The sedimentation and removal of most suspended matter from sewage effluent.
（下水道污水的）初级处理初步处理
as modifiera primary treatment plant
Example sentencesExamples
Most Canadian cities, especially those on the west coast, provide only primary treatment to sewage.
The next stage is primary treatment, which consists of gravity settling to remove suspended solids.
The sand bioreactors described in this bulletin are intended for domestic sewage following primary treatment.
Five out of seven sewage treatment facilities in the Greater Vancouver Regional District provide primary treatment of sewage.
At the time many mills did not have primary treatment for mill effluents (for example, the use of a settling pond) and fewer still had secondary treatment ponds, which used aerobics to reduce drastically the pollution risk.