The blog It's Time To Talk About Water discussed the variations in water from different sources. Today's blog is the start of a series on how to purify and prepare water for use in cleaning and rinsing applications. Water from municipal and other sources may have characteristics that are deleterious to a variety of processes. Many of us have been introduced to this concept by the proliferation of water purifying products that are available from local water "specialists" (I won't do a commercial here but you know who I mean) as well as grocery, department and specialty stores. The popularity of bottled water also attests to the fact that water isn't always what it should be. Interestingly, I can remember my Aunt Blanche collecting rain water in a barrel, not to water her plants, but to wash her hair! So even in ancient times (with apologies to my Aunt Blanche - RIP) people noticed that there were differences in water. The following is a list of some of characteristics of water that can contribute to the success or failure of a cleaning process. 1) Insoluble Particles - Although we seldom aware of it, most water from municipal supplies, wells and other sources brings with it suspended particles. These particles are finely divided minerals, metals and other materials which contribute to both the chemical and physical properties of the water. Insoluble particles collect in still water to cause sediment. In our town (and I assume other places as well), it is a bi-annual ritual to flush the water mains by opening fire hydrants. This causes a temporarily increased flow of water in the water mains which sweeps collected sediment from the pipes. Note - The next two need a little introduction. A salt is a compound formed by reacting an acid with a base. For example, the reaction of hydrochloric acid (HCL) with sodium hydroxide (NaOH) forms sodium chloride (NaCl) and water (H2O). This one is pretty simple as all the chemical element components can be accounted for before and after the reaction as written above even by a non-chemist. Although we are all familiar with sodium chloride (simple table salt) there are hundreds of other "salts" formed by the reaction of various acids with various bases. Since one product of the formation of salts is often water, it is only natural that dissolved salts are commonly found in water. Just a little bit of acid and a little bit of a base would be difficult to avoid completely - especially in nature. 2) Water Soluble Salts - These salts are readily soluble in water. When left behind by the evaporation of water containing them in a dissolved form, their residues can be easily removed by the application of more water. As a result, the residues from these salts, do not build up over time. Re-wetting them will cause them to re-dissolve. 3) Water "Insoluble" Salts - This is the stuff that leaves what are commonly called "calcium" or "lime" deposits in sinks, faucets, toilets, etc. where water repeatedly evaporates leaving them behind. It may seem a little contradictory to call these contaminants "insoluble" since they obviously got into the water somehow. In fact, they are "semi" soluble. Water, often known as the "universal solvent" will dissolve almost anything given enough time. Water collects these contaminants from the earth over a period of years or millennia. Unfortunately, if they dry on parts during the cleaning process and return to their only semi-soluble crystalline form, we don't have the luxury of waiting another millennia for them to dissolve in water again. Something to think about - How does the above apply to the formation of stalactites and stalagmites? Would they form if the dripping water only contained what we call water-soluble salts? 4) Other Dissolved Solids - Although the majority of dissolved solids are salts, there are other things that can be dissolved in water including gasses, other liquids and even a number of solids. 5) Bugs - "Bugs" is a not-so-affectionate term applied to living organisms, both animal and vegetable, or their remains which are commonly found in water. Unfortunately, water, and even some chemistry, provides the ideal environment for their proliferation. Aside from the obvious consequences of the wrong bugs entering living organisms (like humans) there are other effects which are less than contributory to the success of many processes including cleaning and rinsing. The above list, I realize, is far from all-inclusive as any number of other contaminants can be found suspended, emulsified in or dissolved in water. It does, however, comprise a working "HOT" list for contaminants of consequence found in water used in cleaning. Upcoming blogs will explain how to detect and remove, counteract or control a number of contaminants commonly found in water.
- FJF -