< BACK HOME
AVISTA IMPACT STUDY
Municipal Plant Realizes Substantial Savings
in Energy, Waste, and Chemical Costs
in Energy, Waste, and Chemical Costs
Scroll for full case study
A municipality customer located in Florida was experiencing an increase in feed pressure with their 2 nanofiltration skids (8:4 array, 7 membranes per vessel) as well as a decrease in flow in the 2nd stage. The feed source comes from 3 different wells to supply 100% of the planned community’s potable water needs.
After an unsuccessful attempt to clean using generic cleaners, and considering other specialty cleaners, the customer was thinking they may need to replace all 1st and 2nd stage membranes. Avista was asked to evaluate their system to see if we could help them avoid membrane replacement.
APPROACH
First, an autopsy was conducted on a membrane from the second stage to diagnose the cause of the increased pressure and found that the membrane was covered in silica scale. The initial water analysis showed silica levels lower than 1ppm, while a more recent water analysis showed the silica content ranging between 58ppm and 70ppm.
Based on the autopsy, Avista recommended cleaning with RoClean™ P192 (high pH cleaner) and RoClean™ P903 (low pH cleaner) to lower the operating pressures.
Additionally, it was recommended that the customer switch from their previous antiscalant to Vitec™ 1500 at 2.5 ppm due to needing a product aimed at controlling silica scale.
Avista™ AdvisorCi™ modeling was able to predict that Vitec 1500 was the better choice.
Based on the autopsy, Avista recommended cleaning with RoClean™ P192 (high pH cleaner) and RoClean™ P903 (low pH cleaner) to lower the operating pressures.
Additionally, it was recommended that the customer switch from their previous antiscalant to Vitec™ 1500 at 2.5 ppm due to needing a product aimed at controlling silica scale.
Avista™ AdvisorCi™ modeling was able to predict that Vitec 1500 was the better choice.
RESULTS
IMPROVED FEED PRESSURE
After implementing the recommended cleaning chemistries from the autopsy results, the feed pressure showed measurable improvement, dropping from 130psi to lower than 80psi and then stabilizing due to removing the silica scale. Switching to Vitec 1500 allowed for foulant stabilization to ensure operating pressures remained low.
IMPACT = COST REDUCTION
Creative Chemistry. Smart Solutions.
Summary
The outcome of this cleaning study resulted in:
An annual energy savings of $7,296.
An estimated membrane replacement savings of $50,400 (for one train).
An estimated annual savings of $1,200, due to the reduction of cleaning frequency (down from 3-4 times per year) because of stabilized fouling rates.
Although the customer also experienced an approximate additional cost of $3,000 per year due upgrading the antiscalant formulation from the previous antiscalant to Vitec 1500, their overall operating and maintenance expenses have been significantly reduced by switching to specialty chemistry.
Both Vitec and RoClean products continue to be applied on-site. The Avista approach allowed for the identification of the membrane process issues and allowed for the correction and optimization of the NF membrane system.
An annual energy savings of $7,296.
An estimated membrane replacement savings of $50,400 (for one train).
An estimated annual savings of $1,200, due to the reduction of cleaning frequency (down from 3-4 times per year) because of stabilized fouling rates.
Although the customer also experienced an approximate additional cost of $3,000 per year due upgrading the antiscalant formulation from the previous antiscalant to Vitec 1500, their overall operating and maintenance expenses have been significantly reduced by switching to specialty chemistry.
Both Vitec and RoClean products continue to be applied on-site. The Avista approach allowed for the identification of the membrane process issues and allowed for the correction and optimization of the NF membrane system.
Reduced Cleaning Frequency
$7,269 Annual Energy Savings
$50,400 Membrane Replacement Savings
Online Resources
For more case studies, visit the Avista Membrane Treatment Solutions resource page.
LEARN MOREA Global Brand of Kurita