Nitrate Effluent Treatment

Use biological treatment. Use the activated sludge treatment for about 6 - 8 hours to breakdown the organics. This will oxidize the carbon in the waste water. Follow that up with 2 - 4 hours of anoxic biological treatment i.e. stop aeration for 2 - 4 hours. This will dentrify the nitrates and release them as atmospheric nitrogen gas while conditioning the bacteria for luxury update of phosphates commonly found in detergents. Finally, add some methanol into the water and apply aeration for another 4 hours or so. This will result in the oxidation of the methanol and the removal of phosphates from the water. You can now reuse the water if you want.

You can use soap in place of detergent for cleaning.

Your problem is about a combination of nutrients in your water. There are two nutrients which are Nitrates and Phosphates.

Phosphates generally come from the detergents used and Nitrates often come from organic matter in the rinse. Having only Nitrates in the water is not detrimental for rinsing purpose.

The balance between Nitrates and phosphates have to be maintained in order to keep the water live. It is easy to remove Phosphates from water using online adsorbents like Stepsorb-P, which is available in India. You can try on info@stepsnergy.net. More than 95% of the Free Reactable Phosphates (FRPs) can be removed within a few minutes of using Stepsorb-P.

Regarding Nitrates, there are many ways to solve this problem. Easiest is to divert your water to a small container ( open top,) and grow a few Azolla plants. Azolla and water hyacinth will quickly pick up nitrates from water. However, ensure that some of these plants are removed on a daily basis from the water and dried up. Re-use the water with reduced Nitrate load.

The other way is to use specially formulated clay spheres which can house nitrifying and denitrifying bacteria and pass the water through these clay spheres. Once again, you may check with Stepsenergy for this product.

You can also write to me on raotr@hotmail.com, for further information and any assistance

It really depends on the amount of water you are trying to treat and how concentrated is the pollutant.

For large amounts, you will probably have to go with biological systems, making it a pretty complicated system (Plant will be pretty large, you will have to add a carbon source to sustain the biomass, get rid of the sludge, aeration, etc)

For small amounts, you may want to look into Reverse Osmosis or other membrane filtration technologies. RO will leave you with the problem of the brine, but again, all depends on the quantities of water you are treating.

sardman

Several good ideas have been presented in the thread. I am not aware of Stepsorb-P but I suspect it may contain some iron or other metal compound to remove the P. You may also want to consider anion exchange and there are NO3 specific resins available (Rohm and Haas, Sybron SR7, etc). I suspect that you can remove the PO4 with anion resin at the same time. You may need to check other parameters like CO3 concentration, SO4, pH, Alkalinity if you use anion exchange.

Ferric iron is often added to waste flows to precipitate the P and is practiced in many waste treatment plants. You may want to discuss with raotr as he invited you. I am not sure of volumes to be treated and that may dictate the treatment choice.

Stepsorb is a clay based product formulated to adsorb and permanently lock up phosphates in its matrix. P thus adsorbed is no longer bio-available and hence remains inactive. The treatment is very qucik and very effective. It does not require any special equipment either as its a straight mix and filter kind of powder which can be recovered during filtration. An advanced form is the granulated form, which is used as a filtration media in any filter container and water is passed bottoms up. The granules once saturated can be removed and land-filled as the granules pass US EPA tests for leaching.

1Kg of Stepsorb adsorbs app. 2 gms pf Phosphorous which is very high considering Phosporous occurs in ppm levels and 1Kg can effective treat a few thousand liters of water.

Guys, hope the above info. helps.

Ion exchange may work. We would need a water analysis to determine if nitrate selective resin like SIR-100-HP would work.

Please send me an email at srock@resintech.com and I will do my best to help you.

Best regards,

Seth Rockmacher

The best methods will depend on the quantity of waste water being generated. If you do not have to recover the nitrates from the water, I would suggest nutratlizing the solution and going in for a low maintanance reed bed system. if you need help in getting this done you can always email me at urvikp77@gmail.com

Dr. Urvik Patel.

ph.D. microbiology