Sewage sludge which mainly comes from the primary settling tank and discharge of surplus sludge is the deposit produced in each operating unit in municipal wastewater treatmentplant.
城市污泥是城市污水处理厂经各级处理净化污水而产生的沉积物，主要来自初沉池和剩余污泥的排放。
2
The experimental results indicated as well that canceling primary sedimentation tank and cesspool when building houses would avail to stable running of sewage treatmentplant.
试验结果表明：在污水处理厂取消初沉池，及修建住宅时取消化粪池，对污水处理厂的稳定运行有益。
3
The primary biological law, the absorption of union alkali and the physical law of governmental sewage treatmentplant producing odor gas such as H2S, CH4 were emphatically studied.