Eutrophication

Eutrophication is the process whereby water bodies such as lakes, rivers, oceans, aquifers and groundwater become over-enriched with nutrients, leading to the overgrowth of simple plants.

This is a serious environmental problem as it leads to the deterioration of water quality and the depletion of dissolved oxygen in water bodies, making eutrophicated areas ‘dead zones’, inhospitable to life. In terms of sustainability and climate change, therefore, it is crucial to think about how to preserve the ‘Blue Gold’.

Pollution of such a fundamental human element brings with it catastrophic consequences. In this respect, it is essential that companies take action to safeguard these resources by choosing the right partners for water recovery.

What does the definition of eutrophication mean?

The term eutrophication denotes the process of enrichment of water with nutrients, particularly nitrogen and/or phosphorous compounds. This causes a proliferation of algae and/or higher forms of life, such as so-called phytoplankton blooms, which, by lowering the oxygen level, make the environment unsuitable for other species (e.g. fish and other aquatic species).

According to the World Economic Forum, more than 100,000 lakes globally suffer from the problem of potentially harmful algal blooms, affecting public health and access to water for millions of people each year.

What are the consequences on the environment?

Going deeper into the consequences, eutrophication triggers knock-on effects in the ecosystem. The decomposition of algae and other plant matter produces carbon dioxide, lowering the pH and causing acidification of the oceans.

Other effects include:

• a reduction in the depth distribution of macroalgae and sea grasses caused by a decrease in sunlight;
• a decrease in the amount of oxygen in the bottom waters, with an impact on fish and benthic fauna and generalised mortality;
• a shift in biodiversity and ecosystem balance;
• an increase in the toxicity of the water body, with the water losing its transparency and developing a bad odour and colour;
• socio-economic impacts, especially on the fishing industry and the risk of shellfish poisoning in humans.

What causes eutrophication?

The phenomenon is a process mainly due to the use of fertilizers used in cultivation near reservoirs or organic pollution from human activities or industrial waste products. Nitrogen and phosphorus are in fact transported by streams, rivers and rainwater runoff.

Intensive agriculture with the systemic use of fertilizers, but also the discharge of urban and industrial waste water cause the presence of these substances to increase in the soil.

World Economy Forum estimates that 50% of phosphates used in agriculture and industry end up in the soil. Nitrogen in particular is produced by agricultural activity, and phosphorous by domestic and industrial wastewater.

What can large companies do to avoid water eutrophication?

In order to reduce the amount of nitrogen and phosphorus, changes in agricultural practices, better cleaning of wastewater, better control of diffuse sources of urban nutrients and the introduction of wetlands as nutrient sinks are required.

The EU has been moving in this direction for many years, including through the Nitrates Directive (1991), the Urban Waste Water Treatment Directive (1991) and the Water Waste Directive (2000).

All the more reason why companies that have the greatest impact on the release of their wastewater – as may be the case with companies in the textile sector, for example – must choose the right partner. Entrusting wastewater treatment to wastewater professionals capable of recovering a larger quantity can have a huge impact on the territory and on people’s lives.