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Water deionization Government agencies, particularly in industrialized countries, are becoming increasingly intolerant and impatient for environmental cleanliness and absence of known or suspected toxics. Governments are imposing higher and higher environmental cleanliness costs across the board on companies and government agencies that handle water. They are increasingly restricting access to groundwater and to surface water. Without question, there is massively increasing pressure on water supplies throughout the industrialized world (North America, Western Europe, Japan, Oceania), and there is a tremendous amount of wealth that will be mandated to be spent on water whether companies wish to spend it or not. There will be government mandated "impoundments" of funds to effect such cleanup. There is no question about the impetus for "clean, cleaner, cleanest" water in industrialized countries. The developing world has been slow to adopt clean water technologies until now in the sense that companies and governments have been allowed to indiscriminately pollute local water supplies. In poorer countries, clean air and water has been an expensive luxury, but the situation is rapidly changing. International health agencies and funding agencies such as the World Bank have increasingly brought pressure to bear on developing countries to clean up their water supplies and improve their environmental situation. International agencies have often "spoken with their checkbooks," subsidizing water cleanup and purification investments in those countries (not to mention massive irrigation and hydroelectric projects). It is clear that the developing world is increasingly seeking water cleanup technology in order to protect the health of its citizens, to provide clean water for indigenous industry to use in its processes, and to catalyze economic growth and germinating prosperity. The leading cost of infant mortality in many locations in the world is childhood diarrhea, which is a water borne disease that directly results from polluted water. Virtual elimination of waterborne infection, largely eradicated in the developed world, is cited as the leading cause for economic development and well being of populations. There is no shortage today of international financial institutions such as the World Bank or Agency for International Development to hand money over to whomever can make clean water, and the impetus to continue to do so is increasing. Reticle cleans up "dirty water" everywhere and with every concentration of every substance. As the population of the United States, Europe, and assuredly the developing world increases, it is clear that organic and inorganic toxins in drinking water or irrigation water are increasing in magnitude and frequency, and it is clear that such substances harm people, livestock, wildlife, and agricultural products. In addition, they are being decreasingly tolerated by government agencies not only in the "politically correct" and health conscious developed world but also in the developing world that recognizes human capital and human health as a prerequisite to development. Realistically, modern governments, particularly the United States government, will not tolerate ions in waters if the concentration of those ions can be measured at all. It is the increasing accuracy of measurement that has catalyzed the increasing stringency of required ion removal. There is much empirical data to support this view, and even more empirical data to argue that this view will persist and intensify. It is well to emphasize that not all of the toxins that Reticle CDI might remove are randomly or benignly present independent of human activity. On the contrary, they occur because of the presence of polluting industries in countries that cannot afford to implement or enforce pollution controls. In fact, many industries rely on toxic substances as a mainstay in their operation. Cyanide, arsenic, chromium, gallium, etc. are just a few of the inorganic substances that are important chemicals in a wide range of businesses. The gold industry alone uses about 1 million tons of cyanide worldwide. One common feature of the pernicious toxins is that they are able to be environmentally neutralized by simple oxidation-reduction reactions. They are chemically quite active, and they are eliminated quickly by oxidation and reduction reactions. (After all, that is how they harm or kill people and animals—oxidation or reduction reactions!). Consider an example that is persistently in the news--cyanide. The key problem with cyanide (CN-) comes when it is mixed with even weak acids. (Think of the gas chamber scenes in old movies—a pellet is dropped into acid under the chair.) As cyanide is mixed with acid, hydrogen cyanide gas (HCN) is rapidly evolved. This gas is lethal to all animal life in relatively small quantities. Without exception, cyanide solutions are kept at pH>9 in processes to insure its safe use. The economic motivating factor for the use of cyanide arises from its ability to rapidly form complexes with precious metals and base metals in water. Many of these complexes are less likely to degrade into HCN. For instance, iron cyanide will only evolve to HCN at pH below 2 (high acidity), i.e., when it is contacted with a strong acid. The EPA and industry understand this, and have developed regulations restricting cyanide release based on compounds that readily form HCN. The worst compounds are those known as "weak acid dissociable" (WAD) cyanides, because they evolve HCN at pHs near 7 (pure water). Such complexes have to be eliminated from wastes to protect human and animal life. Happily, all WAD cyanides can be oxidized to an environmentally benign form cyanate (OCN-) under moderate oxidizing conditions, and this is the procedure of choice today to neutralize potentially dangerous cyanides. Dilute cyanide solutions produced by industry are subjected to oxidizing conditions to render them benign before discharging any process water that formerly contained them. One popular solution has been to add Caro’s Acid (a mixture of concentrated sulfuric acid and hydrogen peroxide) to cyanide-bearing mine tailings water to destroy free cyanide ions. This is not dissimilar to using an 18 pound sledge hammer to drive in a thumbtack! Obviously, this is very expensive "overkill" and entails its own set of chemical release and contamination risks, not to mention the expensive, corrosion-resistant equipment necessary to handle the acid. The precious metal mining, metal plating and the dye industries are the largest users and creators (and prospective dischargers) of cyanide solutions. We have used Reticle Carbon CDI to concentrate excess cyanide from waste streams for recycle in the gold industry. Interestingly, experiments using Reticle Carbon CDI with cyanide-bearing solutions have shown that not only is the free cyanide concentrated at the anode (as expected), but it was immediately oxidized to cyanate while attached! Not only was the cyanide concentrated, it was immediately oxidized to a benign form. The tests were conducted at very low cell potentials (approximately 1 V), yet 100% of the cyanide was oxidized at the anode, and the power consumption was only slightly higher than observed in typical CDI purification tests. This simple experiment showed the power of the Reticle Carbon CDI process to completely oxidize all CN- species to OCN- at a fraction of the cost of Caro’s Acid, chlorination, or peroxide oxidation. Arsenic, chromium, selenium, gallium, etc. are common metals in certain wastewaters. Processes to treat and remove such pernicious metals have been developed, but the fact that these ions can form several stable species in water has been a problem for all processes. For instance, arsenic when dissolved in water immediately forms arsenates (AsO3-3) and arsenites (AsO4-3), both of which are charged ions in water. Such ions, which are toxic, have obviously created problems in the remediation business because removal procedures have unfortunately been proven to be "selective." That is, they remove one but not the other species. It is usually the case that a process that works on one ion type fails to work on the second. However, Reticle Carbon CDI is nondiscriminatory and nonselective. It works on all "charged" species indiscriminately, taking them all out in parallel. Therefore, Reticle Carbon CDI is easily tailored to not only adsorb a single species, but by merely manipulating the power source, to adsorb, oxidize, or reduce all of the charged species. In summary, Reticle Carbon CDI will not only completely remove pernicious ions, but it converts some of them through oxidation and/or reduction to a form that is more easily removed from the regeneration water in clean-up processes. The range of prospective toxic materials that might be produced as industrial effluent, particularly in the developing world is both long and alarming. In the ideal circumstance, all of these types of substances must be removed before wastewater can be stored, discharged, consumed by animals or humans, or recycled. At present, the technologies for such removal are crude and expensive, and the removal additives are often so pernicious as to eliminate the possibility of recycle from consideration. Such procedures as precipitation, ion exchange, flashing, boiling, and so forth are the costly processes used to treat such toxic contaminants as barium, arsenic, chromium, selenium, mercury, lead, and the like that simply should not be discharged into the environment. Reticle Carbon CDI has the prospect of beating those best in class procedures handily. If all the pernicious ions can be removed from a prospective wastewater stream, realistically, there is no incentive for the industry seeking to eject that wastewater stream to discharge any water at all. Why would they discharge clean water? If one had the capability to cost effectively purify water, no one would ever throw it away. It would have economic value. The owners of that water would be motivated to use it again, or they would sell it at fair market values, often without regulatory intervention. Industries would be motivated to become zero discharge industries. This is a highly desirable, indeed "sustainable," state of affairs. Zero discharge industries assuredly minimize water use, which maximizes the "naturalness" of the environment. It also absolutely minimizes the possibility of environmental contamination from any source, systematic or accidental. If water does not flow out of a plant, there is zero prospect for water borne pollution to flow out of that plant. A state of zero discharge allows industries to totally control their own water quality, meaning they only have to clean it up once and thereafter use it indefinitely. Zero water discharge is a highly desirable state of affairs that is being pushed for example by the United States Environmental Protection Administration as well as many or all state EPAs. Removal of all ions and all organics by a combination of Reticle and organics mineralization technology can achieve that end. |
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