# Measuring the Performance of Wastewater Treatment in China
## 1 Introduction  
Most countries with a highly developed economy need to use a huge amount of energy for people's daily life needs, such as food, clothing, housing, transportation, education, entertainment, etc. However, the great consumption of energy causes severe pollution problems, especially in water pollution. Some researchers of Norway, Italy, Spain, and China have paid great attention to water pollution and study the cost analysis of water treatments. For example, [PERSON] and [PERSON] [1] consider that energy consumption in the operation and maintenance phase of the urban water and wastewater network is directly related to both the quantity and the desired quality of the supplied water/treated wastewater and also contributes to lifecycle environmental impacts. [PERSON] et al. [2] deem that energy consumption played an important role on the operative costs of a wastewater treatment plant. Some researchers study the technology and the water quality regarding water pollution. [PERSON] et al. [3] found that not all pretreatment technologies have the energy self-sufficiency required to be implemented at a wastewater treatment plant (WWTP). [PERSON] and [PERSON] [4] examined the Po river's quality in a small stretch to highlight the entity and the impact of Torino metropolitan discharge on the quality of the same river. In recent years, many researchers have come to consider the treatment of water pollution a sustainability issue. Given the global trend toward sustainable solutions, there exist sustainable solutions for various applications among watertreatment. In desalination analysis, [PERSON] et al. [PERSON] et al. (2015) reported a floating graphene membrane for evaporating seawater into freshwater exclusively, which can float firmly at the air-water interface with self-righting ability and the process is feasible for practical water desalination on ocean surfaces. With regard to wastewater treatment analysis, [PERSON] et al. [PERSON] et al. (2016) proposed a continuous wastewater treatment process and recycled water through membrane fabrication and performance tests, which demonstrated that over 99% of the organic impurities in the wastewater can be successfully removed. In the topic of water management analysis, [PERSON] et al. [PERSON] et al. (2017) firstly integrated water pinch analysis with water footprint concepts, which provided a robust and effective tool for the manufacturing industries for sustainable water consumption. With regard to catalysis analysis, [PERSON] et al. [PERSON] et al. (2018) provided a sustainable membrane-based synthesis-separation platform for enantioselective organocatalysis through the E-factor and carbon footprint, which allow at least 98% product and substrate recovery and quantitative in situ solvent recycling. Regarding extraction analysis, [PERSON] et al. [PERSON] et al. (2015) introduced the environmentally benign green emulsion ionic liquid membrane (GEILM), a new development in the field of emulsion liquid membranes (ELM), which will help in reducing both environmental as well as economic problems. This indicates that water treatment has become a critical topic for every country. Although China has undergone huge economic growth since its economic reforms, it is now facing increasing and serious environmental problems. Over the period of the 12 th Five-Year Plan, gross domestic product (GDP) continued to increase from US$ 1.211 trillion in 2000 to US$ 11.063 trillion in 2015, while during the same time, the country encountered water scarcity and water pollution. The volume of wastewater discharge increased from 41,500 million tons to 73,500 million tons over this period. A World Bank report points out that China's economy incurs losses of up to 150 billion Renminbi (RMB/Chinese Yuan) a year due to water pollution, and the health losses of its residents are even more inestimable. The China government has always attached great importance to environmental issues. In the 1980s, it upgraded the protection of the environment to basic national policy.