Environmental problems such as eutrophication caused by excessive nutrient discharge are global challenges. There are complex pollution sources of nitrogen (N) discharge in many river basins worldwide. Knowledge of its pollution sources and their respective load contributions is essential to developing effective N pollution control strategies. N loads from all known anthropogenic pollution sour...

ing beef cattle feedlot manure under tilled and n-till conditions. This study was conducted on a steep (12% average slope) Monona silt loam (fine-silty, mixed, superactive, mesic Typic Hapludolls) soil near Treynor, Iowa. The experiment was a split-plot with no-till and disked systems as main plots and subplots of manure, fertilizer, and check with or without a grass hedge. A rainfall simulator...

A six months study was carried out in an alternative shrimp paddy cultivation plot situated Khulna District, Bangladesh. In soil, the mean values of sodium (Na) 13.33 mg l-1, calcium (Ca) 42.12 potassium (K) 472.50 iron (Fe) 1.01 phosphorus (P) 7.05 sulfur (S) 46.67 ammonium-nitrogen (NH4+-N) 247.68 nitrate-nitrogen (NO3--N) 114.78 pH 8.09, Electric conductivity (EC) 4.45 ms m-1, redox potentia...

The effectiveness of a nonvegetated lab-scale subsurface flow constructed wetland for wastewater treatment had been evaluated with the feed ammonium concentration of approximately 20-40 mg of NH4(+)-N L(-1) and a hydraulic retention time of approximately 10 d. The present system had a nitrification zone plus a sulfur/limestone (S/L) autotrophic denitrification zone followed by an anaerobic poli...

a biofilm sequencing batch reactor with a volume of 1.42 m3, nylon nets providing a 4,140 m2/m3 support area for biofilms and an automated operation with 8 hour cycles was studied. the duration of the experiment was 135 days. removal efficiencies e≥ 80% were obtained for carbonaceous matter, producing an effluent with 31±26.8 mg/l of filtered cod, 7±3.6 mg/l of bod5 and 12±3.2 mg/l of toc. the ...

We combine field observations, microcosm, stoichiometry, and molecular and stable isotope techniques to quantify N2O generation processes in an intensively managed low carbon calcareous fluvo-aquic soil. All the evidence points to ammonia oxidation and linked nitrifier denitrification (ND) being the major processes generating N2O. When NH4(+)-based fertilizers are applied the soil will produce ...

Anaerobic Membrane Bioreactor technology has great advantages for treating wastewater, including energy recovery from organic matter. However, when the legislation requires that effluent standards be met in sensitive areas, this treatment cannot remove nutrients, thus permeate generated needs post-treatment. Apart biological processes, ion exchange is an alternative stream since it can nutrient...

In this study, a microbial fuel cell (MFC) that can achieve simultaneous anode anaerobic ammonium oxidation (anammox) and electricity generation (anode anammox MFC) by high-effective bacteria fed with purely inorganic nitrogen media was constructed. As the influent concentrations of (NH4+-N) nitrite (NO2−-N) gradually increased from 25 to 250 mg/L 33–330 mg/L, removal efficiencies NH4+-N, NO2−-...

Protylonolide is a lactonic precursor of tylosin aglycone, produced by a mutant of Streptomyces fradiae. It originates from n-butyrate, propionate and acetate units. Studies were carried out using a protylonolide-producing mutant on the correlation between protylonolide biosynthesis, regulation by NH4+ and amino acid metabolism. Protylonolide production decreased in a defined medium containing ...