Field-scale performance of microelectrolysis-Fenton oxidation process combined with biological degradation and coagulative precipitation for landfill leachate treatment

^a Key Laboratory of Water Pollution Control Technology, Hunan Province, Hunan Research Academy of Environmental Sciences, Changsha 410004, China State
^b Chinese Research Academy of Environmental Sciences, Beijing 100012, China
^c China Railway Fifth Survey And Design Institute Group CO., Ltd, Beijing China Railway Ecology & Environment Densign Institute CO., Ltd, Beijing 102600, China

^* Corresponding author: ljm627@126.com

Abstract

In order to verify the feasibility of Fe/C microelectrolysis-Fenton oxidation for mature landfill leachate treatment in industrial application, this study conducted the treatment processes at full-scale by physicochemical and spectral characterization. The full-scale studies showed that 48.17% of the dissolved organic carbon (DOC) and 42.27% of the dissolved organic nitrogen (DON) were removed by the microelectrolysis-Fenton oxidation process, respectively. Spectra analysis further suggested that the mature leachate was mainly composed of tryptophan-like and fulvic-like compounds. The combination of microelectrolysis and Fenton oxidation efficiently decomposed the aromatic C=C into carboxyl-C and decreased the molecular size of DOC, resulting in a dramatic reduce (97.1%-98.3%) of the fluorescence intensity. The DON removal by microelectrolysis-Fenton oxidation likely associated with the NH²-decomposition of tryptophan-like and aromatic compounds into NO³-N. The tryptophan-like compounds may play a dominant role in Ba binding, while Pb and Cd were likely bound to both the tryptophan-like and fulvic-like compounds. Above 60% of the heavy metals were removed in the microelectrolysis-Fenton oxidation section. Results above confirmed the effectiveness of Fe/C microelectrolysis-Fenton oxidation for mature landfill leachate treatment in industrial application.