A feasibility assessment of retrofitting a 25 year-old, 40 MGD surface water treatment plant
(WTP) with membrane microfiltration is presented in this paper. Presently, this WTP employs raw water
ozonation, lime softening, ferric sulfate flocculation, coagulation, sand filtration, fluoride addition
and chlorine disinfection. Capital cost and operation and maintenance costs were evaluated. A
20 year life cycle analysis was utilized to compare between "conventional" rehabilitation and
membrane filtration (MF) retrofit. The study recommended a MF retrofit over a "conventional"
rehabilitation subject to pilot testing confirmation. Because of the superior and consistent quality
of MF permeate, several existing processes were deemed no longer needed and for some a
reduction in number of units. Significant saving in residuals management can be achieved with
MF compared to the existing treatment processes.
The study indicated that the MF with microfiltration/ultrafiltration (MF/UF) technology is feasible,
and is competitive in cost compared to rehabilitation of the existing lime softening plant and
granular media filters if one considers the abandonment of the softening process and its
associated solids handling costs. Instead of raw water ozonation for taste and odor problems, a
permeate ozonation is recommended resulting in significant ozone dose reduction, which in turn
reduces the capacity requirements and power demand on the ozone generation equipment.
Although the feasibility study included the evaluation of split flow water softening using low
pressure reverse osmosis, the discussion is not included in this paper.
A pilot plant demonstration is definitely recommended in order to verify the technology, determine
the design parameters values, and confirm the need for and level of pretreatment required. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 230 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 18 |
| Published : | 11/01/2007 |
