0.99 for all compounds. Recoveries ranged from 65 and 120% with relative standard deviation (RSD) lower than 20%. The method was applied to the determination of PPCPs in samples of surface and drinking water for three months. PPCPs were detected at µg L-1 levels.]]>

A Fenton oxidation system employing zero-valent iron (whose source was swarf, a residue of metallurgical industries, in powder form) and hydrogen peroxide for the treatment of an aqueous solution with six pesticides was developed, and the effect of the iron metal content, pH, and hydrogen peroxide concentration was evaluated. The characterization of the aqueous solution resulted in: pH 5.6, 105 mg L(-1) of dissolved organic carbon, and 44.6 NTU turbidity. In addition, the characterization of the swarf by FAAS and ICP-MS showed 98.43 ± 7.40 % of zero-valent iron. The removal was strongly affected by the content of iron metal, pH, and hydrogen peroxide concentration. The best degradation conditions were 2.0 g swarf, pH 2.0, and 5 mmol L(-1) H2O2. At the end of the treatment, the pesticide degradation ranged from 60 to 100%, leading to 55% mineralization. Besides, all hydrogen peroxide was consumed and the determination of total dissolved iron resulted in 2 mg L(-1). Thus, the advantages of this system are rapid degradation (up to 20 min), high-degradation rates, simple handling, and low cost.

This study aimed to develop and optimize an efficient photocatalytic process employing ruthenium [Ru(bipy) 3 ] 2+ doped TiO 2 -SiO 2 for degrading synthetic wastewater containing six classes of pesticides (bentazone, carbofuran, clomazone, diuron, tebuconazole and pyraclostrobin). To optimize the degradation conditions for the six pesticides and assess the effect of two variables (reaction time and adsorption equilibrium time) on the heterogeneous photocatalytic process, a 2 2 experimental design with a central composite rotatable design (CCRD) was used. The CCRD was suitable for optimizing the heterogeneous photocatalysis, and the generated surface responses indicated that the best removal conditions were 15 min adsorption equilibrium time and 110 min reaction time. Under these conditions, a pesticide removal between 71.00 and 99.98% was obtained. Furthermore, the system yielded an excellent degree of synthetic wastewater mineralization, with 97.60% total organic carbon (TOC) removal after 110 min.