Given the increasing demand for hydrogen, owing to its environmentally friendly nature, it is important to explore efficient methods for hydrogen production. This study investigates dark-fermentative hydrogen production by the co-digestion of food waste and sewage sludge. Both wastes were subjected to alkali pretreatment (at pH 13) to enhance biodegradability. Batch tests were conducted to enhance hydrogen production from food waste and sewage sludge under various volatile solid (VS) concentrations of 1.5–5% and food waste to sewage sludge mixing ratios of 0:100–100:0. We found that alkali pretreatment was effective in increasing hydrogen yields. The maximum specific hydrogen production rate of 163.8 mL H₂/g volatile suspended solid/h was obtained at a VS concentration of 5.0% and food waste composition of 62.5%. Additionally, VS concentration of 2.8% and food waste composition of 100% yielded a maximum hydrogen production potential of 152.1 mL H₂/g VS. Our findings indicate that food waste and sewage sludge with alkali pretreatment are potential substrates to produce biohydrogen.

In this study, we investigated the combination of algal treatment and subsequent oxidation to improve the antibiotics removal and refractory organics degradation in livestock wastewater effluent. We also proposed a better combination of oxidation processes for robust treatment of recalcitrant wastewater, mainly focusing on the removal of antibiotics. Stand-alone processes of O₃, O₃/H₂O₂, ultraviolet C (UVC), and UVC/H₂O₂ as well as their combined effects were evaluated as a downstream oxidation process. Prior to those oxidation processes, the effluent was treated with microalgae under continuous light illumination, which turned it into alkaline wastewater (pH > 10). The algal treatment was feasible not only to directly remove antibiotics resistant to a specific oxidation method, but also to improve the degradation of antibiotics and effluent organic matter in the alkaline wastewater upon subsequent oxidation. The alkaline wastewater was more favorable for the removal of antibiotics (especially for clopidol) with UVC treatment (UVC and UVC/H₂O₂). The algal treatment promoted ozonation to some extent for the degradation of florfenicol in the effluent. The removal of antibiotics by ozonation decreased with added H₂O₂, whereas the UVC performance was improved by adding H₂O₂. For ozonation followed by UVC treatment, the ozonation dominated the degradation of selected antibiotics.