subsurface drainage denitrifying bioreactors have been assessed as removing 20% to 40% of annual nitrate-N loss in the Midwest, and an evaluation across the peer-reviewed literature published over the past three years showed that bioreactors around the world have been generally consistent with that (N load reduction median: 46%; mean ±SD: 40% ±26%; n = 15). Reported N removal rates were on the order of 5.1 g N m-3 d-1 (median; mean ±SD: 7.2 ±9.6 g N m-3 d-1; n = 27). Subsurface drainage bioreactor installation costs have ranged from less than $5,000 to $27,000, with estimated cost efficiencies ranging from less than $2.50 kg-1 N year-1 to roughly $20 kg-1 N year-1 (although they can be as high as $48 kg-1 N year-1). A suggested monitoring setup is described primarily for the context of conservation practitioners and watershed groups for assessing annual nitrate-N load removal performance of subsurface drainage denitrifying bioreactors. Recommended minimum reporting measures for assessing and comparing annual N removal performance include: bioreactor dimensions and installation date; fill media size, porosity, and type; nitrate-N concentrations and water temperatures; bioreactor flow treatment details; basic drainage system and bioreactor design characteristics; and N removal rate and efficiency. Keywords: Groundwater, Nitrate, Nonpoint-source pollution, Subsurface drainage, Tile.

The wind effect on river water quality was illustrated by means of thermohaline measurements carried out in the Tiber River in May 2012. The survey was carried out using a boat, in stations located in the two Tiber\ud branches: Fiumara Grande and Traiano Canal. Thermohaline\ud variables (salinity and temperature) were used to\ud describe the water-type patterns and to define the saltwedge position. Although the river flow rate was rather\ud high, saltwater intrusion happened. Wind data suggested\ud that the more probable cause of salt-wedge intrusion was\ud the wind action. Especially wind speeds higher than 4 m/s\ud are able to dominate the sea current at surface layers,\ud determining an increase in the sea level. Therefore, westerly winds determined a seawater inflow in the river\ud mouths

A yearly survey in a piezometric network was realized in the Litorale Romano Natural Reserve (Rome, Central Italy), collecting water table and chemo-physical data. Monthly chemo-physical surveys highlighted a groundwater salinization variability in a coastal unconfined aquifer. The aquifer is mostly composed by aeolian sands of a still preserved dune ridge environment, on which a pine forest develops. The groundwater salinity variability resulted is connected to the wind pattern and rainfalls. In fact, wind speed higher than 4 m/s is responsible for generating sea salt aerosols (SSA) from sea surface. A statistical analysis was performed for wind with a speed higher than 4 m/s, to detect wind orientation. The dry deposition of SSA on the tree foliage appeared correlated to the westerly winds, blowing in the springtime. When the rainy season occurs, the SSA is washed out from the trees and it is directed to groundwater, where an enhancement of the Electrical Conductivity (EC) values is noticed. Whenever rain events occur and winds are not westerly, a dilution of groundwater salinity takes place and consequently a reduction of EC. Chemical analyzes were realized as well. They confirmed that groundwater of piezometers located close to the coast line is enriched of SSA elements

This paper supports the ‘Hydrogeological map of the Sabatini Volcanic District’. The map provides an overview of the hydrogeological setting of the Sabatini Volcanic District, using experimental water level data integrated with former volcanological and hydrogeological studies. The 1:50,000 scale map was produced in order to provide support to local authorities and professionals working on groundwater management. Fifteen hydrogeological complexes were defined based on volcanological properties and hydrogeological conditions

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