Many fishes are ammonotelic but some species can detoxify ammonia to glutamine or urea. Certain fish species can accumulate high levels of ammonia in the brain or defense against ammonia toxicity by enhancing the effectiveness of ammonia excretion through active NH4+transport, manipulation of ambient pH, or reduction in ammonia permeability through the branchial and cutaneous epithelia. Recent ...

In this work, reactive absorption of gases in aqueous electrolyte solutions has been investigated resulting in the development of a procedure in order to calculate the concentrations of ionic and molecular species in the liquid phase. Two duplicate experiments were conducted to investigate simultaneous reactive absorption of ammonia and carbon dioxide in partially carbonated ammonia solutio...

Most investigators who have studied ammonia metabolism in liver disease have measured the concentration of ammoniat in whole blood.1'° Only a few authors have used the plasma ammonia concentration.ll" Recently, several cation exchange techniques have been developed that measure the ammonia concentration of plasma.1" There are several theoretical advantages to the use of plasma which compensate ...

BACKGROUND Measurement of pH in exhaled breath condensate (EBC) is robust and simple. Acidic source fluid (airway lining fluid) traps bases while volatilising acids, leading to EBC acidification in many lung diseases. Lower airway ammonia is one determinant of airway lining fluid pH, raising the concern that addition of the base ammonia by contamination from the mouth might confound EBC pH assa...

The current study was conducted to determine the LC(50) value of ammonia-N as well as the effects of acute exposure to elevated ammonia on the haemolymph osmolality, ionic composition, ammonia-N and pH levels of early juvenile mud crabs, Scylla serrata. The results show that early S. serrata juveniles have a high 96-h LC(50) value of 95.35 mg/L ammonia-N (6.81 mg/L NH(3)-N) or 6.80 mmol/L total...

There is an increasing concern over the impact of human-related emissions on the acid precipitation in China. However, few measurements have been conducted so far to clarify the acid-neutralization of precipitation on a regional scale. Under a network of 10 sites across Northern China operated during a 3-year period from December 2007 to November 2010, a total of 1118 rain and snow samples were...

This study was accomplished to examine the efficiency of natural zeolite in preventing acute toxicity of total ammonia to Huso huso. The study was performed using Water Static Method in 96 hours. Fish averaged 46 ? 5 g in weight and 22 ? 4 cm in total length were exposed to four different concentrations (15, 30, 50, 75 mgL-1) of ammonia and a group was considered as control. Under stable condit...

Ammonia-oxidizing bacteria (AOB) can use oxygen and nitrite as electron acceptors. Nitrite reduction by Nitrosomonas is observed under three conditions: (i) hydrogen-dependent denitrification, (ii) anoxic ammonia oxidation with nitrogen dioxide (NO(2)) and (iii) NO(x)-induced aerobic ammonia oxidation. NO(x) molecules play an important role in the conversion of ammonia and nitrite by AOB. Absen...

In this work, removal of ammonia from synthetic wastewater using integrated fixed-film activated sludge (IFAS) process was optimized using response surface methodology (RSM). The main operating parameters such as ammonia concentration rate (ALR) and hydraulic retention time (HRT) were optimized to acquire the maximum removal efficiency. The linear, 2FI, quadratic, mean, and cubic models were ut...