Guys can someone answer to my latest query that why the new membrane's permeated watsr flow is decreased just after 5 days from 2300 lyrics/hr to 1800 ltr/hr?
Published by Dharmendra Sharma, Mr.
6 Comments
You should check your water especially for Hardness, Silica and free chlorine.
Send the test report to your antiscalant supplier and choose the antiscalant accordingly.
Published by Asanka Jayasinghe, Mr.
I would also recommend that you perform a raw water analysis to find out if the raw water is out of specification and compare it to the original water quality when the RO plant was design.
Published by Pierre Dreher, Water Treatment Plant Operator III at Olivenhain Municipal Water District
Dharmendra;
You mentioned having a 2 micron filters before the HP pump. To me it seems overkill to have such a small filter and pressure differentials on 2 micron filters are greater than a 5 or 10 micron. My recommendation is to have a 5 or perhaps a 10 micron filter. Do you have pressure differential gauges on your 2 micron filter?
What is the DPSI on your 2 micron filter?
What is the reason for having the carbon filter for pre-treatment? Do you have oxidation prior to this carbon filter?
Published by Pierre Dreher, Water Treatment Plant Operator III at Olivenhain Municipal Water District
Thank you Andrew and Pierre....yes that's what I was also thinking about.
So I have now changed my anti-scaling chemical and now using a chemical which is supposed to be used till 5k TDS raw water treatment plant.
Inlet water temperature is around 30°C and there is no pre-treatment plant as such except sand,carbon and 2 micron filters before high pressure pump.
How would I know whether I need some kind of pre treatment for my raw water?
Should I get it tested in lab?
Published by Dharmendra Sharma, Mr.
Dharmenda
I would have to agree with Andrew and add a possibility of flow restriction on your pre-treatment if you have one. (Filters being plugged) You did not mentioned if you have scale inhibitor injection(s). You may want to look at your chemical injection system(s) to make sure you have a proper dosage for your anti scalant, sulfuric acid etc....
Also, you did not mentioned anything about your influent temperature. Lower temperature require more power to produce same flow through your membranes than higher temperature.
Published by Pierre Dreher, Water Treatment Plant Operator III at Olivenhain Municipal Water District
Hi Dharmendra,
May I ask if you have any pre-treatment for your membrane?
When you replaced the membrane did you notice excessive bio-fouling or scaling issues?
A rapid formation of a biofilm colony or scale development is usually the answer for the decrease in flow rate. In this case, you will need to look at adequate pre-treatment for your membranes to maximize their efficiency.
I specialise in RO pre-treatment in Asia and Australia, please email me at andrew@waterandoilsolutions.com.au and I'll be happy to see if I can help.
Published by Andrew Tran, Engineer