Reverse Osmosis Concentrate (ROC) Management Pilot Project
Sunlight Photolysis
1. Photolysis is a natural process where sunlight breaks apart
large organic molecules that can be more easily removed from the
water.
2. Large organic molecules in the wetland break apart with the
assistance from sunlight.
3. Once the molecules are broken apart, they can be removed
through the biomat. Wetland #2 uses ozone to break apart bonding
agents that prevent the removal of toxic metals.
Biomat Treatment
RO Concentrate
MetalsChemicals of Emerging Concern Nutrients
Biomat
4. Micro-organisms within the biomat work to metabolize and
accumulate organic compounds and metals. The result is a
biologically treated concentrate with reduced organic contaminants
and toxicity.
ROCStorageTank 1
ROC StorageTank 2
Silicon Valley Advanced Water Puri�cation Center
(SVAWPC)
Ozone Injection Trailer
to otheradditionaltreatment
Wetland #1(ROC without Ozone)
Wetland #2(ROC with Ozone)
The Santa Clara Valley Water District is investing in
alternative and environmentally friendly methods for the treatment
and disposal of the reverse osmosis concentrate (RO concentrate)
that results from the water puri�cation process. The water district
partnered with the organizations listed below on a pilot project to
study on the use of an engineered wetland to treat RO concentrate.
The wetland uses a combination of sunlight photolysis, ozone
injection, and a biological mat made of algae and bacteria to
remove nutrients, metals, and contaminates from the RO
concentrate.
The diagram below describes the treatment process. The pilot
project is schedule to sunset at the end of 2019. We expect the
results will yield new and innovative solutions. Visit
www.valleywater.org to learn more about the project.
