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RUNNING HEAD: WASTEWATER TREATMENT METHODS Wastewater Treatment Methods Wastewater Treatment Methods The initial costs of setting up water recycling treatment plant s are very expensive. The equipment found in the treatment plant is determined by the purpose the recycled water is intended to serve. Non-potable water, this is water not fit for human consumption requires only equipment needed for the primary and secondary man. For water fit for drinking, additional equipment for the tertiary process need to be set up.
This means more costs must be incurred. Despite the initial great costs, the benefits of the reclaimed water that has undergone the final stage are more and so it is more economical to set up plants which can handle all the three stages. Therefore as one in charge of the city’s water supply, opting for an all-purpose water plant is more beneficial (U.S. Environmental Protection Agency, 2004).Water treatment involves a variety of stages. It begins at the primary stage which involves a process referred to as sedimentation which allows for all the undesired materials to sink to the ground as the water is left floating.
At this stage, the water cannot be used. The secondary stage follows and this involves processes like biological oxidation and disinfection. The water from this stage can be used for the non-potable purposes. The tertiary or advanced stage is the final stage and the processes found in it include chemical coagulation, filtration and further disinfection. The water from this last stage is what is used for indirect potable purposes like ground water recharging (My Clearwater, 2010). Reclaimed water is mostly used for non-potable; non-drinking processes.
It can however be used for drinking provided the water being recycled undergoes the necessary treatment procedures as outlined by the EPA in their technical document entitled ‘Guidelines for Water Reuse’. The non-potable processes include landscaping irrigation, toilet flushing and in the construction industry. Compared to water reclaimed for drinking processes, these processes require less treatment. It is worth noting that whatever purpose water is reclaimed for, the savings made both from a financial and resources view point are great.
Industries have also benefited from recycled water whereby instead of them using clean fresh water, they opt to reuse treated water that has already been used in their cooling processes (Natural Resources Defense Council, 2011). Water being recycled for potable use is done through recharging the ground water aquifers and augmenting surface water reservoirs with recycled water. Projects like this have been done in states like California and Virginia. The treatment methods in the secondary and tertiary stages differ greatly.
The only similar process is the disinfection process. The water in both stages undergoes disinfection to rid it of all the microorganisms present in it like bacteria that couldn’t be eradicated in the sedimentation process found in the primary stage. The processes in the tertiary stage are more advanced compared to those in the secondary stage because human consumption is inevitable for reclaimed water from the tertiary stage unlike that from the secondary stage. Humans can easily contract diseases from contaminated water thus the precautions taken must be great.
Therefore water from the tertiary stage is fit for drinking.ReferencesMy Clearwater (2010). Public Utilities: Reclaimed Water. Retrieved on 12/1/11 at http://www.clearwater-fl.com/gov/depts/pwa/public_utils/divisions/reclaimed/index.asp Natural Resources Defense Council (n.d.).(2011) Whats on Tap? Grading Drinking Water in U.S. Cities. Retrieved from the web on 12/1/11 at http://www.nrdc.org/water/drinking/uscities/contents.asp U.S. Environmental Protection Agency (2004). Primer for Municipal Wastewater Treatment Systems.
Washington D.C: Office of Water & Office of Wastewater Management. Retrieved on 12/1/11 at http://www.epa.gov/OWM/primer.pdf
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