Page 36 - March 2020 - WT Site

Siemens Water Technology has developed a new synthetic media, 40%. The polymers increase the viscosity of the water thereby
PerforMedia, to replace the nut shells without needing to change slowing particle movement. This translates into heavy loading
the design of an existing filter system. The synthetic media of a downstream traditional nut shell filters. Because of the high
has better oil affinity and can remove oil at significantly higher possible loading and efficiency of PeforMedia, polymer flood
concentrations than walnut shells. A typical specification calls produced water can be treated without frequent back washing and
for nut shells to remove 100 ppm and achieve less than 10 ppm achieve oil concentrations less than 10ppm.
in the discharge. However, the PerforMedia can meet the same
discharge water quality when slugs are as high as 1000 ppm. Adsorbant

Technologies are available for polishing produced water for the
The size and shape of the media is designed to remove solids as removal of dissolved hydrocarbons or very small droplets without
well as free oil. The solid particles are trapped between the media regular media. The ProSep Osorb media is a silicon backbone
particles and will be back washed with the oil. The PerforMedia based adsorbent media. A unique feature of this media is that
will remove most oil droplets and solid particles as well. The under steam or methane the media can be regenerated and the
success of the PerforMedia can be seen in the results of particle hydrocarbons recovered.
size distribution in the effluent. Almost all the particles remaining
in the water are less than 10 microns. Benzene is the most soluble hydrocarbon, with no droplets or
gravity separation possible for concentrations below 300 ppm,
When polymer floods are used to enhance oil recovery, a
flotation treatment system efficiency can be reduced by up to depending on the process conditions. Osorb media is able to
remove BTEX and highly soluble hydrocarbon to concentrations
below 2 ppm.

Because Osorb media has a high affinity to hydrocarbon molecules,
the process can handle upsets and fast changing concentrations
in the inlet conditions. When used as a polishing filter, Osorb will
need regular backwashing if the upstream process is not stable.
However, even if frequent regeneration is required, the discharge
water quality will be maintained.

38 Water Today - The Magazine March 2020