Rod McEachern & William Wist 
Water Softening with Potassium Chloride [PDF ebook] 
Process, Health, and Environmental Benefits

PREFACE.
ACKNOWLEDGMENTS.
1 WHAT IS POTASSIUM CHLORIDE?
Saskatchewan Potash History.
Potash Mining.
Solution Mining.
Processing Potash Ore.
Storage, Transportation, and Distribution of Potash.
Potash Products.
2 WHAT IS HARD WATER?
Definition of Hard Water.
How Hard Water is Created.
Problems Associated With Hard Water.
How Hard Water is Measured.
Uniform Degrees of Hardness.
Types of Hardness.
3 LOWERING WATER HARDNESS.
Ion Exchange.
Deionization or Demineralization.
Reverse Osmosis.
Distillation.
Precipitation.
4 THE ION EXCHANGE PROCESS.
Synthesis and Structure of Ion Exchange Resins.
Types of Ion Exchange Resins.
Household Water Softening.
Typical Household Water Softening.
Cocurrent and Countercurrent Regeneration.
Mathematical Treatment of Ion Exchange Equilibria.
Selectivity of Ion Exchange Reactions.
References.
5 BASIC CHEMISTRY OF ION EXCHANGE.
The Building Blocks of Matter.
Atomic and Molecular Weights.
Cations and Anions.
Chemical Reactions.
6 OPERATION AND TYPES OF WATER SOFTENERS.
Historical Methods of Regeneration.
Operation of a Typical Water Softener.
Common Sequences of Cycles.
Types of Water Softeners.
Sizing a Water Softener.
7 POTASSIUM CHLORIDE REGENERANT FOR WATER SOFTENING.
Alternate Regenerants.
Potassium Chloride Regenerant.
Initial Comparison of KCl and Na Cl.
Challenges When Using KCl as a Regenerant.
Frequently Asked Questions.
8 COMPARISON OF KC1 AND Na Cl AS REGENERANT.
Definition of Terms.
Theoretical Capacities of KCl and Na Cl Regenerants.
Calculation of Regeneration Efficiency.
Sizing a Softener for Salt Efficiency.
Implications for Salt Consumption.
Total Salt Released to the Environment.
Comparison of KCl and Na Cl: Solubility.
Comparison of KCl and Na Cl: Speed of Dissolution.
Comparison of KCl and Na Cl: Capacity.
Comparison of KCl and Na Cl: Used and Unused Regenerant.
Comparison of KCl and Na Cl: Release of Chlorides to the Environment.
Comparison of KCl and Na Cl: Taste.
Comparison of KCl and Na Cl: Generation of Fines.
Comparison of KCl and Na Cl: Sodium Content of Softened Water.
Comparison of KCl and Na Cl: Potassium Content of Softened Water.
Comparison of KCl and Na Cl: Total Dissolved Solids.
9 ENVIRONMENTAL CONSIDERATIONS.
Potassium versus Sodium: Impact on Soil.
Potassium versus Sodium: Impact on Septic Systems.
Potassium versus Sodium: Impact on Sewage Treatment Systems.
Potassium versus Sodium: Sewage Sludge.
Potassium versus Sodium: Algae Growth.
Potassium versus Sodium: Impact on Plants and Animals.
Potassium versus Sodium: Use of Recycled Graywater.
Recycling Regenerant Wastewater.
Use of Regenerant Wastewater Studies at University of California, Davis.
In Conclusion.
10 POTASSIUM AND HUMAN HEALTH.
Overview.
Introduction.
Cellular Physiology of Potassium.
Potassium Balance.
Defects in Potassium Elimination.
Medical Conditions Related to Potassium Excess.
Medical Conditions Related to Potassium Deficit.
Indirect Role of Potassium in Health.
Summary.
11 ONGOING RESEARCH.
Iron and Manganese Removal.
Grade of KCl Regenerant.
Cocurrent versus Countercurrent Regeneration.
Portable Exchange Tanks.
Research into Alternate Regenerants.
APPENDIX 1 STANDARD TEST PROTOCOL FOR COMPARISON OF KCl AND Na Cl REGENERANTS.
Protocol Development.
Standard Test Protocol.
APPENDIX 2 LABORATORY DATA OBTAINED WITH THE STANDARD TEST PROTOCOL.
APPENDIX 3 ACCELERATED MUSH TEST.
Apparatus.
Method.
INDEX

WILLIAM WIST (deceased) spent eleven years at Central Canada
Potash as a lab technician, senior chemist, and chief chemist.
After joining Potash Corporation of Saskatchewan Inc. in 1980 as
chief chemist, he set up and equipped a new research and
development laboratory for them. From 1988 until his retirement in
2005, he was chief chemist and pilot plant supervisor. Bill
spearheaded the research and development of the use of potassium
chloride as a water softening regenerant, in addition to other
projects involving potash product quality and analytical
procedures.
JAY H. LEHR holds a Ph D in environmental science from the
University of Arizona and an engineering degree from Princeton
University. He is the author of twenty-eight books and over 600
journal and magazine articles. He has taught at the University of
Arizona and The Ohio State University, directed a professional
society of environmental scientists, and formed a variety of
environmental teaching and consulting firms.
ROD Mc EACHERN holds a Ph D in chemistry from the
University of Saskatchewan. He currently works as the Director of
R&D with the Potash Corporation of Saskatchewan Inc. in
Saskatoon, Canada. His research interests include the application
of new technology to environmental stewardship through improved air
pollution abatement equipment, improved waste management practices,
and process improvements to potash operations.