Chemicals and Nanotechnology in Water Purification - Essay Example

 Chemicals and Nanotechnology in Water Purification Abstract A study conducted by the World Health Organisation in 2004 identified that nearly 1.1 billion people did not obtain clean water. According to this finding, water borne diseases caused the death of approximately 35% of people in poor countries. Recent developments indicate that world’s water paucity issues can be better addressed using an emerging potential technology called nanotechnology. Currently industries find it difficult to go on with the existing technology due to higher costs and increasing environmental concerns. As a result, various industries and other interest groups have hugely invested in nanotechnology researches as this technology is predicted to be a better alternative to the existing chemical treatments. One of the major issues is that the world has been facing severe water pollution and paucity issues over the last two decades. The existing chemical treatments for water purification have been outdated due to their complexity and higher cost. This paper identifies that nanotechnology is a better alternative to the existing chemical treatments as this technology is more cost efficient and eco-friendly. Contents Abstract Introduction 1 1. Chemical treatments for water purification 2 1.1 Advantages 2 1.2 Disadvantages 3 2. Nanotechnology for water purification 5 2.1 Advantages 6 2.2 Disadvantages 8 3. Discussion 8 Conclusion 10 Reference 11 Introduction Freshwater is essential for human survival and it is a crucial component in many key industries such as electronics, pharmaceuticals, and food. The world is facing potential challenges in meeting the mounting demands of freshwater due to population growth, extended droughts, increased consumption, environmental pollution, and stringent health based regulations. Hence, in order to meet the growing freshwater needs of a huge global population, new methods of water purification have to be invented. Traditionally, industries have been using a variety of chemical treatments to purify water. Recently, nanotechnology has emerged as an alternative to traditional way of water purification. To define, “nanotechnology is the systematic manipulation, production or alteration of structures, systems, materials, or components in the range of atomic or molecular dimensions with/into nanoscale dimensions between 1 nm and 100 nm” (Sepeur 2008, p.14). In addition to water purification, the nanotechnology has a wide variety of applications. Major applications of nanotechnology include diagnostics, drug delivery, cryonics, reduction of energy consumption, efficient energy production, nuclear accident cleanup, information and communication applications, aerospace technologies, construction, foods, household, optics agriculture, and sports. While evaluating the nanotechnology developments till date, it seems that this technology will be widely used for water purification in the near future as this method has numerous competitive advantages over traditional chemical treatments.This paper will critically compare the efficiency of chemical methods and nanotechnology in water purification with specific reference to advantages and disadvantages of both the techniques. This paper will also explore the future scope of nanotechnology in water purification. 1. Chemical treatments for water purification Various industries have been using different methods with different degrees of effectiveness to purify water. Main chemical treatments for water purification are coagulation and flocculation, sedimentation, sludge storage and removal, dissolved air flotation, filtration, and disinfection. Coagulation and flocculation can be simply referred to as the process of addition of chemicals for the purpose of removing particles suspended in the water. These particles may be organic such as algae, bacteria, and/or viruses or inorganic such as clay and/or slit. They are the factors contributing to the water’s turbidity and colour (Chapter 2, n.d). Coagulants such as aluminiumsulphate or iron chloride are added to waste water in order to neutralise negative charges on the particles. Finally, the purification process is completed through natural processes like induced mixing, which is sometimes called flocculation. Sedimentation is another process used to extract suspended solids in water with the application of gravity. Once the sludge is settled at the bottom of the sedimentation basin, it must be removed using a cost effective method. Dissolved air flotation (DAF) is the better method for water purification when particles do not easily settle out of solution. Under this method, water flows to DAF tanks after coagulation and flocculation process. The air diffusers at the bottom of the tank create fine bubbles and this process leads to the formation of a floating mass of concentrated floc. Then the floating floc can be simply removed from the water and hence pure water is obtained. Filtration is the final step to remove unsettled floc. Finally, disinfection process is employed to kill pathogens which pass through filters and also to inactive harmful microorganisms in storage and distribution facilities. 1.1 Advantages The process of water purification using chemical treatments has many advantages. Mainly, chemically treated/purified water can be safely reused as the common chemical processes remove most of the poisonous particles. The coagulation process not only causes coagulation of colloids but also promotes precipitation of soluble compounds like phosphate, which is likely to be present in the unpurified water. Most of the chemical water treatment techniques prevent the spread of infections. In addition, they have the capability to destroy microorganisms including bacteria, algae, and mold that would present on the walls of water storage facilities (Chapter 2, n.d). Another potential benefit of the existing chemical treatment technology is that it can removeodours and unpleasant tastes from the water. Some of these technologies can notably reduce the toxic arsenic levels in drinking water and this feature greatly promotes life safety. Chemical water treatment methods are familiar to most of the industrialists today. Hence, they can better choose different chemical techniques for water purification according to situational needs. One of the most noticeable advantages of the existing technology is that it offers a wide variety of methods for water purification. Therefore, industrialists have the opportunity to choose better chemical treatment that would fit their operational needs. 1.2 Disadvantages Water purification using chemical treatments have some health based side effects. It has been reported that use of chemically purified water causes health issues like allergies and other adverse reactions (WHO 2004). A study by American International Agency on Cancer Research points out that increased exposure to hydrogen peroxide, a chemical used in the water purification process, can be carcinogenic to animals.Chemical treatments can have serious environmental impacts if they are not conducted properly. If improperly purified water is used for irrigation purposes, it would havecontaminated the ground water and the situation may further contribute to paucity of freshwater. The most potential disadvantage of the existing chemical treatment technology is that it causes firms to experience huge costs. It is clear that there is no single chemical method to remove all types of particles containing in the unpurified water. Hence, industrialists or other individual organisations need to employ more complex and costly chemical methods to purify water if contaminant particles are difficult to extract. 2. Nanotechnology for water purification Researchers at the University of Aberdeen have been developing an innovative technology called nanotechnology to meet the increasing concerns over clean water needs. Under this technology, a sunlight powered catalyst is used to purify contaminated water. In this process, an electrochemical cell, which is formed out of photoelectrocatalyst interacts with any organic pollutants in the water, oxidising them across the catalyst’s surface when it is exposed to sunlight (DTI, n.d). Recovery of charge in the cell is a by-product of this process and hence electricity is generated as a by-product of water purification process. At the initial stages of the research, it was found that the cell is to be robust and able to degrade different pollutants (ibid). As Savage and Diallo (2005) note, metal-containing nanoparticles, zeolites, dendrines, and nanomaterials are the four groups of Nano scale materials considered to be functional materials for water purification. The authors argue that these Nano scale materials have numerous physicochemical properties that make them particularly potential for being used as separation and reactive media in the water purification process. Nanoscopic materials such as carbon nanotubes are used in nanotechnology for nanofiltration in the water purification process (ibid). Researchers argue that this technology greatly uses the presence of nanoscopic pores in zeolite filtration membranes. In addition nanosensors are employed for analytical detection of contaminants in water to be purified. Nanotechnology is expected to be used for the removal particles such as sediments, chemical effluents, bacteria, and other types of pathogens (ibid). The most fascinating feature of nanotechnology is that it can remove almost all forms of water contaminants such as turbidity, bacteria, viruses, oil, and organic contaminants (ScienceDaily, 2010).The nanotechnology based water purification has three purposes including ‘treatment and remediation, sensing and detection, and pollution prevention’ (ibid). Generally, nanotechnology is employed in areas where it is necessary to molecular level contaminants. In 2007, the market for nanotechnology employed in water purification and waste water management reached USD 1.6 billion and this figure is expected to further grow to reach USD 6.6 billion by the year of 2015 (OECD, 2011). In order to take advantages of the broader scope of nanotechnology in water purification, many international bodies have invested huge amounts R&D in this area. 2.1 Advantages Nanotechnology is argued to be the potential solution for many issues surrounding water quality.As Savage and Diallo (2005) indicate, nanoparticles have a larger surface area relative to bulk particles and they can be ‘functionalised with various chemical groups’ for improving their affinity towards target compounds. This feature makes nanoparticles potential to be considered as sorbents that are used as separation media in water purification (ibid).Arguably, the most noticeable advantage of nanotechnology is that it can benefit both industrialised and developing countries. It can be applied to recycle industrial waste water through the innovative use of nanoparticles. It is obvious that factories and other industrial concerns generate large amounts of waste water every day. Removal of contaminants and purified water recycling would provide an industry with efficiencies in cost, time, and labour; this situation would add value to the industry’s environmental stewardship.This technology is effective to improve costs related with desalination process and reduce water consumption for irrigation purposes (Barker et al 2010, pp. 279-282). Another potential benefit of this technology is that it is more cost effective as compared to conventional water treatment methods. In the view of chemical experts, the most advantageous feature of nanotechnology is that it can be used for treating both chemical and biological contaminants; and this technology is sustainable as it can be powered by sunlight, which is a free and abundant source of energy (DTI, n.d). Furthermore, recent advancements indicate that nanotechnology can generate electricity as the by-product of water purification process. This feature would greatly assist the industrial world to effectively tackle rising concerns over power deficiency. Nanotechnology has the potential to manage water recycling, seawater desalination, and water remediation effectively (Saliby et al, n. d.). To illustrate, nanofiltration membranes are being widely used in South Africa’s rural areas in order to provide drinking water to people. Saliby et al claim that this method is a good way to promote economic viabilities in rural communities. They add that nanotechnology is one of the best ways to purify water in quick and low energy consumption ways (ibid). The economic use of renewable energy greatly contributes to the efficiency of this technology. 2.2 Disadvantages One of the major demerits of nanotechnology in water purification is that firms need to spend huge amounts for the initial installation of this technology. According to a study of nanomaterials conducted by Freedonia group (as cited in Savage and Diallo, 2005), demand of nanomaterials in the United States is likely to dramatically increase over the next years. In order to take advantages of that favourable market environment, marketers may increase the price of such materials and this situation would badly affect cost efficiency of nanotechnology. In the view of Savage and Diallo (2005), another potential challenge of this technology is that it is yet to develop into a cost effective and environmentally friendly separation and a reactive medium that is applicable in composite packed-red reactors for treatment of water contaminated by mixtures of organic solutes, bacteria, and metal ions. In addition, studies point to the fact that application of carbon nanotubes in water purification process may lead to series of health and environmental risks. A group of researchers argues that carbon nanotubes are potential to damage DNA and hence cause harmful effects to human organs (US Army Public Health Command, n.d). 3. Discussion While analysing the current market trends, it is arguable that nanotechnology would dominate the water purification market over the next years. Nanotechnology appears to be potential enough to replace conventional chemical methods of water purification.According to a group of researchers at the D.J Sanghvi College of Engineering in India, in contrast to conventional water purification techniques, nanotechnology (nanofilters) need(s) less pressure to pass water across the filter, and they are more efficient and can be easily cleaned as a result of large surface areas. The research team adds that “while the current generation of nanofilters may be relatively simple, it is believed that future generations of nanotechnology based water treatment devices will capitalise on the properties of new nanoscale materials” (ScienceDaily, 2010).Relative to conventional water treatment methods, nanotechnology utilises less energy to purify water. This energy-efficient feature may be beneficial to address the mounting energy deficiency issues in the globe. Environmental sustainability is another factor that places nanotechnology ahead of chemical treatment methods. Researchers claim that nanotechnology is more eco-friendly as compared to conventional water treatment mechanisms. To illustrate, Saliby et al (n.d) opine, nanotechnology has many environmental benefits including early environmental treatment and remediation, technologically improved sensing and monitoring devices, and better nanomaterials.Today, conventional water purification technologies are difficult to implement and manage mainly due to cost inefficiency. As a result, these water treatment methods require huge investments in terms of finance, manpower, and infrastructural facilities. Hence, they are difficult to perform locally. The newly developed nanotechnology is capable of addressing such issues as it can cost effectively and efficiently operate with less exception in contaminant detection and filtration. As modern people are becoming more concerned about environmental safety, this technology is likely to meet current environmental needs and requirements.In addition, power generation capacity provides nanotechnology with an edge over existing chemical treatment practices. Referring to the view of Saliby et al (n.d),nanotechnology should be considered as a potential way to promote sustainability of social communities in various territories. Current trends indicate that agriculture sector is going to largely exploit the far reaching benefits of nanotechnology. It is interesting to note that emerging countries like India, China, and Brazil are trying to tackle their water paucity and environment pollution issues using nanotechnology. These countries have already made huge investments in R&D practices related to nanotechnology in water purification. Therefore, it can be predicted that the global water purification market is increasingly moving towards nanotechnology mainly to promote cost efficiency and environmental sustainability. In addition, integrated research practices in nanotechnology by developed and developingcountries would fuel the development of this technology. Even though the application of nanotechnology in water purification is not relatively common in Third World, this innovation is expected to benefit poor countries more as they are highly struggling with water pollution issues. It would seem that industries and other organisations should prefer nanotechnology to existing chemical water purification techniques, because the former has a range of competitive advantages over the latter. Conclusion From the above discussion, it is clear that nanotechnology can have competitive benefits over existing chemical treatment mechanisms if it is well researched and developed. Coagulation and flocculation, sedimentation, filtration, and disinfection are the major existing chemical treatments for water purification. Although the existing technology makes the purified water completely reusable and removes odours and unpleasant tastes from the drinking water, it costs higher due to process complexity and time delay involved in the purification process. Here, nanotechnology can be used as a potential alternative to purify water and manage waste water treatment. Cost efficiency and eco-friendliness are the most potential features of the nanotechnology. Another attractive feature of this technology is that it can be used for removing both chemical and biological contaminants from water. Hence, nanotechnology is likely to obtain broad popularity over the next decades. Hence, far reaching benefits of nanotechnology would outweigh its fewer limitations in near future. Many aspects of this innovation including use of separation and reactive media and power generation capacity are to be further researched. It is recommendable for governments to invest more in nanotechnology’s R&D activities as this policy may help to address the world’s growing clean water needs. References Barker, T. F., Fatehi, L., Lesnick, M. T., Mealey, T. J and Raimond, R. R., 2010. Nanotechnology and the poor: Opportunities and risks for developing countries, In: S. E. Cozzens ans J. M. Wetmore, Nanotechnology and the Challenges of Equity, Equality and Development, New York: Springer. Chapter 2.,n.d. Chemical methods used in purification, pp. 48-62. DTI.,n.d. Nanotechnology for sustainable water purification, Collaborative Research and Development Case Study: Micro and Nanotechnology, pp.1-2. OECD., 2011. Fostering nanotechnology to address global challenges: Water, pp. 1-76. Science Daily., 2010. Nanotechnology for water purification, Science News, [Online] Available at: [Accessed 10 September 2012]. Saliby, I. J., Shon, H. K., Kandasamy, J. K and Vigneswaran, S., n.d. Nanotechnology for wastewater treatment: In brief, Water and Wastewater Treatment Technologies, [Online] Available at: [Accessed 10 September 2012]. Sepeur, S., 2008.Nanotechnology: Technical Basics and Applications. Germany: Vincentz Network GmbH & Co KG. Savage, N and Diallo, M. S., 2005.Nanomaterials and water purification: Opportunities and challenges, Journal of Nanoparticle Research, 7, pp. 331-342. US Army Public Health Command., n.d. Carbon nanotubes in drinking water treatment. WHO., 2004. Chemicals from water treatment and distribution, Guidelines for Drinking-Water Quality, pp. 55-60. Read More