Safety and purity of world waters has been given a very great focus. Water treatment is very essential that we can avoid many possible diseases that are waterborne like typhoid, cholera, jaundice and so on. When dealing with water recycling, there are three important issues to be dealt with and they include; water treatment, water purification and sewage or waste water treatment. Therefore it is paramount to consider the scope and effects of these three terms in order to achieve the goals and aims of this paper. The aims and objectives of the paper involves understanding the meaning and importance of water treatment, water purification, sewage treatment and also to develop the new avenues or alternatives that could be used in the harnessing of clean water for both human and industrial consumption and as to whether these alternatives are best suited for use than the already available methods.
Water treatment entails all the processes involved in attempts to make water much more acceptable to the end user. These could either be for medical, industrial or even drinking purposes. The main aim is to remove the existing contaminants out of the water to render it more consumers friendly (US Bureau of Reclamation, 2000). Water purification on the other hand is usually used when dealing with water for human consumption. It involves the abolition of water contaminants which could otherwise be dangerous to human life if consumed. This is done in order to produce safe and pure drinking water that can support life of most living organisms including man. Substances that are removed during the process here include viruses, bacteria, algae, iron, minerals, sulphur, manganese, suspended solids and other chemical pollutants like the fertilizers (Diaper et al., 2001). Sewage or waste water treatment refers to the process of getting rid of the bulkiness of the contaminants within waste water or sewage to render more human friendly.
Water Treatment Process
Water recycling process and reuse has naturally been done on earth for millions of years. Recycling plants however use modern technology to speed up this natural process, to make water available for the increasing demand (Diaper et al., 2001). The process can therefore be categorised into two. These are the unplanned and planned water recycling (Diaper et al., 2001). Unplanned water recycling is the case whereby the water supplies for towns and cities are drawn from the rivers running across the same cities. These rivers receive lots of waste discharges upstream from these cities, and are continually treated and reused before the water is drawn by the last downstream user (Diaper et al., 2001).
On the contrary, Planned water recycling are established as projects that are aimed at beneficial reuse of recycled water, provided the water is treated aptly to minimise chances of the build up of toxic substances (Diaper et al., 2001). The standards for regulations of water recycling require that more treatment be done in uses where there are greater chances of human contact with the recycled water (Diaper et al., 2001). This is because inadequate treatment of water for human uses such as drinking will lead to health problems, if the water contains disease causing pathogens.
Methods of water treatment
There are several ways or types of water treatment. These are as discussed below;
Sedimentation or Flocculation process involves the combination or coagulation of tiny particles into much larger particles. These larger particles will settle out of the water system and collected as sediments. The catalysts used in this process include iron salts, synthetic organic polymers and the alum. The other way is through the Filtration process which is employed to remove all particles from the water. This process generally promotes the efficacy of the disinfection process and at the same time clarifies the water. Some of the particles removed here include but not limited to the following: Iron, manganese, microorganisms, natural organic matter, precipitates, silts and clay (Nancarrow et al., 2003).
Iron exchange process is used to remove inorganic contaminants where filtration and sedimentation cannot prove to be useful. It is very vital in the treatment of hard water. Substances like chromium, nitrates, uranium, radium and arsenic can be removed during this process. Adsorption process involves the removal of organic contaminants, taste and colour causing compounds and unwanted colouring which could otherwise stick to the surfaces of the granular or powder activated carbon. Disinfection which is conventionally known as chlorination or ozonation is done in order to kill the potential dangerous microbes. Chlorine and its derivatives are most commonly used in this process since they are very effective at both the treatment plants and at the pipes of distribution of water. Ozone is a very powerful disinfectant while the Ultra violet radiation is used in relatively clean waters (ACIL, 2005).
The Hanahan water treatment system has multiple water sources. It however gets it water from the Edisto River and Bushy Park Reservoir. The process here involves four major steps which are chemical treatment, physical treatment, chlorination and disinfection in that order. Chemical treatment involves the addition of Chlorine, ammonia and Lime. These helps in killing the harmful bacteria found in the water. Physical treatment involves the process of flocculation. Alum is used to act as a coagulant which then forms large particles called floc. Filtration is also done at this stage. Chlorine and Ammonia are then added again to disinfect the water against harmful bacteria and viruses to protect distribution pipes and storage tanks.