An Extensive Analysis of the Engineering Design of Underground Sewage Plants in China

In recent years, underground sewage treatment plants that can remarkably reduce land occupation with less environmental pollution are gradually entering the popular consciousness and are now being used widely. However, problems associated with the traditional treatment plants, such as high construction and operation cost, severe health and safety risks, and monotonous landscape design have limited their value and restricted their application and promotion. Through the literature and field investigations, the value of underground sewage treatment plants (STPs) was analyzed, their engineering and landscape design were studied, and their development direction was explored in order to supply a theoretical basis for further application and development of underground STPs. The analysis showed that as a new model of environmentally friendly sewage treatment and resource conservation, underground STPs have the apparent advantages of lower cost of land use for construction and pipeline as well as an outstanding value for the urban landscape and ecological environment. These factors can offset its relatively high construction and operating costs to a certain extent, especially when compared with above-ground STPs. The engineering design study results showed that significant differences existed between underground STPs and traditional above-ground STPs, and that the main contents of the engineering design of underground STPs consist of treatment scale and degree, influent and effluent qualities, site selection, design model, underground arrangement and structure, main treatment process, monomer structure, ventilation and deodorization, daylighting and artificial lightings, fire safety, operation and maintenance, and the linkage design between the above-ground landscape and the underground STP.