Water and soil are essential resources for nutrition and food security. Agricultural sustainability promotes environmentally friendly practices, avoiding the use of pesticides and opting for more friendly methods. Taking care of these resources is essential for our health and that of future generations. Water and soil conservation protects biodiversity and creates a balanced ecosystem. Agricultural sustainability requires awareness and responsible practices, prioritizing the implementation of sustainable alternatives to conventional pesticides. The goal is to produce food efficiently and in an environmentally friendly way. In short, water and soil are essential for food. Their conservation is key to a sustainable future and healthy agriculture, using environmentally friendly methods instead of pesticides.
How do pesticide particles behave in soil and water?
The behaviour of pesticide particles in soil and water is influenced by three fundamental processes that determine their movement and persistence. These processes are the following:
1. Absorption: This is the first step in the behaviour of pesticides. It consists of the binding of soil particles, especially clays and organic matter, with pesticides. This interaction can determine the retention or release of pesticides into the environment.
2. Transfer: Once pesticides have been applied, the transfer process begins. This involves the movement of pesticides from one location to another. It can occur through different pathways, such as drift (movement in the air), volatilization (conversion into gaseous form), erosion, and runoff (movement by water), among others.
3. Degradation : Pesticides can be degraded through various processes. Degradation can be photochemical (caused by the action of sunlight), chemical (by hydrolysis or oxidation) or microbiological (through metabolic or enzymatic activity of microorganisms present in soil and water). These transformations contribute to the decrease in the concentration and persistence of pesticides in the environment.
In addition to these fundamental processes, there are other factors that influence the behavior of pesticides, such as diffusion, volatilization, drift, erosion and runoff, absorption by plants, accumulation in organisms and leaching.
Leaching, in particular, is a relevant phenomenon in the behaviour of pesticides. It refers to the movement of pesticides into deeper soil layers and their eventual arrival at groundwater sources. Leaching tends to be more pronounced in pesticides with low absorption capacity and high persistence, in areas with high levels of precipitation and low temperatures, as well as in soils with low organic matter content and sandy texture.
“Removing waste is complex, expensive and time-consuming, which is why photochemical technology is used, which is capable of removing or reducing pesticide concentrations through mineralisation, rather than passing the problem on from one place to another.”
Advanced Oxidation Processes (AOPs) offer a fascinating solution for the oxidation of surface photons present in pesticides. Through heterogeneous photocatalysis, which involves the acceleration of a photoreaction in the presence of a semiconductor material as a photocatalyst, renewable energy such as sunlight can be harnessed to generate in situ oxidation. This innovative approach makes it possible to combat pesticides in an effective and environmentally friendly manner.
When we apply pesticides to plants, it is estimated that approximately 50% of the substance is deposited in the soil. However, when pesticides are applied directly to the soil, the concentration is higher, which requires a deep understanding of their behavior and the possible associated impacts.
· Risks depend on many factors such as:
What Environmental Problems in the Soil Does the Use of Herbicides Generate?
Although pesticides have proven to be an effective tool in controlling weeds and pests, it is essential to consider the risks associated with their use. The United Nations International Agency for Research on Cancer has carried out a toxicological evaluation of more than 1,000 active substances, classifying 121 as carcinogenic to humans, 89 as highly probable and 315 as possibly carcinogenic. In addition, in recent years, a significant number of pesticides have been labelled as endocrine disruptors, raising additional concerns in terms of human and environmental health.
In this context, understanding the behaviour of pesticides in soil and water becomes even more relevant. It is essential to adopt a professional and responsible approach to their use, valuing safer and more sustainable alternatives. The application of processes such as heterogeneous photocatalysis using PAOs opens up a world of possibilities for eliminating pesticide residues, using renewable energy as an ally in the degradation of these harmful substances.
How to decontaminate water from pesticides?
Decontamination of water affected by pesticides is a major challenge in the protection of the environment and human health. To achieve this, various strategies and technologies are used to eliminate or reduce the presence of these harmful compounds. Below are some of the main techniques used in the process of decontaminating water from pesticides:
1. Physical treatments : Techniques such as sedimentation, filtration and adsorption are used to remove pesticides from water. These methods take advantage of the physical properties of the compounds to separate them from the aqueous medium.
2. Chemical treatments: Chemical reactions are used to transform pesticides into less toxic or non-active compounds. Common chemical methods include oxidation, reduction and hydrolysis. These reactions can be carried out using chemical agents or advanced oxidation processes.
3. Biological treatments: Microorganisms, such as bacteria and fungi, are used to break down pesticides in water. These organisms have the ability to use pesticides as a food source, transforming them into more harmless products.
4. Advanced techniques : More sophisticated technologies are used, such as heterogeneous photocatalysis and electrocatalysis, which harness the energy of sunlight or electricity to degrade pesticides present in water.
It is important to note that the choice of decontamination technique will depend on various factors, such as the characteristics of the pesticides, their concentration in the water, and the availability of resources and technologies. In addition, it is essential to carry out continuous monitoring to assess the effectiveness of the treatments and ensure that the decontaminated water meets established quality standards.
It is vital to clean soils and waters of pesticides to protect the environment and health. We must adopt sustainable methods without toxic chemicals in agriculture. Organic farming, agroecology and permaculture are alternatives that conserve soil, water and biodiversity. Let us raise awareness among farmers, consumers and legislators about these responsible practices. Together, let us build a sustainable future and preserve our planet.
To read the full article, visit the following link: (25) Pesticides: remediation of soils and aquifers. | LinkedIn