Laboratory and field studies on bioremediation of point-source contamination in horticultural crops using biobeds

Abstract

Biobeds are technological tools to minimize point-source contamination on productive farms. A four-step workflow for the efficient setting of biobeds in farms and its proof-of-concept is presented: (1) developing a fit-forpurpose pesticide multiresidue analytical method for pesticides in biomatrix; (2) launching biobeds at lab scale for pesticide degradation evaluation; (3) setting up the biobeds in the field; (4) evaluating the pesticide degradation in the biobed during an agricultural year. An ethyl acetate/sodium tetraborate multiresidue method was adapted and validated for 35 pesticides in the biomixture; lab biobeds were installed, and the degradation of 11 pesticides was confirmed. Then, biobeds were installed in two horticultural farms of different productive profiles, considering farmers’ conditions, and included in the farmers’ routine work. High dissipation rates (∼80%) in both bioreactors were observed for 10 pesticides. This research studies the performance of biobeds in reducing point source contamination and diminishing pesticide concentration from contaminated machinery washings not only at the lab scale but also at in-field experiments performed in productive farms. Moreover, the evaluation of biobeds in actual conditions where different chemical families of pesticides were applied together and the confirmation that repeated applications and accumulation of some compounds throughout the cycle proved biobeds’ versatility in diminishing the point of pesticide contamination in farms.