Abstract

In this study, the occurrence and removal of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in an anaerobic migrating blanket reactor (AMBR) were investigated. The chemical analyses were performed on leachate samples from different treatment processes, using solid-phase extraction and gas chromatography (GC), and inductively coupled plasma�optical emission spectrometry (ICP�OES). The organic loading rate (OLR) applied to the system gradually increased from 1 to 19.65� g COD/l� d in 11 runs during a 280 d study period. The concentration of Σ8PAHs in the raw composting leachate was 50.13� μg/l. The main component of PAHs in the raw composting leachate was pyrene, when the average removal efficiency of Σ8PAHs in AMBR was 73. The optimum OLR for removal of heavy metal was 10.1� g COD/l� d. In this OLR, maximum and minimum removal efficiency for Pb and Cd were 55 and 42, respectively. The order of heavy metal concentration in AMBR sludge was: Ni� <� Zn� <� Cr� <� Cd� <� Pb� <� Cu. The AMBR process presented high removal efficiency in treatment of COD organic loading rate, especially when OLR was lower than 4� g COD/l� d. The AMBR could be an appealing option for treatment of PAHs and heavy metals in composting leachate and changing it into non-hazardous products and also a suitable option for the pre-treatment method. �© 2016 Balaban Desalination Publications. All rights reserved.