Prevention is always better than cure. This especially applies to ensuring the safety of your drinking water at home. The Center for Disease Control (CDC) has released a guide on how you can make sure your drinking water is free from harmful chemicals and metals. One way to do this is by using a reverse osmosis system, which can remove common contaminants like sodium, chloride, copper, chromium, and lead; as well as reduce arsenic, fluoride, radium, sulfate, calcium magnesium, potassium , nitrate , and phosphorous levels .
In this guide, I’ll go into detail to explain if reverse osmosis can remove salt from water, and the pros and cons of using this method.
What is reverse Osmosis?
Reverse osmosis is a filtration process that uses pressure to force water molecules through a semi-permeable membrane. This leaves contaminants behind, and the clean water is collected on the other side.
Reverse osmosis can be used to filter out a wide range of contaminants, including bacteria, viruses, protozoa, parasites, dissolved minerals, and even some synthetic organic chemicals .
How does reverse osmosis work to remove salt?
Reverse osmosis works by passing water through a semi-permeable membrane. This membrane is designed to allow water molecules to pass through, but to block larger molecules like salt.
The water pressure on the side of the membrane with saltier water is greater than the pressure on the side with less salty water. This creates a osmotic pressure, which pushes the water molecules through the membrane and into the less salty water. The salt is left behind on the other side of the membrane.
Humans need sodium – Chemical Properties of Sodium and Sodium Salts:
Sodium ions are an essential component of the human body and play an important role in regulating osmolarity (concentration) and extracellular fluid volume. The body’s sodium content as well as its concentration in bodily fluids are both under homeostatic control. Sodium is essential for maintaining acid-base balance, cell membrane potential, and the regulation of acid-base balance.
EPA’s drinking water advisory(PDF) has listed Sodium(Na), Sodium Chloride (Na NaCl) Sodium Carbonate(Na CO 2 3) Sodium Hypochlorite(NaOCl) Sodium Silicate(Na2SiO3) and Sodium Sulfate(Na2SO4) as secondary maximum contaminant levels (SMCLs).
The FDA has also set a Reference Daily Intake (RDI)for sodium of 2,300 mg/day for healthy adults. This is the level at which people would consume if they were to consume an adequate diet and not fall below the Estimated Average Requirements(EARs) for any other nutrients.
The FDA has also set a Tolerable Upper Intake Level (UL) of 2,300 mg/day for sodium for healthy adults. This is the highest level of daily intake that is unlikely to pose any risks to health.
The CDC recommends that people with high blood pressure, diabetes, or chronic kidney disease limit their sodium intake to 1,500 mg/day.
The World Health Organization recommends that adults consume less than 2,000 mg of sodium per day.
Below is a table from EPA’s advisory on safe drinking water with chemical composition of sodium and sodium salts.
Is reverse osmosis the most effective way to remove salt?
Reverse osmosis is one of the most effective ways to remove salt from water. It can remove up to 99% of dissolved salts, making it ideal for those who want to improve the taste of their water or remove impurities .
Reverse Osmosis is widely regarded as the most efficient method of desalination. Reverse Osmosis removes up to 99%+ of the dissolved salts (ions), particles, colloids, organics, bacteria, and pyrogens from the feed water (although an RO system should not be relied on to remove 100% of germs and viruses). Based on size and charge, contaminants are rejected by an RO membrane.
There are other methods of salt removal, such as distillation and ion exchange. However, these methods are not as effective as reverse osmosis and can be more expensive.
What are the benefits of using reverse osmosis to remove salt?
There are many benefits of using reverse osmosis to remove salt from water, including:
- It’s an effective way to improve the taste of your water by removing dissolved minerals.
- It can also remove harmful contaminants that may be present in your water supply.
- Reverse osmosis is a relatively simple and straightforward process.
- It’s a cost-effective way to remove salt from water
- Reverse osmosis can be used to treat both municipal water supplies and private wells.
What are the drawbacks of using reverse osmosis to remove salt?
There are some drawbacks of using reverse osmosis to remove salt, including:ยท
- It requires a significant amount of water pressure to function properly. This means that it may not be suitable for all homes.
- Reverse osmosis systems can be expensive to install and maintain.
- They can also be slow, taking up to 24 hours to produce clean water.
- Reverse osmosis systems require a reliable source of water pressure to work properly.
- -Reverse osmosis membranes can become clogged over time, and will need to be replaced periodically.
How do I choose the right reverse osmosis system to remove sodium salts?
There are a few things you’ll want to keep in mind when choosing a reverse osmosis system, including:
- The size of the system. Choose a system that is designed for the size of your home and family.
- The quality of the system. Look for a system that has been certified to remove salt and other contaminants from water.
- The cost of the system. Installation and maintenance costs can vary significantly, so be sure to compare prices before making a purchase.
Aside from salt, what other impurities does reverse Osmosis systems remove:
- Reverse Osmosis systems are very effective at removing a wide range of impurities from water, including:
- Bacteria
- Viruses
- Protozoa
- Parasites
- Dissolved minerals
- Synthetic organic chemicals
What is not removed by reverse osmosis?
Reverse osmosis systems do not remove all impurities from water. They are not designed to remove solid particles, such as dirt, sand, or sediment. Additionally, they will not remove dissolved gases, such as chlorine or fluoride.
Most organic compounds, bacterial microorganisms, chlorine by-products, or dissolved gases like carbon dioxide, methane, and radon are not effectively removed by reverse osmosis units.
Do I need a reverse osmosis system?
If you’re concerned about the quality of your water supply, or if you want to improve the taste of your water, reverse osmosis may be a good option for you. However, it’s important to keep in mind that reverse osmosis systems can be expensive to install and maintain. Additionally, they may not be suitable for all homes.
If you’re not sure if reverse osmosis is right for you, it’s a good idea to consult with a water treatment specialist. They can help you determine if reverse osmosis is the best option for your home and family.
How often should I change the filter on my reverse osmosis system?Most reverse osmosis systems will have a filter that needs to be changed every 6 to 12 months. However, it’s important to check your system’s manufacturer recommendations to be sure.
Failure to change the filter on your reverse osmosis system can lead to decreased performance and reduced water quality. Additionally, it can cause damage to the system itself.
How much does a reverse osmosis system cost?
The cost of a reverse osmosis system varies depending on the size of the unit and the quality of the system. Generally, systems start at around $300 and can go up to $1,500 or more.
Installation costs will also vary depending on the type of system you choose. Some systems can be installed by a homeowner, while others will require the help of a professional.
Reverse osmosis systems are a significant investment. However, they can save you money in the long run by providing clean, safe water for your home and family. Additionally, they can improve the taste of your water, which may save you money on bottled water.
Why you need to remove sodium in your drinking water:
According to the Environmental Protection Agency(EPA), sodium may alter drinking water flavor by as much as 30 and 60 mg/L. Water with a high amount of sodium is also more corrosive.
If you have a pre-existing medical condition, sodium in drinking water can be a more serious concern. Specifically, high blood pressure, heart conditions, kidney or liver diseases can all be exacerbated by consuming large amounts of sodium. If this is something that worries you, be sure to speak with your health care provider about it so they can help put your mind at ease.
For persons on very low sodium diets, federal and state agencies suggest that water contain no more than 20 mg/L of sodium (mg/L) and that individuals on moderately restricted salt diets should stay below 270 mg/L. The majority of the salt we consume comes from food. According to the US Department of Health and Human Services, most people consume around 3,400 milligrams each day from their meals.
The chloride drinking water quality limit is 250 mg/L. Rather than safety concerns, this guideline is based on aesthetic criteria.
Recommended Residential Water Quality Testing & Sodium levels
New York State has put out a recommended chemical composition of safe drinking water and Sodium is last on the list. See the chart below;
FAQs
Why is drinking salt water harmful?
Drinking salt water can be harmful because it causes the body to lose water. When the body loses water, it becomes dehydrated. Dehydration can cause symptoms like thirst, dizziness, headache, and fatigue.
In severe cases, dehydration can lead to serious complications like heat stroke, kidney failure, or even death. Therefore, it’s important to drink only safe, clean water to avoid dehydration and its potential consequences.
What is the purpose of sodium in water?
Sodium is an essential mineral for the human body, particularly when it comes to blood pressure, fluid balance, and nerve and muscle function. Sodium in drinking water is not hazardous for most individuals but may be for someone who has certain health problems that necessitate a sodium-restricted diet. Reverse osmosis is one way to remove sodium from water.
How does salt affect reverse osmosis?
Salt has no direct effect on reverse osmosis, but it can cause problems indirectlty. When water contains dissolved minerals like salt, those minerals can build up on the membranes of the reverse osmosis system over time. This can decrease the system’s performance and eventually damage the membranes. That’s why it’s important to use only clean, filtered water in your reverse osmosis system.
Why does bottled water have sodium?
Harmful bacteria can grow in water with high concentrations of salt, so water bottlers often add small amounts of sodium chloride to their products to keep it safe. The FDA has set a maximum contaminant level goal for sodium in drinking water at 160 parts per million (ppm), which is the equivalent of about 10 mg/L.
How does reverse osmosis remove salt from water?
Reverse osmosis is a process that removes dissolved particles from water. The process works by passing water through a semi-permeable membrane. The membrane allows water molecules to pass through, but it traps larger particles, like salt.
What are signs of too much salt?
Long-term exposure to elevated sodium levels will result in health symptoms including;
- High blood pressure (hypertension)
- Heart disease.
- Stroke.
- Kidney disease.
- Kidney stones.
how do I test for salt in drinking water?
The term ‘salinity’ is used to express the concentration of dissolved salts in water. It’s usually shown as a percentage or parts per thousand. To get an estimate, you have to measure the conductivity of the liquid with a toroidal conductivity sensor or contactless conductivity sensor. The sensor measures the ability of the water to conduct an electric current, which is directly related to the concentration of dissolved salts.
Whilst not the most accurate method, tasting your water is the quickest way to find out if there are high levels of salt. If your water tastes salty, then it likely contains high levels of sodium chloride.
You can also test for salt using a home testing kit. Home salt testing kit will come with instructions, but generally, you’ll need to:
- Fill a container with your water sample.
- Add the contents of the testing vial.
- Compare the color of the solution to the included chart.
If the solution changes to a deep blue or purple color, then your water contains high levels of salt.
What is the difference between sea salt and table salt?
Sea salt and table salt are both about 40% sodium by weight. The main difference between the two is that sea salt also contains other minerals like magnesium, calcium, and potassium. These minerals can give sea salt a coarser texture and a slightly different flavor than table salt.