Samrat,

if you need some papers on H2O2 and other oxidants use this links:

Article Wastewater treatment by means of Advanced Oxidation Processe...

Article Wastewater treatment by means of advanced oxidation processe...

Article Effective method of treatment of industrial effluents under ...

Article Highly effective degradation of selected groups of organic c...

Article Effective method of treatment of effluents from production o...

Article Study of Different Advanced Oxidation Processes for Wastewat...

regards,

G

It depends on pollutants type. Some will oxidize and some not. If you will assure accwptable rime of oxidation, at the end all H2O2 will be used for oxidation reactions (or will decompose). Thus, you will not realese it to the environment.

What is your treatment sequence? What types of compounds are present in the effluent for 500mg/L.

Probably the effluent will contain compounds there are not effectively oxidized by H2O2 in this case you can think aboutother oxidants or adsorption.

Regards

G

Dear,

H2O2 has strong oxidation, you know. But there is a method to treat wastewater contains dyes, following.

https://www.researchgate.net/publication/239217264_Kinetics_of_Decolorization_and_Mineralization_of_Reaction_Azo_Dyes_in_Aqueous_Solution_by_the_UVH2O2_Oxidation

H2O2 and O3 are used for decoloration of wastewater, mainly. But maybe this method is used for treatment high BOD concentration wastewater. But I don't know appropriate papers in English. But, this meshod is famous. So someone introduced this method in detail.

I am sorry that I can not become a force.

Best reagrd.

Samrat,

if you need some papers on H2O2 and other oxidants use this links:

Article Wastewater treatment by means of Advanced Oxidation Processe...

Article Wastewater treatment by means of advanced oxidation processe...

Article Effective method of treatment of industrial effluents under ...

Article Highly effective degradation of selected groups of organic c...

Article Effective method of treatment of effluents from production o...

Article Study of Different Advanced Oxidation Processes for Wastewat...

regards,

G

Thank you Grzegorz Boczkaj, Satoshi Nakao, and Kanhaiya Lal for your comments.

The waste water was treated with combined dose of Alum and Polyelectrolyte followed by activated carbon filtration. The elute thus obtained is yellowish and I am attempting to remove the yellow colour while improving the BOD compliance.

Interestingly, the addition of Hydrogen Peroxide to make the final concentration of waste water to 40 mM has clarified the treated waste water; however, the concentration of 4 mM, 8mM and 16 mM (I tested today!) of Hydrogen Peroxide further made the elute hazy. I am afraid addition of Hydrogen Peroxide >3 mM is too much to protect the aquatic animals.

What is the wastewater that you are treating?

I would suggest that activated carbon should be used as a polishing step after BOD is reduced to levels much less than 500 ppm. Activated carbon would likely be overwhelmed or all adsorbsion sites would be saturated at a rate that renders the carbon innefective after a short time as a primary/secondary treatment step for your wastewater.

As said above and without knowing the specifics of your WWTP I would suggest the peroxide step should be combined with ozone and possibly a catalyst and or UV treatment (advanced oxidation), before the activated carbon step.

Also as others have said if your peroxide levels after treatment are too high yet BOD is not reduced satisfactorily, then the reaction time may not be long enough for the peroxide to fully react.

Also investigate the dosing rates of your polyelectrolyte as this will put an oxidant load on the peroxide. A better coagulant than alum along with some testing of this with various floculants (polyelectrolyte) may also aid in more effective initial reduction of BOD

Dear Jared Rose,

Thank you so much for your recommendations.

We are a tablet and capsule manufacturing pharmaceutical industry. At the moment our treatment sequence follows:

A) Alum + Polyelectrolyte treatment

B) Mixing with aeration and allowing for sedimentation overnight

C) Ozone treatment to the supernatant

D) Multimedia (peebles) filtration

E) Activated carbon adsorption

F) Hydrogen Peroxide dosing (200uM?) before elute collection

As per your suggestion, step F) should precede step D). I need to give a try!

In addition, do you recommend chlorination over hydrogen peroxide for disinfecting elute ?

Thank you!

Hi Samrat, thanks for your reply. I would be combining Step C (Ozone) with peroxide treatement to make an Advanced Oxidation step and recirculating the solution past your ozone injection source if you have a tank available to perform this step in a batch style. R

Once this batch/step is complete (peroxide residual is low enough to safeguard aquatic species) I would then media filter and finish with activated carbon.

The articles attached above by Dr Nakao and Boczkaj would be worth reading to help to understand the principals and kinetics of advanced oxidation processes. If your treated water is still too high in BOD I would also investigate the addition of iron type or similar catalysts and or UV into this step, as further avenues for advanced oxidation process improvement

I recommend peroxide over hypochlorite for your situation as peroxide is a much stronger oxidising agent and will not form as many harmful disinfection byproducts when treating water high in organic matter (BOD/colour etc), such as yours.

In your step B you also mentioned you have an aeration source. One method for the degradation of hard to oxidise species is advanced oxidation, as described above, before aerobic biological treatment. The physio chemical advanced oxidation step can break down difficult species into simpler molecules, which can be further oxidised in an aerobic treatment process (activated sludge, attached growth etc).

H2O2 + O3 is called peroxone it gives higher effectiveness comparinf to sole use of this oxidants (check the papers I listed above).

Regards

G

Dear Jared Rose,

Thank you so much for the recommendations. In that case, what do you think about the optimum final concentration of Hydrogen Peroxide in the effluent water. I think not more than 2 mM final concentration is maximum that can be used without expecting much harm to the aquatic species; is 200 uM still effective targeting dual functions, disinfection and oxidation ?

Thank you!

Hi Samrat, you will have to perform testing for E,Coli / Total Coliforms etc to confirm disinfection effectiveness. Depending on the suspended solids concentration and other factors, the required effective disinfectant dose for Peroxide or any other disinfectant will vary. Aquatic toxicity will vary and is very dependent on the specific types of flora and fauna in your receiving watercourse.

Regards

Jared

Dear Jared Rose,

Thank you so much for the suggestions. I will optimize accordingly. Thank you and have a great day!

Dear Dr. Grzegorz Boczkaj,

Thank you so much for the references and recommendations.