Water is the essence of life, a vital resource that sustains both human civilization and the ecosystems of our planet. However, the purity of water is often compromised by contaminants, which can range from naturally occurring minerals to man-made chemicals. Ensuring that our drinking water is clean and safe is a paramount concern, leading many to turn to water purification methods such as reverse osmosis (RO). This article delves into the depths of water contaminants and elucidates the capabilities of reverse osmosis in removing these unwanted substances.

The Water Contamination Challenge

Water contamination can occur from multiple sources, including agricultural runoff, industrial discharges, urban development, and natural geological processes. The contaminants range broadly in type and effect:


Bacteria, viruses, and parasites that can cause disease.


Lead, mercury, arsenic, and cadmium that can be toxic in certain concentrations.

Chemical Compounds

Pesticides, herbicides, and industrial chemicals such as polychlorinated biphenyls (PCBs).


High levels of nitrates and phosphates can lead to eutrophication in bodies of water.

Total Dissolved Solids (TDS)

A measure of the combined content of all inorganic and organic substances.

The presence of these contaminants can lead to not only adverse health effects but also ecological damage. Therefore, it’s crucial to have effective water treatment systems in place.

What Is Reverse Osmosis?

Reverse osmosis is a water purification technology that utilizes a semi-permeable membrane to remove ions, molecules, and larger particles from drinking water. In reverse osmosis, water pressure is used to overcome osmotic pressure, a colligative property, to remove water impurities on a molecular level.

The Process of Reverse Osmosis

The RO process involves several steps:

Sediment Filtration

Water first passes through a sediment filter that removes large particles.

Carbon Filtration

Next, a carbon filter removes chlorine and other organic compounds that might damage the RO membrane.

RO Membrane

The critical step involves forcing water through the semi-permeable membrane, which blocks contaminants but allows clean water molecules to pass through.

Polishing Filter

Finally, the water goes through a post-filter to polish the water before it’s ready to drink.

The Effectiveness of Reverse Osmosis Against Contaminants

Reverse osmosis systems are known for their ability to purify water significantly, but what exactly can they remove?


RO systems are extremely effective at removing protozoa such as Giardia and Cryptosporidium, as well as bacteria like Salmonella, Shigella, and E. coli. Viruses such as Enteric, Hepatitis A, and Norovirus are also largely eliminated by RO filtration.


Heavy metals, which are hazardous even in trace amounts, are one of the groups of contaminants that RO systems handle effectively. They can typically remove common metal contaminants like lead, mercury, and arsenic close to 95-99%. This capability is crucial for homes with lead pipes or in areas with heavy metal contamination.

Chemical Compounds

RO systems can handle various chemical compounds, including chlorine and chloramine residuals left from municipal water treatment. Volatile organic compounds (VOCs), herbicides, and pesticides are also largely reduced by RO.

Total Dissolved Solids (TDS)

One of the hallmarks of RO is its ability to significantly reduce TDS in water. It is known to remove up to 99% of dissolved salts (sodium, potassium, and calcium), thereby improving the taste and color of the water.


Nutrients like nitrates and phosphates, which can be harmful at high levels, especially for babies and pregnant women, are effectively removed by RO systems to safe levels.

Limitations of Reverse Osmosis Systems

While reverse osmosis is a robust method for water purification, it has certain limitations. It does not remove gases, so contaminants that are gaseous at room temperature, like radon or some VOCs, may not be fully removed. Additionally, while RO systems reduce the hardness (calcium & magnesium) of water, they are not specifically designed as water softeners.

RO systems also require regular maintenance, including membrane and filter replacement, to function optimally. Moreover, the process is water-intensive, as only a portion of the water entering the system comes out as purified water; the rest is wastewater containing concentrated contaminants.

Understanding the contaminants present in our water is the first step towards ensuring a safe supply. Reverse osmosis offers a powerful solution to a wide array of these pollutants. It is an advanced filtration method capable of reducing nearly all dissolved solids, microorganisms, and chemical contaminants to safe levels. While it may not be a panacea for all water quality issues, an RO system is undeniably a cornerstone technology for modern water purification efforts. As we continue to grapple with the challenges of water contamination, technologies like reverse osmosis will remain invaluable tools in our pursuit of pure, safe drinking water.

By employing a reverse osmosis system in your home or community, you’re taking a significant step toward safeguarding health and ensuring the longevity of your water supply. However, always remember to consider the specific contaminants in your local water when choosing a water treatment solution, as this will help tailor the most effective strategy for your needs. Contact our team today for your water treatment!