Off-site Cleaning and Restoration (OSCAR)
Off-Site Cleaning and Restoration (OSCAR) is available when cleaning on-site is not practical or possible. Reverse Osmosis (RO) membranes are pre-tested, cleaned and post-tested with the goal of restoring performance to original factory specifications.
OSCAR, developed by Avista, uses equipment specifically designed to provide ideal flow rates, water temperature, and cleaning pressures. OSCAR pressure vessels accommodate a maximum of three standard 40″ membranes. This means that the applied pressure necessary to for optimum flow rates is significantly lower than that required to clean the six or seven membranes typically housed in on-site vessels.
This evaluation validates the effectiveness of a cleaning regimen. Pre- and post-cleaning test data confirm improved permeate flow and rejection and reduced delta pressure to predict the results of a full-scale system cleaning.
Why Clean Off-site?
- Inadequate clean-in-place (CIP) systems
- Lack of personnel
- Discharge restrictions related to cleaning solutions
OSCAR Cleaning Study
The Avista OSCAR Cleaning Study is a troubleshooting tool where we clean a single element with heavy debris or feed spacer channel blocking and identify what stage the failure exists in the system.
Laboratory Cleaning Study
Laboratory cleaning studies have become an integral part of the Avista membrane autopsies and a useful tool in validating the effectiveness of a cleaning regime against a site-specific foulant.
While Autopsies identify foulants and recommend solutions to minimize future fouling, cleaning studies identify the best cleaner(s) and procedure to address fouling on the membranes or MF/UF already affected.
This approach can also provide an opportunity for us to custom blend and test chemistries specifically for your application or site-specific foulant.
Samples of a dissected membrane or casing are placed on a clear cell tester and baseline flow and rejection performance are established under crossflow conditions. A cleaning solution is then recirculated through the tester at optimum temperature. Upon completion, post-clean data is recorded to determine the effectiveness of that particular chemistry. If necessary, this process continues until we’ve identified the cleaner that provides the best result.
If a second, intact membrane element has also been provided, then the cleaning regimen identified in the laboratory study is tested on our full scale OSCAR cleaning skid or full module. Pre-test and post-test data validates the effectiveness of the chemistry and procedures.
A thorough and up-to-date water analysis is a critical aspect in selecting a targeted and properly-dosed antiscalant product for reverse osmosis (RO) or nanofiltration (NF) systems of any size and water quality. Selective ions must be tested in the feed water in order to predict the scale/fouling potential in the system. The specific ions tested are then entered into the Avista Advisor Projection software where recovery rates, antiscalant selection, dose rates and potential scales/foulants are determined.
The MMF Filtration Study helps determine the most efficient and cost-effective dosage of RoQuest® coagulant for site-specific feedwaters. The MMF Laboratory Analysis uses particle counts, zeta potential, and turbidity to characterize a water sample for colloids and silt and determine its fouling potential. The analysis can be done on feedwater or filtrate to gain a better understanding of the foulant parameters.
To assist you in identifying site-specific foulants, we offer Membrane Autopsies. Our Autopsies include Chromatic Elemental Imagingsm (CEI), an innovative technology first introduced by Avista that can identify the location and relative concentration of elements in a membrane fiber sample.