Water Footprint Inventory Construction of Cathode Copper Products in a Chinese Eco-Industry

Abstract

Copper is an important strategic resource for the national economy and social security of China. Water use is a significant component of copper production. However, water shortages and water pollution are two global crises in water resource management. In this study, a copper production industry in China was studied from the perspective of water footprint (WF) and ecological industry (eco-industry). A WF inventory was built by accounting for the entire production and supply chain process, including mining, ore dressing, transportation, smelting, and electrolysis. An index system comprising target, criterion, and variable layers was established to evaluate the sustainable utilization of water resources. It was observed that the studied industry showed a good sustainability for water resource utilization. Only 65.67 tons of freshwater per ton of product was inputted in the entire process due to virtual water (VW) and the use of reclaimed water. However, the WF of each ton of cathode copper product was 162.58 t, and the imported VW of the eco-industry accounted for 92.45%. Increasing the VW import and reducing the VW export can alleviate water shortages. A detailed WF analysis showed that the effects of evaporation and different types of losses on the blue WF (BWF) were significant and should be considered. Upstream water consumption of electricity and other energy sources were also observed to be an important part of the BWF. Regardless of whether freshwater or recycled water was used, the WF can be reduced only by effectively reducing water consumption.