Rising demand for remineralization creates need for sustainable solutions

According to the United Nations, global water use is growing at around 1% a year^1. This may not sound like much, but that 1% represents an additional 40 billion cubic meters of water to find every year. At the same time, climate change is putting pressure on water availability, causing severe flooding in some regions and prolonged droughts in others. Rising temperatures are increasing evaporation rates and the glaciers are melting at an accelerated rate, reducing long term water storage.  

The UN describes water as ‘a finite resource in growing demand’²and is predicting a 40% water deficit in the next five years. Since only 0.5% of the water on earth is useable and available freshwater³, most of the water we use and drink comes from treated supplies. To keep up with growing demand for treated water, the industry is focusing on new technologies that offer efficient ways to remove contaminants and meet strict water quality standards. The reverse osmosis market is predicted to reach $32 billion by 2030⁴, partly driven by the growing number of desalination plants, which in turn is creating growth in the remineralization market.

Why remineralization matters

Purified or desalinated water is low in mineral content, low in pH and lacking in buffer capacity, and must be remineralized before it can be used.  This post-desalination treatment removes acidity, adds minerals and improves water palatability. Nicholas Nelson, Director Innovation and Technical Marketing Water & Air Treatment at Omya, has written extensively on the subject. He says remineralization has benefits for infrastructure, the environment, but especially human health.

“The World Health Organization has recognized a dietary deficiency of both calcium and magnesium in people all around the world, causing health issues such as muscle cramps and weakness, heart problems, and inability to regulate blood sugar and pressure. Remineralization of drinking water can provide these essential minerals in a form easily absorbed by the body. Drinking hard water has been shown to reduce the incidence of cardiovascular disease, for example, and water quality target specifications are now beginning to reflect the need for higher levels of calcium.”

Comparing remineralization methods: finding the right fit

Remineralization is a critical step in water treatment, especially after purification processes like reverse osmosis or desalination, which strip water of its natural mineral content. Whether the goal is to improve taste, restore pH balance, or meet health and infrastructure standards, choosing the right remineralization method is essential.

There are three main approaches commonly used in the industry:

• Chemical dosing: precision at a cost

Chemical dosing, typically using sodium bicarbonate and calcium chloride, allows for precise control over ion concentrations. However, as Nicholas Nelson, Director Innovation and Technical Marketing Water & Air and Consumer Solutions at Omya, explains, this method comes with trade-offs. 

“It’s relatively simple and inexpensive to set up, but the ongoing operational costs are high. Plus, it reintroduces chlorine and sodium ions — which were costly to remove in the first place.”

• Lime cosing: widely used but operationally complex

Lime dosing has long been a standard method for remineralizing desalinated water, valued for its low cost and wide availability. Yet, Nelson points out that it’s far from straightforward. “Temperature affects the solubility of lime and carbon dioxide, which disrupts the balance between calcium ions, alkalinity, and pH. This leads to turbidity and requires frequent maintenance to manage limescale buildup.”

• Calcite contactors: simplicity meets sustainability

Increasingly, operators are turning to calcite contactors — a method that uses calcium carbonate to remineralize water. This approach is gaining traction for its simplicity, safety, cost-effectiveness, and low carbon footprint.

“Calcium carbonate is chemically stable, non-corrosive, and widely available. It’s safer to handle than lime and significantly reduces operational costs,” says Nelson.

Omya’s expertise: simplicity and sustainability with calcite contactors

Omya has developed the Omyaqua range of high purity calcium carbonate for remineralization to take advantage of these benefits.  Nelson elaborates, “The choice of products for calcite filters depends on the operator’s priorities, which might include meeting regulatory standards, hitting water composition targets, increasing the speed of reaction, or reducing turbidity. With Omyaqua, operators can strike a balance between these priorities by choosing the reactivity or durability that suits their needs.”

A big benefit of calcium carbonate, and one that water treatment plant operators increasingly care about, is its sustainability profile. As a natural resource it has a very low carbon footprint compared with the chemical alternatives. Nelson explains, “Calcium carbonate is abundant across the globe. The reserves we use for Omyaqua have high purity, which makes them very reactive, reducing the amount of material needed to do the job. The production process is straightforward and doesn’t require much energy, and it reduces risk to operators and plant.”

The Omyaqua range is available in different formulations across the world. For details of availability in your region, visit here.

¹ UN world water development report 2019.

² UN water scarcity.

³ UN sustainable development ensure access to water and sanitation for all.

⁴ BCC research global water crisis fuels growth in reverse Osmosis Market.