The plant was required to treat 30m³/day
of effluent from potato washing. Both home produced and imported
potatoes were being processed at the site in Cambridge and
it was necessary to segregate the washings to avoid the possibility
of imported bacteria or viruses in soil washed from imported
potatoes being released.
Process design and equipment specification.
The plant consists of a collecting sump and separate primary
settling tanks for soil bearing wash water from the home produced
and imported potatoes. After settlement wash water from the
home produced potatoes is treated biologically. Settled washwater
from imported potatoes is treated in the rinse recovery section.
Spray rinse water from both home produced and imported potatoes
is collected and treated in the rinse recovery section which
comprises crossflow microfiltration followed by ultraviolet
disinfection. This combination is effective in removing bacteria
and viruses from the recovered water and renders it suitable
The concentrate from the crossflow microfiltration unit is
treated with settled sludge in the biological treatment plant.