Comparison of carrier particles in the gas-liquid-solid inverse fluidised bed bioreactor

The performance and energy consumption of a gas-liquid-solid inverse fluidised bed bioreactor (GLS-IFBBR) using polyethylene (PE) particles with different surface coatings (zeolite, lava rock, activated carbon and multi-plastic) as media for synthetic wastewater treatment were investigated at loading rates of 1.64-3.38 kg COD/(m³·d) and 0.17-0.34 kg N/(m³·d) to determine the optimum carrier media. The results showed that PE coated with other inorganic materials could increase the nutrient removal efficiency at the same influent conditions. Compared with other media, PE coated with zeolite (PEZ) was the optimal carrier particles in this study as reflected by the highest COD and nitrogen removal, stable effluent, low biomass yield at different hydraulic retention times (HRT). In addition, the energy consumption of lavarock-coated PE (PEL) with a highest density was the lowest.