Avista Technologies offers an array of technical and support services which can be effective tools in improving the performance of reverse osmosis membranes.
Water Analysis: using a minimum of half a gallon (2 liters) of RO feedwater, this test provides the cation and anion data necessary to obtain an accurate and site specific antiscalant recommendation.
Avista Advisor Program: using a complete mineral analysis, this program supplies the user with detail ion saturation data, product selection, dosage, and usage information.
Foulant Identification: requires a membrane leaf which is examined to determine the nature of any foulants present and their effect on the membrane. Potential foulants can include scale, biological matter, metals, etc.
Filtration Study: requires a minimum of five gallons (20 liters) of feedwater to the multi-media or sand filter sent to Avista. From this sample, jar test procedures allow for optimum RoQuest coagulant /filter aid recommendation. Dosage determinations provide the most efficient and cost effective coagulation within the filter.
Particle Counts: using a minimum of a pint (0.5 liters) of filter feedwater, this test provides total particle data ranging from 2-50 µm.
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 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 are placed on a RoVision 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.
The physical dissection of an RO membrane and the laboratory analysis of its foulants can be one of the most definitive methods of troubleshooting an RO system. An Avista autopsy includes a wide range of procedures, as shown below, and concludes with our written report and recommendations.
- External visual examination
- Internal visual examination
- Wet test of the element
- Chemical identification of surface foulants using:
- FTIR spectrometer
- Energy Dispersive X-Ray Spectrometer (EDX)
- Scanning electron microscope (SEM)
- Loss on ignition test
- Cell and dye test
- Fujiwara Test
Off-Site Cleaning and Restoration (OSCAR™)
OSCAR is Avista Technologies proprietary Off-Site Cleaning and Restoration service. This intensive testing and cleaning procedure was developed to restore membrane performance to at or near original specifications. Special cleaning techniques combined with our own RoClean formulations allow us to obtain significantly better results than can generally be achieved on-site.
The OSCAR Advantage:
The excellent results typically achieved during OSCAR are possible because the equipment was designed specifically to clean membrane elements. This cleaning and restoration process is unlike conventional on-site clean-in-place (CIP) systems.
Among the specialized OSCAR features is a novel sealing arrangement which allows the membranes to be cleaned in a reverse direction (brine to feed). This significantly improves the removal of particulate matter from the element feed spacer.
Ideal solution temperatures are maintained throughout the cleaning sequence with the use of a dedicated heating system.
Membranes submitted for OSCAR undergo the following procedures at Avista:
- Physical inspection to identify any signs of telescoping, etc.
- Wet pre-test at standard operating conditions to compare permeate flow, salt rejection, and differential pressure against original performance specifications.
- Thorough cleaning using OSCAR and Avista Technologies own RoClean formulations.
- Post-test and normalization of the data to identify the improvements achieved during OSCAR.
- Upon completion, element are preserved, heat-sealed in a poly bag, and packed in a new box.
- A full report outlining the pre and post-test data is included with the return shipment.
- Each box is marked with the element serial number to assist operators in determining the re-load sequence of the membranes into the system.
Avista personnel are available to perform a variety of on-site support functions including; clean-in-place (CIP) supervision, chemical dosing, troubleshooting, system audits, and training. They can also oversee the commissioning of chemical dosing systems, set up chemical calibrations, and assist with demonstration CIP operations.
Avista Advice Training
Avista personnel believe that the experience gained over decades in the membrane industry should be shared with as wide an audience as possible in the interest of promoting best practice. It is mutually beneficial for our customers to have detailed knowledge of our product line, design tools, and technical services to ensure our formulations are applied in a safe and efficient manner.
The Avista Advice Training Program offers a series of short presentations on the theory, application and design aspects of our products and/or services. We also have a full range of presentations on wider membrane related topics including; system design, operational monitoring, and troubleshooting common problems. Presentations have also been prepared for OEM’s and end users to assist with employee training.
Avista encourages the customization of presentations using the list below and discussing specific requirements with our technical staff.
The Avista Advice Training Program covers the following topics:
- Membrane fundamentals and construction
- How antiscalants, coagulants and cleaners work
- Chemical selection and dosing unit design
- Cleaning plant design and recommended cleaning procedures
- Types of pre-treatment and chemical application
- Membrane plant monitoring and troubleshooting
- Membrane fouling and cleaning
- LSI or CCPP
- OSCAR and the membrane autopsy
- Avista Advisor