Within the first 17 months of operation, the pressure filters at a 1.8 MGD (78.9 l/s) water
treatment plant began having trouble. The operator first observed problems by a shortening of
the filter run. When one of the hatches blew out, the operator had his first look at what was
going on inside of his filters. He saw an orange slime coating the interior walls. Further
inspection of all the filters showed an accumulation of fine sediment on the top of the media and
mud balls, in addition to the orange film. In spite of corrective actions by its second year the
plant was reduced to half the design capacity, well below its operating efficiency and required
extensive maintenance.
Review by the manufacturer and engineer recommended media replacement, as they
attributed the plant's poor performance to damaged media. The cause of the crushing was
unclear. In the absence of a directed investigation it was probable that media failure would
recur.
This study was performed as an academic research project and incorporated analytical
evaluation and physical testing, adapted from conventional gravity systems for pressure
filtration. Working together with the local water department and manufacturers, the authors
conducted this independent plant study with the support of Northeastern University's College of
Engineering. It has enabled effective identification of equipment shortcomings, implemented
structural corrections, improved plant productivity and increased media life. Includes 10 references, tables, figures.
| Edition : | Vol. - No. |
| Number of Pages : | 54 |
| Published : | 06/01/2007 |
