Alternative approaches to determine the efficiency of biomixtures used for pesticide degradation in biopurification systems

Abstract

Biopurification systems were developed for the biological treatment of pesticide-containing wastewaters originated from agricultural production. They are aimed at reducing point-source contamination related to the inadequate handling of pesticides during filling and cleaning of spraying equipment or improper disposal of application residues. These systems contain a biomixture, which comprises their biologically active core where accelerated pesticide degradation takes place. It is a common practice to determine the efficiency of biomixtures by analytical approaches that are focused on the quantification of the pesticides and their subsequent dissipation in time. Nonetheless, the simple removal of original pesticide molecule does not necessarily indicate that the treatment process is ecologically friendly, due to the possible formation of transformation products of high toxicity that are difficult to identify and quantify. This chapter discusses alternative approaches to obtain a more complete scenario regarding biomixture efficiency. These approaches include the determination of the pesticide mineralization using radiolabeled pesticides and ecotoxicological assays to determine the detoxification degree achieved by the matrix. Similarly, as the useful life of biomixtures varies according to the materials employed in its production and the climatic conditions of every region, the authors also suggest a methodology to monitor the performance of biomixtures during their aging process.