A Pythagorean language neutrosophic set method for the evaluation of water pollution control technology in pulp and paper industry

With the increasingly strict supervision of the ecological environment and the continuous improvement of pollution control requirements, there are many options for water pollution control technology in the pulp and paper industry. How to choose reasonable and effective control technology has become the focus of attention. In this paper, a water pollution control technology evaluation model based on the Pythagorean language neutrosophic set (PLNS) is proposed for the first time. Firstly, the concept of PLNS is defined and its characteristics are discussed. Then the score function and accuracy function of the Pythagorean language neutral number (PLNN) are defined. To apply PLNNs to multi-attribute decision-making, PLNN power-weighted geometric operator (PLNNPWG) and PLNNPWG geometric Heronian mean operator (PLNNPWG-GHM) are proposed and a multi-attribute decision-making method is proposed. Finally, this method is used to evaluate the water pollution control technology of the pulp and paper industry. Through the experimental results, it can be seen that if the comprehensive weights are used, elemental chlorine-free (ECF) clean bleaching technology is the best choice, when using single weights to calculate, in technical characteristics, ECF clean bleaching performed best. In economic cost, chlorination, enhanced alkali treatment, hypochlorite (CEH) three-stage bleaching performed best. In operation management and environmental impact, ECF clean bleaching and total chlorine-free (TCF) clean bleaching had almost the same score. This model can provide a reliable basis for enterprises to choose the appropriate water pollution control technology and also provide strong support for the management department to recommend the best feasible technology.