Evaluation and case study of typical wastewater resources utilization technology based on FAHP method

The wastewater resources utilization is a major national demand to solve the problem of water scarcity and water environmental pollution. It has been implemented in China for many years with great progress. Wastewater resources utilization can alleviate the water shortage， while also achieving resource and energy recovery， carbon reduction， and carbon neutrality. However， at present， the evaluation methods for wastewater resources technology are not unified in China， and the evaluation index system is not yet sound， which makes it difficult to support the rapid development of safe and efficient wastewater resources utilization. Faced with the demand for multidimensional evaluation of wastewater resources technology under the Dual Carbon Goals， this article summarized the current status of global wastewater resources technology evaluation， and innovatively constructed a scientific and reasonable evaluation index system for wastewater reclamation technology from four dimensions： technology， economy， environment， and low-carbon， by fully considering the concept of wastewater resources utilization in the future. Several secondary indicators were also set under each evaluation dimension to reflect its performance characteristics. In order to quantitatively evaluate and compare the implementation effects of wastewater reclamation technology， a four-dimensional comprehensive evaluation method based on fuzzy analytic hierarchy process was proposed. Taking the wastewater reclamation technology of a certain reclaimed water plant in city A as an example， the specific process of using fuzzy analytic hierarchy process for comprehensive evaluation was elaborated in detail. The results showed that the effluent quality and electricity consumption cost accounted for the largest proportion in the evaluation index system， at 14.16% and 14.11% respectively， and had the greatest impact on the comprehensive evaluation of wastewater reclamation technology. The next largest factors were drug consumption cost， pollutant removal rate， resource recovery amount， and energy recovery amount， all account for about 11%. The technical index， economic index， environmental index， and low-carbon index of this wastewater reclamation technology scored 42.51， 28.66， 6.04， and 5.54， respectively， with a comprehensive evaluation score of 82.75， indicating this wastewater reclamation technology is at a good level. In the future， the water plant needs to enhance the contribution to environmental and low-carbon indicators of this wastewater reclamation technology.