CHAPTER-3 3.1 Introduction As the given situation describes, eutrophication is a result of the presence of nitrogen and phosphorus in river since no protection methods are carried out to end the release of waste into the water bodies. Such rivers are commonly known as sensitive rivers. These nutrients excite the production of algae providing food for their growth under the accurate circumstances thus causing eutrophication. Eutrophication can harm the ecosystem causing unwanted alteration in aquatic population, extreme reduction of oxygen, health issues to human-beings and animals, expensive water treatment costs and, interfering with recreational significance of water (Kuba et al., 1997). Thus the wastewater must be maintained from nitrogen and phosphorus before disposing into water bodies. The removal of such harmful nutrients must be carried out efficiently in the secondary treatment itself. Wastewater treatment includes two procedures as standard: Primary Treatment (elimination of rock-solid materials) and Secondary Treatment that uses microorganisms to eradicate organic wastes by disintegration. Tertiary treatment may also be mandatory in case of removing phosphorus and nitrogen when wastewater is discharged into sensitive rivers. The biological secondary treatment is the major type of treatment for elimination of the organic materials from wastewater (up to 90% elimination). The two usual procedures used in the treatment are: • Attached Growth Method (Fixed film system) • Suspended Growth Method (Free-film system). Each of the above types has been described within the subsequent section. 3.2 Activated Sludge Treatment (AST) – Free Film System This is the most familiar suspended devel... ... middle of paper ... ...is a simple procedure of secondary treatment where the sewage is held in a basin where the disintegration takes place by micro-organisms, air and sunrays. The steady sludge is disposed as treated seepage. This method does not required trained labourers and can be setup in a reasonable priced property. Constructed Wetland They are capable of filtering suspended solids, degrading organic matter and decompose nutrients from wastewater. Removal of ammonia by denitrification is also possible by this method. References Kuba, T.; van Loosdrecht, M.C.M; Brandse, F.A; Heijmen, J.J, (1997) Occurrence of denitrifying phosphorus removing bacteria in modified UCT type wastewater treatment plants. Water Res., 31 (4), 777 - 786 FAO Corporate Document Repository (n. d.) [online] available from [16 february 2014]
Use of pesticides & other fertilizers infuse nitrogen oxide into the water bodies acidifying the water which kills the plants and aquatic animals living in
Treatment methods at these nine plants vary slightly according to the water it treats and where it is going. However, all plants use filtration, disinfection and fluoridation methods.
Disinfection is applied in water as well as wastewater treatment as a finishing step so as to destroy pathogens but the cause of concern regarding the disinfection process is the formation of disinfection byproducts (DBPs). Natural organic matter (NOM) in water has been considered as the predominant DBP precursors. Disinfectants are powerful oxidants that oxidize the organic matter present in water forming DBPs. Chlorine, ozone, chlorine dioxide, and chloramines are the most common disinfectants used nowadays and each produces its own suite of chemical DBPs in finished drinking water (Richardson, 2003). DBPs so formed pose a threat to human health because of their potential to cause cancer and reproductive/developmental effects. Most developed nations have regulated concentration of DBPs so as to minimize exposure to potentially harmful DBPs while maintaining adequate disinfection and control of targeted
Stephenson, R., & Blackburn, J. J. (1998). The Industrial Wastewater Systems Handbook. New York: Lewis Publishers.
They also help remove “plankton and organic particles from the water column; and are capable of filtering up to 50 gallons of water per day which makes them improve water quality and clarity” (Oyster…2014:[sp]).
There are several types of treatment methods present but biological treatment methods have gained much traction in the recent years due to their low operation costs, comparatively benign effects on the environment and their ease of handling and maintenance. Biological wastewater treatment methods can be subcategorized into dispersed growth systems and attached growth systems. Biofilms fall under the latter category (Sehar & Naz, 2016)
The bacteria and wastewater is mixed in an aeration tank and therefore the contaminants are removed by action of sorption and series of breakdown by the bacteria.
Phase one in process of waste water treatment begins in the home, local businesses and community. Waste water from these buildings and surrounding areas travel through a pipe, or sewer which is sloped downward, and with the assistance of gravity, travels toward the waste water treatment plant. However, in larger communities or communities with unevenly leveled terrain, waste water cannot keep getting deeper to rely on gravity to transport the waste water and must pumped up by the assistance of a lift station so it may continue to travel to the water treatment plant. Once the waste water arrives at the waste water treatment plant, the first step is the removal of large debris such as diapers, underwear or other non-biological...
The process of disposing waste, producing food, and purifying bodies of water is useful today. For example, communities that live in the desert, like in the southwestern United States and in the Middle East, can use this process to farm and survive. They can use the newly purified water for their crops or for their own consumption. In addition, when algae purifies water, it releases oxygen.
Eutrophication is the reaction resulting from the addition of harmful substances to aquatic ecosystems. Eutrophication causes decreased biodiversity, changes in species composition and dominance dissolved oxygen depletion and problems in water treatments. Eutrophication is currently happening to many of the Canadian Lakes including Lake Winnipeg. Since 1969, it has been observed that Cyanobacteria (blue-green algae) has been the reason for the 90% hike in the algal blooms.Cyanobacteria causes a smelly odour and releases toxins that are detrimental to humans and some other organisms. When the lake is enriched with phosphorus, cyanobacteria thrive due to nitrogen-fixing. Due to the unfair advantage cyanobacteria has over other non-nitrogen-fixing species and its cause in oxygen depletion, other species die off causing decrease in biodiversity. It has been proven through the recoveries of lakes in many countries, including Canada, that reducing phosphorous is the most inexpensive and efficient way to solving the Cyanobacterial blooms. Synthetic fertilizer applications and manure from ca...
Safe water and sanitation as a basic human right, household water treatment, rainwater harvesting ... and reports from Kyoto, Madagascar, Uzbekistan, Guinea and other countries around the world.
the disposal of garbage into a water stream. Some of the water pollution is from
The terms secondary and primary treatment have been used to basically describe a degree of treatment; for example, biological wastewater treatment and settling. Tertiary treatment has been regarded as different from secondary and is the advanced one. It comprises of the use of sand filters to separate the solid particles from the wastewater. Tertiary treatment has also been regarded as the treatment involved to remove plant nutrients, primarily nitrogen and phosphorous.
Chemicals and impurities removed from water may not be disposed properly thus polluting the environment. A sheet volume of discarded filters may add up to landfill mass. The system itself may take up large amount of spaces and cause lots of noises and destructions. There may also be chemical or wastewater spills if not handled properly.
Fresh water is a limited resource in many parts of the world. And this will become more dearth due to increasing in population, urbanization and climate change. The major fact for this paucity of fresh water is not only due to demand for water but also due to pollution in freshwater ecosystem. Due to the pollution created by human beings in this ecosystem, the usable water has decreased drastically and the cost of purifying the water has increased dramatically. The main sources of water pollution are point source and non point source. Point sources include pipeline discharge of pollutants such as domestic sewage discharge industrial waste effluents from factories or plants, to receiving waters. In contrast, non-point pollution results from storm runoff, which transports polluting materials diffusely over land.