How is water contaminated by nitrates?

How to remove nitrates from water?

What is the problem?

Nitrates are inorganic chemical compounds that are naturally found in the environment. In fact, nitrogen is an essential nutrient that helps plants and crops grow by forming plant tissue and chlorophyll for plant photosynthesis.

Their natural presence in the ecosystem maintains a balance. However, there are some areas where human action has altered this natural cycle. It has resulted in large excesses of nitrates that cannot be absorbed naturally.

High nitrate concentrations in groundwater and surface water have different origins. They mainly come from percolation of agricultural runoff, loaded with traces of nitrogen fertilisers and herbicides, from industrial effluents and from leaks from septic tanks and sewage networks. Deposits also occur naturally, generated by nitrifying bacteria that oxidise ammoniacal nitrogen into nitrates. Another important factor is the carry-over of nitrogen contained in animal manure from intensive livestock farming. What is clear is that human activity plays a major role in the pollution of water bodies.

What are the consequences for ecosystems?

Excess nitrates have serious impacts on ecosystem stability and species survival.

The abusive use of composting or nitrogenous fertilisers is a major source of pollution for both surface and coastal waters and groundwater. These polluted, nutrient-laden discharges exceed the natural self-purification capacity of ecosystems and promote the overgrowth of organic matter.

Este fenómeno provoca un  crecimiento acelerado y descontrolado de algas, que rápidamente cubren la superficie del agua. Además, este tipo de alga provoca un enturbiamiento del agua que impide que la luz penetre hasta el fondo del ecosistema.

This phenomenon causes an accelerated and uncontrolled growth of algae that quickly covers the surface of the water. In addition, this type of algae causes turbidity in the water, which prevents light from penetrating to the bottom of the ecosystem.

Source: BIOBOX® Nitrates piloting in the Mar Menor Murcia | 2022

As a result, the vegetation cannot photosynthesise and dies. A large amount of settleable solids and dead plant debris is generated, causing other micro-organisms such as bacteria to feed on this dead matter.

This causes the oxygen in the available body of water to be depleted (anoxia). The result is a major natural disaster that causes the death of thousands of aquatic species and organisms.

BIOBOX Nitratos eutrofizacion
Source: Rtve
consecuencias de nitratos en agua eutrofización
Source: WWF ; ANSE; Jorge Sanchez

Are there human consequences?

Nitrates also have harmful effects on human health.

Altas concentraciones de nitratos en agua potable están asociadas con la enfermedad conocida como metahemoglobinemia, que generalmente afecta a niños menores de 6 meses de edad. Asimismo, diferentes tipos de cáncer del tracto gastrointestinal han sido atribuidos a la acción de compuestos nitrosos. Esto se debe a que los nitratos pueden formar nitrosaminas y nitrosamidas, compuestos potencialmente cancerígenos.

High concentrations of nitrates in drinking water are associated with the disease known as methaemoglobinaemia. This disease usually affects children under 6 months of age. It also causes different types of gastrointestinal cancers. This is because nitrates can form nitrosamines and nitrosamides, potentially carcinogenic compounds.

Therefore, for an aquifer to be used to supply a population, it is mandatory that it contains less than 50 mg/l de NO3-. If it does, it must be removed before the water reaches the consumer.

What is the regulation?

The problem is of great dimension and global importance. A European directive has been in place since 1991 and there are action plans for all EU members to reduce the generation of nitrates. Today, the presence of nitrates in drinking water sources is a recurrent problem in various parts of the world, such as the Middle East, North America, Australia, North Africa and Europe. This has led to a focus on investment and research into more efficient ways to solve the problem.

Source: MITECO map of waters affected by nitrate pollution in Spain
Source: European Commission

What is the solution?

There are currently several techniques for the removal of nitrates from water. These can be classified into two groups:

Source: BIOBOX®

Separation technologies have traditionally been used to separate nitrates from the water stream to be treated. However, they do not solve the problem as they generate concentrated discharges of the pollutant that must be stored and further treated.

Transformation technologies transform nitrates into other harmless chemical compounds through the natural action of bacteria.

Differences Reverse Osmosis vs. BIOBOX® Nitrates

Source: BIOBOX®

BIOBOX® Nitrates integrates the market-leading biological denitrification technology called Puremust-sn®. This technology has been created in our own Innovation and Development Centre based on the experience and lessons learned by two leading companies in the sector, Ingeobras and Filtralite (Saint-Gobain).

Characteristics of BIOBOX® Nitrates technology:

  • Patented technology
  • Certified by SGS and several references for many years
  • No pollutant rejects
  • NO3 removal efficiency above 95%.
  • No residual COD in the treated water
  • OPEX around 0,10€/m3

How is BIOBOX® Nitrates designed?

BIOBOX® solutions are tailor-made to meet the specific needs and space requirements of each customer. Standard manufacturing cycles are 6 to 10 weeks.

All plants have common components and a design basis made by water treatment experts. They repeat the same process that happens in nature, intensified and automated.

Source: BIOBOX®
  1. Pumping unit for water intake
  2. Treatment line with a single biological denitrification filter
  3. Automatic chemical dosing system
  4. Instrumentation panel
  5. Pumping unit for backflushing
  6. An electrical and automation cabinet

Plants can also be built in skid format or a bespoke design to fit in with the company’s existing facilities. All formats include transport to destination, on-site installation, commissioning and knowledge transfer for operation and maintenance.

Main advantages of BIOBOX®

  • Less space required: One of the premises of our proprietary technologies involves the use of a much smaller surface area than other technologies on the market. This also leads to lower operating and investment costs.
  • Quixk construction: We minimize execution and start-up times. We reduce the investment costs of the solution as a whole, in addition to avoiding civil works.
  • Demonstration pilots: Tailor-made pilots in our own research and development centre and on-site.
  • Remote control 4.0: The plant can be visualized and controlled in real time from any device with an internet connection. It is a completely autonomous technology that has a messaging alert system that notifies operating staff of any need.
  • 100% automated Plug&Play Plants: The plants are delivered pre-assembled and completely finished, ready for start-up. Thanks to their automation and sensors, all key parameters are monitored. This facilitates self-management, optimizes resources, avoids potential problems and achieves continuous improvement. All this results in minimal intervention by operating staff.
  • Designed by water treatment experts: We are experts in water treatment for 25 years. We create tailor-made designs based on both our experience and massive digital data collection from our operating plants. We use a big-data and smartwater approach. This, allows us to make new optimized, very robust and highly competitive designs.
  • Sustainable proprietary technology: We make available to all types of companies advanced technology whose alternatives are only available to large plants and investors. Our processes are clean and safe for the environment.
  • Operation and maintenance training
  • After-sales service
  • Guaranteed results

Success stories

Take a look at some BIOBOX® Nitrates case studies

We are here to help you!

We will be happy to study your case, answer any questions you may have and provide you with a no-obligation quote.

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