COD Removal

Published on by in Technology

What is the best method for COD removal of treated sanitary water that feeds to RO?

Taxonomy

7 Answers

  1. UASB or any anaerobic treatment is most economical and best solution for the reduction of COD level. Higher the COD better the results. a reduction of 60-70 is guaranteed and in certain cases, it reaches up to 90% also in single stage UASB. A second stage activated sludge process will bring it within limits for RO feed.  Treatment scheme  UASB>ASP> Tube Settler> MGF> ACF>UF>RO

  3. COD if contributed by organic matter can be removed by Activated Carbon Filter or ozonization.  It depends on the quality of treated sewage

    Rajendrakumar V Saraf

    Viraj Envirozing india Pvt. Ltd. Pune

  4. Alireza,

    It will depend on the flow, concentration of the COD and other parameters.

    Regards,

    Orlando D. Gutiérrez Coronado

  5. Good Morning Alireza;

    The best solution process application depends on the source water analysis.  Do you have that information?

    Warmest regards,

    FOR THE BEST TASTE IN LIFE &

    38 Years Pure Excellence

    ...into another Quarter Century re-inventing the water industry !

    Think Aquathin...AquathinK !

    ( visit the all new www.aquathin.com )

     

    ** AN ISO9001:2000, ISO9001:2008 QMS REGISTERED / CERTIFIED COMPANY - (IMS 0192, NQA 12635) **

    & 2008 PRESIDENT'S E STAR AWARD RECIPIENT ( visit www.aquathin.com/estar2008.pps )

     

            Alfie

    Alfred J. Lipshultz

    President & CEO

    Aquathin Business Center  /  950 South Andrews Avenue / Pompano Beach, FL  33069

    T 954 781 7777 / F 954 781 7336 /E info@aquathin.com  / Skype aquathinhq.alfie

  7. COD is also a measure of the organic pollution present in the water. COD is a measure of the oxidisability of waste, expressed as the equivalent amount in oxygen of a strong oxidizing agent consumed by the waste under fixed laboratory conditions. The dichromate reflux method is preferred over other methods using other oxidants such as potassium permanganate because of:

    1. Its superior oxidising ability,
    2.  Applicability to a wide range of wastes, and
    3.  Ease of use.

    In the dichromate reflux method, a predetermined amount of waste is dissolved or dispersed in water and oxidised by potassium dichromate in a strong sulphuric acid medium with silver sulphate as the catalyst under reflux for two hours. The residual dichromate is determined by titration with standardised ferrous ammonium sulphate. In the case of wastes containing chlorine, mercuric sulphate is added to reduce chloride interference. The result of analysis for COD is expressed in mg/L (ppm).

    Hydrogen peroxide (H2O2) has been used to reduce the BOD and COD of industrial wastewaters for many years. While the cost of removing BOD and COD through chemical oxidation with hydrogen peroxide is typically greater than that through physical or biological means, there are nonetheless specific situations which justify the use of hydrogen peroxide. These include: Predigestion of wastewaters which contain moderate to high levels of compounds that are toxic, inhibitory, or recalcitrant to biological treatment (e.g., pesticides, plasticizers, resins, coolants, and dyestuffs);

    Pre-treatment of high strength / low flow wastewaters – where bio-treatment may not be practical – prior to discharge to a Publicly Owned Treatment Works (POTW);

    Enhanced separation of entrained organics by flotation and settling processes; and

    Supply of supplemental Dissolved Oxygen (DO) when biological treatment systems experience temporary overloads or equipment failure.

    “EFFECT OF AERATION AND RECIRCULATION IN THE REMOVAL OF NITROGEN AND CHEMICAL OXYGEN DEMAND FROM SANITARY SEWAGE IN A STRUCTURED BED REACTOR.”

    The high efficiency of COD removal in this type of reactor is explained by the fact that organic matter can be removed in both aerobic and anoxic phases. In the aerobic phases, in presence of DO, aerobic heterotrophic bacteria acts, that use DO as final acceptor of electrons. In the anoxic phases, heterotrophic denitrifying bacteria uses N-NO3- as final acceptor of electrons and organic matter as a source of energy and carbon.

    the effectiveness of chemical oxygen demand (COD) removal from synthesized lignin wastewater using photo-Fenton reaction over Fe-Ce-Zn catalysts. The synthesized lignin wastewater had the same COD concentration as the pulp processing wastewater. The treatment using photo-Fenton reaction with the metal catalysts (Fe-Ce-Zn). Moreover, the high surface area of Fe-Ce-Zn catalyst enhanced the COD removal due to the synergy of the high adsorption capacity.. pH, the concentration of hydrogen peroxide (H2O2), and the concentration of catalyst. The optimal condition was obtained using the Box-Behnken statistical experiment design (BBD) and the response surface methodology.

    1 Comment

    1. This is a great review.  We have been involved in a project which utilized H2O2 advanced treatment and Fenton for reducing recalcitrant COD from pulp and paper mills.  In monitoring the process it was determined that the COD dichromate method is affected by a positive interference from this method, increasing the results.  A new COD photocatalyst method utilizing TiO2 did not exhibit this interference and had the added benefit of green chemistry and results in