Groundwater flow and nutrient transport were studied in a riparian meadow during a three-year period. The meadow is situated along a first order stream in the River Gjern catchment area, Jutland, Denmark. Field data included measurements of hydraulic head, hydraulic conductivity and soil characteristics. Groundwater sampled from piezometers was analysed for nitrate, ammonium and phosphate. Nitr...

A novel combined system established for nitrate removal from aqueous solution consisted of two parts: sulfur autotrophic denitrification and bio-electrochemical denitrification based on proton-exchange membrane electrodialysis (PEMED). The system was operated at various hydraulic retention times (HRT) and current intensities. Its optimum operation condition was also determined. The combined pro...

This study investigated the potential of aeration control for the achievement of N-removal over nitrite with aerobic granular sludge in sequencing batch reactors. N-removal over nitrite requires less COD, which is particularly interesting if COD is the limiting parameter for nutrient removal. The nutrient removal performances for COD, N and P have been analyzed as well as the concentration of n...

The present study aims at optimising the nitrification and denitrification phases at intermittently aerated process (activated sludge) removing nitrogen from municipal wastewater. The nitrogen removal performance recorded at 22 intermittently aerated plants was compared to the results obtained from the simulations given by the widely used ASM1. It is shown that simulations with a single value f...

Two-chamber Microbial Fuel Cells (MFC) using graphite rods as electrodes were operated for simultaneous anaerobic sulfide and nitrate removal coupled with electricity generation. The MFC showed good ability to remove substrates. When the influent sulfide and nitrate concentrations were 780 mg/L and 135.49 mg/L, respectively, the removal percentages of sulfide and nitrate were higher than 90% an...

The discharge of excess nitrogen to streams and rivers poses an existential threat to both humans and ecosystems. A seminal study of headwater streams across the United States concluded that in-stream removal of nitrate is controlled primarily by stream chemistry and biology. Reanalysis of these data reveals that stream turbulence (in particular, turbulent mass transfer across the concentration...

The efficiency of the application of a chemically-modified activated carbon surface was investigated. The purpose of this study was to examine the effect of treatment with CaCl2 solution at a concentration of 2000 mg.L on the sorption of nitrate ions from aqueous solutions in successive sorption/t reatment cycles. The sorbent was initially subjected to chemical treatment with CaCl2 and subseque...

Nitrate-containing compounds are considered as groundwater contaminants, the concentration of whichhas been growing in these resources during recent years. As a result, it seems necessary to use effectivemethods to remove nitrate from water and wastewater. Adsorption is generally considered moreeconomical in water treatment compared to other feasible a...

Hewletts Creek, in Wilmington, North Carolina, drains a large suburban watershed and as such is affected by high fecal bacteria loads and periodic algal blooms from nutrient loading. During 2007, a 3.1-ha wetland was constructed to treat stormwater runoff from a 238-ha watershed within the Hewletts Creek drainage. A rain event sampling program was performed in 2009-2010 to evaluate the efficacy...