How to Remove Phosphates From Water?

The presence of phosphates in water is not a piece of good news! They are harmful to health. That is why phosphate removal is necessary for having quality drinking water. The phosphorus in drinking water and wastewater can be removed using specific methods.

We will inform you about how to remove phosphates from water at a great length here.

phosphate-free water using effective ways of phosphate removal

Effective Ways of Phosphate Removal

Phosphate removal from wastewater is not tricky if done using proper methods. According to civil and environmental engineering research, various methods are effective for phosphate removal. Let’s find out about some effective ones.

Chemical Precipitation for Phosphate Removal

This method is very efficient for phosphorus removal as it can remove dissolved phosphorus too. You can use chemical precipitants that incorporate phosphorus as total suspended solids. These TSS can be removed later.

The most common coagulant to remove phosphate is ferric chloride. The wastewater treatment plants use chemical precipitation more frequently than other methods, and the common chemical for this is iron.

Another coagulant used to precipitate phosphorus from municipal wastewater is aluminum. Aluminum as hydrated aluminum sulfate breaks down its ions and forms aluminum phosphate.

You can find 50 mg/l to 200 mg/l of phosphorous in municipal wastewater. Chemical precipitation is effective in treating influent wastewater, which is then passed through other processes for secondary treatment.

The first step is primary sedimentation with the addition of chemicals that causes waste sludge production. Then the remaining water is passed through an aeration tank and goes through secondary sedimentation. The secondary sedimentation produces the final effluent, which has a 0.5 mg/l concentration.

Biological Removal

The biological method is a cost-effective method to remove phosphorus by using the biological metabolism of organisms in their natural environment. This method treats raw wastewater and secondary effluent produced by other primary treatments.

You have to use the bacteria and other P accumulating organisms (PAO) that remove phosphorus in the metabolic processes. A biologic treatment plant has two types of tanks for this purpose, i.e., anaerobic tank and activated sludge tank. 

PAOs assimilate the volatile fatty acids into fermentation products to release phosphorus. This step occurs in the anaerobic zone that has anaerobic conditions. They assimilate fermentation products to produce storage products.

In the aerobic zone, these products are oxidized to produce energy. This energy is used to incorporate phosphorus into polyphosphates which are biological solids. 

These biomass or biological solids are removed with sludge and return activated sludge goes to the anaerobic reactor again.

Sand Filtration for Wastewater Treatment

water testing for wastewater treatment

Sand filtration is a conventional way of removing impurities from wastewater. This technology is an effective removal method against influent wastewater to eliminate suspended impurities. There is a bed of sand through which wastewater flows. This sand-bed filter media removes the impurities by physical encapsulation.

It effectively decreases phosphate levels by removing phosphate bound to organic matter.

 What Are Phosphates?

Phosphates are compounds that are derived from phosphoric acid. The phosphates can be in two forms, but both have negative charges.

Phosphates exist either as hydrophosphate with a hydrogen atom or a simple phosphate group of one phosphorus atom and four oxygen atoms. The phosphate anion has a charge of -3 on it in any form.

Phosphate is good for health if present in low levels. It is also a good nutrient for bones and teeth. It is present as an inorganic anion in aqueous solutions so that the body can utilize it.

Sources of Phosphate Contamination

Phosphorus occurs naturally in rock or some ores. The rainwater runoff adds it to the water bodies. Mining and agriculture also add phosphate to the water sources.

The fertilizers have high phosphorus concentrations and cause an increase in phosphate levels. Another source of phosphate contamination is human sewage and vegetables processing units.

Many chemical manufacturing plants and industries like the paper industry cause P discharges in water bodies. It is present in aquarium water as well. When this aquarium water is discharged into water sources, phosphate levels become high.

The Symptoms and Danger of Phosphates

The most significant danger of phosphorus in the production of algae blooms. Eutrophication occurs when there is too much phosphorus in water sources and an aquarium, altering species composition and biomass. This eutrophication leads to dead zones not allowing oxygen to penetrate.

Eutrophication is the decrease of oxygen levels in water bodies. It is dangerous for animals present in an aquarium. The growth of algae causes increased levels of algal toxins. This is dangerous for an aquarium remarkably, as the fish starts dying quickly in the aquarium.

Phosphorus works along with nitrogen to speed up the growth of algae. If there is too much phosphorus in your water supply, you will notice an algal increase in pipes.

The high phosphate level is harmful to health as well. When there is an excessive intake of phosphate, it causes hyperphosphatemia. This condition is the increase of phosphorus levels in the blood.

Excessive phosphorus is harmful to kidneys as well. It causes kidney damage, and the body starts showing symptoms of high phosphate concentration.

It causes the calcium level to become low. You may experience muscle cramps, pain in joints and bones, itchy skin, rashes, and a tingling feeling around the mouth.

Does Water Filter Remove Phosphorus?

Yes, water filters effectively remove phosphate, mainly activated carbon filters. The carbon filters absorb the phosphorus and other impurities and make the water pure. In addition to these charcoal filters, the reverse osmosis technology removes phosphorus as effectively as it removes other impurities.

Many filters have either Granular Activated Carbon filters or a reverse osmosis membrane. Each of these filters readily removes phosphorus either physically or with any chemical.

Which Water Filters Remove Phosphorus?

  1. Reverse Osmosis Systems:

Reverse osmosis systems are vital in purifying the wastewater to make it drinkable by removing impurities like phosphorus.

These systems are very effective in phosphate removal. Due to their ability to purify wastewater, they have a competitive advantage over other methods to help cope with the shortage of drinking water.

Reverse osmosis systems have the core semipermeable reverse osmosis membrane that performs the process of filtration. This membrane is suitable for purifying water contaminated with micro and macro impurities. A best RO filter can remove pollutants as small as 0.00001 microns.

  1. Under Sink Water Filters:

Under sink water filter systems are a thrifty way to save water. They have economic advantages over other filters because of their reasonable price. Moreover, they don’t take much space. Thus, they are compatible with small places and kitchens as well.

Your kitchen needs a filter to remove phosphate from the water more than any place. This under-sink water filter goes right under your sink. And these filters also have reverse osmosis technology to purify the water for you while preserving the nutrient value. 

But it would be best if you replaced the cartridges after a specific time for their better working.

reverse osmosis system under the sink filters phosphorus from water
  1. Gravity Water Filters:

Gravity water filters are suitable for you if you want a filter that does not require much maintenance. These filters are effortlessly effective for the removal of contaminants like phosphate. Whether you want them for outdoor or indoor installment, they work efficiently in both settings.

These filters use a combination of granular carbon filters and sediment filters. But some of them have a specialized reverse osmosis system for making pure water.

You don’t need to worry about their capacity for handling water as they come in both large and small sizes. So, buy the filter that meets your need for water. You can easily take the smaller filters from one place to another and even outdoors. In contrast, large filters are perfect for countertops and the whole house.

  1. Caravan and RV Water Filters:

Caravan and RV water filters are a good choice if you like to travel often. The surface water at picnic spots is not clean and contains phosphate, nitrogen, etc. So, getting a caravan and RV filter will help you get pure water after nitrogen and phosphate removal, even outdoors.

They use a variety of filters like sediment filters, GAC filters, reverse osmosis filters, and ultraviolet light purification. It depends on the type of contaminant and needs which filter you should install to get pure water.

FAQs on How to Remove Phosphates From Water?

How do I know if my house is contaminated with phosphorus?

If your house water is contaminated with phosphorus, there will be algae eutrophication in water and algal growth in pipes. The water will give off a pungent smell like garlic. You will feel a sour or tangy taste.

Does boiling water remove phosphorus?

Yes! Boiling the phosphorus-contaminated water significantly removes the p content of water. Though it does not eliminate phosphorus, it lowers phosphate to a safe level. The boiling method decreases the p content of food as well.

Does Brita remove phosphorus?

No! Brita water is not effective in phosphate removal. Phosphate goes undetected and as it is from Brita filter along with nitrates. They might remove a minimal amount, but there is no indication of that.


We have mentioned all the effective methods for your benefit. The harms of phosphorus emphasize the need for removal even more. Thus it would help if you had any of the filters as mentioned earlier to have phosphorus-free water for the sake of your health. Do not hesitate to share your feedback in the comments about this guide and the filters.