Figure 1. Sewage Sludge Production Process
Worldwide Sludge Treatment, Statistics and Processing
For wastewater treatment plants, the World Water Environment Federation (WEF) has adopted the ”NEW” paradigm (Nutrient-Energy-Water). This concept is centered on converting individual wastewater treatment plants into units that produce recovered resources. Climate change and population shifts are the foundations of this paradigm, as increasing biogenic contamination of water, which accelerates the eutrophication process, and the need for sustainable development. Developed countries now have the biggest sewage sludge output (Yesil et al., 2021). Sludge utilization is largely limited to sewage sludge and biosolids, and it is only reported in industrialized nations (LeBlanc et al., 2009). Many of these nations had trouble disposing of sewage sludge from treatment facilities after recognizing that traditional sewage sludge disposal in landfills was no longer an option.
With the increased use of wastewater treatment, many nations are tackling one problem while creating a new one: managing or disposing of sewage sludge. While wastewater treatment results in cleaner water being released to oceans, rivers, and lakes, it also results in a substantial volume of sewage sludge being created (Table 1).