Toxicity assessment of tannery effluent treated by an optimized photo-Fenton process

Abstract

In this work, an optimized photo-Fenton process was applied to remove pollutants from tannery industrial effluent (TIE) with its final toxicity level being assessed by a lettuce-seed-based bioassay test. A full 33 factorial design was applied for the optimization of long-term photo-Fenton experiments. The oPtimum conditions of the photo-Fenton process were attained at concentration values of 0.3 g Fe(2+) L(-1) and 20 g H2O2 L(-1) and pH3, for 120 min UV irradiation time. Reactor operating parameter (ROP) effects on the removal of chemical oxygen demand, colour, turbidity, total suspended solids and total volatile solids were evaluated, suggesting that a broad range of ROP values are also suitable to give results very near to those of the photo-Fenton experiments under optimal conditions. Based on the low calculated median lethal dose (LD50) values from a lettuce-seed-based bioassay test, we suggest that recalcitrant substances are present in treated TIE samples. A possible cause of the high toxicity level could partly be attributed to the nitrate concentration, which was not completely abated by the photo-Fenton process. Apart from this, the photo-Fenton process can be used as a part of an industrial effluent treatment system in order to abate high organic pollutant loads.

Recent advances and prospects of catalytic advanced oxidation process in treating textile effluents

“…This process generates ·OH through the reaction of H 2 O 2 and ferrous salt in acidic environment. The use of Fenton processes for treating various types of wastewater has also been studied (Bauer et al 1993, Perkowski et al 2000, Modenes et al 2012, Tony et al 2012, Borba et al 2013 , as depicted in Equation (8) (Rigg et al 1954, Walling 1975, Buxton et al 1988, Neyens and Baeyens 2003. The generation of the radicals involves a complex reaction sequence in an aqueous solution.…”

“…The most widely researched AOPs include heterogeneous photocatalytic oxidation (Bauer et al 1993), ozone (O 3 )-based processes (Meric et al 2005), Fenton reaction, photo-Fenton reaction (Bouafia-Chergui et al 2010, Borba et al 2013, and electrochemical oxidation. These techniques are promising in treating contaminated groundwater, surface H 2 O, and wastewater containing nonbiodegradable organic pollutants.…”

Degradation of sulphamethazine by means of an improved photo-Fenton process involving a hydrogen peroxide systematic dosage

“…More recently, research in this field has also deepened into the effect of the effect and toxicity of reaction intermediates. [8,9] The treatment of pharmaceuticals and personal care products in water solutions has also received attention. Photolysis of antibiotics has been addressed in the literature, as reviewed by Canonica et al [10] The photodegradation of sulphonamides such as sulphamethoxazole [11,12] and sulphadiazine [13] has been reported.…”

Aplicação Da Reação Foto-Fenton Em Ph Neutro Utilizando Ferricarboxílicos De Edta Para O Tratamento De Lixiviados De Aterro Sanitário

“…Esta técnica vem se mostrando eficiente no tratamento de diversas matrizes ambientais tais como lixiviado de aterro sanitário (SILVA et al, 2013;VILAR et al, 2012); efluente têxtil MANENTI et al, 2014); fármacos (DIAS et al, 2014) e curtume (BORBA et al, 2013). Entretanto, há inconvenientes associados a esta prática, tais como: (i) a necessidade de um meio reacional ácido para que o íon ferroso mantenha-se solúvel; (ii) a complexação/precipitação dos íons ferrosos com elevados conteúdos orgânicos como os fosfatos dissolvidos, por exemplo (VILAR et al, 2012;SILVA et al, 2013;MANENTI et al, 2014).…”