Abstract
Population explosionmediated demand has led to an unprecedented increase in the consumption of natural resources across the globe. Most of the nonrenewable natural resources have failed to meet the ever-increasing demand, resulting in a gradual widening of the supply and demand gap. Therefore, in the recent decades, the mainstream research focus has aimed at developing technological solutions to recover secondary resources from anthropogenic wastes or waste streams. This chapter discusses about the technical possibilities and the bottlenecks associated with the recovery of cellulose, polyhydroxyalkanoate (PHA), and extracellular polymeric substances (EPS) from sewage sludge. Basic resource recovery techniques involve biochemical, physicochemical, and some of the previously unexploited biological processes. The important applications of sludge-derived cellulose fibers for the production of cellulose nanocrystals and cellulose nanofibers, recovered PHA for biopolymer synthesis, and extracted EPS application as a bioflocculant, along with other diversified application prospective have also been deliberated in this chapter. The sources and extraction methods of various resources to be recovered are highlighted in this chapter that can be helpful in choosing the suitable extraction methods depending on the sources from which the secondary resources are to be recovered and the intended use of the recovered resources. The recovery of secondary resources from waste sources is a very essential practice from the global sustainability view point.
