Background information
The need for clean water for use by humanity has since time immemorial been an area of concern with scientists and scholars inventing methods that prove to be more efficient than their predecessors. The ultimate goal has always been the removal of undesirable chemicals and pathogens that would, however, render the water unfit for human and industrial consumption. In today’s contemporary society, human activity has culminated into pollution of the natural environment including water catchment areas. This has therefore made water unfit for consumption thereby prompting for more cost-effective and efficient methods for purification of this natural resource. As a result, most water is disinfected for consumption purposes. Water purification has not only been applied when it comes to human consumption but also for an array of other reasons including medical pharmacology among other chemical industrial applications. Such methods entail basic purification procedures common to mankind like filtration, decantation or sedimentation as well as distillation (Sinclair, 2016).
History of purification
The initial experiments on water filtration began in the 17th century and were pioneered by Sir Francis Bacon in an attempt to reduce salt content in sea water, a process known as desalination. This involved the passing of sea water through a sand filter. The process, however, was not successful but it, at least, elicited mixed reactions among scholars leading to microscopy which was pioneered by Robert Hooke. Sand filters, however, proved useful in water filtration. By the end of 1804, most of the people had these sand filters installed in their homes (Sinclair, 2016). This was followed by chlorination of water, which involved the use of chlorine to disinfect water. Such methods included the use of chlorinated lime in sewage plants
Impact made globally
Water purification has helped humanity curb waterborne diseases by significantly reducing the amount of concentration of unwanted matter in the water. Such unwanted matter may occur in the form of suspended particles, bacteria, and viruses which arise in the form of fungi and parasites besides reduction of an array of dissolved particulate material derived from surface runoff water. These standards of safe purified drinking water are professionally monitored by governments to ensure that they conform to international standards that include a minimum or maximum concentration of contaminating agents, depending on the intended purpose for water use. It is important to note that visual inspection is not enough to confirm the purity of water as most contaminants are usually microscopic organisms.
Most of the countries have not able to meet these standards for their citizenry mainly because of the insufficiency of water as a natural resource. Secondly, many of these countries which mainly comprise of third world countries have not had sufficient resources to finance mass water purification plants. In light of this, a report produced about a decade ago by the world health organization has indicated that over one billion people globally do not have access to improved drinking water supply. As a result of this, about 90% of the total reported diarrhea cases can be attributed to contaminated drinking water besides other forms of inadequate sanitation and hygiene (Semenza, 2015). This results in 1.8 million fatality cases from diarrhea. The WHO (world health organization estimates that a staggering 94% of such diarrhea cases are preventable using basic domestic water purification techniques such as boiling water. However, poverty levels do not allow this to take place due to increased costs of fuels required to facilitate the boiling as many people in these third world countries are living below a dollar a day. This makes the reduction of mortality rates resulting from waterborne diseases especially in third world countries a nightmare.
The occurrence and presence of water pollutant contaminations in the form of microorganisms has been investigated in ground and runoff water from rains, and the results have pioneered new and improved methods of purifications that do not include the introduction of chemicals to eliminate these microbes. This presence of microorganisms as stated earlier has been a significant factor that has increased the vulnerability of societies to waterborne diseases and those majorly affected being the elderly and the children who pass insignificant attention on purification of water. Also, conventional water treatment methods such as coagulation and flocculation, filtration, boiling, disinfection using chemicals and sedimentation are particular in the elimination of colloidal particles from water which is not a guarantee of purity. Such methods have as a result proved to be ineffective in overall water treatment of water since they do not ensure the removal of microorganisms from drinking water (Semenza, 2015). Highly efficient mechanisms for removal of these microorganisms which account for up to 99% include techniques such as absorption and inactivation. This, however, is subject to the media for filtration as well as the local climatic conditions of the area in question. Occasionally the efficiency of the unwanted microbial matter is directly proportional to the particle distribution as well as the amount of time invested in the filtration process. This implies that the removal efficiency increases as the particle deposition and distribution increases along with the filtration period. The porosity of filtration media is also an important factor that attributes to flaws in the filtration process through an increase in surface area for absorption as in the case of flocculation helps mitigate the situation. Scientists across the globe have in effect been tasked with the responsibility of providing a reliable and efficient technology that provides an effective solution to the problem of water purification.
High-voltage water purification
Background information
Scientists at NASA’s Glenn Research Center have pioneered research in the field of electrotechnology and have thus found out that high voltage could be one of the most efficient and latest methods of purification of water (Hu et al., 2016). This unique water purification method was developed as a way to facilitate water purification at the point of use and was initially developed as a means to recycle water in space. This technology has been globally accepted and is now embraced in industrial water treatment, water recycling and purification for military bases, disaster sites as well as marginalized areas without access to clean water supply in the United States of America. The technology relies primarily on the use of electricity whereby plasma generated reactive species are used to decompose organic water pollutants and contaminants. These contaminants vary from submicron particles to organics that are highly soluble in water like industrial dyes, glycol, and ethanol among others. As a result, the technology has proven to be very useful in industrial large-scale water treatment, waste water treatment, pretreatment of contaminants, the point of use drinking water, ground water treatment, pharmaceutical food and beverage water treatment and hydraulic fracturing water reuse (Hu et al., 2016).
How the technology works
The contemporary world which is fast paced in nature has embraced technology and as a result of most of the inventions taking place currently revolve around technology as man seeks for a better-advanced method that is cost effective and efficient in nature. In the light of this highly oxidizing water treatment procedure like ozonation and UV-ionization have been used widely across the globe (Li et al., 2016). However, humanity has had to suffer the high investment costs involved in setting up purification plants that utilize these technologies besides the high amounts of wasteful energy consumptions. The method used by NASA in water purification involves the use of high voltage electricity in the purification process. Such includes the use of a high-voltage nanosecond pulsed non-equilibrium plasma in the treatment of water, whereby the pulsed electrical discharge destroys microorganisms in liquid water thereby sterilizing the water (Li et al., 2016). This method, however, does not involve the use of chemical substances and filters in the purification process.
The high-voltage plasma creates numerous high reactive, negatively charged OH particles like hydroperoxyl, hydrogen peroxide as well as supercharged ionized oxygen to break down the organic pollutants and contaminants into carbon IV oxide (carbon dioxide) and water in a chemical reaction. Here the high voltage electricity acts as the primary catalyst in the reaction. An increased production of these Nano-pulses could have the potential to warm and even heat up the water and as a result, there is a need to ensure that only enough energy is produced to destroy the pollutants in the water (Li et al., 2016). This serves as a cost effective measure in the overall process of purification as it eliminates the eventual need to incorporate cooling mechanisms in the entire process. Also, it significantly reduces the downtime that is associated with other forms of water purification such as UV-ionization (Imai et al., 2015). The result of the exact amount of energy require in the generation of ionized plasma is referred to as a non-thermal plasma. This is then channeled into electrical discharges in the liquid, or at a gas-liquid interface which results in the formation of charged oxidizing ions and molecules discussed above, which are the active ingredients required for the removal of organic pollutants in the water.
Analysis of the sustainability of the technology
Effectiveness of removal of microorganisms
In an experimental system with ground and rain run-off water, the results in the Labs of NASA indicate that the efficiency of the method can be scaled up by enhancing the pulsed high voltage of the plasma to suit the concentration of microorganisms present in the water. In addition to increasing the time required for water to run in the reactor. The optimum time can be adjusted to about 60-100 minutes to ensure that all microorganisms are oxidized by into carbon dioxide and water. Research findings indicate that fecal coliforms in ground and surface water can be fully oxidized by voltages of up to 10KV (Li et al., 2016). As a result, it is easy to conclude that the higher the voltage used, the higher the rate of oxidization which scales up to 100% when the optimum voltage is applied.
Impact on the environment
Over the years, man has relied on other conventional methods of water purification which have had a direct environmental impact. Taking third world and other underdeveloped countries whereby the chief method of water purification is boiling, a lot of fossil fuel is used in the process. This results in air pollution which has a resulting impact on climate change experienced across the globe. The use of chlorination has a direct impact on the consumers of the water as it causes skin irritations albeit the emission of harmful chlorine gas in the environment (Simazaki et al., 2015). Emitted chlorine gas has the potential to react with oxygen and water vapor in the atmosphere resulting in the production of acidic rain which has the potential to corrode infrastructure. The use of high voltage in water purification involves only the use of electricity which makes it an environmentally friendly method of water treatment (Simazaki et al., 2015).
Economic impacts
The use of electricity as the primary raw material for the process could become a limiting factor in the case developing countries whereby the production of sufficient electricity is stumbling block. This implies that only places with an adequate and constant supply of electricity such as developing countries could reap the benefits of the use of the method. In such countries whereby the nuclear power has professionally harnessed the process could be very useful in the provision of purified water. The absence of additional chemicals and equipment such as filters and sedimentation tanks makes the method cost effective and adds simplicity to the process of purification. The incorporation the method in households could cripple the bottled water industry due to its cost effectiveness.
General benefits
Future trends
The effectiveness of the method of the elimination of pollutant microorganisms in water is a guarantee and as a result, the method is a game changer in the water purification methods especially factories and production industries. The government is channeling more resources in the research as it could become an effective procedure in water recycling in space. This has the potential to solve the problem of water supply in the case whereby mankind wishes to explore the universe and save on resources that could otherwise be used in the provision of safe water for human and industrial consumption (Imai et al., 2015). Homesteads are also likely to embrace this technology and have purification compartments installed in their residents to save on costs involved in the purchase of bottled water especially in the United States of America. Developing countries are likely to have reductions in the number of deaths reported as a result of consumption of contaminated water, thereby saving resources otherwise used for medical bills, leading to development.
The method also comes as a significant relief for water shortages especially in the occurrence of disasters such as earthquakes and tsunamis which destroy and contaminate water supply areas. The technology could be used to offer small mobile units of water purification that could make millions of gallons of untreated water safer for human consumption. This is because of the simplicity of the method and its cost effectiveness
References
Sinclair, R. (2016). U.S. Patent No. 20,160,009,577. Washington, DC: U.S. Patent and Trademark Office.
Semenza, J. C. (2015). Global Climate Change and Human Health: From Science to Practice, 103.
Hu, J., Chen, Y., Zhu, L., Qian, Z., & Chen, X. (2016). Production of high purity water using membrane-free electro deionization with improved resin layer structure. Separation and Purification Technology, 164, 89-96.
Li, B., Sun, Z., Wang, Z., Jin, Y., & Fan, Y. (2016). Effects of high-frequency and high-voltage pulsed electric field parameters on water chain formation. Journal of Electrostatics, 80, 22-29.
Imai, S. I., Kumagai, H., Iwata, M., Onodera, M., & Suzuki, M. A. (2015). In-Water Plasma Generation on a Liquid Wall Using a Compact Device and Dedicated Power Supply. Plasma Science, IEEE Transactions on, 43(7), 2166-2173.
Simazaki, D., Kubota, R., Suzuki, T., Akiba, M., Nishimura, T., & Kunikane, S. (2015). The occurrence of selected pharmaceuticals at drinking water purification plants in Japan and Implications for human health. Water Research, 76, 187-200.
