It is the age of packaged drinking water as everybody is becoming conscious about the quality of water consumed by man. This has led to mushrooming of mineral water plants around the country thus leading to heavy exploitation of the underground water resources on one hand while mass urbanization and concreteness is leading to very little scope for percolation of surface water into the aquifers.
The after effect of this phenomena is that dissolved and undissolved minerals and chemicals in the groundwater are getting more concentrated. The problem starts here as most of these water plants do not effectively dispose of the residual waste water of the RO system , in most cases it is letdown in the drains raw without any treatment which leads to enhance the balance of the ratios of chemicals where it ends up.
My main motive to write this pointer was to get a proper response from someone who is a master of this subject as to what should be an ideal way to dispose such waste liquid .
Not only hoping but trusting that some good samaritan will quench my thirst for this knowledge in a very simple and effective manner.(can write me up on my email ID also: aquatekjsr@rediffmail.com)
Regards to all those who read my article.
Comments
Wonderful
Thanks everybody for your valuable inputs regarding my query , as of now still no established and consolidated solution has been cited except evaporation but than it has got its own hassels viz. land, adequate sunshine ( which may not be available during monsoon) etc.Nevertheless once again my heartfelt thanks to all of you for your efforts .
Dear Sir,
Before suggesting any idea of dispose of RO reject. it is necessary to know the physio-chemical properties of such water.
i agree to solar dry but we can chose other option having little residual impact..
like mix the resulting salts with manure, Salt tolerant trees & Halophytic treatment and many more..
the management plan will be altogether based on project specificity.
TDS level
& more
hello Mr. Singh,
My primary area of research dealt with reject treatment from industrial use of RO. As a thumb rule, the reject would contain >90% of the TDS in < 90 % of the volume. hence the problem is not the volume but concentration. solar drying pans are ideal as they are less energy intensive. After solar drying the sludge needs to be dried and disposed in scientific landfill.
Here disposal plan of reject water is important. At one place I had designed and installed spray evaporation system to increase salt concentration @ 70000 mg/l and then used solar evaporation for further evaporation. At another place we mixed it with some of the treated water in such a proportion that resultant TDS should not exceed 2000 mg/l and then used it in gardens and fountains.
Dear all
Package drinking water generally receives series of treatment like PSF,ACF,Softner etc. prior it goes to RO...During auditting more than 15 PDW industries i have personally observed that life of the RO membrane is depend on the raw water quality and preliminary and primary treatment...so water supplying local bodies should supply minimum quality water and packaging industries should provide proper prior treatment....cluster of such industries can form a group with other industries and can combine the waste water which can reduce the load of TDS by some extent....
Sumeet..while i would not know the difference between concentrated salt to diluted one for discharge standards by PCB ..as regards TDS it depends on effluents from industry to industry..my suggestion was in relation to water plants where the TDS in comparison is in low concentration which could be toned down by some %...before being fed to R O....whereby reducing reject by some %...
Cheers
Madan Iyengar
www.ozosciences.com
@Madan: The problem is that RO is designed to treat a particular type of problem and that is TDS. Now regardless of what one might do, I dont think there is any pre-treatment out there which can take care of this problem before the water is fed into the RO. And all the salts are bound to come out in the Reject side, highly concentrated with no proper disposal mechanism. One very impractical rule by the PCB is that diluted effluent can be discharged on land for plantation, but when the same is concentrated through a RO, it cannot. Does it really matter when the salt loading is the same?
Dear harjinder..i highly appreciate your concern..but then clients too should look for possibilities of toning down the toxicities before being fed to R O.. pre-treatment is a primary requirement before R O....@ Sumeet..PCB too does not have a researched solution to suggest...most of the time in the name of compliance it is forced to adopt certain methodologies for treatment..evolving and emerging technologies have solutions...one would be shocked to see many R O systems in textile industries being positioned as monument for display with a few being operated out of no choice due to compulsion..
Cheers
Madan Iyengar
www.ozosciences.com
I'm facing the same problem. The only viable alternative which vendors have suggested is evaporation. Now an evaporator like MEE is expensive both on the CAPEX and OPEX front and solar evaporation requires atleast 100 m2 land per m3 of effluent. But if you have the land and if PCB allows, this seems to be the only possible alternative. Any one else have any bright ideas, please share on the public forum.