A laboratory simulation of &lt;i&gt;in situ&lt;/i&gt; leachate treatment in semi-aerobic bioreactor landfill

Shou-liang Huo,Bei-dou Xi,Su Jing,Hong-liang Liu,Hai-chan Yu,Shi-lei Fan

doi:10.4314/wsa.v34i1.180889

Abstract

In this study, two laboratory-scale simulated landfill bioreactors were established, of which Reactor A was operated only with leachate recirculation and served as the control, and Reactor B was operated as semi-aerobic bioreactor landfill with leachate recirculation. In situ leachate treatment and accelerating organic decomposition in semi-aerobic bioreactor landfill was investigated. The results indicated that the introduction of air into the landfill was favourable for optimising the micro-organism growth environment and accelerating the degradation off organic matter. It can be seen clearly from the results that NH4+-N can be removed in situ in the semi-aerobic bioreactor landfill with leachate recirculation. Moreover, semi-aerobic bioreactor landfill showed lower emissions for leachate than those in leachate from anaerobic landfill, with low concentrations of COD, VFA, NH4+-N and TKN, and which saved the disposing process off the discharged leachate. The three-dimensional excitation-emission matrix fluorescence spectroscopy (EEMs) of dissolved organic matter (DOM) in Reactor B changed greatly, and fluorescence peak changed from protein-like fluorescence at Day 60 to humic-like fluorescence at Day 95 and 250, while in Reactor A, fluorescence peak of DOM was always protein-like fluorescence. The comparison of the EEMs indicated that the semi-aerobic landfill accelerated the organic decomposition.

Highlights

In 2002, approximately 94% of the municipal solid waste (MSW) generated in China was disposed of in landfills (Wang et al, 2006)
The main objective of the research was to investigate in situ leachate treatment and accelerating organic decomposition and stabilisation of solid waste in semi-aerobic landfill by chemical analysis and fluorescence analyses
Three sample collection ports of solid wastes were set in the middle of the reactors; the leachate outlets, which were connected to the leachate recirculation tanks, were under the reactors

Summary

Introduction

In 2002, approximately 94% of the municipal solid waste (MSW) generated in China was disposed of in landfills (Wang et al, 2006). Anaerobic degradation of solid waste results in the production of leachate and landfill gas for a very long time in a conventional landfill. There has been increased emphasis on the operation of landfills as bioreactors to enhance decomposition of solid waste, provide a reduction in landfill emissions over a relatively short time, and dispose leachate in situ (Price et al, 2003; Mehta et al, 2002; Pohland et al, 2000; Reinhart et al, 2002; Reinhart, 1996; Pohland et al, 1994; Townsend et al, 1996; Chan et al, 2002; Demir et al, 2004; Bilgili et al, 2004; Mark and Cristina; 2006). That is the reason why ammonia removal is an important aspect of longterm landfill pollution control

Objectives

Methods

Results

Conclusion