Constructive Approaches Toward Water Treatment Works Sludge Management: An International Review of Beneficial Reuses

Virtually all known drinking water processing systems generate an enormous amount of residual sludge, and what to do with this rapidly increasing “waste” stream in an economic and environmentally sustainable manner remains a significant environmental issue. Perhaps the realization of this fact has led to a series of concerted efforts aimed at beneficial reuses in an effort to close the loop between efficient water treatment and sustainable sludge management. This article therefore presents a comprehensive review of available literature on attempts at beneficial reuses of water treatment plant sludge, in an effort to provide a compendium of recent and past developments, and to update our current state of knowledge. Four broad categories of uses, which included more than 11 possible ways in which waterworks sludges can be reused, are identified and examined. Obvious advantages of such reuse options are highlighted and knowledge gaps are identified. Future issues that will assist in the development of sustainable waterworks sludge management options with a multiprong approach are discussed.