Jingjing Huang
University of Stuttgart, Germany
Title: Study on the Co-fermentation of separated press water of biowaste with sewage sludge
Biography
Biography: Jingjing Huang
Abstract
The Waste Framework Directive requires the Member States to respond appropriately to promote the separate collected bio-waste for fermentation and composting. In Germany, the separately collected bio-waste is usually used for energy purposes in fermentation plants, and then for materials reuse in composting plant. At the same time, the capacities of fermentation tank for sewage sludge (FT) in existing wastewater treatment plants (WWTP) are not fully used. The separate utilization of the liquid and solid components of bio-waste represents an innovative concept for Germany to use and treat bio-waste energetically with the existing capacities in fermentation tank in WWTP and to recycle the solid fraction of pressed bio-waste (SF) in composting plants.By pressing bio-waste, the easily degradable organic compounds are concentrated in press water (PW) from bio-waste, which is ideally suited to use as a co-substrate with sewage sludge in fermentation tank of WWTP. Due to significantly higher energy content and the rapid degradation kinetics compared to sewage sludge, relatively high-performance gradients could achieve in biogas production. Through a targeted co-fermentation of PW, it can significantly increase the biogas production to cover its own energy requirements of the WWTP. Additionally, a demand-oriented flexible biogas production to adapt of the varying power requirements of the WWTP and to the power grid could be possible. The hard-to-decompose solid components of the pressed bio-waste, can be treated in existing composting plants, so the recycling of bio-waste, as a higher valued recovery, given by the waste hierarchy can be fullfilled.