Teaming Up to Meet Startup Goals at Las Vegas' BNR Facility

Abstract

Using a startup team that was responsible for operational decisions and intensive data collection were the two major success factors during the smooth startup of Las Vegas' 30 mgd BNR plant. The startup team continued to function after initial startup to optimize operations and improve performance.Much of the credit for success is due to the City of Las Vegas' vision. This startup process followed the plant's business plan and let employees get involved in decision making. The payoff was team buy-in for the project, and processes came online with only minor problems. Overall the project has been a huge success, creating a sense of pride for all members involved. Las Vegas also officially recognized startup team members for their contributions.The startup team itself was comprised of plant employees from the operations, maintenance, laboratory, management and electrical groups. The plant designer and operations specialists also helped the start up team with training and phone consultation prior to start up. The team met weekly to discuss problems and to review progress and process performance data. During this time, the team determined process adjustments. Once the process met permit requirements, the team's focus shifted to optimizing plant performance.Process changes focused on sludge age set point and control, DO control, RAS and internal recycle flow rates, the use of ferric chloride for odor control and effluent phosphorus trimming and other process related targets. Phosphorus, ammonia and nitrate profiles demonstrated process startup and provided feedback for optimization. These data profiles are useful to show when phosphorus release and uptake is taking place, whether there was a lack of nitrate to assure anoxic conditions, if secondary phosphorus release is occurring in the aeration basin/secondary clarifier, any failure of the internal mixed liquor pump and the importance of the influent BOD/P ratio.

Mathematical Modelling and Computer Simulation of Activated Sludge Systems

“…Schonberger 1990;Wouters-Wasiak et al 1996;Mulkerrins et al 2000;Hughes et al 2004;Batista et al 2005;Barnard and Abraham 2006;Mikola et al 2009) Substantial amounts (up to 60%) of the phosphate taken up in the aerobic stage of the bioreactor were subsequently released in the clarifier. Schonberger 1990;Wouters-Wasiak et al 1996;Mulkerrins et al 2000;Hughes et al 2004;Batista et al 2005;Barnard and Abraham 2006;Mikola et al 2009) Substantial amounts (up to 60%) of the phosphate taken up in the aerobic stage of the bioreactor were subsequently released in the clarifier.…”