Raw sewage of 12 MLD having 300 mg/l of suspended solids enters into a sedimentation tank which has an efficiency of 70%. The raw sludge in the sedimentation tank has moisture content of 95% and specific gravity of solid is 1.2. The total volume of sludge produced daily is m³

The influent suspended solids concentration to a primary settling (clarifier) tank is 300 mg/L. The average flow rate is 0.037 m3/s. If the suspended solids removal efficiency is 65 percent, how many kilograms of suspended solids are removed in the primary settling tank each day?

A waste sludge flow of 40 m³/day is gravity thickened in a circular tank with a diameter of 6.8 m. The solids concentration is increased from 4.5% to 7.5% with 85% suspended- solids capture. Calculate the solids loading in kg/m² d and the quantity of thickened sludge in m³/d.

The 750-bed Associated Center of Medical Excellence (ACME) Hospital has a small activated sludge plant to treat its wastewater. The average daily Medical Center discharge is 1,250 L per day per bed, and the average soluble BOD5 after primary settling is 450 mg/L. The aeration tank has effective liquid dimensions of 10.0 m wide by 25.0 m long by 3.5 m deep. The plant operating parameters are as follows: MLVSS = 2,750 mg/L MLSS = 1.25 (MLVSS) Settled sludge volume after 30 min = 250 mL/LDetermine the following: aeration period, F/M ratio, SVI, solids concentration in return sludge.

Coagulation aided sedimentation produces 135m³ of sludge per day. The solid content of sludge is 1% by weight and specific gravity of sludge solid is 2.7. If 20 my of suspended solids are removed from the raw water by the Al(OH)3 precipitate formed, and flow through the treatment plant is 40 MLD, then the amount of alum required per day in kg is

Only find the BOD of the mixture.

A complete-mixed activated sludge process (CMAS) is to be designed to treat 6.0 MGD of primary effluent having a BOD5 of 190 mg/L. The requirement is that the effluent BOD5 and TSS concentrations be 20 mg/L or less on an annual average basis. The following biokinetic coefficient obtained at 15°C: Y = 0.6 mg VSS/mg BOD5, k = 2.85 d-1, Ks = 70 mg/L BOD5, and kd = 0.041 d-1. Assume that the MLVSS concentration in the aeration basin is maintained at 2,500 mg/L. Determine: a. The minimum MCRT (d) b. The MCRT necessary to meet the requirement (d) c. The volume of the aeration basin (ft3)

A rectangular settling basin has a depth of 3 m, a length of 40 m and a width of 6 m. The water treated in the basin has a flow rate of 500 L/s and contains 50 mg/L of type a particles, 100 mg/L of type b particles and 180 mg/L of type c particles (particle type letters refer to the particles listed in problem 1). What is the suspended solids concentration in the effluent from the settling basin? Determine the overall percent removal of suspended solids from the water achieved by the settling basin.