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]
Due to the Water Pollution Control Act of 1970, there are stringent standards that need to be considered when depositing wastewater from the process. It was not possible to show the path that the wastewater would take after leaving the system, however, the pollution standards were considered. The water that was produced in the reaction were present in streams with other components such as CO2, butadiene, and maleic anhydride. Due to this exposure, the separated water will be sent to a waste water treatment plant where it will undergo many steps to ensure that the pollutants have been properly removed (Plant Design Book
Stephenson, R., & Blackburn, J. J. (1998). The Industrial Wastewater Systems Handbook. New York: Lewis Publishers.
Here, in the initial treatment period, large chunks of garbage are removed, grit and scum are filtered, and sludge continually is separated from water and is treated separately.
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)
Removal/ wasting of activated sludge during this stage if the amount of activated sludge presence in excess.
Water treatment is considered to be a relevant action to ensure environmental sustainability. With an increase in water pollutants, water treatment plants are forced to develop additional processes in order to adequately purify the polluted water. In a report for the Chesapeake Bay Watershed it was stated that the presence of non-point source pollutants caused “a 35% increase” in cost for the wastewater treatment plant (Rees 2014). As well, a study in
... Activated Sludge Unit for retreatment. Once water is cleaned to the appropriate standard it is discharged to WASA’s municipal wastewater treatment system. Salt water used as cooling water is not contaminated under normal circumstances, so is subject to a different treatment process. The heated water passes through three separators during which time it cools down prior to discharge. If oil is visible in any cooling water, actions are taken to isolate the source of the leak.
This review shows the pros and cons of using the combination of various technologies for industrial wastewater treatment plant. Rapid industrialization, intensive agriculture and other human activities cause soil degradation, pollution and lowers the productivity and sustainability of the crops that further increase the pressure on natural resources and contribute to their degradation. Environmental bioremediation is an effective management tool for managing the polluted environment and in restoring the contaminated soil. The use of microbial sources, coupled with advanced technology is one of the most promising and economic strategies for the removal of environmental pollutants. There is a strong scientific growth with both the in situ
A settling tank (usually referred to as a clarifier or "settler") to allow the waste sludge to settle. Part of the waste sludge is recycled to the aeration tank and the remaining waste sludge is removed for further treatment and ultimate
To recommend an appropriate system for treatment of organic solid waste by using indegenous microbial consortia.
separate solids from the liquid; digest the organic matter and allow the liquid waste to discharge in a storm drain. It is used to provide a storage place so as to give opportunity for the bacteria to reduce all solids to liquid form, and to provide a breeding place to increase the number of bacteria to accelerate the decomposition of solids. Desludging is the process of removing or vacuuming the septic tank content. The septic tank content or Septage, is the combination of scum (masss that floats on the tank surface), sludge (solids that settled on the bottom) and liquid pumped out from a filled-up septic tank.
Conventional centralized systems require a huge financial investment, and have relatively high maintenance and operation costs. The difficulties caused by these expenses do not only prevent developing nations from correctly building and operating centralised sanitation systems, but industrialised nations also
Hazardous waste management is defined as the collection, treatment and disposal of unwanted material that poses the threat to the environmental chemical under managed conditions. In the hazardous management system, the treatment technologies are an inevitable method for a waste management stream. Treatment process is a significant method used to minimise the amount of hazardous waste produced and recover useful products. It can be classified into chemical, physical and biological methods. One of the best ways to get rids of waste is through chemical treatment process. Chemical treatment methods mostly use different properties of chemical to alter the characteristic of hazardous element into less hazardous elements. It is usually required an
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 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.