Sulfide, phenols and chromium (VI) removal from landfill leachate and domestic wastewater by ZELIAC, zeolite and activated carbon augmented sequencing batch reactor (SBR)

Abstract

Leachate is created, while water penetrates through the waste in a landfill, carrying some forms of pollutants. Sequencing Batch Reactor (SBR) is one of the biological methods for treating wastewater. The current research studied the removal of sulfide, phenols and hexavalent chromium from landfill leachate and domestic wastewater using Powdered ZELIAC (PZ), Powdered Activated Carbon (PAC) and powdered zeolite (PZE) augmented SBR process. The ZELIAC is a new adsorbent, which consists of zeolite, activated carbon, limestone, rice husk ash and Portland cement. Based on batch experiments and optimization experiments, powdered adsorbents dosage (PZ, PZE and PAC dosages = 3 g L -1), settling time (90 min) and leachate-to-wastewater mixing ratio (20%; v/v) were fixed. The results indicated that the PZ-SBR showed higher performance in removing phenols, sulfide and hexavalent chromium compared with SBR, PZE-SBR and PAC-SBR. And also the PZE-SBR showed higher performance in removing Cr (VI) compared with SBR and PAC-SBR. In the PZ-SBR, the removal efficiencies for phenols, sulfide and Cr (VI) were 67.71, 74.13 and 79.24%, respectively.