Calculation : The daily sludge mass produced = ( 100,000 ) ( 0.080 ) = 8,000 kg dry SS / day. Since 97 % MC is 3 % SC or approximately 30 kg dry SS / m 3 sludge, the daily volume produced is 8,000 / 30 = 267 m 3 .
What is sludge rate?
The sludge loading rate relates the daily wastewater load (kg BOD / d) and the available sludge mass. The sludge loading rate is, in addition to the sludge retention time, the main design variable of an activated sludge plant.
How do you calculate sludge?
Sludge volume index ( SVI ) is calculated by dividing the settleability by the MLSS concentration. The SVI is always expressed in mL/g.
How is sludge produced?
Primary sludge is generated from chemical precipitation, sedimentation, and other primary processes, whereas secondary sludge is the activated waste biomass resulting from biological treatments. Some sewage plants also receive septage or septic tank solids from household on-site wastewater treatment systems.
What is sludge processing? An introduction to sludge treatment
What do you mean by sludge?
Definition of sludge
1 : mud, mire especially : a muddy deposit (as on a riverbed) : ooze. 2 : a muddy or slushy mass, deposit, or sediment: such as. a : precipitated solid matter produced by water and sewage treatment processes.
What is the amount of sludge in wastewater in percentage?
The volume of sludge produced in a WWTP is only about 1% (dewatered sludge is 0.5‰) of the volume of influent wastewater to be treated.
What is FM ratio wastewater?
What is an F-M ratio? Simply put, the F-M ratio is a measure of the amount of food, or BOD, that is given to the microorganisms in the aeration tank. The microorganisms are the mixed liquor volatile suspended solids, or MLVSS.
How much sludge does a person produce per day?
Estimates of average sludge accumulation rates have ranged from 0.19 L/person/day (Weibel et al., 1949), 0.13 L/person/day (Bounds, 1995), 0.18–0.29 L/person/day (Brandes, 1978), 0.225 L/person/day declining to 0.164 L/person/day after 3.5 years (Philip et al., 2010), 0.254 L/person/day falling to 0.163 L/person/day in ...
How is sludge concentration measured?
How to calculate the SVI?
Take a sample from the aeration tank. ...
Let the sample settle for 30 minutes before analysis begins.
Analyze the sample and find out the concentration of suspended solids. ...
Divide the wet volume of the settled sludge (represented in mL/L) by the MLSS value from the last step.
What is a good SVI number?
SVI = 100 to 200 mL/g. Most activated sludge plants seem to produce a clear, good-quality effluent with an SVI in this range.
How do you calculate sludge age?
The sludge age of an activated sludge process can be calculated by dividing the pounds of suspended solids or MLSS in the aeration tanks by the pounds of suspended solids that enter the aeration tanks (Equation I.
What is sludge density index?
A calculation used to indicate the settleability of sludge in a secondary clarifier or effluent that is related to the calculation for sludge volume index (SVI). The weight in grams of 100 milliliters of sludge after settling for 30 minutes. SDI = 100/SVI.
What is SVI in wastewater treatment?
Sludge Volume Index (SVI) is used to describe the settling characteristics of sludge in the aeration tank in Activated Sludge Process. It is a process control parameter to determine the recycle rate of sludge.
How is SVI calculated?
calculate SVI by dividing the measured (or observed) wet volume (mL/L) of the settled sludge by the dry weight concentration of MLSS in grams/L.
What is the viscosity of sewage?
R e s 0.27 R e w 0.25 = 1.0139 . in which μ w is viscosity of water, Pa · s. The results of (19) are detailed in Table 2. Therefore, the equivalent viscosity of the raw sewage is two to three times the viscosity of water at the same temperature.
How do you calculate waste activated sludge flow rate?
The equations used are as follows:
Qr = (X - Xo)/(Xw - X)
Qw = (8.34*V*X)/(8.34*SRT*Xw)
VMG = V*7.48/1,000,000.
F:M = (8.34*So*Qo)/(8.34*%Vol*X*VMG)
How do you calculate wastewater?
Multiply your Minimum Population (P) by 150 to get your daily estimated wastewater production. For example, a three bed house with a Minimum Population (P) of 5 people would have a daily estimated wastewater production of 750 litres per day (5 x 150).
How is generation of sewage calculated?
SIZE OF SEWAGE TREATMENT PLANT / CAPACITY OF SEWAGE TREATMENT PLANT (STP)
Total domestic (raw) water demand = TWD.
Estimated Sewage X = 90 % of TWD.
Estimate Sewerage X = 90/100 * TWD For Eg If TWD = 1500 KLD.
Summary. There are two significant retention times in an anaerobic digester. These are solids retention time (SRT) and hydraulic retention time (HRT). The SRT is the average time that bacteria (solids) are in the anaerobic digester. The HRT is the time that the wastewater or sludge is in the anaerobic digester.
What is a good f m?
The optimal range for the F:M ratio in a complete mix system is 0.2 to 0.6 lb BOD/lb MLVSS (kg BOD/kg MLVSS).
What is a good sludge age?
Optimum MLSS concentrations should be determined experimentally for each plant. - A sludge volume index of about 100 and a sludge age of three to fifteen days are normal for most plants.
How do you calculate water content of sludge?
■ Calculation example
Material weight after drying（kg/h）＝ (1－0.8) × 330 kg/h ÷ (1－0.4) ＝110 kg/h.
Material weight before drying（kg/h）＝ (1－0.4) × 110 kg/h ÷ (1－0.8) ＝ 330 kg/h.
Amount of evaporated water （kg/h） ＝ 330 kg/h － 110 kg/h ＝ 220 kg/h.
How do you reduce sludge production?
The new wastewater treatment processes including SANI®, high-rate activated sludge coupled autotrophic nitrogen removal and anaerobic membrane bioreactor coupled autotrophic nitrogen removal also have a great potential to reduce sludge production.
What is an example of sludge?
Sludge is a substance that is between solid and liquid form. An example of sludge is a mass of mud formed in a river bed after a flood. An example of sludge is the treated material from a sewage plant.