High-solid co-digestion performance of lipids and food waste by mesophilic hollow fiber anaerobic membrane bioreactor

Immobilized bioreactor for enhanced ammonia, phosphorus, and phenol removal and effects of phenol on microbial communities, potential functions, and nitrogen metabolism

In the present study, an immobilized bioreactor was established to remove ammonia (NH4+-N), phosphate (PO43--P), and phenol using composite mycelium spheres (CMP) as the immobilization material in combination with Pseudomonas sp. Y1. Under optimal operating conditions, the bioreactor achieved 98.07, 91.71, and 92.57 % removal of NH4+-N, PO43--P, and phenol, respectively. The results showed that the bioreactor removed PO43--P by biomineralization and co-precipitation. Phenol removal relied on a Fenton-like reaction achieved by CMP-induced quinone redox cycling. High-throughput sequencing analysis and functional gene prediction indicated that Pseudomonas was the dominant genus and that the bioreactor had much potential for nitrogen removal, respectively. In addition, phenol affected the performance of functional genes and the associated enzymes, which influenced the nitrogen metabolism process in the bioreactor. This work serves as a guideline for the development of more stable and sustainable composite pollution removal technologies and fungal-bacterial symbiotic systems.

Advanced biofuel production, policy and technological implementation of nano-additives for sustainable environmental management - A critical review

This review article critically evaluates the significance of adopting advanced biofuel production techniques that employ lignocellulosic materials, waste biomass, and cutting-edge technology, to achieve sustainable environmental stewardship. Through the analysis of conducted research and development initiatives, the study highlights the potential of these techniques in addressing the challenges of feedstock supply and environmental impact and implementation policies that have historically plagued the conventional biofuel industry. The integration of state-of-the-art technologies, such as nanotechnology, pre-treatments and enzymatic processes, has shown considerable promise in enhancing the productivity, quality, and environmental performance of biofuel production. These developments have improved conversion methods, feedstock efficiency, and reduced environmental impacts. They aid in creating a greener and sustainable future by encouraging the adoption of sustainable feedstocks, mitigating greenhouse gas emissions, and accelerating the shift to cleaner energy sources. To realize the full potential of these techniques, continued collaboration between academia, industry representatives, and policymakers remains essential.

Enhancing methane production from food waste with iron-carbon micro-electrolysis in a two-stage process

A two-stage process, consisting of a leach-bed reactor (LBR) and an up-flow anaerobic sludge blanket reactor (UASB), has been commonly adopted to improve food waste anaerobic digestion. However, its application is limited due to low hydrolysis and methanogenesis efficiencies. This study proposed a strategy of incorporating iron-carbon micro-electrolysis (ICME) into the UASB and recirculating its effluent to the LBR to improve the two-stage process efficiency. Results showed that the integration of the ICME with the UASB significantly increased the CH4 yield by 168.29%. The improvement of the food waste hydrolysis in the LBR mainly contributed to the enhanced CH4 yield (approximately 94.5%). The enrichment of hydrolytic-acidogenic bacterial activity, facilitated by the Fe2+ generated through ICME, might be the primary cause of the improved food waste hydrolysis. Moreover, ICME enriched the growth of hydrogenotrophic methanogens and stimulated the hydrogenotrophic methanogenesis pathway in the UASB, contributing partially to the enhanced CH4 yield.