Vermicompost Incorporation into Soil Contaminated with Deltamethrin as an Attempt to Reduce the Toxicity Caused by this Pyrethroid: A Structural Study of Soil

Fernanda Benetti,Maria O.O Rezende,Rut Naiara Rodrigues,L&Iacute;Via B.F Pigatin,Michelle M Kanashiro

doi:10.3844/ajessp.2017.297.306

Abstract

The use of vermicompost for remediating soil contaminated with the commercial formulation containing deltamethrin was proposed. Biotoxicity tests with the goal of evaluating the potential remediation degree of the vermicompost after its addition to contaminated soils were performed. The tests lasted 56 days and involved Eisenia foetida earthworms. Possible structural changes in humic acids from these soils were evaluated by means of FTIR spectroscopy. The soil contaminated with deltamethrin offers toxicity to the earthworms. However, the vermicompost addition caused great positive impact on soil contamination level, which became quite similar to the reference soil. The vermicompost remedial effect depends on the source material. In this study the vermicompost were from filter cake and orange peel. The results obtained by FTIR pointed out for a weak interaction such as van der Waals type between the pyretroid and humic acids.

Highlights

Deltamethrin ((S)-α-cyano-3-phenoxybenzyl (1R, 3R)-3-(2,2-dibromovinyl) dimethylcyclopropanecarboxylate) is a pyrethroid that kills insects such as flies and cockroaches, by contact and ingestion
According to the results presented for toxicity tests and Fourier Transform Infrared Spectroscopy (FTIR), the interaction between deltamethrin and humic acids can be Van der Waals type according to Fig. 5
The great advantage of evaluating the interactions between deltamethrin/dispersant and vermicomposts throughout FTIR spectra is the increase in intensity of some bands in relation to the reference soil

Summary

Introduction

-3-(2,2-dibromovinyl) dimethylcyclopropanecarboxylate) is a pyrethroid that kills insects such as flies and cockroaches, by contact and ingestion. It was synthesized in 1974 and first marketed in 1977. The low toxicity of pyrethroid insecticides to mammals, birds and limited persistence in soil has encouraged the widespread use of pyrethroids in agriculture and vector control diseases. They are used to protect stored products such as cereals, grains, coffee and dried beans and for the control of diseases such as malaria and Chagas (via vector control). The pyrethroid impairs the transmission of nerve impulses, which can lead to death (Santos et al, 2011; Velki and Hackenberger, 2013)

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