Life cycle assessment of water reuse systems in an industrial park.

The rapid development of industrial parks in China has resulted in large resource consumption and pollutant emissions, especially freshwater use and wastewater discharge. Water reuse has attracted much attention from governments because of its potential to conserve freshwater and reduce pollutant emissions. However, water reuse usually means adding advanced treatment which consumes chemicals, materials and energy. Is the water reuse beneficial for the environment from a life cycle perspective? To answer this question, we quantified the environmental impacts of reusing treated wastewater at industrial parks under different scenarios through a comparative life-cycle assessment (LCA). Four scenarios are assessed: wastewater is treated and discharged, 20% and 99% of wastewater is treated and reused as industrial process water, and treated wastewater is used for horticulture. Inventory data were mainly obtained from a facility which manages the wastewater treatment and reuse system of an industrial park in Jiangsu Province. Environmental impacts were evaluated using the CML2001 method built into the GaBi version 4.3 database. The results show the water reuse is beneficial and the reuse rate significantly affects environmental performance of the system. It is also found that using the reclaimed water for higher value applications results in larger environmental credit. Decision makers in water management should consider both water quantity and quality and associated environmental impacts for different water reuse applications.