Energy production through enhanced organic matter recovery in high-rate contact stabilization with Klebsiella pneumoniae

Abstract

The study focuses on identifying cultivable microbial species within the sludge of a high-rate contact stabilization (HRCS) process and evaluating the enhancement of organic matter recovery using Klebsiella pneumoniae as the sole inoculum. The Klebsiella pneumoniae, identified as a cultivable microorganism from sludge in the HRCS process, exhibited rapid growth with a doubling time of 2.4 h. Comparative analysis between the standard HRCS system and the HRCS-K system, inoculated exclusively with Klebsiella pneumoniae, results in organic matter removal efficiency and methane production. The HRCS-K system, despite being less efficient in removing overall organic matter, nitrogen, and phosphorus, demonstrated enhanced energy recovery due to its high sludge yield and efficient degradation during anaerobic digestion. Significantly, the carbon recovery rate (CRR) in the HRCS-K system was 0.567 ± 0.130 g-COD_CH4/g-COD_inf. This value indicates a 48% enhancement in comparison to the microbial consortia. This progress establishes a basis for further research into the feast-famine regime of wastewater treatment and contributes to enhanced energy production efficiency in the sector. Furthermore, the enhanced methane production capability of the HRCS-K system offers a promising approach to energy recovery and supports more sustainable wastewater treatment practices.