This paper explores the process selection decisions and design considerations that have to be
addressed when installing membrane filtration processes at an existing treatment works. To
illustrate these considerations, examples are drawn from recent Black & Veatch projects
ranging from simple treatment of groundwaters subject to contamination with surface waters
to multi-barrier, multi-stage processes. Design considerations include necessary pre-
treatment, hydraulic design, interface with existing control systems, impact on upstream and
downstream processes including dosing systems, integrity testing and finding and repairing
damaged membranes, process optimization, commissioning and waste disposal. The need for
meaningful pilot testing is also discussed, again with reference to recent projects.
The reasons behind the increase in use of membrane technology are also reviewed. Factors
considered include regulatory drivers, Cryptosporidium oocyst removal, asset renewal,
automation, future-proof technology, minimizing use of chemicals and reduced footprint to
minimize construction cost and land use. Selection of the correct type of membrane is also
paramount to the success of a project. The merits of micro, ultra, nano and tighter membranes
are discussed with their advantages and disadvantages. Similarly, the relative benefits of
submerged and encased membranes is described with reference to recent projects. The lower
capital cost of submerged membranes needs to be evaluated carefully against the higher cost
of pressure driven systems with the need for other supporting infrastructure so that a holistic
appraisal is made. The increased cost and attention to the design of civil works and assessing
the suitability of using existing structures such as clarifier basins and rapid gravity filter shells
is discussed and how this can impact on existing works operation during construction. Includes 3 references, table, figure.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 320 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 9 |
| Published : | 06/16/2002 |
