The project team of MWH and the City of San Diego recently completed a 12-month membrane
bioreactor (MBR) pilot testing program at the Point Loma Wastewater Treatment Plant (San
Diego, California). This U.S. Bureau of Reclamation funded study assessed the performance of four
newly developed MBR systems recently available to the U.S. municipal wastewater treatment
market. Pilot systems (capacities 5-20 gpm) were operated on raw municipal wastewater for a
target period of 3,500 hours under average and peak flow conditions. The productivity of the
systems was evaluated by measuring the increase in transmembrane pressure (TMP) under
constant flux conditions. Each system was also evaluated for its ability to meet Title 22 Water
Recycling Criteria for membrane systems as outlined by the California Department of Health
Services (CDHS). Test results from this study showed the newly developed MBR systems
operated with cleaning average intervals of 300 - 1200 hours under average design conditions. In
addition each system consistently produced effluent water quality expected from MBR
technology for municipal wastewater treatment (i.e. BOD5 < 2 mg/L, ammonia < 0.3 mg-N/L,
turbidity < 0.2 NTU and total coliform < 100 CFU/100 ml) and based on results from this study
were granted conditional approval by CDHS. Though overall the new MBR systems
demonstrated good productivity and water quality performance, the performance of several of
the systems degraded during the test period due to issues such as loss of membrane integrity,
mechanical failures and/or pilot design issues. MBR systems operated with minimal or no
fouling under peak flux conditions over a 6-day period; however, the specific flux of the
submerged MBR systems decreased during peaking (i.e. 4 hours per day) while that of the
external MBR remained constant. Cost estimates of the newly developed MBR systems revealed
capital costs ($K) of 1 MGD capacity reclamation systems ranged from $7,990-9,850 while
O&M costs ($K/year) for this capacity ranged $218-$302. Includes 15 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 570 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 18 |
| Published : | 03/01/2007 |
