HW 4 - 53:050 Natural Environmental Systems Homework Assignment No 4 Spring 2011 Due Friday February 11 at the beginning of class(8:30 am Assume T

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
53:050 Natural Environmental Systems Homework Assignment No. 4 – Spring 2011 Due Friday February 11 at the beginning of class (8:30 am) Assume T = 25 o C, unless otherwise stated. 1. Lead is a particularly toxic heavy metal, especially to children. The EPA lists the “action level” for lead as 0.015 mg/L and the MCL as “TT”, which effectively means best treatment technology available. A common method for removing heavy metals such as lead is pH adjustment to precipitate the metal hydroxide. What pH is necessary to lower the Pb 2+ concentration in water to 0.015 mg/L? Based on this answer, do you think removal of lead by pH adjustment is a good way to remove lead from drinking water? Why or why not? The following may be useful: Pb(OH) 2 (s) Pb 2+ + 2OH - pK sp = 15.6 2. Problem 2-28 in Davis and Masten. 3. A 55-gallon drum contains some solvents dissolved in water. The drum is partially empty and contains a gas phase. One of the solvents, trichloroethene (TCE – C 2 HCl 3 ), has a
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 06/03/2011 for the course 53 50 taught by Professor Parkin during the Spring '11 term at University of Iowa.

Ask a homework question - tutors are online