• Mahika Weerasekare

Hard Water: Good for You and Planet Earth

Updated: Sep 28, 2021

What is hard water?


Traditionally, hard water has been measured by how well soap reacts with water. If water is hard, more soap is required to form a lather.


Chemically, hard water contains higher amounts of calcium and magnesium ions. (You might recognize these minerals from the nutrition labels found on your favorite snack…and we’ll get to that in a bit. Water naturally absorbs these minerals from the Earth as it seeps through soil, flows over rocks, and courses down riverbeds. Not surprisingly, the ratio of minerals in hard water mirrors the ratio found in the Earth’s crust: 63% of water hardness comes from calcium and 37% from magnesium.(1)



Why don’t we like hard water?


As water dries or evaporates the minerals in hard water, especially calcium, bound to carbonate form calcium carbonate deposits, that are visible as white spots on freshly washed glass and flatware, faucets, and other fixtures. Initially, these deposits are simply an unsightly, but benign, nuisance. Over time, as more calcium carbonate settles, these unsightly mineral deposits compound and form hardened scale. Scale can build up and destroy water heaters and boilers, clog showerheads and faucets, and reduce the lifespan of appliances like dishwashers and steamers.


What are the benefits of hard water?


Take a look at the nutrition label on your favorite snack. Do you see calcium and magnesium in it? (If not, it may be time to find a new favorite snack!) Calcium and magnesium are essential nutrients and inadequate consumption of either can result in adverse health effects. The World Health Organization (WHO) cites several studies that find consuming hard water is beneficial to human health.(2) Additionally, these studies have

found no adverse health effects associated with the consumption of hard water.


Blue Zones


In addition to supplying essential nutrients, the same studies suggest there are tangible benefits of consuming hard water that are linked to the lower corrosivity of hard water compared to soft water. The minerals in hard water shield exposed metal surfaces from corrosive substances, like chloride and oxygen, commonly found in water. When you remove those minerals in hard water through artificial water softening (think ion-exchange softeners), the water turns corrosive, increasing your exposure to harmful metals extracted from pipes and fixtures.


How do traditional water softeners work?


Traditional water softening methods work by removing the natural minerals from hard water. The most common method of treating hard water, ion-exchange water softening, replaces the beneficial calcium and magnesium in your water with sodium or potassium. Reverse osmosis (RO) is another method of removing minerals by forcing hard water through a semipermeable membrane. The WHO actually discourages the use of RO to soften drinking water as the resultant water is so devoid of minerals it can absorb minerals from the human body after consumption.


What are the environmental impacts of these traditional water softening methods?


Fresh water is a dwindling commodity as freshwater sources across the United States are increasingly contaminated with salt. For instance, in New Mexico over 75% of groundwater is too saline for use without treatment.(3)


Neither method can be considered environmentally friendly as both ion-exchange and RO water treatment methods waste a significant amount of water and degrade the quality of fresh water supplies. For every gallon of drinking water produced, an RO system releases gallons of water with high mineral content into the environment. Ion-exchange systems are even less environmentally friendly. During the regeneration process they release chloride (salt) into the environment. Chloride was a major contributor to the Flint water crisis.(4)


Is it possible to keep beneficial minerals in water and prevent scale?


Yes, it is quite possible. There are several new methods for treating hard water that allow water to retain its beneficial minerals. Unfortunately, many of these methods only change the physical properties of hard water minerals and are temporary, easily reversing over time. Since scale forms when water is resting and not moving these methods will not prevent scale buildup with time.


Nuvoh2o’s CitraChrage is a natural chelator that binds hard water minerals, changing chemical properties of scale. This process is irreversible and therefore a more permanent way to prevent scale buildup.


What is a chelator?


You have likely encountered chelators every day without knowing it. Most cleaning products available today, be it soap, detergent, or shampoo, contain added agents called chelators. Chelators improve the function of the soap by keeping minerals away from the active cleaning agent, improving the lathering ability and cleaning power of the soap (remember the traditional measure of hard water).


Citrate, the active ingredient in Nuvoh2o’s CitraCharge, is one such chelator. Citrate is a natural chelator and is the only safe and biodegradable chelator currently in use. Like the added chelators in soap, citrate (think citrus fruit) keeps minerals away from your pipes and fixtures, preventing scale build up.

(Citrate is also produced in our bodies as an intermediate in the process of turning food we eat into energy)


How does Nuvoh2o’s CitraCharge prevent hard water scale?


Calcium carbonate is the principal component of hard water deposits and scale, if you can eliminate calcium carbonate, you eliminate hard water scale. Ion-exchange systems eliminate calcium carbonate by substituting the calcium with sodium or potassium, while Nuvoh2o’s CitraCharge works by substituting the carbonate with a small amount of citrate (40 times less citrate per gallon than in a glass of orange juice) to disrupt the formation of calcium carbonate. The citrate works to prevent and remove scale in two ways:


1. Nature loves symmetry, and hard water scale is no different. Calcium carbonate forms organized molecular structures, like in the image to the right, to create scale. Citrate displaces the carbonate ions in scale, destabilizing the chemical structure, causing it to collapse. Even displacing just a few carbonate ions is enough to disrupt the formation of hardened, calcified scale.

2. Altering the pH of the water increases the solubility of the carbonate ions in the water. Increasing the solubility means minerals are more likely to remain in the water and not settle out of water onto surfaces such as pipes, fixtures, and appliances.


Both actions even dislodge deposited minerals, allowing water to wash away mineral buildup.


Kidney Stones


Is CitraCharge a green hard water treatment method?


Yes, citrate is both naturally occurring and biodegradable. It won’t harm you or the environment. Unlike other treatment methods, no water is wasted while operating a NuvoH2O system and no salts or pollutants are released into wastewater.


About the Author


Dr. Mahika Weerasekare is a synthetic organic, and analytical chemist with over 20 years of work in research and development. Her experience ranges from small molecular drug development to biomaterial synthesis. Dr. Weerasekare became interested in water chemistry while developing synthetic biopolymers that mimic natural underwater glues for use as water-borne surgical adhesives.

 

References


1. http://ocean.stanford.edu/courses/bomc/chem/lecture_12.pdf

2. WHO/HSE/WSH/10.01/10/REV/1

3. https://www.usgs.gov/special-topic/water-science-school/science/saline-water-and-salinity?qt-science_center_objects=0#qt-science_center_objects

4. https://www.acs.org/content/acs/en/education/resources/highschool/chemmatterpast-issues/2016-2017/december-2016/flint-water-crisis.html

5. https://www.khanacademy.org/test-prep/mcat/biomolecules/krebs-citric-acid-cycle-and-oxidative-phosphorylation/a/the-citric-acid-cycle-2




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