Decentralized Wastewater Management and Its Application in an Urban Area of Beijing, China

A centralized wastewater treatment system has always been regarded as a successful approach during the last century. However, the transfer of this highly water-, energy- and cost-consuming system, and "end-of-pipe" technology to developing countries like China has been proved to be extremely limited and not always feasible. Decentralized water management based on ecological sanitation (EcoSan) turns out to be a promising alternative approach that does not have the pitfalls of the centralized wastewater approach, and represents a holistic solution for ecologically and economically sound sanitation. The main objective of EcoSan is to close both nutrient- and water cycles with as small an expenditure of material and energy as possible. Such implementation could result beneficially in natural resources conservation with greater reliability, flexibility, and cost-effectiveness. This study investigated the needs and potential for wastewater management in China, and compares a centralized with a decentralized approach to water management. The utilisation of both decentralized greywater treatment/reuse and rainwater harvesting in a semi- urban area of Beijing demonstrated the benefit of such a decentralised system. In addition, the application and implementation of the decentralized approach based on ecological sanitation in both rural and urban areas in China are discussed.