Raw Influent (Sewage) is the liquid waste from toilets, baths, showers, kitchens, sinks Household waste that is disposed of via In many areas sewage also includes some liquid waste from industry and In the UK, the waste from toilets is termed foul waste, the waste from items such as basins, baths, kitchens is termed sullage water, and the industrial and commercial waste is termed trade The division of household water drains into greywater and blackwater is becoming more common in the developed world, with greywater being permitted to be used for watering plants or recycled for flushing A lot of sewage also includes some surface water from roofs or hard-standing Municipal wastewater therefore includes residential, commercial, and industrial liquid waste discharges, and may include stormwater Sewage systems capable of handling stormwater are known as combined Such systems are usually avoided since they complicate and thereby reduce the efficiency of sewage treatment plants owing to their In addition, heavy storms may overwhelm the sewage treatment system, causing a spill or It is preferable to have a separate storm drain system for The construction of combined sewers is a less common practice in the United States and Canada than in the past and is no longer accepted within building regulations in the UK and other European Instead, liquid waste and stormwater are collected and conveyed in separate sewer systems, referred to as sanitary sewers and storm sewers in the US and as foul sewers and surface water sewers in the UK Overflows from foul sewers designed to relieve pressure from heavy rainfall are termed storm sewers or combined sewer As rainfall runs over the surface of roofs and the ground, it may pick up various contaminants including soil particles, (sediment), heavy metals, organic compounds, animal waste, and oil and Some jurisdictions require stormwater to receive some level of treatment before being discharged directly into Examples of treatment processes used for stormwater include sedimentation basins, wetlands, and vortex separators (to remove coarse solids)The site where the process is conducted is called a sewage treatment The flow scheme of a sewage treatment plant is generally the same for all countries:Mechanical treatment;Influx (Influent)Removal of large objectsRemoval of sand and gritPre-precipitationBiological treatment;Oxidation bed (oxidizing bed) or aeration systemPost precipitationEffluentChemical treatment (this step is usually combined with settling and other processes to remove solids, such as The combination is referred to in the US as physical-chemical )希望我的回答能帮到你,祝你学习愉快,希望被采纳为最佳答案。(Hope my answer will be of help to you, wish you learning time, hope to be adopted as the best )