Influence of sewage treatment on China׳s energy consumption and economy and its performances

The sewage treatment industry may affect China׳s energy-saving and economic growth related goals to some degree. This study investigated influence of sewage treatment on China׳s energy consumption and economic growth and its performances from 2008 to 2013. We adopted a set of indicator system based on energy, emergy and money to depict these interactions, including Energy use per unit emission reduction (EUER), Cost per unit emission reduction (CUER), Environmental benefit per unit investment (EBUI), Ratio of energy consumption from sewage treatment to national total energy consumption (REST), Ratio of cost of sewage treatment to the Gross Domestic Product (RCSG), Structural Coordination degree of sewage treatment (SCDS), and Scale harmony degree of sewage treatment (SHDS). Here emergy was used to quantify the environmental impact of water pollutants. The study results show that energy efficiency of sewage treatment keeps relatively stable, the economic cost of sewage treatment increases obviously, the environmental performance of sewage treatment investment slightly rises, and the sewage treatment has an increasing impact on the energy consumption and economic growth of this country. As far as the relationships between different indicators or factors are concerned, the structure of China׳s sewage treatment industry worsens obviously due to rising energy consumption and economic cost; meanwhile, the relationship between economic cost and energy consumption for sewage treatment, domestic water consumption, and discharged sewage׳s impact seriously deteriorated. Finally, some corresponding issues are discussed and the related policy implications are put forward.