Development of a pilot fluidised bed reactor system with a formulated clay–lime mixture for continuous removal of chemical pollutants from wastewater

Abstract

This study was to determine the prospective application of a newly developed fluidised bed reactor (FBR) system using a formulated clay–lime mixture for a large-scale wastewater treatment implementation. A lab-made FBR was designed to assess the application of this formulated clay–lime mixture for the removal of several potential pollutants present in wastewater streams. The operating conditions of the FBR system was first optimised in batch mode by individual experiments prior to progressing into the continuous scheme. The results revealed that the dye elimination was enhanced significantly, by which 99% removal of 30 mg L −1 dye can be achieved with 0.8 g L −1 loading and aeration rate of 1 L min −1. This process was found effective in removal of anionic dye and phosphate while less favourable towards nitrate. This can be attributed to the different dominant removal mechanisms i.e. precipitation and adsorption. The potential reaction time of the formulated clay–lime mixture was found to be pH dependent where the removal performance was superior in strong alkaline conditions. Several municipal primary effluent samples were also treated using the developed FBR system in continuous operation mode. This system contributed an average 10–15% and 20–40% reduction of the nitrate and COD, respectively, while 100% removal of phosphate was obtained over the experimental period. This study demonstrated that the developed FBR system with the formulated clay–lime mixture can be a cost-effective alternative treatment process for a large-scale application for the treatment of industrial wastewater.