Biosolid Soil Application: Toxicity Tests under Laboratory Conditions

Abstract

A large volume of generated sewage sludge makes its disposal a problem. The usage of sludge in agriculture is highlighted by a number of advantages. However, heavy metals and other toxic compounds may exercise harmful effects to soil organisms. This study evaluated the possible toxic effects of a biosolid sample, under laboratory conditions, for 30 days, using diplopods Rhinocricus padbergi and plants Allium cepa (onion) as test organisms. The data obtained demonstrated that the biosolid raw sample had genotoxic potential for Allium cepa root tip cells. In the diplopods exposed to biosolid sample, epithelium disorganization in the midgut and a reduction of the volume of the hepatic cells were observed after 7 days of exposure. After 30 days, the animals still showed a reduction of the volume of the hepatic cells, but in minor intensity. Allium cepa analysis showed genotoxicity, but this effect was reduced after 30 days of bioprocessing by diplopods. This study was important to know the effects as well as to determine how this waste could be applied concerning the soil living organisms and plants.

Diplopods as Soil Bioindicators of Toxicity After Application of Residues From Sewage Treatment Plants and Ethanol Industry

“…Analyses involving the morphology and histology of tissues of invertebrates have been frequently used in the identification of different types of damage caused by harmful substances to individuals (Triebskorn et al, 1991, 1999; Köhler & Triebskorn, 1998; Fontanetti et al, 2010). However, most studies on the histopathology of the midgut of diplopods exposed to different samples of sewage sludge, landfarming, and herbicides were focused on the qualitative alterations observed in this organ (Nogarol & Fontanetti, 2010, 2011; Christofoletti et al, 2012; Merlini et al 2012; Perez & Fontanetti, 2011a, Souza & Fontanetti, 2011). According to Dittbrenner et al (2011), it is crucial to combine a qualitative description of histological conditions and a semi-quantitative analysis in order to better classify the effects observed.…”

“…Diplopods are important cosmopolitan soil macroinvertebrates capable of colonizing different soil layers, and act as decomposers (Petersen & Luxton, 1982). Because of these traits and the responsiveness of their tissues as biomarkers (Fontanetti et al, 2011), diplopods have been successfully used as bioindicators of soil quality (Godoy & Fontanetti, 2010; Nogarol & Fontanetti, 2010, 2011; Perez & Fontanetti, 2011 a ; Souza & Fontanetti, 2011; Bozzatto & Fontanetti, 2012; Christofoletti et al, 2012; Souza et al, 2014).…”

Study of mercury behavior and earthworm bioassays in three solid environment components from selected areas of Eastern Slovakia

“…Also, morphological and histopathological analyses have been used to identify tissue damage caused by exposure to sewage sludge in terrestrial invertebrates (Eisenia fetida), in order to gain a better understanding of adverse effects caused by sewage sludge and to analyse its impact on the production of reactive oxygen species and lipid peroxidation in earthworms, were measured (Nogarol and Fontanetti, 2010;Christofoletti et al, 2012;Babić et al, 2016).…”

Toxicity evaluation of vinasse and biosolid samples in diplopod midgut: heat shock protein in situ localization

“…Some procedures can be used to form a biosolid that increases the solid content while decreasing the number of pathogenic microorganisms in the sewage sludge (Haynes et al 2009). However, studies by Christofoletti et al (2012Christofoletti et al ( , 2016 using the plant A. cepa and the millipede Rhinocricus padbergi as bioindicators showed the genotoxic and toxic potential of this residue, even after treatment.…”