Analysis of Triazole Fungicides in Aqueous Solutions and Their Removal on Modified Activated Carbons

Abstract

Using liquid–liquid extraction and GC-MS/MS analysis, triazoles employed as fungicides in sawmills were studied in polycontaminated aqueous solutions. Their removal was estimated using activated carbon (AC) modified with NaOH as adsorbent. Granular and powder carbons exhibited similar results (abatement of 99.6 and 99.7% in mean, respectively for a dose of 3 g $$\hbox {L}^{-1}$$ and a concentration of 1 mg $$\hbox {L}^{-1}$$ for each fungicide in a mixture), suggesting that the capacities of these two adsorbents will be mainly due to their basic surface properties. Using a granular carbon dose of 1 g $$\hbox {L}^{-1}$$ for the same concentrations in fungicides, a mean value of 95.3% was reached. Nevertheless, at lower doses, the adsorption capacities decreased (< 57%) and some differences appeared between triazoles. Use of AC to eliminate triazoles of leaching waters of wood-treated pieces permitted the retention of more than 80% of propiconazole for formulations without dye (only 37–55% with dye), which can induce some competition effects for organics to the active site access.