Analysis of electrocoagulation process efficiency of compost leachate with the first order kinetic model

Marjana Simonič,Mirjana Čurlin,Lidija Fras Zemljič

doi:10.33765/thate.10.2.2

Marjana Simonič, Mirjana Čurlin + Show 1 more

Open Access

https://doi.org/10.33765/thate.10.2.2

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Abstract

Large quantities of leachate are generated from the water release during the decomposition of the biodegradable waste. The composition of compost leachate is very complex and its treatment is necessary before releasing into the environment. The possibilities of treating compost leachate by electrocoagulation have been extensively studied. The scope of this work was to investigate applicability of the first order kinetic model for degradation of metal and organic compounds from compost leachate by electrocoagulation process. Experimental results showed 75 % removal efficiency of Cu2+ and 65 % of Zn2+, while chemical oxygen demand was reduced by 36 %. According to obtained kinetic parameters, simulation of metal removal efficiency was performed in batch reactor. This way optimal electrocoagulation time which is needed for 95 % efficiency of metal removal was determined at 120th min for Zn2+ and 102nd min for Cu2+.

Highlights

Compost leachate is generated during the decomposition of the biodegradable waste
The batch EC reactor was filled with brown coloured leachate that changed its colour during the electrocoagulation process
Even though the model solutions suggested the removal of only metals, the aim of our study was to decrease the content of organic compounds expressed as chemical oxygen demand (COD), which was huge, determined at 85.4 g/L O2

Summary

Introduction

Compost leachate is generated during the decomposition of the biodegradable waste. The aqueous leachate cannot be released into the environment due to its hazardous nature. The composition of compost leachate is very complex and its treatment is necessary before releasing into the environment. Using the electrocoagulation (EC) process for compost leachate treatment has a lot of advantages [1]. Electrocoagulation was chosen due to promising results in treating industrial waste water [1]. Using this technique there has been a little consideration of the factors that influence the effective removal of ionic species, metal ions and organic matter (Chemical oxygen demand, COD) from wastewater [2]. Successful removal, up to 95 %, of metal ions such as Pb2+, Cu2+, Zn2+, Co2+, Cd2+ and Ni2+ was achieved after 45 min of electrocoagulation in EC reactor with iron electrode [3]. It was reported that after 75 min at the 3 cm distance between aluminium electrodes at 20 V, the COD removal reached 92 %

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