Approach to the Dynamic of Carbamazepine and its Main Metabolites in Soil Contamination through the Reuse of Wastewater and Sewage Sludge

Abstract

The release of pharmaceutically active compounds to the soils through the application of sewage sludge and the irrigation with wastewater, or even with surface water, is constant. The adsorption of these compounds onto the soil is one of the key factors affecting their fate in the environment and their potential environmental risks. In this work, the adsorption of carbamazepine (CBZ) and its metabolites, 3-hydroxy-carbamazepine (3OH-CBZ), carbamazepine-10,11-dihydro-10,11-epoxide (EP-CBZ), and 10,11-dihydro-10-hydroxycarbamazepine (10OH-CBZ), in three Mediterranean soils was evaluated using single-solute and four-solute experiments. The highest adsorptions were measured for 3OH-CBZ, followed by CBZ, EP-CBZ, and 10OH-CBZ, in that order. A high influence of the physicochemical characteristics of the compounds, pH, and soil characteristics in the adsorption of the studied compounds was observed and corroborated by the statistical analysis of the results. Moreover, a good fit was observed in the three isotherm models evaluated (linear, Freundlich, and Langmuir) in single-solute experiments (R2 > 0.90). However, a decrease of the measured adsorptions and a worse fit to the isotherm models were observed in the case of multiple-solute experiments. This could be mainly due to the competition established between the studied compounds for the active sites of the soils.

Pharmaceuticals and Their Main Metabolites in Treated Sewage Sludge and Sludge-Amended Soil: Availability and Sorption Behaviour

“…The same pattern was observed for all the compounds. There is scarce information about the presence of metabolites in solid environmental samples [ 14 ]. Therefore, it was not possible to compare measured K d data with other data in the literature.…”

“…The concentrations of IBU and its metabolites decreased to below the method quantification limits (<MQL) in compost samples, indicating a possible degradation under aerobic conditions. According to Malvar et al, (2020) [5], IBU concentrations decreased from 28.1 ng g −1 to 204 ng g −1 dm in mixed sludge and from 12.4 ng g −1 to 14.2 ng g −1 dm in aerobically digested and dehydrated sludge.…”

“… a Rosal et al, 2010 [ 25 ]; b Muñoz et al, 2008 [ 26 ]; c Lee et al, 2011 [ 27 ]; d Huntscha et al, 2012 [ 28 ]; e Miao et al, 2005 [ 29 ]; f Ferrando-Climent et al, 2012 [ 30 ]; g Baumer et al, 2017 [ 31 ]; h Berthod et al, 2016 [ 22 ]; i Barron et al, 2009 [ 32 ]; j Malvar et al, 2020 [ 14 ]; k Wojsławski et al, 2019 [ 7 ]; l Mitra and Benfield 2018 [ 33 ]; m Gielen et al, 2009 [ 34 ]; n Andriamalala et al, (2018) [ 20 ]; o values not found; p value not calculated. …”

“…The K d values of sulphonamides in five different soils were in the range from 0.10 to 4.39, whereas the K d values for five different soils amended with manure were 1.89 to 11.69. However, only a few studies have reported the sorption behaviour of the metabolites of these PhCs [ 7 , 13 , 14 ] despite these metabolites being present at higher concentrations and showing even higher toxicity than their parent compounds [ 14 , 15 ]. Moreover, most of the studies reported in the literature were based on batch experiments carried out by mixing the solid phase with a solution of the emerging pollutants.…”

“…Moreover, most of the studies reported in the literature were based on batch experiments carried out by mixing the solid phase with a solution of the emerging pollutants. In addition, in most cases, single-compound systems were used, and the studies were mainly focused on carbamazepine and its metabolites [ 7 , 13 , 14 ].…”