Case studies on municipal wastewater reclamation and reuse in China

Water shortage and water environmental pollution have promoted the development of wastewater reclamation and reuse in China in recent years. Different treatment processes are employed for this purpose, such as pond-farmland systems using solar radiation as initial energy source, treating wastewater at low cost and low energy consumption to realize wastewater reclamation and reuse for irrigation on farmland to provide both water and nutrients. Some full-scale projects on municipal wastewater reclamation mainly based on activated sludge and/or submerged biofilm processes followed by some advanced treatment processes such as filtration and disinfecting, from which the effluent is reused in agriculture, industry and domestic uses except for drinking purpose have been built and put into operation in some water shortage cities, which are described in this paper. In some water scarce cities the domestic wastewater reclamation and reuse (dual water system) is employed for a building, a group of buildings or a sub-residential district, whose treatment system consists of submerged biofilm process, dual-media filter and disinfection.