Feasibility assessment and underlying mechanisms of metabisulfite pretreatment for enhanced volatile fatty acids production from anaerobic sludge fermentation.

Employing chemical pretreatment for waste activated sludge (WAS) fermentation is crucial to achieving sustainable sludge management. This study investigated the feasibility of metabisulfite (MS) pretreatment for enhancing volatile fatty acids (VFAs) production from WAS. The results show that after 24-h MS pretreatment, the content of soluble organic matter and loosely bound extracellular polymeric substances (LB-EPS), especially proteins, increased significantly.

In-situ sulfite treatment promotes solid reduction during aerobic digestion of waste activated sludge: Feasibility for small-scale wastewater treatment plants.

Aerobic digestion remains the preferred choice for small-scale wastewater treatment plants (WWTPs) in some developing countries, largely due to economic viability and operational simplicity. The escalating production of waste activated sludge (WAS) has prompted small-scale WWTPs to improve efficiency. To address this issue, this study employed an in-situ sulfite treatment as a non-intrusive method to augment aerobic digestion.

Achieving efficient methane production from protein-rich organic waste in anaerobic digestion: Using conductive materials or regulating inoculum-to-substrate ratios?

The contribution of inoculum-to-substrate ratios (ISRs) and conductive materials (CMs) on the productivity of anaerobic digestion (AD) remains unclear, particularly for protein-rich organic waste. This study investigated whether the addition of CMs, i.e.

Evaluating Fouling Control and Energy Consumption in a Pilot-Scale, Low-Energy POREFLON Non-Aerated Membrane Bioreactor (LEP-N-MBR) System at Different Frequencies and Amplitudes.

Continual aeration, a fouling control strategy that causes high energy consumption, is the major obstacle in the deployment of membrane bioreactors (MBRs) for wastewater treatment. In recent years, a technology has been developed which adopts mechanical reciprocity for membrane vibration, and it has been proven efficient for membrane scouring, as well as for saving energy: the low-energy POREFLON non-aerated membrane bioreactor (LEP-N-MBR). In this study, a pilot-scale LEP-N-MBR system was designed, established, and operated at various frequencies and amplitudes, and with various membrane models, so as to evaluate energy usage and membrane fouling.

Insights into the role of biochar on the acidogenic process and microbial pathways in a granular sulfate-reducing up-flow sludge bed reactor.

In this study, the effect of biochar on sulfate reduction and anaerobic acidogenic process was explored in a granular sulfate-reducing up-flow sludge bed reactor in both long-term operation and batch tests. Both bioreactors had a high sulfate reduction efficiency of over 95% during the long-term operation, while the reactor with biochar addition showed higher sulfate reduction efficiency and stronger robustness against volatile fatty acids accumulation with a higher organic loading and sulfate loading rate. Batch tests showed that adding biochar significantly lessened the lag phase of the sulfate-reducing process, accelerated the adaption of acidogens, and facilitated both production and utilization of volatile fatty acids.