What is the procedure for cleaning RO membrane? What chemicals should be used?
RO membrane cleaning should be performed with high and low pH cleaning chemicals. The high pH cleaning should always be performed first to remove biological or organic foulants, both of which contain carboxylic functional groups. These weak...
Does reverse osmosis desalination of sea water remove viruses from the product water?
Yes, viruses are substantially removed by reverse osmosis membranes. However, studies performed have shown varying viral removal efficacy, varying from 2 log removal (99% rejection) to 5.9 log removal (99.99987% rejection). This is believed...
What is the maximum Calcium Sulfate (CaSO4) level in brine side that A-102 plus can deal with?
A-102 Plus can handle up to 300% calcium sulfate saturation on the brine side. CaSO4 saturation will vary according to concentrations of dissolved calcium and sulfates, temperature and salinity. If you already have high sulfate levels, avoi...
How do I determine anti-scalant dosage for a 2300 gpd R/O unit, when CaCO3 is 255 gpg?
When calculating antiscalant dosage, inhibition of all scales must be considered. Potentials scales that can form are: Calcium carbonate Calcium phosphate Calcium fluoride Calcium sulfate Barium sulfate Strontium sulfate metal hydroxides (i...
What is the disadvantage of raw water disinfection by chlorine in RO desalination?
Chlorine will irreversibly damage a polyamide RO membrane, and as such, a chlorine residual cannot be allowed to contact the membrane. This means that once you dechlorinate, surviving bacteria will once again flourish, and dead bacteria wil...
Can Sulfuric acid or HCl be used with the addition of Citric acid for the control of iron and other scales in a reverse osmosis plant?
Using citric acid is very expensive. If the water source contains oxygen, has been exposed to oxidizers, or ferric based coagulants have been used, the iron will be in the ferric state and can typically be controlled by dosing sulfuric acid...
Is sodium metabisulfite an effective disinfectant for my RO system?
Sodium metabisulfite (SMBS) is not a disinfectant. When used in high dosages, it is an oxygen scavenger and many biofilm forming bacteria are anaerobic, making oxygen scavenging useless. SMBS does however prevent fungal growth in membranes ...
How can I clean a membrane that has been clogged with suspended solids and sludge?
This is a very common problem and there is no single solution. Some suspended solids consist of natural organic matter (NOM) or dead bacteria, and can be removed by performing a high pH cleaning. Other suspended solids (such as limest...
Can hydrogen peroxide be used effectively in place of sodium bisulfite for dechlorination of seawater RO feedwater? We are concerned about dissolved oxygen levels in the concentrate that is disposed back into the sea…
Q: Can hydrogen peroxide be used effectively in place of sodium bisulfite for dechlorination of seawater RO feedwater? We are concerned about dissolved oxygen levels in the concentrate that is disposed back into the sea… Sodium sulfite ...
How can we determine whether the membranes in our Reverse Osmosis system are damaged?
There are two major symptoms that we typically associate with membrane damage: 1. Increase in permeate conductivity coupled without a loss in productivity, or in extreme cases, with an increased productivity– this could indicate delaminat...
