Abstract

The current work studied the removal of heavy metals (HMs) in the anaerobic migrating blanket reactor (AMBR) and anaerobic sludge bed reactor (ASBR) installed consecutively. In this work, the organic loading rate (OLR) was adjusted to vary from 1.8 to 19.7 g·COD/L·d at 11 runs for a period of 280 d. After the preparation of the samples, the Series Optima Perkin Elmer 4000 ICP-OE 5 was utilized to measure the level of heavy metals including Cr, Zn, Ni, Cu, Cd, and Pb. The min-imum and maximum rates of heavy metal removal were 86.18 for Cu and 94.5 for Cd. In the studied AMBR-ASBR consecutive system, the observed order of heavy metal removal efficiency was as follows: Cd > Pb > Ni > Cr > Zn > Cu. The consecutive AMBR-ASBR system is an efficient system for the removal of heavy metals, and it has high efficiency of 87.3 ± 4.63. Increasing the OLR to 10.1 improved the removal efficiency of copper, chromium, and cadmium, and also enhanced the removal efficiency of zinc up to 19.7. Investigation of the heavy metal concentration in the sludge showed that most of the metals removed from the leachate had accumulated in the sludge and biomass. Therefore, biosorption and adsorption of metals on the biomass was the main process in the removal of heavy metals from compost leachate. Moreover, the results of this study showed that heavy metals in compost leachate can be effectively removed in a sequential AMBR-ASBR reactor by the biosorption process. © 2022, Desalination Publications. All rights reserved.