Shrinking
fresh water supplies and increasingly stringent
discharge criteria have many utility providers seeing the millions
of gallons discharged by their wastewater treatment facilities
as a supplemental supply and potential source of revenues. In
order to realize sustainability in wastewater reuse opportunities,
a utility must have confidence in its ability to reliably produce
high-quality effluent.
A
recent six month case study completed by Garver Engineers
evaluated two pilot-scale membrane bio-reactor (MBR) plants
that were targeting extremely low-level effluent phosphorus
concentrations. Both MBR systems proved to be an effective
barrier to particulate matter, including unhydrolyzed solids,
suspended solids and chemical precipitants. Overall, the plant
achieved 99.49% phosphorus removal while producing an effluent
turbidity value an order of magnitude less than typical drinking
water standards.
If
implemented on a full scale system, the effluent produced
by the proposed MBR process could have significant value.
Preliminary estimates for this mid-sized municipality practicing
non-potable reuse of 1.0 million gallons per day indicated
a potential payback for the MBR equipment of approximately
2 years. |
