A multi-criteria decision analysis of management alternatives for anaerobically digested kraft pulp mill sludge

Abstract

The Multi-Criteria Decision Analysis (MCDA) procedure was used to compare waste management options for kraft pulp mill sludge following its anaerobic digestion. Anaerobic digestion of sludge is advantageous because it produces biogas that may be used to generate electricity, heat and biofuels. However, adequate management of the digested sludge is essential. Landfill disposal is a non-sustainable waste management alternative. Kraft pulp mill digested sludge applied to land may pose risks to the environment and public health if the sludge has not been properly treated. This study is aimed to compare several recycling alternatives for anaerobically digested sludge from kraft pulp mills: land application, landfill disposal, composting, incineration, pyrolysis/gasification, and biofuel production by algae. The MCDA procedure considered nine criteria into three domains to compare digested sludge recycling alternatives in a kraft pulp mill: environmental (CO2 emission, exposure to pathogens, risk of pollution, material and energy recovery), economic (overall costs, value of products) and technical (maintenance and operation, feasibility of implementation). The most suitable management options for digested sludge from kraft pulp mills were found to be composting and incineration (when the latter was coupled with recycling ash to the cement industry). Landfill disposal was the worst option, presenting low performance in feasibility of implementation, risk of pollution, material and energy recovery.

Multiple Criteria Decision Making for the Achievement of the UN Sustainable Development Goals: A Systematic Literature Review and a Research Agenda

“…Table 10 summarizes the articles reviewed in this category and the contributions of MCDM methods for achieving SDG 12 [96][97][98][99][100][101][102][103][104][105].…”

“…Several conflicting criteria were considered before establishing a remanufacturing facility. MCDM and non-MCDM methods were combined in three studies to support decisions concerning responsible consumption and production issues [96,98,102].…”

“…Concerning the MCDM taxonomy adopted in this review [34], most of the MCDM methods employed are utility-based methods, namely AHP [96][97][98]101,102] and ANP [103]. For example, Khakzad and Reniers [96] combined the AHP method with Bayesian Network (BN) to find an optimal layout for chemical plants by taking safety measures and land using planning regulations.…”