Organic matter removal under high loads in a fixed-bed sequencing batch reactor with peach pit as carrier

Abstract

In this study, the evaluation of organic matter removal at high loads from synthetic wastewater was performed using a Fixed-bed Sequencing Batch Reactor (FSBR), in which peach pits were used instead of conventional carriers. The FSBR performance on organic matter removal at different organic loading rates (2–12 kg COD m⁻³ d⁻¹) was significant. Organic matter removal efficiency was >90% at a loading rate less than 7.2 kg COD m⁻³ d⁻¹. When the organic loading was 12 kg COD m⁻³ d⁻¹, organic matter removal in the FSBR and SBR reactors reached 71.84 and 56.57%, respectively, indicating that the FSBR performance is significantly higher than the SBR reactor. According to the higher efficiency of SBR with media, this comparison shows that bio-film bioactivity (7.06 ± 0.3 mg O₂ mg-VSS⁻¹ d⁻¹) is significantly higher than suspended biomass bioactivity (2.92 ± 0.149 mg O₂ mg-VSS⁻¹ d⁻¹). As the OLR increased from 3.4 to 10 kg COD m⁻³ d⁻¹, the observed yield (Y_obs), the specific biomass growth rate (μ_overal) and the endogenous decay rate (k_d) increased from 0.018 to 0.02 g VSS g⁻¹ COD⁻¹, 0.1 to 0.2 d⁻¹, and from 0.082 to 0.067 d⁻¹, respectively, while the solid retention time (SRT) decreased from 40 to 19.8 d. © 2012 American Institute of Chemical Engineers Environ Prog, 2012