2. The average wastewater flow from a community of 20,000 is 125 gpcd. The 5 day, 20 deg CBOD is 250 mg/L. The suspended solids content is 300 mg/L. A final plant effluent of 50 mg/L ofBOD is to be achieved through the use of two sets of identical settling tanks and trickling filtersoperating in parallel. The settling tanks are to be designed to a standard of 1000 gpd/ft2. Thetrickling filters are to be 6 ft deep and operated at an organic loading of 55 lbm/1000ft³.d.There is no recirculation.(1) What settling tank surface area is required?(A) 2500 ft²(B) 3000 ft²(C) 3500 ft²(D) 4500 ft²(2) What settling tank diameter is required?(A) 40 ft(B) 50 ft(C) 65 ft(D) 80 ft(3) Estimate the BOD removal in the settling tanks?(A) 15%(B) 30%(C) 45%(D) 60%(4) What is the trickling filter diameter?(A) 65 ft(B) 75 ft(C) 85 ft(D) 95 ft

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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/ft². The trickling filters are to be 6 ft deep and operated at an organic loading of 55 lbm/1000ft³.d. There is no recirculation.

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/ft². The trickling filters are to be 6 ft deep and operated at an organic loading of 55 lbm/1000ft³.d. There is no recirculation.

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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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 domeved Ward
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
The town of Gatesville has been directed to upgrade its primary WWTP to a secondary plant that can meet an effluent standard of 30.0 mg/L BOD5 and 30.0 mg/L suspended solids (SS). They have selected a completely mixed activated sludge system. Assuming that BOD5 of the SS may be estimated as equal to 57 percent of the SS concentration, estimate the required volume of the aeration tank. The following data are available from the existing primary plant. Existing plant effluent characteristics Flow =0.150 m3/s BOD5 =82.0 mg/L Assume the following values for the growth constants: Ks= 100 mg/L BOD5; µm =2.5 d-1; kd =0.050 d-1; Y = 0.50 mg VSS/ mg BOD5 removed. Assume the concentration of MLVSS is 2000 mg/L.
5. A pilot column breakthrough test has been performed with a wastewater that has a trichloroethylene (TCE) concentration of 400 mg/L as TOC (total organic carbon). Pertinent design data are ID = 0.095 m, length = 1.04 m, mass of carbon = 2.98 kg, liquid flow rate = 17.42 L/hr, unit liquid flow rate = 0.679 L/s-m², and packed carbon density = 401 g/L. The breakthrough data are given in Table 1. Determine: a. The liquid flow rate in bed volumes per hour and the volume of liquid treated per unit mass of carbon using an allowable breakthrough concentration of 35 mg/L of TOC. b. The kinetic constants ki in L/s-kg and qo in kg/kg. Table 1. Throughput Volume (L) 15 69 159 273 379 681 965 1105 1215 1287 1408 1548 Effluent TOC (mg/L) 12 16 24 16 16 20 28 32 103 211 350 400
Question: A wastewater with a BOD5 of 326 mg/L and a Total Suspended Solids (TSS) of 392 mg/L is sent to primary treatment. The average flow rate is 0.050 m³/s. a. If the BOD5 removal efficiency is 33%, how many kilograms of BOD5 are removed in the primary settling tank each day? b. If the TSS removal efficiency is 57%, how many kilograms of TSS are removed in the primary settling tank each day?
A plastic media biotower has vertical flow packing with n = 0.5 and k20 of 0.045min-1. The tower is cylindrical with a diameter of 10 m. Depth of packing medium is 6 m.Primary effluent flow rate is 2500 m3/day with a soluble BOD5 of 250 mg/L. The average wastewater temperature is 16 oC. 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
The 550-bed Atlanta Hospital has a small, activated sludge plant to treat wastewater from the hospital. The average daily hospital discharge is 1.50 m3 per day per bed, and the average soluble BOD5 after primary settling is 450 mg/L. The aeration tank effective liguid dimensions of 10 m x 10 m x 5 m. The plant operating parameters are as follows: MLVSS - 2,600 mg/L; MLSS - 1.20 (MLVSS); Settling sludge volume after 30 min. = 200 mL/L. The aeration time is nearly?
An industrial wastewater discharged at a flowrate of 1000 m³/d having 220 mg/l initial concentration of total suspended solids (TSS). If this wastewater is to be treated individually by one of the following processes: 1. Primary settling tank which should remove 60% of TSS. 2. Coagulation unit using 40 g ferric chloride (FeCl3) as a coagulant /m²³ of wastewater. The coagulation unit will remove 85% of TSS. Estimate the mass and volume of the sludge generated from each suggested unit. Assume the following sludge specification: Source of sludge Primary settling tank Coagulation tank Specific gravity 1.03 1.05 Moisture content 94% 92%
12.50 Determine the activated-sludge aeration volume required to treat 2.64 mgd with a BOD of 120 mg/l based on the criteria of a maximum BOD loading of 40 lb/1000 ft³/day and a minimum aeration period of 5.0 hr. Assuming an operating F/M of 0.20 lb BOD/day per lb of MLSS, calculate the MLSS to be maintained in the aeration tank. Estimate the operat- ing sludge age (mean cell residence time), assuming an effluent suspended solids of 30 mg/l and the daily amount of waste-sludge solids from Figure 13.1. Determine the diame- ter and side-water depth of two identical final clarifiers of the type shown in Figure 10.12 for this activated-sludge system.
A completely mixed activated sludge process is being designed for a wastewater flow of 3 MGD using kinetic equations. The influent BOD of 180 mg/L is essentially all soluble and the design effluent soluble BOD is 10 mg/L. The mean cell residence time is selected to be 8.0 days for sizing the aeration volume tank, and the MLVSS is 2500 mg/L. The kinetic constants from a bench-scale treatability study are Y = 0.60 Ib VSS/Ib BOD and Kd = 0.06 day-1. ---Determine the efficiency of soluble BOD removal. For this, you will have to recognize substrate concentration in the coming flow (So) and the concentration of substrate in the exiting flow (Se).
Determine the size (diameter and depth) of the secondary clarifier (s) in a municipal activated sludge treatment facility: The wastewater characteristics are: Population 250,000, Average per-capita flow rate = 380 1/capita-day and Peak factor = 2.2. The suspended solids concentration is assumed to be 2500 mg/L. The over flow rate is 110 and 60 m3/d-m2 for peak flow and average flow respectively and solids loading at average flow is 110 kg/d-m2. Estimate detention time if the depth is 4.5 m. What would be the weir loading? Also answer the following questions. (hint : you should use all 3 loading criteria) a. How many kilograms of solids are loaded onto each clarifier per day? b. If the removal efficiency is 65% then how many kilograms of solids are removed from the total flow per day? C. What is the concentration of solids in the wastewater leaving the clarifier? Determine the size (diameter and depth) of the secondary clarifier (s) at a municipal activated sludge treatment facility:…
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…