Proposal of an Encapsulation-led Disposal Method for Tannery Sludge – A Circularity Approach

Abstract

In the context of achieving sustainable development goals, continuously pushing possible extended research and attempting to implement the respective outcomes in expanding a circular economy for a broad range of products are high priorities. In this paper, we considered disposable tannery sludge as a matter of concern and proposed an innovative framework for placing tannery sludge in the economic value chain via an encapsulation technique-based construction product development. We used polypropylene plastic and a cement-water matrix as encapsulation materials, and the encapsulated tannery sludge bodies were tested for their drop strength, water absorbing behaviour, ability to leach chromium and tendency to lose weight upon ignition. Value of water absorption for the prepared double layered encapsulated tannery sludge bodies was 1.332%, the drop strength performance index arrived was 90% and 0.0001 µg/g of Chromium leaching was found in Toxicity Characteristic Leaching Procedure (TCLP) and shown 67% weight loss in thermogravimetric (TGA) analysis. The results confirmed the possibility of ecocompatible disposal and recirculation of tannery sludge for the sustainable production of building blocks in the form of encapsulated bodies. The outcomes of our work add upon a new perspective to the existing literature regarding the environmentally positive utilization of tannery sludge in the production of building blocks.