Anaerobic treatment of leachate using sequencing batch reactor and hybrid bed filter

Abstract

Landfill leachate taken from a young municipal landfill site (≈3.5 years old) containing high organic contaminants (Total Organic Carbon -TOC of about 5000 mg 1−1) was treated in bench-scale Anaerobic Sequencing Batch Reactors (ASBR) and an Anaerobic Hybrid Bed Filter (AHBF) at mesophilic conditions. Twenty months of testing has been conducted at varied influent leachate concentration of 546–5770 mgTOC 1−1, Hydraulic Retention Time (HRT) of 10–1.5 days and Solid Retention Time (SRT) of 40–9 days in ASBR's, and influent leachate concentration of 1250–4490 mgTOC 1−1 and HRT of 5.1–0.9 days in AHBF. ASBR achieved 73.9% TOC removal at maximum organic loading rate of 2.8 kgTOC m−3 d−1 at 1.5 days of HRT, and 65.3% at 0.561 kgTOC kgVSS−1 d−1 of maximum specific loading rate and 2 days of HRT. The AHBF maintained 81.4% TOC removal at 1.2 kgTOC m−3 d−1 of loading and 2.4 days of HRT. Methane conversion ratio averaged 0.742 m3CH4 kgTOC−1 removed at (STP).