In 2004,ammonia concentration in raw water of Sitalakhya River at the eastern periphery of Dhaka was found higher than the expected rate of 4 mg/Lforecasted in feasibility studies,with a value of about 8 mg/L, which could not be removed by conventional treatment chain employed at Dhaka, hence, recentlyan ammonia removal plant has been constructed. This important background has ledto the current...

Fluorescence and electrophysiological methods were used to determine the effects of intracellular pH (pHi) on cellular NH4+/K+ transport pathways in the renal medullary thick ascending limb of Henle (MTAL) from CD1 mice. Studies were performed in suspensions of MTAL tubules (S-MTAL) and in isolated, perfused MTAL segments (IP-MTAL). Steady-state pHi measured using 2,7-biscarboxyethyl-5(6)-carbo...

the effects of different concentrations of cdcl2 and alcl3 on nh4+ and no2? oxidation in an aqueous system were investigated. alcl3 had no effect on nh4+ removal and its oxidation to no2?, whereas no2? disappearance was greatly enhanced by alcl3. in contrast, cdcl2 delayed removal of nh4+ and its subsequent oxidation to no2? and also decreased the rate of no2? disappearance. when compared to th...

On the base of land disposal, the objective of this study was to use constructed rapid infiltration (Abbreviation: CRI) to improve slightly polluted surface water in town. The data indicated that the average removal rates of BOD5 and NH4 -N were 80% and 65% in summer, respectively. In winter, the removal rates of BOD5 decreased evidently with the lowering of water temperature, but the change of...

Nitrogen (N) enrichment of biochar from both inorganic and organic waste N sources has the potential to add economic and environmental value through its use as a slow release N fertilizer. We investigated the sorption of N by, and its release from, biochar made at pyrolysis temperatures of 400, 500 and 600 °C from three feedstocks: poultry litter (PL with a carbon (C) to N ratio (C:N) of 14), s...

The simultaneous removal of formaldehyde and ammonium in a lab-scale activated sludge unit was investigated. The unit was operated at a hydraulic retention time of 2.4 days with an ammonium concentration in the influent of 350 mg NH4+-N/L, maintaining the ammonium loading rate at 0.15 g NH4+-N/Ld during the operation time. However, the applied organic loading rate was increased stepwise by incr...

Beef cattle feedlots contain unconsolidated material that accumulates on the feedlot surface during a feeding cycle. This study was conducted to measure the effects of varying diameters of unconsolidated surface material and varying flow rates on nutrient concentrations in runoff. Unconsolidated surface material with an average diameter of 4.76, 9.53, 19.1, or 47.5 mm and a composite sample wit...

A batch sorption process for removal of ammonium ions from aqueous solution using natural zeolite was studied. Tree different particle sizes of zeolite (1-2 mm, 2-4 mm and 4-10 mm) were used in the experiments. Sorption of ammonium ions on natural zeolite were carried out at 298 K with the initial concentrations of ammonium in the range of 1000 – 7000 mg NH4 -N/dm. Equilibrium data were fitted ...

Streams alter the concentration of nutrients they transport and thereby influence nutrient loading to estuaries downstream; however, the relationship between in-stream uptake, discharge variability, and subsequent nutrient export is poorly understood. In this study, in-stream N and P uptake were examined in the stream network draining a row-crop agricultural operation in coastal North Carolina....