Brown and Caldwell Home Page
Technical Papers RECENT PAPERS    ALL PAPERS      LOG IN

Brown and Caldwell engineers and scientists are technical and thought leaders in the environmental sector. Meet the people who have been advancing innovation for more than 70 years.
Author      Title/Abstract      

Comparing Implementation of MBBR versus BAF on a Space Constrained Site
Author: Seval Sen, Victor Occiano, Pete Wong, and Alan Langworthy
Date: 10/08
Preprint WEFTEC ’08, Chicago, IL, October 18-22, 2008

The City of San Diego has been evaluating high-rate technologies for the possible use at the Point Loma Wastewater Treatment Plant should an upgrade from chemically enhanced primary treatment be needed. The results of a biological aerated filters (BAF) pilot test conducted earlier by Brown and Caldwell shows that the BAF process should be considered. In addition, a concept involving high rate plate settler followed by moving bed bioreactor (MBBR) and dissolved air flotation clarification was investigated and compared with the BAF. Although the proposed MBBR process train seems viable, the proposed loading rates for each process unit were at the upper end of the typical operating range. The total project capital cost was about $116 million lower for the MBBR alternative as compared to BAF alternative. However, the net present value for the MBBR alternative was $40 million higher, mainly because of increased chemical and power demands.