CONICET | Buscador de Institutos y Recursos Humanos

Several years ago, the agrochemicals were introduced to the field with the objective of enhance crop yields and also to protect crops against pests [1]. Then, the pests have been adapted to chemicals becoming resistance and, so that, every year, greater amounts of agrochemicals and with new chemical compounds have to be used in order to protect the crops, producing undesired effects and also increasing the costs for the production of food. Although agriculture based on chemical-free is in advance, now it is not capable to respond for the needing of production of substantial amounts of food and thus, the agrochemicals, including pesticides, are still being used. Nevertheless, pesticides produce severe damage not only to the agricultural but also to natural ecosystems [2] and becoming the water not suitable for consumption [3, 4].Usually, groundwater was known as pristine and cleaner source of water. Whereas bacterial and nitrate contamination were known in some places; it was thought that groundwater was immune to more severe pollution as industrial ejections, dangerous waste dumps or pesticides leaching from agricultural processes. However, in the last decade, different organic compounds from synthetic origin were discovered in groundwater and, in several times, at higher concentrations than existing from surface water supplies[5]. The development of environmental regulations during the last years has encouraged strong motivation for the development of alternative treatments of wastewater [6]. The processes to treat urban or industrial effluents, that contain organic as well as mineral substances, involve several strategies that depend mainly on the type of contaminants (dyes, metal ions, pharmaceutical ingredients, among others), the concern on recycling or using the by‐products obtained from the treatment and also the toxicity [6].It is known that the contamination of water with chemical products, mainly including aromatic molecules, dyes and heavy metals is a really huge environmental problem mainly due to their potential toxicity for humans. Because of this, new technologies are necessary and should be employed in order to eliminate pesticides from aquatic sources [7]. These new technologies must be non-toxic, economically viable, and should be capable to act effectively in the treatment of water for pesticide removal. Several technologies, with different achievements, being able to control or minimize the pollution of water are available [8]. Specific treatments are proposed for the water treatment according to the contaminant that is present. For example, enzymatic biodegradation, adsorption, ozonation, photolysis, electrochemistry, incineration and chemical degradation are some of them [9, 10]. However, some of the above mentioned treatments would not be accepted due to the addition of other chemical compounds to the water [11]. Thus, adsorption processes, in comparison with other procedures, constitute a good alternative for the treatment of wastewater due to the simplicity of operation and the easy of design, together with its relative low cost [12?14]. A big variety of adsorbents with low-cost (chelating or ion-exchange resins, mineral supports, active carbon, and residues from chemical industry, agriculture or fishing) have been analyzed in terms of their capability to remove several kinds of pollutants present in both water and wastewater [6]. Adsorption is the based on specific interactions among an adsorbent and the adsorbate (i.e. the compound to be adsorbed). Adsorption is commonly useful to remove not only insoluble but also soluble organic pollutants. Removal capacities reached by this method could be up to 99.9%. Essentially, adsorption can be defined as the accumulation of a substance at a surface or interface. During water treatments the process takes place at an interface between contaminated water and the solid adsorbent [14]. There are widely abundant, biodegradable, non-toxic and low cost polymers that constitute good alternatives as adsorbents to be used in water treatments [15, 16]. Among biopolymers, polysaccharides such as starch [17, 18], chitin [19?21] and derivatives as chitosan [22, 23] and cyclodextrins [24?26] have obtained special attention. These biopolymers are attractive and interesting due to their structure, chemical stability, physico-chemical properties, great reactivity and selectivity towards certain reactive groups (as hydroxyl, acetamido or amino functions) [16, 27]. The removal capacity towards a pesticide will depend on the chemical interaction between polymer-pesticide, as well as on the external conditions such as pH and medium temperature [16, 27].Pesticides are potentially toxic to humans and can have both acute and chronic health effects, depending on the quantity and the ways in which a person is exposed [28]. Some of the older and cheaper pesticides can remain in both the soil and water for years. They have been banned in developed countries for agricultural use but are still used in many developing countries. There are more than 1,000 pesticides used around the world to ensure food is not damaged or destroyed by pests. Each pesticide has different properties and toxicological effects (and the toxicological effects of multiple pesticides can be greater than the sum of their parts). Individual pesticides have unique properties, and many variable factors determine the specific risk in terms of water pollution. The active ingredient(s) in the pesticide formulation is referred to any chemical, plant extract, pheromone, or microorganism (including viruses), that has action against ?pests?, or even on plants, or parts of plants or plant products. Different kinds of additives such as wetting agents, diluents or solvents, extenders, adhesives, buffers, preservatives, and emulsifiers are mixed with the active ingredient(s) and also, contaminants are present as impurities in the active ingredient(s).The aims of this chapter is to review the pesticides present on industrial effluents and the possibilities of remove them by using biopolymeric materials.

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