Soda Ash Water Treatment
How Much Soda Ash Should Be Injected To Raise the pH of my well water from 5.0 to 7.5?
Generally, you want to inject 100 to 200 mg of soda ash for each liter of water (mg/L). Milligrams per liter is the same as parts per million (PPM).
Soda ash systems are commonly used to raise the pH of acidic water sources, ensuring effective water quality management. Soda ash plays a crucial role in these systems by neutralizing acidity and preventing corrosion.
Mix up the soda ash solution
Soda ash is a powder mixed with water to form a saturated solution. You can make the solution stronger or weaker. At a water temperature of 50F, it is easy to keep a 10% soda ash solution dissolved in water, and this is what we recommend you start with.
To make a 10% solution, mix 4 lb of soda ash powder for every 5 gallons of water, which is approximately a 10% solution by weight. It is best to use warm purified distilled or reverse osmosis water to make your solution, although if your untreated well water is very low in total dissolved solids and other minerals, you can generally use the untreated water to make up the solution.
Start with a couple of gallons only in your solution tank and test the pH to see how it works.
Set the Pump Output
We will use the Stenner pump as an example since the 85MHP-40 pump is suitable for residential well water applications.
Set the Stenner pump “Feed Rate Dial” to 5 (which means that it is set to pump 50% of its output).
Run the water and test the pH to ensure it is at the desired 7 to 8.0 pH range.
You don’t have to change the solution or the Stenner pump setting if the pH is fine. Otherwise, if the pH is still too low, you can first try turning up the Stenner pump adjustment ring to 10, which means 100%.
Formulation for Understanding Stenner Pump Sizing
For most residential soda ash applications, the Stenner 85MPH40 injects a proper amount of soda ash solution to raise the pH to the 7.0 to 8.0 pH range. The pump has a maximum output of 40 gallons of solution pumped in a 24-hour period.
For the soda ash feeder, one generally has to inject about 100 to 400 ppm of a saturated soda ash solution into the water to raise the pH to 7.0 to 7.4.
For instance, say it was set up to inject it into your pipe before the pressure tank, and your well water flowed at 15 gallons per minute.
You can use 4 lbs of soda ash powder dissolved in 5 gallons of water. Water weighs 8.34 lbs, so 5 gallons of water weighs 41.7 lbs, or about 42 lbs. That makes your solution a 10% solution, which is the same as 100,000 parts per million.
Say you had 10 gallons per minute and wanted to inject 150 ppm of soda ash.
150 ppm X 10 gpm X 1440 (minutes in a day) divided by the solution strength of 100,000 = 22 gallons per day. This means that you would inject 22 gallons of soda ash solution every 24 hours after the well pump has turned on and pumped.
NOTE: Your well pump likely only runs 30 minutes to an hour a day. So, if it ran for one hour a day, you would use about one gallon of solution daily.
Therefore, if your well flow rate were 10 gallons per minute, you would need a metering pump that pumped 22 gallons in 24 hours or “22 gallons per day.” The Stenner 85MPH40 will work fine because you can set the Feed Rate Dial to 55%. 22 divided by 40 is 55%.
Note that your water may not need 150 ppm of the 10% soda ash solution; it might only need 50 ppm to bring up the pH to the 7.0 – 8.0 range. You will be able to know immediately after turning on the system by checking the pH.
What is Sodium Carbonate?
Soda ash, or sodium carbonate (Na₂CO₃), is a naturally occurring mineral used in many industries, including water treatment. Acidic water (pH below 7) can corrode pipes and fixtures, so it's important to neutralize it for safe use.
Sodium carbonate is a strong alkaline compound. It's highly effective at raising the pH of acidic water. By increasing pH, soda ash reduces corrosion risks and makes water safer to drink.
It also helps soften water. Soda ash removes carbonate hardness by causing calcium and magnesium ions to form solids that can be filtered out. Its versatility makes it a key component in many water treatment systems.
Soda Ash Systems for Water Treatment
Soda ash systems are designed to treat acidic water. They use sodium carbonate to raise the pH, making water less corrosive and safer to use.
These systems also reduce water hardness. Soda ash causes dissolved minerals like calcium and magnesium to solidify and drop out of the water. This helps protect pipes, appliances, and fixtures from scale and damage.
Because of these benefits, soda ash systems are used in both homes and industries to improve water quality and extend the life of plumbing systems.
Using Soda Ash for pH Adjustment
Soda ash raises pH levels by releasing sodium and carbonate ions into the water. These ions react to form bicarbonate and hydroxide, which increase alkalinity.
This reaction also helps soften hard water. The carbonate in soda ash bonds with calcium and magnesium, forming solids that can be filtered out.
Using soda ash for pH adjustment makes water less acidic and easier on plumbing systems. It’s an efficient way to protect your home or facility from scale and corrosion.
Water Softening with Soda Ash
Soda ash also plays a key role in water softening. When paired with lime, it reduces both carbonate and non-carbonate hardness.
Hard water contains high levels of calcium and magnesium. These minerals cause scaling and reduce the lifespan of plumbing and appliances. Soda ash neutralizes them by forming insoluble compounds, which are easy to remove through filtration.
This not only softens the water but also protects your system from future damage. Soda ash can also help stabilize chlorine disinfectants, like sodium hypochlorite, boosting their ability to kill bacteria and viruses.
Heavy Metals Removal
Soda ash is also an effective agent for removing heavy metals from water, addressing a critical concern in water treatment. Heavy metals such as lead, mercury, and arsenic can enter water supplies through environmental pollution and pose significant health risks.
Soda ash precipitates heavy metals out of the water, forming insoluble compounds that can be easily removed through filtration. This process makes the water safer for consumption and helps meet regulatory standards for water quality.
Additionally, soda ash can be used alongside other water treatment methods, such as activated carbon adsorption, to enhance the removal of a wide range of contaminants, ensuring comprehensive water purification.
Advantages of Using Soda Ash
There are numerous advantages to using soda ash in water treatment processes. One of the primary benefits is its effectiveness in adjusting pH levels and softening water, making it a versatile solution for various water quality issues.
Additionally, soda ash is a relatively inexpensive and environmentally friendly option compared to other water treatment methods. It is a safe and non-toxic substance for drinking water and wastewater treatment.
