ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Pretreatment of landfill leachate by chemical oxidation processes
Ján Derco, Andreja Žgajnar Gotvajn, Jana Zagorc-Končan, Beáta Almásiová, and Angelika Kassai
Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovak Republic
Received: 30 June 2009 Revised: 16 November 2009 Accepted: 23 November 2009
Abstract: Kinetics and efficiency of Fenton’s and ozonation processes for the pretreatment of two landfill leachates (fresh and mature)
resulting from municipal waste disposal were studied. Both samples presented high organic load, high toxicity and low biodegradability.
These were the reasons why oxidative treatment was proposed. Fresh and mature leachate showed different behaviors in the oxidation
experiments. The final extents of removal were attained in comparable time intervals in both oxidation systems. Maximal removal
of organics by the Fenton’s oxidation reached more than 50 % according to COD. Zero or first order kinetics were found the
best to describe the organic components (in terms of COD and DOC) removal by the Fenton’s oxidation for both landfill leachates.
Higher reaction rate values of the Fenton’s oxidation were achieved with fresh leachate samples. The efficiency of initial
organics removal with ozone was about 70 % for mature leachate, while in case of the fresh one only 41 % of COD were removed.
The best fits of COD and DOC experimental data from oxidation of fresh and mature leachates were obtained by a combined kinetic
model. No significant improvement of the biodegradability of landfill leachates was achieved using these treatment procedures.
Regarding toxicity, ozonation showed to be more effective than the Fenton’s oxidation. Advanced oxidation experiments confirmed
that the Fenton’s oxidation and ozonation are comparable oxidative treatment techniques for the reduction of organic pollution
in the investigated municipal landfill leachates. However, neither of them is effective enough to be used as a pretreatment
method followed by biological treatment.
Keywords: biodegradability - Fenton’s reaction - kinetics - landfill leachate - ozonation - toxicity
Full paper is available at www.springerlink.com.
Chemical Papers 64 (2) 237–245 (2010)