Assessment of nitrogen cycle processes by evaluation of redox potentials in seawater and soil at the Santa Ana River salt marsh restoration project.

摘要

Nitrogen cycle processes were assessed by evaluating reduction-oxidation potentials in seawater and soil for a 92 acre reconstructed salt marsh in southern California. A digital device named the Redox Profiler was developed to simultaneously record the redox potential and the distance traversed by the electrode through the water column. Nitrate, nitrite, ammonia, and ammonium ion concentrations were evaluated spectrophotometrically; ammonium ion was the dominant form of nitrogen in the system at levels near 0.1 mg/L. Nitrate reached levels of 3.4 mg/L coincident with high fresh water flows in the Santa Ana River channel. Thermodynamically predicted cell potentials at pH 8.1 and 18