Development of a Predictive Model for Removal of Organic Matter from Leachate Landfill by Catalytic Oxidation Using Response Surface Methodology

Milton Rosero-Moreano,Cristina Nerín

doi:10.5923/j.aac.20120204.04

Abstract

In this work the heterogeneous Fenton catalytic experiments were arranged in a CCF experimental design and analyzed by response surface methodology, for every peroxide concentration. These response surfaces were the representation of a quadratic predictive model developed for improving of biochemical o xygen demand at five days/chemical o xygen demand (BDO5/COD) ratio, trough the optimizat ion parameters of reaction. For this proposal 18 catalytic tests were carried out evaluating three main factors: pero xide concentration, catalyst loading and the peroxide addition rate. The results in confronting with the experimental data showed that fro m 60 minutes the catalytic wet pero xide oxidation (CWPO) react ion was stationated in focusing the chemical COD removal, inclusively in any opportunities these values were decreased maybe because new co mpounds had been formed and we supposed that these new co mpounds were with biodegradable character because this behavior was perfect ly answered by the prediction model, hence with this new and enhancent ratio there are possibilities to get in to the biological process again for the refine the effluent and co mply with the actual regulation. The best conditions predicted for the model are at 4.68M pero xide concentration, catalyst loading charge (CL) (0.5 - 0.6%) and pero xide addit ion rate (PAR) (7.5 - 10 mL/h) to imp rove its biodegradability to 0.30, thus this effluent might come back to the begin of plant fo r refin ing the treatment.

Highlights

Landfill is nowadays the main way of disposal for the enormous charge of municipal solid wastes generated all around the world[1]
In catalytic wet pero xide oxidation (CWPO) the hydrogen peroxide is the source of the powerfu l hydro xyl radicals, whose generation can be activated by using inexpensive solid catalysts like Al/Fe -pillared clays, and the process can be efficiently carried out at very mild conditions of ambient temperature and pressure
Design of Experiments Since all the trends till found for every factor at a time have shown to strongly depend on the chosen conditions for the rest of parameters, their simu ltaneous observation was tried to get better insight of the experimental system

Summary

Introduction

Landfill is nowadays the main way of disposal for the enormous charge of municipal solid wastes generated all around the world[1]. Rain and liquid percolation throughout them p rovokes the side production of significant volumes of a strongly contaminant liquid, the so-called leachate of landfill. In general terms, it is a dark liquid of offensive odor, high loading of organic compounds and complex chemical co mposition, wh ich usually includes not negligible charge of bio-reluctant compounds[2]. The aim of this work was to develop a response surface methodology (RSM) to find a model ab le to predict the optimu m parameters of react ion improv ing either, COD removal, BOD5/COD ratio of the output stream or both, emp loying for that purpose a central co mposite face (CCF) quadratic e xperimental design tool

Leachate Characteristics

Results and Discussion

Overall Performance

Conclusions