Since concrete is an alkaline material subject to attack by acids, it should not be used for small-size sanitary sewers where hydrogen sulfide production can cause internal corrosion.

• 由于混凝土管是一种碱性材料易受酸的腐蚀，它不能应用在较小的污水管道上，由于产生的硫化氢会腐蚀管子内壁。