Design wastewater quality of municipal wastewater treatment plant

The design wastewater quality of municipal wastewater treatment plant is one of preconditions of selection of wastewater treatment technologies. There is a great difference between the design wastewater quality of municipal wastewater treatment plant and factual wastewater quality at present. The difference of wastewater quality between the rainfall period and the non-rainfall period should be taken into account as for wastewater treatment plant of combined system. The calculation formula of combined wastewater quality is put forward. The domestic wastewater quality relates to living level and is discussed. The industrial wastewater quality relates mainly to the industry type and technology level. The municipal wastewater quality relates to the wastewater composition and the condition of drainage system as well.