The following article will guide you about how to estimate the quantity of sewage. Estimation of Dry Weather Flow: The dry weather flow (D.W.F) includes: (i) Domestic or sanitary sewage which is the sewage or wastewater derived from residential buildings and from commercial, institutional and similar public buildings such as offices, schools, cinemas, hotels, stations, etc.; (ii) Industrial sewage which [...]
The following points highlight the four main factors affecting the quantity of dry weather flow through the sewers. The factors are: 1. Rate of Water Supply 2. Population Growth 3. Type of Area Served 4. Infiltration and Exfiltration. Factor # 1. Rate of Water Supply: It is evident that a considerable part of the water supplied to the public through [...]
The rate of domestic or sanitary sewage produced is generally expressed in litres per capita per day (lpcd). The rate of domestic or sanitary sewage produced may be assumed to be equal to about 70 to 80% of the rate of water supply. Thus knowing the per capita rate of domestic or sanitary sewage produced and multiplying it by the [...]
The priliminary treatment of sewage involves the use of only physical unit operations such as screening, comminution, grit removal, skimming, floatation, etc. The physical unit operations involved in preliminary treatment of seawge are accomplished by employing various units or appurtenances which include screens, comminutors, grit chambers or detritus tanks, skimming tanks, floatation units, etc. 1. Screening—Screens: Screening is the first [...]
The biochemical oxygen demand (BOD) of sewage can be determined by the following two methods: 1. Dilution Method 2. Direct Method. 1. Dilution Method: This is the most commonly used method, as it represents the conditions that can be applied to sewage to be discharged into natural water bodies (disposal by dilution). The method is based upon determination of dissolved [...]
In this article we will discuss about:- 1. Necessity of Pumping of Sewage 2. Problems in Sewage Pumping 3. Centrifugal Pumps 4. Factors to Consider for a Sewage Pumping Station 5. Components of a Sewage Pumping Station. Contents: Necessity of Pumping of Sewage Problems in Sewage Pumping Centrifugal Pumps Factors to Consider for a Sewage Pumping Station Components of a [...]