Advanced Landfill Waste Alleviation and Resource Mining Strategies

Landfilling is one of the cheapest options for municipal solid waste management, which has been in practice for centuries. However, generation of municipal landfill leachate (MLL) with concentrated hazardous pollutants is the biggest downside of this process. MLL treatment is challenging with conventional treatment technologies due to its intrinsic toxicity and to date, none of the technology can provide a single-stage carbon and nutrient removal at a low carbon footprint and energy expenditure. For instance, in Europe, MLL is mostly managed in urban wastewater treatment plants (UWTPs) using combined pre-treatment and energy-intensive post-biological strategies yet many small UWTPs fail to comply with the discharge limit of ammonia and emerging pollutants. This is emphasizing an urgent need to develop a new decentralized single-stage solution. In ALARMS, we propose to develop an integrated purple non-sulfur bacteria (PNSB)-based biotechnology for onsite MLL treatment and resource recovery at low-carbon footprint. PNSB own versatile metabolic pathways, enabling them to participate in the natural nutrients fixation cycle using photosynthesis process. Thus, most of the studies utilized PNSB as a superior heterotroph to treat a wide range of wastewater. To date, a few recent research uncovered unlimited potential of PNSB as cathode respiring bacteria to derive biofuels (e.g., H2) at high conversion efficiency from synthetic media, which is yet to be explored for real wastewater treatment, especially for MLL. Here, we will isolate mixed PNSB from natural sources and electrochemically activate it to induce a desired metabolic response and utilize it as both autotroph and heterotroph to efficiently remove/recover nutrients and organics in a single stage from MLL using novel electrochemical photobioreactors. This project is interdisciplinary combining material science, biotechnology, electrochemistry, and metabolic engineering, and is aligned with the EU's 2050 goal of zero carbon footprint.