Diclofenac Toxicity Abatement in Wastewater with Solar Disinfection: A Study in the Rural Area of Brazil’s Central−West Region

Nathália Dos Santos,Priscila Cavalheri,Fernando Filho,Guilherme Cavazzana,Laura Marquiza,Beatriz Machado,Cristina Calheiros

doi:10.3390/w13081043

Nathália Dos Santos, Priscila Cavalheri + Show 5 more

Open Access

https://doi.org/10.3390/w13081043

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Journal: Water	Publication Date: Apr 10, 2021
Citations: 2	License type: CC BY 4.0

Affiliation: Universidade Católica Dom Bosco, University of Porto

Abstract

Domestic wastewater has been targeted for the presence of emerging contaminants such as antibiotics, of which diclofenac is one of the most frequently detected. Many studies have focused on the removal of these emerging pollutants. However, the legislation has focused on toxicity monitoring. In search of simplified solutions for rural areas, and to guarantee the safe reuse of effluent in agriculture, this study evaluated the efficiency of a decentralized solar disinfection (SODIS) system regarding the reduction of ecotoxicity, phytotoxicity, and pathogens in domestic wastewater after adding diclofenac potassium. For this purpose, the bioindicators Artemia sp., Allium cepa L. and Lactuca sativa were used, after 1, 2, and 3 h of exposure to solar radiation. After 3 h of exposure to solar radiation, toxicity was reduced and root growth inhibition was noted, which indicates low effluent toxicity after treatment by the SODIS system. It was achieved a reduction of 3 and 2 log units in the concentration of total coliforms and Escherichia coli, respectively.

Highlights

The occurrence of emerging contaminants has become a question of global importance due to the concern they pose, regarding possible undesirable effects on the environment [1,2]
Samples of post-septic tank domestic wastewater with diclofenac potassium (ST), without diclofenac potassium (WD), and samples submitted to 1 h (S1), 2 h (S2), and 3 h (S3) of solar disinfection (SODIS) treatment were collected to evaluate the reduction of ecotoxicity, phytotoxicity, and fecal indicator organisms
Was lower than the size observed in the assay negative control, evidencing the toxicity of the post-septic tank domestic wastewater with diclofenac in all dilutions evaluated

Summary

Introduction

The occurrence of emerging contaminants has become a question of global importance due to the concern they pose, regarding possible undesirable effects on the environment [1,2]. The emerging contaminants include a range of synthetic and natural chemical compounds, such as drugs, hormones, endocrine disrupting chemicals, personal care products, pharmaceuticals, pesticides, surfactants, and flame retardants, whose occurrence and removal are often reported in the literature, there is still a lack of knowledge concerning the various contaminants’ fate [6,7,8,9,10,11,12] They are found in varied water matrices (e.g., wastewater, surface water, groundwater) in concentrations ranging from ng·L−1 to μg·L−1 [1,6,13]. Smaller concentrations (ng·L−1 and μg·L−1 ) may not have associated ecotoxicity

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