Water pH adjustment

hello everyone Our well water has a pH of 11.85 after water treatment of sand filter-activated carbon - sodium ion exchange -micro filter-reverse osmosis-UV-tatanium filter the pH is not change to much  it is 10.5 ph so it is more basic first what make this and also i want to adjust the ph to 6.8-7.8 so what type and amount of chemical do i use or machine i use to adjust the ph and make suitable for juice production thanks

Hello,

I would recommend getting a water analysis completed before and after the filtration/RO process. This should be able to tell you what is causing the pH to be so basic and why it is not being taken out by the filter. 

A lot of juices that contain citrus already can most likely have the pH adjusted by citric acid, but it is important to see why the pH of your potable water is that far off of where it should be. 

I also recommend getting your water tested. Groundwater typically is between 6-8 pH. A ph >8 usually means hardness caused by high concentration of dissolved minerals, specifically calcium and magnesium. But those should be removed by your sodium ion exchange. 

Other problems might be your sodium ion exchanged isn't sized properly or you need to replace the ion exchange resin. 

the TDS of the well water 100ppm and after all water treatment it is 13 ppm but the problem is on ph only i think it is because of nitrate and bicarbonate so how i can adjust with citric acid or other chemical to make the ph 11 to 7-8 ph

Also on this, it may be a good idea to review how you are testing your pH, and ensure that it is calibrated correctly. Perhaps verify it with another method, i.e. pH strips when using a probe. This reading is very abnormal for potable water even before the RO system. 

I agree with the other posters who are suggesting further analysis of your water / treatment process to understand what is or isn't working.
Adding things to the water may partly solve an issue with pH, but doesn't address the actual cause of the unusual alkalinity, and may also present you with labelling and/or quality issues, depending on finished product formulation, where it is being sold etc.

Yeah definitely i will further do analysis of the water/treatment process by sending the sample but now we need to check the line of juice production this wee k so i need an urgent solution to fix this problem for temporarily so after that i focus on the analysis and will finding out what happen there in the mean pls help me how i reduce the ph 11 to 7-8 by acid dosing or on final juice by acid correction details explanation i need pls thanks so much u really appreciate ur supports

You might find that the juice itself is enough to achieve the required pH in the final product - the water is surprisingly alkaline, but may have a very limited buffering capacity.

I'd personally still be rather nervous about using the water given that you don't yet know what the actual issue is, but you could do a quick test by making a lab-scale batch using one of your normal recipes, to see how the final pH turns out?

K i will do that will inform the result thanks my bro

I have other question if it is must to use acid injection by dose pump to reduce ph 11 to 7.5 in water treatment how i calculate with dosage pump ,acid concentration, flow rate and what requirements do i need and if any one explain by example am glad thank u so much

Our company wants to inject citric acid on our water system to reduce the ph 11 to ph 7-8 our water flow rate 32000 liter per hour
And the dosing pump 4.8 liter per hour how can i prepare citric solution and calculate the dosing and injection amount i attached below the dosing pump photo we have thanks

Calculating a pH is potentially quite a complex undertaking, and in this case I'm not entirely sure where you'd start - 1g of acid may change the pH by a lot or by a little, depending on the buffering capacity of the water itself, and that is presently an unknown.
Again I'd suggest doing some experiments to determine how much citric acid is required to achieve the change you need.

There are A LOT of ways you can do this.  

1. Dosing pump that runs at set speed based on an on/off signal.
2. Dosing pump that runs at varying speeds based on a 4/20mA signal.
3. On / off pump you manually turn it on and off.

If the water is always "on" and your pH doesn't have to be perfect you can use option 3.  If the water goes on and off and your pH doesn't have to be perfect you can use option 1.  If you need to dial in the pH use option 2.  It will require a flow metering device that can provide a 4/20mA signal to your pump.  I've had good success with Prominent pumps, but LMI makes some good pumps as well.

https://www.prominen...ring-pumps.html

https://www.lmipumps.com/

Tech support and engineering from both companies can help provide further insight.  LMI does have flow metering devices that are plug and play with their pumps.

If this will be a long term solution, you may have to use a potable water tank or two. You can use an inprocess pH probe and connect that with a pump to add the acidic solution of your choice.

Not sure if you could do this inline or not, as it would depend upon the buffering capability of your water. If that is a near constant, you could do this and fine tune the adjustment later, as well as a before and after pH probe. This would work best after the RO system when I assume buffering would be at its least.