Photo-fenton remediation of wastewaters containing agrochemicals

Abstract

The photochemical degradation of agrochemicals in aqueous solution by means of advanced oxidation processes (AOPs) was studied. The photo-Fenton process was evaluated in terms of the time evolution of dissolved organic carbon (COD) and chemical oxygen demand (DOC), their total removals, and increase in biodegradability of treated wastewater. Under the experimental conditions studied, the process showed to be superior to other AOPs, at any Fe(II) and H2O2 concentrations. The results pointed towards the use of solar irradiation and low cost commercial application.<br>Neste trabalho, estuda-se a degradação fotoquímica de defensivos agrícolas presentes em efluentes aquosos, por meio de processos oxidativos avançados (POAs). Tais processos são baseados na ação do radical hidroxila (HO•), oxidante poderoso e não seletivo. Em particular, o processo foto-Fenton é avaliado quanto à redução da demanda química de oxigênio (DQO) e do teor de carbono orgânico dissolvido (COD), e ao aumento de biodegradabilidade dos efluentes. Os resultados abrem perspectivas para emprego de irradiação solar e aplicação em escala comercial a baixo custo

Utilisation of respirometry to assess organic matter reduction of effluents from the Camaçari industrial complex (BA, Brazil)

“…On the other hand, respirometry seems to be more accurate than Microtox to assess the toxicity reduction at this WTP, since it is a more direct method for assessing sludge activity and thus toxicity to sludge (Ren, 2004) and the whole microbial community is involved in the process, instead of only one organism (Vibrio fischeri), in the Microtox test. Due to the importance of COD reduction in the activated sludge process as it represented the quality of the wastewater treatment (Ubay Çokgör et al, 1998;Baker et al, 1999;Vidal et al, 1999;Reis and Nozaki, 2000;Teixeira et al, 2005), the COD of each effluent treatment step was assessed. EE and TE-COD mean values were 1,576.4 (1,444.5-1,708.4) and 257.7 (226.2-289-1) mg l -1 (Fig.…”

“…The inadequate management of these residues can have harmful consequences to human health (Teixeira et al, 2005). Wastewater treatment is carried out by a combination of physical, chemical and biological methods, being activated sludge, the most used biological treatment, due to its high performance (Pujol and Canler, 1992).…”

Degradação fotoeletroquímica do herbicida bentazona sobre eletrodos de carbono modificados por TiO2

“…Entre eles, Teixeira et al 17 analisaram a eficiência dos POA na remediação de águas residuais contaminadas por inseticidas e fungicidas e a influência da concentração de Fe 2+ e peróxido, do pH, da temperatura e da radiação no processo foto-Fenton. Estudos de degradação do pesticida clorado DDT em solo através da reação de Fenton foram realizados por Villa et al.…”

Optimization of acetaminophen degradation by fluidized-bed Fenton process

“…Since then, modifi cations of Fenton technology were carried out primarily to reduce if not eliminate sludge production inherent in the process. Through the years, Fenton-based processes were proven effective in treating wastewaters of industries such as textile [2], alcohol production or distilleries [3], sugar [4], pesticides [5], insecticides [6], dyestuffs [7], explosives [8] and pharmaceuticals [9].…”