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?

Problem 1. A wastewater sample is examined for its solid contents. The ionic strength (μ) of wastewater is 0.01. It is known that 30% of total dissolved solids (TDS) is organic. The volumetric settleable solid concentration is determined as 20 mL/L using Imhoff Cone. It is assumed that 40% of total suspended solids (TSS) is equal to dry-settleable solids. The volumetric settleable solids composes of 2% of dried solids and 98% of water. The density of volumetric settleable solid concentration is given as 1020 g/L. Use information given in problem, calculate: a) Total Dissolved Solids (TDS) concentration as mg/L. b) Total Suspended Solids (TSS) concentration as mg/L. c) Total Solids (TS) concentration as mg/L.

An aeration tank has an MLSS concentration of 2000 mg/L. After settling for 30 min. in a 1-L graduated cylinder, the sludge volume is measured to be 150 mL. Compute the SVI of the sludge.

3. Circular clarifiers are used to remove solid materials from water. They allow continuous treatment of water and can handle fairly large flows. Solids settle to the bottom of the clarifier and are carried away by a small stream of water (the waste stream). Most of the water exits the tank as treated effluent. Assume a clarifier receives a flow of 0.10 m3/s with a solid concentration of 800 mg/L. If the waste stream consists of 3% of the incoming flow and carries 90% of the incoming solids,   a) what is the solids concentration in the waste stream, and b) what is the solids concentration in the treated effluent?

1. A 770,000 gal conventional activated sludge pro- cess has a recycle ratio of 0.25, an influent flow rate of 1 MGD, a mixed liquor volatile suspended solids (MLVSS) concentration of 700 mg/L, and an influent BOD; of 160 mg/L. What is most nearly the F:M ratio of the process? (A) 0.1 lbm/day-lbm (B) 0.2 lbm/day-lbm (C) 0.3 lbm/day-lbm (D) 0.4 lbm/day-lbm В. D.

Answer question 13

wet sludge contains 3% solid by weight is pumped to a filter belt press at the rate of 170,000lb/day. the dewatered sludge is 18% by dry weight and the filtrate has total nitrogen concentration of 100 mg/l as nitrogen. assume the belt press has 100% solid capture and specific gravity of the sludge in all forms is 1. Calculate the amount of nitrogen (lb/day) in the filtrate returned?   Please explain with details   a) 4 b) 9 c) 14 d)19   The answer is one of these options

A completely mixed activated sludge process operating at equilibrium is designed to treat 300 MLD of waste water. The influent and effluent BOD are 200 mg/1 and 18 mg/1 respectively If the F M then the hydraulic retention time is A 0.125 day B 4.21 hours C 8.42 hours D 0.225 day = 0.3 and MLSS is 3800 mg/1,

A wastewater stream A with 200 m3 /h of flow rate and BOD of 300mg/I mixes with stream B having flow rate of 400m3/h and BOD 225mg/l. A completely mixed activated sludge process is used to treat the mixture. BOD of effluent stream is 10 mg/l. Given Y= 0.5, k=5 day", Kd=0.06 day ; Ks=100 mg/l and MLVSS= 2000 mg/l. Assume all other parameters if necessary Find (a) BOD and flow rate of mixture (b) Mean residence time (c) Oxygen requirement (d) F/M ratio (e) Recycle ratio (f) Sizing of the tank

A Granulated Activated Carbon (GAC) adsorption laboratory column 10cm in diameter and 3m deep, is found to produce good results in COD removal when operated at a flow of 50L/h. The porosity of the GAC is 0.5 Calculate the following:   You need to design a GAC system consisting of two columns in series for treating the same water at a rate of 0.5 ML/d. Practical considerations limit the diameter of the columns to 3m. Calculate the minimum required height of the columns. Area=7.854×10−3m3 Volume= 6.3660m/hr t=0.47123 Q=2.122 bed volume /hr