SOLUTIONS MANUAL FOR
Water Treatment Unit
Processes
Physical and Chemical
by
David Hendricks
Complete Chapter Solutions Manual
are included (Ch 1 to 21)
** Immediate Download
** Swift Response
** All Chapters included
, Water Treatment Unit Processes
Physical and Chemical
Solutions Manual
David Hendricks, PE, BCEE
Professor of Civil and Environmental Engineering (Emeritus)
Colorado State University
Guidelines to the Solutions Manual
The solutions manual has a table of contents that lists problems in each chapter followed by a
table of spreadsheets for each chapter, followed then by solutions provided for each of the
chapter problems. The first few pages given here are intended to provide guidance on utilization
of the manual and the associated spreadsheets.
Format of Solutions Manual The WTUP Solutions Manual consists of both text and
spreadsheets. The Manual is contained in an MS Word® file (or perhaps a .pdf file) and is about
330 pages. The spreadsheets are in MS Excel files. The text associated spreadsheet files were
given a yellow tint and those associated with problem solutions were given an orange tint. Both
may be downloaded from the CRC web site as explained in the following paragraph.
Web Site Address The Solutions Manual and associated spreadsheets are found on the CRC
website, www.crcpress.com. To access these documents, under the menu, “Electronic
Products”, located on the left side of the screen, click on “Downloads and Updates”. A list of
books with web downloads will appear, in alphabetical order; go to Water Treatment Unit
Processes and click. Or instead, locate the files using the search window (use either the book
title or it’s catalog number, “DK2270”). After clicking on the book title, a brief summary of the
book will appear. Go to the bottom of the screen and click on the hyperlinked, “Download”.
Alternatively, you can go to the web site directly, which is,
www.crcpress.com/e_products/downloads/download.asp?cat_no= DK2270
Access to Solutions Manual Access to the Manual, i.e., text and spreadsheets, is not restricted,
i.e., anyone can download the files. This may be contrary to the preferences of some professors;
there seemed to be no good way to restrict access. On the other hand, graduate students, as a
rule, seek understanding and thus, hopefully, the solutions will be used only after some amount
of effort in trying to approach and solve the problem-at-hand. The students may not agree with
my solutions anyway. Even if the solutions are turned-to immediately, they are of such nature
that they must be studied, which should lead to the goal of understanding the issues and an
original response.
Solutions Manual - i
,Alternatively, the professor may wish to use vary the quantities assumed for the problem, which
provides a basis for a different response quantitatively, albeit using the same algorithm. Also,
many problems posed are of a character that may provide fodder for discussion and comment.
The professor should feel free to contrive other problems using those given as a foundation or
inspiration.
The main point of the foregoing discussion is that unrestricted access to the problem solutions
may not be a problem due to the nature of the problems. As a note, the author has always
evaluated solutions based on the clarity of the solution. the reasonableness of assumptions, the
logic, the citations, the alternatives explored, and whether the discussion addresses the pertinent
issues. Thus, the idea of a single answer is moot. When teaching an undergraduate course, e.g.,
fluid mechanics, most responses to problems given in texts have been single answers. The
author has always provided answers from the respective solutions manual with little loss in
learning for serious students. Problems were always checked with respect to clarity and
procedure (not wit respect to answers).
Nature of Problems Most of the problems given here are of the “open-ended” category. Very
few are single answers. The “solutions” given are, as a rule, not unique. They depend upon the
assumptions and the approach used. Further, in the “real-world” of engineering design other
factors must be considered, e.g., financial feasibility, cost, political feasibility, available land,
labor costs, reliability of performance, etc. For the problems given here, however, the problem
solutions focus on applying unit process principles, i.e., only one aspect of an engineering
project.
References to Text Most of the solutions are referenced to equations, figures, tables, sections
from the text. Such referencing was done so that its clear how unit process principles and the
associated text sections apply to the problems. Thus, the problems are best understood if the text
is at hand. In some cases, e.g., if the problem required frequent reference to the text, paragraphs,
equations, and figures were copied from the text to the problem solution in order to reduce back-
and-forth motion and to make the solution more coherent. In many such cases, the respective
solution will stand alone, i.e., without reference to the text.
Spreadsheet Designations - Nomenclature Spreadsheets were used routinely in the solutions
and as was useful for the respective problem solutions. They were copied from those used in the
text and modified as necessary for the respective problem solutions.
The spreadsheets for the problems may be identified by an admittedly cumbersome designation,
e.g., CDprob7.4/7.7GritPars.05/30/05.xls. The coding is:
CD – compact disk;
prob7.4 – problem number 7.4 from Chapter 7;
7.7 – Table CD7.7 in the text of Chapter 7 from which the problem spreadsheet was derived;
GritPars – grit chamber using Parshall flume as control;
05/30/05 – date the spreadsheet was generated or last modified; .
xls – Excel™ spreadsheet.
Solutions Manual - ii
, Figures that were generated within a given spreadsheet and extracted for use in the text or in this
Solutions Manual are also designated with the “CD” prefix, e.g., Figure CDprob7.7.
Utility of Spreadsheets Developed for Solutions Manual As a “technology” the spreadsheet, as
used in this text, has much the same role as the slide-rule that was prevalent in my generation of
students, i.e., its always with you and its difficult to function effectively without it. Professors
and students may have alternative ways of using the spreadsheet. They may be modified as may
be useful, in assumptions, algorithm, linked plots, etc.
The spreadsheets may have various kinds of utility, depending upon the objectives of the
instructor. Examples include: (1) exploring “scenarios”, i.e., a set of conditions that may be
imposed on a design; (2) in sensitivity analysis, i.e., to examine the effect of changes in a
selected independent variable on a design outcome; (3) to facilitate iterations of a design using
different values of an independent variable in order to find a design that is both reasonable and
near the proverbial “optimum”, and (4) as a means for computation that would otherwise be
more laborious. Other uses may be evident to professors and students.
A dilemma in teaching with already developed spreadsheets is that the student may be less likely
to obtain a “feel” for the physical aspects of the problem. To counter this, the professor may
wish to ask the students to modify or improve the spreadsheet to fit another problem, or to
develop a different spreadsheet. A positive “tradeoff” in using the spreadsheet is that the student
and professor may focus on design. The spreadsheet, in most cases, is a “model” and as such has
the inherent limitations, e.g., whether the model is “valid”, the appropriateness of the input data,
etc. These are well-known caveats dating back to the days when Fortran programming was
prevalent.
Design of Spreadsheets The spreadsheets are intended to be self-explanatory (if one is familiar
with the theoretical basis for its construction). The columns are given headings that are
descriptive, with supplemental descriptions and/or equations given at the bottom of respective
columns. Units for each variable are given in the line below. [More often than not, a variable is
understood unequivocally if its units are stated.] I have used SI units because they are used
world-wide and are becoming common in the USA, they are simple, mistakes are minimized by
their use, and the dimensions (e.g., mass, length, time, force, etc.) of variables are clear if defined
in SI units (e.g., kg, m, s, N, etc.). In cases where one’s experience is with a particular unit, e.g.,
“mgd” for flow, this unit is given, but then is converted to SI units, e.g., “m3/s” for the
computations.
Significant Figures Concerning significant figures, the idea that the number of places is
indicative of the accuracy of a result is a sacrosanct part of engineering tradition and practice and
is respected and has been never forgotten by the author since instilled as a part of undergraduate
engineering education. I mention this because some who have valid concern over this issue may
question my apparent lack of awareness of this idea. On the other hand, the use of several
significant figures permits one to follow more easily the sequence of calculations in a
spreadsheet and so the tradition is violated when its felt to be warranted for the sake of clarity.
There should be a “rounding-off”, however, in the final result that recognizes the accuracy of the
Solutions Manual - iii
