industrial waste water treatment

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We have a situation where the feed water is having 300 ppm of BOD, 4700 ppm of COD, TSS is less than 150 ppm and TDS 3000 ppm. This water to be treated up to Less than 10 ppm of BOD , 50 ppm of COD and Less than 50 ppm of TSS, TDS less than 100.

We have designed the plant with following scheme

Pre screening - oil water seperator - coagulation - flocculation - DAF system - Collection tank - MBBR treatment - Collection tank - DMD - Ultrafiltration - RO treatment.

At DAF outlet we are getting 150 ppm of BOD and 800 ppm of COD. As such this water is not suitable for MBBR treatment since biology BOD load is very low. So not much COD reduction is happening in MBBR treatment. Also as per UF membrane manufacturer recommendation we need to reduce the COD to the level of 150 ppm before allowing water to pass through UF.

We tried using secondary DAF by passing primary outlet and found only 100 ppm reduction in COD ( It is coming down from 800 ppm to 700 ppm only. Whereas we require 150 ppm to pass in to UF)

We need to solution to reduce DAF outlet COD reduction from 800 ppm to 150 ppm. Can any one suggest suitable solution please?

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22 Answers

  1. I don't mean this to be insulting to any of the other responses. You need stop and look at what you wrote COD 800ppm. What is COD? Chemical Oxygen Demand. This is going to be created by some form of reducing agent or an organic than can be oxidized by an oxidizing agent under the COD digestion conditions The easy way to identify which it is will be to use a milder oxidant to see if you can reduce the COD. Try using hydrogen peroxide or even bleach at room temperature and pH 7. If that works, you have your easy fix. Also remember that the COD will do very little to feed your bugs. Hope this helps.

  2. ir, a biological solution to your problem is extremely easy to apply.

    Our companies SOLUTEK has been used in waste water treatment plants in numerous situations in a umber of countries.

    The fully organic, biodegradable solution we produce has no enzymes or GM modified microbiota, therefore the product is vey safe to handle.

     

    We have very successfully been able to remove hydrocarbons from car/trick washing used water.

    Please see our web site:  www.biophysics-research.net

    Email me directly if you wish:  pettman@soleco-technology.com

     

    Stay safe,

    Hugh.

  3. I would look at your C:N:P ratio. Don't think you have a balanced food source. Nitrogen or phosphorus could be your limiting factor.

  4. Thank you sir. Source of water is wash water which contains oil and other cleaners collected from dubai dry dock. They use to clean all ships. There could be traces of hydrocarbon. Raw effluent is black in colour. DAF outlet is honey colour. We are getting 80% reduction of COD in DAF.

    feed BOD is only 150 ppm and COD is 4700 ppm. After DAF BOD come down to 100 and COD come down to 800 ppm. We have MBBR treatment . But due to low BOD biological reduction is not happening

    Plant capacity is 50 M3/day of treated water. Feed water analysis as follows

    BOD - 150 ppm, COD - 4700 ppm, TSS - Less than 200 ppm, TDS 4000 ppm

    Permeate water quality required as follows

    BOD - Less than 10 ppm

    COD - Less than 50 ppm

    TDS - Less than 500 ppm,

    TSS - Less than 50 ppm

    Application of product water is Irrigation.

  5. First of all effluent is from what type of Industry.

    If O G is not much, you can use DAF after MBBR, so-that, you can get enough BOD in MBBR Tank.

    Secondly, if COD is Refractory, then, you can either try Anaerobic Treatment or use Bioculture to crack Refractory COD, followed by MBBR followed by DAF / Sec. clarifier.

    Thanks,

    Sanjay Sheth

  6. Mr. Raju Viswanatha,

    What is source of feedwater please? It would be useful to understand what are the typical types of molecules giving rise to BOD and COD requiring removal then we should be able to recommend a suitable process train.

    We offer a modelling software that can be used to model your first order design.  Contact us at enquiries@waterhoundfutures.com

  7. Please check the quality & quantity of coagulant & flocculant chemicals.  Jar test may help to achieve desired outcomes.

  9. Mr Andre Visser  has RIGHTLY  asked you to provide details with water qty. flow per hr and per day.  TDS  BOD COD are VAGUE terminology .   We mean business on sustainable way forward.

    amdyrana@gmail.com

    1. It appears to be the COD reduction carry over is from the oil and water separator upstream. Please let me know the complete influent (At the inlet of pre-screening) including the free O&G and emulsified O&G. Also let me  know the type of Oil water separator installed. My email address is scs.rajaraman@gmail.com

    2. Dear Sir,

      We, Pristine Water would like to offer our Electro-coagulation system to you in place of the chemical coagulation method that you are currently using. In the Electrocoagulation process, water contaminants such as ions of heavy metals and colloids are destabilized by the addition of ions having a charge opposite to that of the colloid. The destabilized colloids become larger particles and are aggregated and subsequently removed by sedimentation and/or filtration. The anodes used in our systems are known as “Sacrificial anodes” as they dissolve during the Electrocoagulation process.

      We need to know the water capacity that you need to treat so that we can offer accordingly.

      You can contact us at sales@pristinewater.in. For more information about our company and products, please visit our website www.pristinewater.in.

       

      Thanks & Regards

      Sharon George

      Engineer- Projects

      Pristine Water

    3. send your contact details by email on our email id "shreesaisiddhi@hotmail.com".

      We are WWTP Co. & may be able to provide solution.

      Thanks,

      Sanjay Sheth

    4. Have you conducted bench scale tests on the polymers used in the DAF? You might need a blend of cationic and anionic polymers suitable for the wastestream.  Is the O/W/S functioning properly (feed and speed) and sized properly for the desired detention time to allow for optimum removal rates for oils? You could consider adding hydrocyclones to the first EQ tank to add DO to the wastewater going into the MBBR as the F/M ratio might be off and bring DO into the process first will help keep CFUs aerobic.

    5. Hey Raja,

      As you can see from the answers below you have generated more questions than answers. The different streams making up your influent could hold the answer to your treatment problem. I am thinking you may need to pre-treat a stream prior to introducing it into your influent. Can only guess with out more information.

    6. WHICH INDUSTRY

      1 Comment

      1. Raju Viswanathan please provide more details os the members can help you better: type of industry, effluent analysis, idea of potential pollutants, flow

    7. PLEASE SHARE YOUR DETAILS ON EMAIL : INFO@TRANSCENDCLEANTEC.COM, WE CAN DO TREAT IT.

    9. You don't mention the flow.  I am guessing it to be fairly high.  The COD is probably tied up in some type of emulsion that the DAF can't break.  Vacom has an MVR evaporator that can do the job but the capital cost is quite high.  The evaporator would also take the place of the UF and RO if the flows make sense (not too high).  The Vacom evaporator can process  up to 80-100,000 gpd for about $4,500,000.  If this isn't practical or it is too expensive, you can go back to a "knowledgeable" DAF manufacturer and see if they have some type of chemistry that will break the emulsion.  I don't know of anything else that might help you.

      Bob Torstrick

      Vacom Systems

      678-825-2608

      btorstrick@vacomsystems.com

    10. Questions

      1. What is the volumetric flow rate of the feed wastewater?

      2. What is the intended purpose Of the treated wastewater?

      3. How many streams Make up the feed wastewater?

      4. Did your physico-chemico analysis consider each stream? Or was it a composite analysis?

    12. Once you analyze and get the chemical and physico-chemical characteristics of your COD you can find out. 

    13. Is it possible to share a scheme of the ETP?
      What is the use of the feed water in this industry production process?

      1 Comment

      1. you can try to install a filter after DAF ,than directly to UF,try other membrans,may be ceramics,that can deal with 150 ppm COD

        You can eliminate MBR

        Shar Gin.

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