A Large Automotive manufacturer in India was operating a traditional ETP (Effluent Treatment Plant) with UF (Ultra Filtration) and RO (Reverse Osmosis) for treated water recycling for 5 years.
Last year, they modified their effluent treatment plant and adopted MBR (Membrane Bioreactors) based treatment. Naturally, being the latest trend, they were expecting better performance and a smaller footprint.
But, to their surprise, after this modification, the RO system did not give the expected or better performance, which was reflected in the replacement of the membrane, costly downtime. A shorter life of the membrane was a question, and this resulted in a panic situation……
This Automotive giant approached us with their problems, and we suggested that they do a RO Membrane Autopsy. Based on our recommendation, they selected the RO membrane for autopsy and sent it to us with the recommended packing. We studied this case and came up with very interesting facts.
So, this blog is about this case and the findings
The principal Effluent treatment flow diagram is as follows :
Chemicals used for Effluent treatment are :
1. Ferric Chloride
2. Lime
3. Flocculant
4. Chlorine
Chemical used for RO feed treatment :
1. SMBS
2. Antiscalant
All these chemicals were common and standard chemicals available in the market.
After receipt of the membrane, while carrying out autopsy we came up with very valuable observations and findings as follows :
Fiberglass cover damaged
Compression observed
Delamination observed
Mild blister formation
Chemical fouling observed
Each of the above pictures reveals some situation and understanding of this condition, and an exact interpretation is necessary
Some of our analytical findings and interpretation of foulants deposited on the membrane leaf are as follows
1. The chemical analysis revealed more deposition of calcium, silica, magnesium and heavy metals like copper, chromium, iron, and cobalt.
2. Microbiological deposition was very low.
3. The Fujiwara test and the Dye test were positive at various locations.
FAQs: MBR Support for RO Membrane in Engineering Industries
Q1. Does an MBR system always support RO membranes in industries?
A: Yes. MBR (Membrane Bioreactor) produces high-quality effluent with very low suspended solids and organic content, which makes it highly supportive as a pre-treatment stage for RO membranes.
Q2. Why is MBR considered better than conventional pre-treatment before RO?
A: Unlike conventional treatment methods (like clarifiers and sand filters), MBR provides consistent and superior water quality, reducing fouling and scaling risks for RO membranes.
Q3. Can MBR completely replace RO in industrial applications?
A: No. MBR improves water quality but does not remove dissolved salts. RO is still required for desalination or achieving very high-purity water. MBR works as a strong complement, not a substitute.
Although MBR has been introduced, traces of coagulant were prominently observed on a membrane, which was due to uncontrolled dosages of flocculant and coagulant or inadequate settling time. Also, due to heavy metal contamination found, the question arises: Is it worth switching to MBR to reduce the footprint of the plant if it is going to affect RO feed quality in terms of heavy metals ???????
So, RO Membrane Autopsy gives a very valuable input to plant designers and plant operators on ‘what should be a correct approach in such modifications or adoption of MBR’.With this stud, your costly downtime, replacement of membranes, and future panic situations can be avoided.