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Removal of COD
Apr 28^th, 2012, 12:07pm

Good Evening..!

I want to remove BOD & COD from rejected water of ROP # 1 Cause it is been used as feed for ROP # 2 but, if we look into the water analysis report the COD is 98mg/l & BOD is 2.0mg/l.

So we required you involment in this project, some small modification can be done to remove COD from water.

Need your suggestions..! Attached water analysis report FYI

Hope to here you soon.! If you requires any details please let me know

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Jeff Naumann God Member Offline I love Water and Wastewater.com Posts: 1133 Torrance, California Gender: Company or Organization: Jeff Naumann & Associates	Re: Removal of COD Reply #1 - Apr 28^th, 2012, 12:35pm I don't see an attachment. Are "ROP#1" and "ROP#2" the two stages of a reverse osmosis system?
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Audioslave YaBB Newbies Offline I love Water and Wastewater.com Posts: 5 Company or Organization: Siddiq Company W.L.L	Re: Removal of COD Reply #2 - Apr 28^th, 2012, 1:51pm ROP # 1 is double pass RO Plant & the rejected water of it is being used as feed for ROP # 2.
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grrun God Member Offline WaterandWastewa ter.Com is the best! Posts: 3525 Pekin, IL Gender: Company or Organization: Freelance Environmental Engine	Re: Removal of COD Reply #3 - Apr 28^th, 2012, 1:59pm If Jeff's comments are correct, you still need more information about the COD analysis. I would suggest that you first run a TOC analysis to determine if the COD is mostly long chain organics or an oxidizable inorganic substance (either may exhibit COD, but low BOD) and work from there to determine a possible treatment. grrun
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Re: Removal of COD
Reply #4 - Apr 28^th, 2012, 3:09pm

this is the full water analysis report of that rejected water of ROP # 1

1. floating particles nil
2. pH@ 25 C 6.7
3. TSS 2.6mg/l
4. turbidity 1.5 NTU
5. BOD 2 mg/l
6. COD 98mg/l
7. temp 24.3 C
8. TOC 1mg/l
9. total kjeldahl nitrogen (as N) 0.28mg/l
10. oil & gresase NDLT 1mg/l
11. florecent petroleum matters NDLT 0.05mg/l
12. phenols NDLT 0.002mg/l
13. NH3-N 0.18mg/l
14. free residual chlorine NDLT 0.02mg/l
15. Total cyanide NDLT 0.01mg/l

these are the details. nee you suggestions.

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grrun

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Re: Removal of COD
Reply #5 - Apr 29^th, 2012, 12:55pm

Now you need to look for oxidizable inorganics such as ferrous and other metallic compounds, sulfides, sulfites, etc.

I think that you need to know more about the source of water to ROP #1 to determine the source of the inorganic COD. This COD may not interfere with ROP #2 unless low solubility causes membrane plugging.

What are the processing problems that ROP #2 is experiencing?

grrun

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Audioslave YaBB Newbies Offline I love Water and Wastewater.com Posts: 5 Company or Organization: Siddiq Company W.L.L	Re: Removal of COD Reply #6 - Apr 29^th, 2012, 2:54pm the membranes for ROP 2 are getting choked with a period of min 2years..! as compare to other it is perfectly workin for max 5 years..!
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grrun

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Re: Removal of COD
Reply #7 - Apr 30^th, 2012, 2:24pm

You need to explore the inorganics in the ROP#1 reject to determine which may be responsible for the membrane fouling. I would check AA or ICP tests for likely candidates and then see if they may form insoluble precipitates when oxidized. Another possibility is biological growth which can increase with time. There are "dip sticks" that can measure biological contamination in water.

Unless you have other data (such as the composition of the membrane fouling constituents), you are on your own to find the source of membrane fouling.

grrun

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Audioslave YaBB Newbies Offline I love Water and Wastewater.com Posts: 5 Company or Organization: Siddiq Company W.L.L	Re: Removal of COD Reply #8 - May 5^th, 2012, 2:11am HI all, I am much concern about the COD present in water. It will effect the membrane in what basis? what is normal life of membrane if we are using raw water in which COD is 100mg/l.
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grrun

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Re: Removal of COD
Reply #9 - May 5^th, 2012, 4:15pm

COD is not a chemical compound! If the COD is responsible for membrane fouling; you'll have to determine which chemical or biological component that is a constituent of the COD that causes the fouling. My guess is that you need to focus on the fouled membranes to determine which constituent is causing the fouling. The identified constituent may be treated to eliminate it or you may have to live with shortened life if you cannot treat or remove it.

grrun

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