Evaluation of Ammonia and Phosphate Analyzers for Use in Low Nutrient, High Mixed Liquor Applications at BRWRF

摘要

Broad Run Water Reclamation Facility (BRWRF) in Ashburn, VA is a membrane bioreactor facility owned and operated by Loudoun Water. In November 2018, Loudoun Water began an Analyzer Pilot Program to evaluate the performance and maintenance requirements for two ortho-phosphate and two ammonia wet chemistry analyzers in side-by-side comparisons. The ammonia analyzers were placed in the final zone of one of BRWRF's Biological Reactor Basins, where the mixed liquor suspended solids concentration is typically between 8,000 - 10,000 mg/L and the ammonia concentration is typically below 0.20 mg/L. The ortho-phosphate analyzers were placed in the membrane permeate, where the ortho-phosphate concentration is typically below 0.05 mg/L. Results from the Analyzer Pilot Program demonstrated that all four wet chemistry analyzers were able to reliably provide nutrient concentration measurements at or near the analyzers' lower limits. The results also demonstrated that neither filter unit used alongside the ammonia analyzers required excessive maintenance due to clogging at the high MLSS concentrations at BRWRF.