Effective aggregation of expert opinions to inform environmental management: An integrated fuzzy group decision-making framework with application to cadmium-contaminated water treatment alternatives evaluation

Application of group decision making to practical environmental management problems indicates that effectively avoiding the loss of decision information and reasonably aggregating expert views are two main challenges during the decision-making process. Hence, this paper focuses on the utilization of interval-valued triangular fuzzy numbers for expressing expert opinions and the introduction of Group-G1 and Hamming-based weighted polymerization operator to incorporate the fuzzy information provided by individual experts, into group consensus opinion. The developed integrated fuzzy group decision-making framework was then applied to the evaluation and selection of the most desirable technology for removing low-concentration cadmium ions from water. It has been determined that hydroxide precipitation was the most preferred option at the current stage because of its relative simplicity and high maturity. However, the rankings generated based on expert opinions suggested that adsorption technologies, especially biosorption, could also be preferred because of its low-cost and environment-friendly characteristics. Finally, the reliability of the resulting priority-rankings was investigated by sensitivity analysis. The result showed this fuzzy group decision-making framework is potentially of great value for developing robust environmental recommendations and thus enables experts to make informed decisions and achieve optimal results.