The development and future prospect of urban sewage treatment

(2) Implementation of innovative technologies. The representative new technology is anaerobic ammonia oxidation, which effectively circumvents the traditional nitrification/denitrification route, thus greatly reducing energy consumption, and effectively realizes energy-producing carbon bioconversion processes, such as anaerobic membrane bioreactors.

(3) The development of efficient facilities and materials and better process control techniques can optimize water plant operations. Advances in this area include the development of effective carrier materials for biofilm growth, better aeration equipment for efficient oxygen supply, advanced membrane technology to improve wastewater quality, and on-line monitoring/intelligent control technology to improve process stability. In particular, recent developments in low-pollution ultrafiltration and reverse osmosis technologies are making it possible to recycle wastewater at scale and steadily.

While resource-oriented wastewater treatment is gradually becoming the theme of the global wastewater industry, China is also actively exploring its own path. In order to transform sewage treatment plants from pollutant removal sites into factories for energy, water and fertilizer as well as integral parts of urban ecosystems, in 2014, several experts from Chinese research institutions, universities and government departments jointly proposed the construction of a completely new value-added wastewater treatment plant. Due to its forward-looking and exploratory nature, the plant is expected to be built in the next few years and serve as a pilot plant to guide the large-scale, sustainable treatment of wastewater in the near future.

Therefore, it is named "New concept sewage treatment plant". The plant aims to achieve the four-fold goals of sustainable water supply, energy self-sufficiency operation, resource recovery and environmental harmony by integrating various innovative designs and leading technologies. In 2018, the first groundbreaking conceptual wastewater treatment plant was completed in Wuxi, Jiangsu Province, opening a new chapter in sustainable wastewater management and urban water ecological harmony in China.

4. Conclusion

Looking back on China's rapid development history of more than 40 years, there are both impressive achievements and many shortcomings. Although China has almost completed the construction of wastewater infrastructure at a rate far exceeding that of Western countries, many problems remain, including underdeveloped sewer and sludge treatment facilities, high energy consumption, inadequate operational performance, and poor linkages between wastewater discharge standards at sewage treatment plants. As well as local conditions and environmental protection needs, the global idea of harmonious development between man and nature is lacking.

Looking ahead, there will be increasing challenges and uncertainties due to multiple pressures such as environmental protection, economic development and water scarcity, especially as China is transitioning from a developing country to a developed one. Addressing these challenges requires China's wastewater treatment sector to explore its unique path of sustainable development based on its own characteristics and needs, including the development of new concept plants to highlight resource recycling and establish an integrated and harmonious water ecology.