19. Two circular primary clarifiers are to be installed in a sewage treatment plant processing the wastewater for a town of 10 000 PE. Each clarifier has side water depth of 3.3 m. Design criteria for surface overflow rate has been set by local authority at a maximum of 40 m/d for average condition. The clarifier is designed to remove 35 percent BOD, and 65 percent SS. The wastewater contains 200 mg/1. BOD, and 240 mg/L SS. Based on the information given, determine : The dimension of the clarifier (i) (ii) HRT (iii) Weir loading rate (iv) BOD, and SS concentrations in the effluent of the clarifiers

19. Two circular primary clarifiers are to be installed in a sewage treatment plant processing the wastewater for a town of 10 000 PE. Each clarifier has side water depth of 3.3 m. Design criteria for surface overflow rate has been set by local authority at a maximum of 40 m/d for average condition. The clarifier is designed to remove 35 percent BOD, and 65 percent SS. The wastewater contains 200 mg/1. BOD, and 240 mg/L SS. Based on the information given, determine : The dimension of the clarifier (i) (ii) HRT (iii) Weir loading rate (iv) BOD, and SS concentrations in the effluent of the clarifiers

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

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Two circular clarifiers operated in parallel service a single stage bio-tower system (plastic media) that receives municipal wastewater at an average flow (Qaverage) of 2000 m³/d, with BOD5 = 200 mg/L. The internal flow recirculation ratio is 2.4. The maximum overflow rate for the clarifiers is 1.8 m³/m²-hr. The design procedures require that the sizing of the clarifiers be based on "PEAK" flow which is twice the average flow (Qpeak = 2 × Qaverage), and media depth in the biotower is 3.0 m. Determine: (a) The overall BOD5 removal. (b) the surface area and the diameter of each clarifier. (k = 0.06 min¹; n = 0.5),
Please only answer (iv)
Question- A circular primary clarifier processes an average flow of 3000 m³/d of municipal wastewater. The overflow rate is 25 m³/d. Find the diameter of clarifier.
Assume that taal lake is 100m2 and its average height is 5ft. Wastewater thatflows into the lake are the following: a. Food square kitchen waste 5m3/hr; Total Dissolved Solids (TDS) is 50g/L whichoperates 8hrs per dayb. CIH 5m3/hr kitchen waste; TDS is 20mg/L which operates 4hrs per dayc. PCH 20m3/day diluted laboratory waste ; TDS = 40mg/L (1)Determine the volume of wastewater which taal lake can still be contained withoutrainfall.(2)During operational hours a heavy rain fall, the rain gauge reading is 1.5m. Will the taalLake overflow? What is the volume of water that will over flow?(3). Compute the TDS concentration of the overflow.
Seatwork No. 4 A residential area of a city has a population density of 15000 per km2 and an area of 1800000 m2. If the average sewage flow is 225 L/cap-day. Use the maximum sewage flow in the design which has 50% increase from the average flow. The Infiltration rate is 0.055 cu.m. per second and the consider leakage of 0.025 cu.m. per second. Estimate the maximum rate of flow in m3/s. Seatwork No. 5 The present population is 28,000 and the average water consumption is 16,000,000 L/day. If the Maximum sewage flow is 225 L/cap-day and the Infiltration rate is 0.055 cu.m. per second and the leakage of 0.025 cu.m. per second. Use the population data for year 2000 is 10000. Estimate the maximum rate of flow in m3/s after 5 years.
a) A wastewater treatment plant consists of primary treatment followed by an activated-sludge secondary system. The plant processes 7000 m3/d of wastewater with 180 mg/L of BOD5 and 150 mg/L of suspended solids. The primary sludge contains 500 kg of dry solids per day with 4.5% solids content. The plant produces 760 kg of total sludge (primary and secondary) per day. Assume 30% removal efficiency of the primary clarifier and F/M ratio of 0.2 for the aeration tank. b) The thickened sludge from problem a) is to be digested in a standard-rate mesophilic anaerobic digester (MAD). The sludge has 68% organic content, and approximately 60% of the organic fraction is digested after a 30-d period. The digested sludge has a solids content of 6% and is stored for a period of 90 d. Calculate the volume of the standard-rate digester
a) A wastewater treatment plant consists of primary treatment followed by an activated-sludge secondary system. The plant processes 7000 m3/d of wastewater with 180 mg/L of BOD5 and 150 mg/L of suspended solids. The primary sludge contains 500 kg of dry solids per day with 4.5% solids content. The plant produces 760 kg of total sludge (primary and secondary) per day. Assume 30% removal efficiency of the primary clarifier and F/M ratio of 0.2 for the aeration tank. Determine the following: a. Primary sludge volume and removal efficiency of primary clarifier b. Influent and effluent BOD5 of the secondary activated-sludge system c. Volume of secondary sludge with 1% solids content. b) In problem a), the primary and secondary sludges are mixed in a gravity thickener and sent for further treatment. The thickened sludge contains 4% solids. Calculate the percent volume reduction in the gravity thickener. c) The thickened sludge from problem b) is to be digested in a standard-rate mesophilic…
An average wastewater flow of 20 000 m³ / day is to be treated by a clarifier with surface overflow rate (SOR) of 25 m/ m?.day and hydraulic retention time of 3 hours. Determine: Diameter of the clarifier (use two clarifiers) Depth of the clarifier.
Design a circular settling tank unit for a primary treatment of sewage at 20 million litre per day. Assume suitable value of detention (presuming that trickling filter are to follow the sedimentation tank), and surface loading.
A plastic media biotower has vertical flow packing with n = 0.5 andk20 of 0.045 min–1. The tower is cylindrical with a diameter of 10 m.Depth of packing medium is 6 m. Primary effluent flow rate is 2500m3/d with a soluble BOD5 of 250 mg/L. The average wastewatertemperature is 16°C. Direct recirculation is practiced at 1:1 ratio.Calculate the following:a. Organic loading rate of the biotowerb. Hydraulic loading rate of the biotowerc. Recirculation ratiod. Effluent soluble BOD5 concentration
2. The average wastewater flow from a community of 20,000 is 125 gpcd. The 5 day, 20 deg C BOD is 250 mg/L. The suspended solids content is 300 mg/L. A final plant effluent of 50 mg/L of BOD is to be achieved through the use of two sets of identical settling tanks and trickling filters operating in parallel. The settling tanks are to be designed to a standard of 1000 gpd/^2. The lbm/1000*3 Ibm/1000.^3.d. trickling filters are to be 6^ deep and operated at an organic loading of 55 There is no recirculalon. (1) What settling tank surface area is required? In ft^2 (A) 2500 ft^2 (B) 3000 ft^2 (C) 3500 ft^2 (D) 4500 ft^2 (2) What settling tank diameter is required? In ft (A) 40 ft (B) 50 ft (C) 65 ft (D) 80 ft (3) Estimate the BOD removal in the settling tanks? In percent % (A) 15% (B) 30% (C) 45% (D) 60% (4) What is the trickling filter diameter? In ft (A) 65 ft (B) 75 ft (C) 85 ft (D) 95 ft
2. The average wastewater flow from a community of 20,000 is 125 gpcd. The 5 day, 20 deg C BOD is 250 mg/L. The suspended solids content is 300 mg/L. A final plant effluent of 50 mg/L of BOD is to be achieved through the use of two sets of identical settling tanks and trickling filters operating in parallel. The settling tanks are to be designed to a standard of 1000 gpd/^2. The trickling filters are to be 6^ deep and operated at an organic loading of 55 lbm/1000^3 d. There is no recirculalon. (1) What settling tank surface area is required? In ft^2 (2) What settling tank diameter is required? In ft (3) Estimate the BOD removal in the settling tanks? In percent % (4) What is the trickling filter diameter? In ft File Explorer O Expert Q&A | Cheq... (66) These