Water Treatment - Case Study Example

 Introduction: Water Treatment with the help of conventional or innovative methods is important because access to pure drinking water is essential for health protection. At the same time, research on recycling/reusing sewage as grey water and for potable use must come under consideration because water is one of the essential components which help the human race to survive. But, large scale exploitation limits the distribution of pure water to ever growing population. Besides, water pollution and related health hazards are becoming worse than ever. So, it is vital to develop innovative methods for Water Treatment and to convert impure water for grey water (other than drinking purposes) use and potable (say, drinking) use. Aims & Objectives: The aim of the report is to explore the possibility to convert/recycle polluted water to grey water usage/ potable usage through different ways. The core aspects of the report will critically analyze the scope of different types of recycling methods in water treatment, and its pros and cons. The objectives of the report are pointed out below. To investigate: 1. Issues related to recycling and potentially toxic organic pollutants. 2. Water recycling and its social impacts (special attention to negative public perceptions). 3. Different regulations and precautions related to water recycling (grey water and potable water). 4. Alternatives to water recycling (special attention to areas under water scarcity). 5. Problems caused by hard water (special attention to typical limits of hard water ions accepted in domestic water) 6. Scope of common available treatment techniques and its applicability in different situations. I. Issues with build-up of potentially toxic organic pollutants from recycling There are a number of issues on build up of potentially toxic organic pollutants from recycling of sewage/water treatment. Some are mentioned under. According to Karre (2005, p.9), ‘Flushing any synthetic materials or chemicals down your drain can jeopardize the system’s function’ public must cautious about the problem created by toxic pollutants that they flush out into the drainage system because it is so difficult to remove toxic waste materials by recycling sewage. When chemicals are used to disinfect drinking water, there exist high chances for building up of potentially organic pollutants in the same. For example, disinfection using Chlorine cannot withstand the protozoan pathogens. Large scale use of chemicals for disinfection purpose eventually leads to the formation of by-products which cause health problems in human beings. When one regularly comes in touch with chemically contaminated water, there is high chance for severe health problems. But the issue of chemical contaminants/ potentially toxic organic pollutants which originate from recycling can be eradicated by continuous monitoring and effective remedial measures. As people flush out medicines and other pharmaceutical products for easy disposal, these toxic materials may reach recycling plants. So, these pharmaceutical products and hormones may remain active and re-enter human body through drinking water. For instance, according to Science Daily (2004), research conducted on reclamation plants by Penderson and other environmentalists /scientists from University of California, situated in Los Angeles prove that reclamation plants are more effective than conventional filtration/treatment processes for waste water recycling. Penderson and others conducted experiments on water from 3 treatment plants in America. Besides, the research aimed to detect 19 contaminants like testosterone, caffeine etc which are harmful for human life. The sampling for the research included examining water before/after additional treatment. The research proves that conventional water treatment is able to remove large particles of waste materials from sewage. But, on the other side, reclamation plants are able to remove smaller particles of waste materials. This prove that additional treatment methods like adding lime, Reverse Osmosis etc can remove more toxic waste materials than conventional treatment modes. But people are not satisfied with the fact that wastewater reclamation plants which treat and recycle sewage to drinking water can remove toxic waste materials. Instead, they consider the recycled water as sewage which contains potentially toxic organic pollutants. So, it is important to implement effective measures to make sure that treated sewage is away from harmful chemicals and hormones. Treatment methods: Pre-treatment: Pre-treatment is helpful to reduce the amount of microbial matter in drinking water. Filtration: Filtration is helpful to remove waste particles like micro organisms and is an effective barrier against potentially toxic organic pollutants. Chlorination: Chlorination is helpful to kill bacteria, viruses etc which cause harmful diseases in human beings. Reverse Osmosis: Kurion Technologies Limited website (2009) makes clear that innovative recycling method namely Reverse Osmosis is helpful to remove chemical components from sewage. This will eventually lead to reduction in issues related to the build up of potentially toxic organic pollutants from recycling. When one consider conventional mode of water treatment, there is high possibility for build up of potentially toxic organic pollutants from recycling. But advanced processes of wastewater management prove that it is effective to withstand the build up of potentially toxic organic pollutants. II. The social impact of water recycling Kurion Technologies Limited website (2009) in U.K. offers different types of techniques to recycle wastewater like Reverse Osmosis system, membrane system, Ion exchange system etc. Negative public perception on water recycling is a major issue which hinders further progress in the field of water treatment. But this hindrance can be avoided by creating awareness on scarcity of drinking water and the importance of water recycling. Nowadays, people are more and more health conscious and have awareness on water borne diseases. As the quantity of potable water from natural sources is becoming less, it is essential to reuse sewage water for drinking purposes. For instance, the treatment plant which is situated in the southern part of Dulles international Airport, Washington, D.C., provides drinking water to San Diego region. The interesting fact is that sewage water is purified here for the usage of drinking purpose. So, it is the responsibility of the authorities to make the public aware that proper filtration system can recycle impure water to potable use. The public perception on recycling/water treatment is that it is to mix sewage with drinking water without prior treatment/purification. This misunderstanding is the focal point of public protest against water treatment and reuse. As a fact, mixing sewage with drinking water without purification will cause health hazards. But Kurion Technologies Limited website (2009) makes clear that waste water treatment plants can recycle sewage and can be used for domestic purposes. For instance, in Northern Virginia in the United States, sewage is used for recycling and reused as drinking water for the last 30-40 years. In this area, sewage is purified and mixed with drinking water stored in the reservoir. So, it is better to create awareness among the public that water treatment is most helpful to remove impurity from drinking water. Besides, the best possible way to fight scarcity of drinking water in urban and rural area is recycle sewage by the means of different modes of treatment. For instance, in Orange County, sewage undergoes treatment in underground filter, kept for six months and is mixed with natural water. When the public realize that water treatment is capable to clean water so thoroughly that it can be used for drinking, the negative perception will come to an end. This will help to get rid of the negative perception of ‘drinking sewage’, instead of drinking water. Sydney Airport website (2010) thinks that recycling and reuse of sewage can resist scarcity of water and the attempt by Sydney Airport Authorities to recycle sewage by implementing a water treatment project to use recycled water for airport maintenance purposes prove their keen interest in this matter. The below figure is helpful to have a clear understanding of water treatment project by Sydney Airport Authorities to recycle sewage. Figure 1: Shows the water treatment project by Sydney Airport Authorities to recycle sewage (Sudney Airport’s, 2010). It is difficult for the pubic to accept treated sewage as drinking water. But scarcity of pure drinking water forces the governments to mix treated sewage with natural water. Besides, innovative techniques and methods adopted by the governments help to test the purity of treated sewage and there exist less chance for large scale impurity in treated sewage. III. Different regulations and precautions involved with recycling water As the regular usage of impure water for domestic purposes cause severe health problems, to implement strict regulations on sewage treatment is important. Besides, recycling of potable water must be done under strict regulations because the public is more conscious on water borne diseases. Regulations: There are different regulations and precautions involved in the recycling of grey water. Different countries have diverse regulations on the topic of the water recycling. According to Chiras (2004, p.526), ‘In 1996, Congress toughened the U.S. drinking water law by adding regulations that protect ground water’. The U.S. government is cautious about the toxic waste materials that badly affect the quality of ground water. In 1996, the U.S. government added regulations to drinking water law to protect the public from health problems. For instance, in California, code of regulations under the title 22, states that water safety should be controlled and regulated before the public use. Each and every agency including U S Environmental Protection Agency, State Water Control Board should follow this rule. The recycling of grey water is very essential to withstand scarcity of drinking water.  In California, there are different laws and acts such as Water Reuse Law, Water Reclamation Law, Clean Water Act, Water Recycling Act etc to ensure water quality and availability. The water reuse law stresses the reuse of waste water. Water reclamation law states that states should encourage meeting the water requirements of people. The clean water act, approved by the Congress, aims to reduce water pollution. The California water recycling act (California water code 13577) had set a goal to produce 700 acre-feet of water by 2000 and one million Acre feet annually by 2010. All these laws encourage waste water management. The Assembly bill 331, aims to form a water resource department to investigate the opportunities to increase the industrial and commercial importance of recycled water. Precautions: The recycling of grey water undergoes different filtration processes. The first two steps consist of passing water through different screens which include beds of anthracite coal (hard coal having less flame and smog which generates heavy heat). After completing these two steps, water can be used for agriculture and other domestic purposes, not for drinking. The next level of purification is micro filtration which aims to remove other remaining solids. Then water is allowed to undergo reverse osmosis, which pumps the same through special covering with small pores. Besides, water is cleaned by ion exchange, which reduces the nitrate concentrations from water. Finally, water will be mixed in the surface water reservoirs and again passes through the normal filtration process. But according to Science Daily (2004), still the public shows hesitation to use recycled water because they do not believe that recycling can reduce the amount of toxic waste in recycled water. For instance, in Milwaukee, in the year 1993, cryptosporidium virus happened to enter drinking water. The public criticized that the reason behind the stomach flu and other diseased due to cryptosporidium virus is the sewage water mixed with the drinking water. Different types of treatments in wastewater management can be considered as effective precautions to withstand further criticism from the side of public. So, importance must be given to precautions on recycling water for ‘grey water’ use and ‘potable’ use.    IV. Alternatives to water recycling to secure water in ‘water poor’ areas The alternatives instead of water recycling to secure water in water poor areas are mentioned under. First of all, scarcity of drinking water limits the scope of water recycling. But alternatives like desalination of sea water, restrictions on ground water exploitation, measures to lift water table, sand dams, collecting rain water etc can be implemented to secure water supply in these areas. The East Asia, Central Asia, Africa, North America, Australia, China etc face the severe problem of scarcity of drinking water. For instance, the Murray River near to Adelaide in Australia faces the problem of high concentration of salt in drinking water. According to O'Loughlin and Vidal (2009), Eastern part of Adelaide in Australia is facing the problem of high content of salinity in drinking water. Annual droughts badly affect the water supply system in Australia. The below image is helpful to have a look on the severe draught that hit Lake Hume in Australia. Figure 2: Shows the draught that hit Lake Hume in Australia (O'Loughlin and Vidal, 2009). But in China, industrialization and rapid rate of urbanization badly affect the water supply systems and the Northern parts of China face the problem of shortage in drinking water. Here are some alternatives to water recycling and to secure water in water ‘poor’ areas. Desalination: Desalination is an alternate to the traditional process of recycling, i.e., conversion of waste water to usable water for consumption and irrigation. This process is relevant on the grounds that it ensures availability of water supply and helps to produce salt as a by-product. Middle Eastern countries employ this method because these countries face the problem of inadequate water supply. There are some other desalination plants at Tampa bay, Florida in US. But large scale desalination is expensive because of high energy consumption and costly infrastructure. In traditional operations, desalination is conducted with the help of vacuum distillation i.e., boiling water at lesser temperature than the average point. Collecting rain water: This method is one of the best methods to secure water in water ‘poor’ areas. Collecting rain water is not so costly but when it is raining no one may consider its value. Collecting rain water in underground tanks will be helpful for families to meet their daily usage of water. Large scale collection of rain water can save water scarce areas from severe droughts. Sand dams: This is an ancient method developed by the Romans to save rain water. At the time of rain fall, water is collected in dams which are filled with sand. The sand acts as a natural filter which reduce evaporation. This method is effective in African dry lands, where water is insufficient to meet the needs of thousands. V. Problems caused by hard water Generally, water collected from rivers and other sources contain mineral components like calcium, magnesium etc. But when mineral content of water is high, it is said to be hard water, harmful to health. Besides, low mineral content water is called soft water or pure water. When hard water is boiled, it releases calcium carbonate and other harmful salts. When one use a household utensil to boil hard water, there exist high chance for harmful substances to deposit and will cause health problems. When one use hard water to wash cloths, the quality of the material gets worsened but it will not cause serious health problems. When hard water is used to wash dishes and other crockery items, quality of household utensils gradually gets reduced. Hardness of water can be reduced by Softening, a process to remove substances like Calcium and Magnesium. Reverse osmosis, Pellet Reactor and ion exchange are the important methods used to soften hard water. Mahvi, et al. (2005) show that Hard Water softening using pellet reactor possess some unique advantages like lower time consumption, hygienic, industrial importance of crystal(waste) etc. On the other side, in Ion exchange, sodium is used to reduce calcium dissolved in water. When water contains 120 mg of calcium/magnesium per liter, it is considered as unsuitable for domestic usage. In addition, usage of softened water for domestic purposes is not good because softening does not guarantee the removal of sodium. So, one can see that hard water is not so harmful to human health but can be softened by different treatment techniques and used for industrial purposes. VI. Scope of common available treatment techniques and its applicability U.S. Environmental Protection Agency (2009) website shows that, ‘The Safe Drinking Water Act (SDWA) is the main federal law that ensures the quality of Americans' drinking water.’ So, one can see that The Safe Drinking Water Act in USA plays the vital role in guaranteeing sufficient quality to drinking water. The common available treatments which are used to treat sewage are with wide scope. Some of the treatment methods/techniques, its scope and applicability in different situations is discussed under. Settling: Settling is a treatment technique which allows waste particles to settle at the bottom of treatment plant. But this treatment technique is with limited scope because it does not purify waste water completely. Moreover, the waste materials that settle at the bottom of the treatment plant create further ecological problems. The applicability of settling is limited to the areas which face scarcity of drinking water. Aerated basin/lagoon: Aerated basin/lagoon is a common treatment technique which helps to treat waste water in a treatment pond with artificial aeration. This technique is a biological treatment mode which makes use of oxygen/air to treat sewage. The scope of Aerated basin/lagoon treatment technique is wide because it is biological and not harmful to living things. This treatment technique is applicable to almost all fields which depend upon treated sewage/waste water. Activated sludge: Activated sludge is another treatment technique developed in the 20th century to treat sewage. In this technique, air is used to mix with primary treated sewage. When one consider the scope of this technique, its role in treating primary treated sewage and to convert it into potable water come into focus. Besides, this technique is most helpful and applicable in different situations because it provides pure water equal to the same from natural sources. Rapid sand filter: In this water treatment technique, sand is used as a medium to remove impurities. In this technique, water is allowed to flow through a filter medium and waste particles get trapped. But rapid sand filter is unable to change taste and smell of impure water. So its scope and applicability is limited to the sphere of grey water treatment, not potable water treatment. Slow sand filters: Slow sand filters are used to purify water for primary usage. Besides, this technique is helpful to treat surface water which is considered as pure. This method is used in United Kingdom, especially in London to purify drinking water. Slow sand filter technique is a slow process but water produced by this process is pure and healthy. This process is with wider scope because it is economical. In addition, ability to produce potable water helps this technique to be applicable in different situations. Reverse Osmosis: Reverse Osmosis is similar to membrane filtration which allows water to pass through a membrane. According to Science Daily (2004), an online news source, the sewage treatment plants which use Reverse Osmosis as the treatment method is able to remove toxic Chemical waste materials. It is commonly used for desalination purpose of sea water. As pointed out earlier, the scope of reverse osmosis in areas which face the problem of scarcity of drinking water is unlimited. The below diagram designed by Engineers for Res-Kem Corporation for Reverse Osmosis is helpful to understand the process of Reverse Osmosis. Figure 3: Shows a diagram designed by Engineers for Res-Kem Corporation for Reverse Osmosis (Science Daily, 2004). Concluding, its applicability is limited to the sphere of desalination and related methods to fight scarcity of drinking water. Findings The main findings derived from the discussion are pointed out below. 1.The issues with buildup of potentially toxic organic pollutants from recycling is related to the conventional mode of water treatment, but reclamation plants and other innovative modes of filtration can withstand these issues. 2. Awareness created by the governments, with the help of government departments, private agencies, the WHO etc, among the public can reduce the negative public perception of ‘drinking sewage’. 3. The different regulations/laws like Water Reuse Law, Water Reclamation Law etc and other precautions are helpful to make sure the quality of grey water and potable water. 4. The alternatives like Desalination, Limiting groundwater exploitation, measures to lift water table, collecting rain water, sand dams etc prove effective to secure water in water poor areas. 5. Hard water does not cause any significant health problems in human beings and different treatment techniques are helpful to reduce its hardness and it can be recycled and reused for industrial purposes. 6. Some common available treatment techniques like Filtration, Slow Sand Filters and Chlorination prove effective in different situations. On the other side, treatment techniques like Settling, Aerated Basin/Lagoon, Activates Sludge, Rapid Sand Filter etc prove less effective in different situations. Conclusion Summing up, human intrusion and exploitation is depleting the natural sources of renewable resources. Moreover, the world population is increasing day by day and it will be grave to exploit the nature anymore. In this critical situation, special attention must be given to recycling and reusing available resources. If we recycle and reuse water and other natural resources, our future generations will live peacefully. If we consider treated sewage as impure, there is little scope for its reusability. So, recycling and reusing of sewage for drinking and other purposes must come under immediate consideration of world nations. One must realize the fact that treated sewage similar to natural water, and nature itself is incapable to produce water. So the best possible way is keep human race away from scarcity of drinking water is to recycle and reuse sewage as grey water and potable water. References: 1. Chiras, D.D., 2004. Environmental Science: Creating a Sustainable Future. 6th ed. USA: Jones & Bartlett Publishers. 2. Karre, A., 2005. The complete guide to home plumbing. 3rd ed. Minnesota: Creative Publishing international. 3. Kurion Technologies Limited, 2009. Kurion Technologies Ltd - Solutions to Pollution. [Online] Available at: http://www.kurion.co.uk/ (Updated 27January 2009) [Accessed 5 January 2010]. 4. Mahvi, A.H. et al., 2005. Feasibility study of crystallization process for water softening in a pellet reactor. International Journal of Environmental Science & Technology, 1(4), pp. 301-30. 5. O'Loughlin, T. & Vidal, J., 2009. Adelaide latest victim of global water shortages. Guardian.co.uk, [internet] 28 September. Available at: http://www.guardian.co.uk/environment/2009/sep/28/adelaide-water-drought. [Accessed 31 December 2009]. 6. Science Daily, 2004. Do Treatment Plants Effectively Remove Drugs, Hormones From Wastewater? Science Daily, [internet] 27 August. Available at: http://www.sciencedaily.com/releases/2004/08/040826085912.htm. [Accessed 02 January 2010]. 7. Sydney Airport, 2010. Water Treatment Project [Online] Available at: http://www.sydneyairport.com.au/SACL/Water-Treatment-Project.html. [Accessed 02 January 2010]. 8. U.S. Environmental Protection Agency, 2009. Safe Drinking Water Act (SDWA). [Online] Available at: http://www.epa.gov/safewater/sdwa/index.html (Updated 17 March 2009) [Accessed 6 January 2010]. Read More