Assignment 1 sol

# Assignment 1 sol - CIVL 242 Homework Assignment 1 1...

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CIVL 242 Homework Assignment 1 1. Calculate the hardness of a water sample containing 20 mg/L K + , 30 mg/L Ca 2+ , 50 mg/L Mg 2+ , 100 mg/L Cl - , and 40 mg/L SO 4 2- . Key point: Hardness: A total concentration of all divalent metallic ions (M 2+ ), such as Ca 2+ , Mg 2+ , Fe 2+ , Cu 2+ , and etc., expressed in mg/L as CaCO 3 . Solution : Ions concerned are Ca 2+ and Mg 2+ Hardness 50 2 2 × Σ = + + M q M H mg/L as CaCO 3 3 / 918 . 279 50 2 . 12 50 20 30 CaCO as L mg H = × + = 2. Calculate the TN of a solution containing 30 mg/L glycine (C 2 H 5 O 2 N), 100 mg/L NaNO 3 and 50 mg/L NH 4 Cl. Key point: Total nitrogen (TN): A total concentration of ammonia nitrogen, organic nitrogen, nitrate nitrogen and nitrite nitrogen, expressed in mg/L as N. Solution: Compounds concerned are C 2 H 5 O 2 N, NaNO 3 and NH 4 Cl N as L mg TN / 15 . 35 5 . 35 4 1 14 14 50 3 16 14 23 14 100 14 2 16 5 1 2 12 14 30 = + × + × + × + + × + + × + × + × × =

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3. Residential water demand:
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## This note was uploaded on 09/13/2011 for the course CIVL 242 taught by Professor Gh during the Fall '09 term at HKUST.

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Assignment 1 sol - CIVL 242 Homework Assignment 1 1...

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