Waste equals energy: decentralised anaerobic waste treatment and local reuse of return flows

Abstract

In the built environment, the distance created between the (environmental) problem and its solution leads to more and more complexity. The process of changing the interrelated public and private services, systems and infrastructures is becoming more and more complicated and less predictable. Together with the increased scaling, the convergence of utilities and the growing number of parties and techniques involved, the end users’ (consumers’) subjective dependence (heteronomy) has increased. This asks for a simplification of the processes, products (or rather, services). A larger concentration on integral provision of services, or, in other words, the supply and management of integral packages, offers possibilities. This seems to be reinforced by the ongoing liberalization processes. This paper will focus on an innovative concept of integrated decentralised technologies for wastewater and organic waste treatment with energy and nutrients recovery. The concept is called Sustainable Implant (SI). Principally, the concept is based on a small-scale biogas installation (with treatment of blackwater and organic waste), Combined Heat Power (CHP) and accompanying closed glasshouse with ‘hanging gardens’. These ‘hanging gardens’ are situated in a non-ventilated space with heat (and water) recovery, heat/cold storage (in an underlying aquifer) and with injection of the surplus CO2 of the biogas plant. The SI will be realized as a part of this semi-public building and has an interconnecting role between both district and building, inhabitants and visitors. The system layout and the dimensioning backgrounds are explained in this paper. Additional emphasis is put on maintenance, conservation and administration of the integrated whole, and the possible consequences for the district and its inhabitants.