This research focuses on anaerobic (co-)digestion of waste streams (sewage sludge and food waste) to promote circular economy and sustainability in the waste sector. The key research focus is 1) to assess system performance and  stability of single- and two-stage anaerobic (co-)digesters by using carriers treating sewage sludge and food waste; 2) Phosphorous recovery from digestate by exploiting sulphur redox communities; 3) to perform life cycle assessment to improve systems sustainability performance by ensuring more sustainable value chain management.