An Integrated Process, Fenton Reaction−Ultrafiltration, for the Treatment of Landfill Leachate:  Pilot Plant Operation and Analysis

Abstract

The treatment of a mature landfill leachate, from a municipal landfill located in northern Spain (Cantabria), by an integrated system [Fenton reaction−neutralization−ultrafiltration (UF)] was carried out in a pilot plant that operated either in batch and continuous mode. The initial average chemical oxygen demand (COD) concentration of the leachate was 2100 mg/L, with a biological oxygen demand (BOD5)/COD ratio of 0.08. The sequence of stages implemented was (i) Fenton oxidation, (ii) neutralization of Fenton's effluent to pH 7, and (iii) ultrafiltration with submerged membranes. The influence of different parameters, such as redox potential evolution, H2O2/COD mass ratio, and hydraulic retention time, was investigated in the Fenton oxidation process. The effect of neutralization and UF steps was also studied. COD reduction after the integrated treatment was up to 80%. The final effluent was free of solids, color, and iron. The results demonstrated the high potential of Fenton's reagent in combination with membrane filtration in the remediation of recalcitrant wastewaters on a pilot plant continuously operated.

Microwave enhanced Fenton-like process for the treatment of high concentration pharmaceutical wastewater

“…In previous study [45], membrane separation was introduced during the process of Fenton reaction due to the poor settling quality of sludge produced in Fenton process. In the present investigation, there is no need to use membrane separation because of the high settling quality of sludge produced in MW-Fenton-like system.…”

Optimization of Fenton oxidation pre-treatment for B. thuringiensis – Based production of value added products from wastewater sludge

“…Moreover, the hydroxyl radicals oxidize the recalcitrant compounds in sludge into biodegradable ones which are further subject to biological treatment (Neyens et al, 2004). Fenton was successfully applied to degrade leachate organics with the objective of improving its overall biodegradability (Hagman et al, 2008;Primo et al, 2008). Fenton oxidation was also employed for the enhancement of anaerobic digestibility as well as dewaterability of WWS Lo et al, 2008;Tokumura et al, 2009).…”

“…Fenton oxidation is capable of generating free hydroxyl radicals (OH ), a very powerful and non-selective oxidizing agent with an oxidation potential of 2.8 V. Fenton oxidation includes a range of reactions as follows: in an acidic aqueous solution, ferrous iron (Fe 2þ ) initiates and catalyses the decomposition of H 2 O 2 , resulting in the generation of hydroxyl radicals, and then the hydroxyl radicals oxidize organics (RH) by abstraction of protons producing organic radicals (R ), which are highly reactive and can be further oxidized Primo et al, 2008). The hydroxyl radicals pass easily through the microbial cell membrane in the sludge, leading to oxidative decomposition of the cell wall.…”

Photoelectrochemical treatment of landfill leachate in a continuous flow reactor

“…Biological methods are very effective for the treatment of landfill leachate with a high value of biological oxygen demand (BOD) but are ineffective if recalcitrant compounds are present, so that a physical-chemical process is required (Lei et al, 2007). Great attention has been directed toward either new chemical and physical processes or traditional methods (Rivas et al, 2005;Primo et al, 2008). O 3 , O 3 /H 2 O 2 , and O 3 /UV have been used in treating landfill leachate recently (Wu et al, 2004).…”