One of our clients is setting up a new factory and had the ground water (only source there) tested. The sample does not qualify the WHO standards. Please can someone suggest the appropriate water treatment system / technology ( other then RO ) for making ground water potable? The client would need around 5 kl to 7 kl of treated water per day. The specific parameters are as follows: pH 7.6, Total hardness 956 ppm, Total Dissolved Solids 3349 ppm, Chloride 1235 ppm, Sulphate 577 ppm, Sodium 1000 ppm, Calcium 143 ppm, Magnesium 115 ppm, Flouride 1.4 ppm The client is keen to avoid using RO plants (that are all too common in India!) as they do not want to have high rejects and also have heard that RO water is not good for human consumption since required minerals are also removed. Any insights from the community would be highly appreciated! Thanks
We purify any kind and flow of wastewater into potable effluent with 95% minimum efficiency and low operating costs, but for industrial purpose we just manufacture WWP plant for 1 lps (86.4 m3/d); we don't use RO niether chemical dossing.
In case you were interested I need the wastwater quality or what will be the industrial process to estimate BOD & COD of your wastewater in case you don't have it.
WHO & BIS standard are liberal when no alternate source of water is available. Where is the location? If in Rajasthan then people are accustomed with such type of water. However as such there is no process available which can remove soluble solids from water without using RO. You can try softener, Blend soften water to 50 mg/l of hardness.
It look based on the analysis, that RO would be apart of the solution, as the chloride and sodium levels are above WHO limits, and these minerals can only be effectively/efficiently removed via a membrane or evaporation process.
What you require is to compare the results on analysis with the WHO Standards for Drinking water. Where it varies then you should be able to decide on the way to reduce the the excess dissolved minerals.There are various methods available.
Please fill free to come back to us in case you get stuck at info@merry waters.com
without knowing the details, if you need 5000 l/day you could think of SolarDew (www.solardew.com) . But any methode has of course a brine disposal problem (with SolarDew 10%- 20% of the water intake). Remineralisation, if desired, is also unavoidable this is relatively simple and cheap.
According to water analysis I think the best option is applying RO and for decreasing the concentrate flowrate another RO should be used.I also heard about EDR systems but dont have any experience to share.
using this plan is common in Iran as the main concern is shortage of water .
Achieving to WHO standards for drinking water mineralization(calcium chloride and sodium bicarbonate) or also marble filters would be effective.
chemical precipitation is also an option. This would require addition of lime to say pH 11 to precipitate the temporary hardness (Ca and Mg). To precipitate the permanent hardness would require addition of barium carbonate (precipitate the sulphates as BaSO4). Barium carbonate is expensive, but could be recovered and re-used. The fluoride levels are not a problem at 1.4 ppm. sodium and chloride cannot be removed through chemical precipitation, but could use a other alternatives to RO such as ion exchange (on a side stream to just reduce sufficient to blend to WHO standard). As others have said though, RO is probably the optimum solution, and perhaps the focus should be on ways to treat the RO reject??
Without a doubt, RO is the best and least expensive. The percentage of minerals obtained from water required for the human body is so small, their removal is immaterial. Food is the source of minerals. The system can be set up to waste little water. I am writing an article about this very subject.
See www.watsan.in. we can give alternate solution using nano filtration using clay candles. See www.watsan.in. i have wriiten in linkedin a detailed article on why R.O is bad for health and how we choose bad elements only to get removed...
Peter Cartwright please post your article when completed on The Water Network, as well as a link here in this thread. We are sure that it will help many members.
Thanks Peter! Would like to figure out how to adjust the reject ratios. I was given to understand that (for a given membrane installed in the system) the input water TDS level basically decides how much is rejected.... Please share your article when it is released. Thanks!
I recommend MMF, Manganes e Iron removal and then REVERSE OSMOSIS 15 m3 storage tank an UV-disinfection 60 mW/cm2 @ 254 nm. after storage and circulation pump 7 m3/h with VFD 0,5 bar only tank circulation and by consumption increase speed. recommended Grundfos CRN-E type. CRN10E. Don't be afraid about minerals as we get most minerals by food.
Yes, Infinite Water, Australian technology, you can use. I have conducted a three month piloting with Bangladesh ground water matrix, where arsenic, manganes, TDS, iron, bacterial contamination, turbidity, can remove nicely up to WHO std.
Interestingly Jo, the client site is no where near the sea! But this region had salt mines in the past - hence the high Na levels! Thanks for your response
You will need a combination of technologies for the best effect. Don´t overlook the need for removing organic pollutants for drinking water (PFAS, organc residues etc.)
www.watsan.in natural purifiers, we have fluoride remover system, as well. No electricity, no wastage of water. Send email, to chandra@watsan.in how much water per day usage