Resources metabolism problems are the main reason resulting in the eco-environmental impacts of industrial system. Material flow analysis is a methodology that focuses on tracking and quantifying a substance or substance group as it moves through a system and is the primary tool used to understand the metabolic processes of anthropological activity. Based on analyzing the resources metabolism of the pulp and paper industry in Wuhan by the methodology of MFA, an analysis indicator system was built, which included four aspects: resources input, resources consumption, environmental stress and circular symbiosis. The fuzzy comprehensive evaluation method and the problem tree model were used to evaluate metabolism of raw materials, water, and energy of the pulp and paper industry in Wuhan. Five grades were included: excellent, good, moderate, bad and very bad. The results were compared with the national average level in 2007. The results showed that the evaluation grade of resources metabolism of the pulp and paper industry in Wuhan is excellent,while it is still slightly lower than the national average level. When evaluating the resources metabolism separately by resources input, resources consumption, environmental stress and circular symbiosis, we found that: (1) The grades of the ecological efficiency of raw material input, energy input and water input were excellent, good and excellent respectively; (2) The grade of the energy consumption per unit product was good, and that of the water consumption per unit product and the raw material consumption per unit product were excellent; (3) the grades of the output value per unit pollutant and the pollutant emission per unit product were excellent, and the grade of the compliance rate of pollution emission was good; (4) The grade of the proportion of cleaner production was good, and that of the pollution treatment and the sustainable utilization of resources were excellent, but that of reuse water rate was bad.
Based on the resources metabolic analysis for the pulp and paper industry in Wuhan, we can draw some conclusions as follows: (1) The problems on energy consumption, water consumption and pollution discharge mainly arise from pulp and paper production, suggesting great potentials on reduction of energy and water consumption and pollution emission in these processes. (2) Comparing with national average level, the use rate of the wastepaper pulp is higher and that of the wood pulp is lower. (3) The ecological efficiency of the energy input and the energy consumption per unit product are below the national average level, and the proportion of cleaner production is also below the reference value. They all should to be improved. (4) There is great potential for improvement in reuse of water resource.
This study demonstrates the use of resources metabolism analysis approach we posed before, and highlights the need for the evaluation standard and database for analysis of the resources metabolism for industrial ecosystems.