Municipal solid waste landfill leachate treatment by fenton, photo-fenton and fenton-like processes: Effect of some variables

Abstract

Advanced oxidation processes like Fenton and photo-Fenton have been effectively applied to oxidize the persistent organic compounds in solid waste leachate and convert them to unharmful materials and products. However, there are limited data about application of Fenton-like process in leachate treatment. Therefore, this study was designed with the objective of treating municipal landfill leachate by Fenton, Fenton-like and photo–Fenton processes to determine the effect of different variables, by setting up a pilot system. The used leachate was collected from a municipal unsanitary landfill in Qaem-Shahr in the north of Iran. Fenton and Fenton-like processes were conducted by Jar-test method. Photo-Fenton process was performed in a glass photo-reactor. In all processes, H2O2 was used as the oxidant. FeSO4.7H2O and FeCl3.6H2O were used as reagents. All parameters were measured based on standard methods. The results showed that the optimum concentration of H2O2 was equal to 5 g/L for the Fenton-like process and 3 g/L for the Fenton and photo-Fenton processes. The optimum ratio of H2O2: Fe+2/Fe+3 were equal to 8:1 in all processes. At optimum conditions, the amount of COD removal was 69.6%, 65.9% and 83.2% in Fenton, Fenton-like and photo–Fenton processes, respectively. In addition, optimum pH were 3, 5 and 3 and the optimum contact time were 150, 90 and 120 minutes, for Fenton, Fenton-like and photo–Fenton processes, respectively. After all processes, the biodegradability (BOD5/COD ratio) of the treated leachate was increased compared to that of the raw leachate and the highest increase in BOD5/COD ratio was observed in the photo-Fenton process. The efficiency of the Fenton-like process was overally less than Fenton and photo-Fenton processes, meanwhile the Fenton-like process was at higher pH and did not show problems.

Utilisation des procédés électrochimiques et leurs combinaisons avec les procédés biologiques pour le traitement des lixiviats de sites d’enfouissement sanitaires - revue de littérature

“…Par exemple, ZHAO et al (2010) ont observé une augmentation de 27 % de l'abattement de la DCO en couplant l'EO avec une source de radiation UV. En réalisant le même couplage, XIAO et al (2013) ZAZOULI et al (2012) et KRZYSZTOSZEK et NAUMCZYK (2012 ont réalisé des études sur le procédé classique de Fenton couplé avec une radiation UV (photo-Fenton) pour le traitement des lixiviats. Leurs résultats ont montré une augmentation de l'abattement de la DCO (13,6 % et 22,4 % respectivement) avec le procédé photo-Fenton comparé à l'utilisation du Fenton seul.…”

Kinetic study of inorganic carbon (IC) removal and COD removal from refinery wastewater by solar Photo-Fenton.

“…OH) up to a certain concentration, when the hydrogen peroxide ratio increased. When hydrogen peroxide increased more, it started to react with hydroxyl radicals, acting as a free-radical scavenger (Zazouli et al, 2012).…”

Optimization for Fenton Process in Removal of COD for Landfill Leachate Treatment

“…So that in the absence of any other oxidizable substance, the net reaction of H 2 O 2 , gives as result the formation of H 2 O and O 2 catalyzed by iron [10]. Marí a Santin-Gusman, Javier Moreno-André s, Mónica Cisneros-Abad, and Silvio Aguilar-Ramí rez application of system for the treatment of landfill leachate, which have reported promising results reaching removals between 60%-75% COD [10], [12], [15]- [18]. Taking into account the importance of natural resources and the level in that the leachate affects the environment was proposed to do the present research work with the main goal to optimize the Fenton process for the treatment of these fluids.…”

“…While old leachate (over 10 years old) is methanogenic type, have a high concentration of organic matter where the refractory type is predominantly and therefore are not biodegradable with an index BOD 5 /COD <0.3 because this inhibits biomass action [3], [11], [12].…”