STP

IDENTIFICATION OF STP
S.NO	Name	Description	Particular
	Sewage Treatment Systems	Sewage treatment is the process of removing	The microbial population in treatment process can be
		contaminants  from waste water,  primarily  from	cultured using the following systems:
		household sewage. It includes physical, chemical and	a) Suspended growth system — In this system,
		biological processes to remove these contaminants and	microorganisms remain in suspension and
		produce environmentally safe treated waste water	their concentration is related to mixed liquor
		(or treated effluent).	suspended solids (MLSS).
		The  by-product  of  sewage  treatment  is  usually  a	b) Attached growth system — In this system,
		semisolid waste or slurry, called sewage sludge, that	microorganisms are developed over mobile or
		has to undergo further treatment before being suitable	immobile solid covered in biomass (slime).
		for disposal or further application .	c) Combined growth system — In this system,
		The main objective of treating waste water is to	both systems are used to attain the shock
		stabilize decomposable organic matter present in the	loads.
		sewage so as to produce treated effluent and sludge,
		which can be disposed of in the environment without
		causing health hazards or nuisance.
	Technologies	a) Extended  aeration with  activated  sludge
		process (EAASP) — Activated sludge process
		is  the  biological  process  by which  non-
		settleable substances occurring in dissolved
		and  colloidal  forms  are  converted  into
		settleable sludge which is removed from the
		liquid carrier (water).
		This process is well suitable for completely
		populated community and does not require
		skilled labour for handling the plant. It is time
		tested and requires more number of units to
		achieve biological oxygen demand (BOD) less
		than 10 ppm, like coagulants required for
		better quality.
		b) Sequential batch reactor (SBR) — It is an
		activated sludge process designed to operate
		under non-steady state conditions. An SBR
		operates in a true batch mode with aeration
		and sludge settlement both occurring in the
		same tank. There is a degree of flexibility
		associated with working in a time rather than
		in a space sequence.
		Plant for this process requires less space due
		to batch process, well suitable for modular
		growth. It can handle smallest flows and the
		desired  quality  can  be  achieved without
		coagulants.  It  requires  good  quality  of
		decanters, and skilled labour as the process is	Pollutants in sewage
		timer-based automation.
			• BOD(Bio Chemical Oxygen demand)
		c) Membrane  bio-reactor  (MBR) —  It  is  a	•COD(Chemical Oxygen demand)
		continuous  process  of  activated  sludge	•TSS(Total Suspended Solids)
		treatment,  but  solids  separation  is  done	PH
		through pressurised system or through media.
		As  there  is  physical  barrier  for  solid	BOD(Biochemical Oxygen demand)
		separation, quality of treatment is good.
		It is suitable for any type of growth pattern	The BOD is an important measure of water quality .It is measure of the amount of oxygen needed by bacteria and other organisms to oxidize the organic matter present in a water sample over a period of 5 days at 20 degree C.
		and can handle smaller flows. It requires less
		space, and skilled labours to handle.	COD (Chemical Oxygen Demand)
		d) Rotating bio-bed reactor (RBBR) — It is
		combined  growth  process.  Bacteria  are	Ø COD Measures all organic carbon with the exception of some aeromatics (BENZENE,TOLUENE,PHENOL etc.) which are not completely oxidized in the reaction.
		allowed to grow on media, which is exposed	Ø COD is a chemical oxidation reaction
		to atmospheric air. It is also known as rotating	Ø Ammonia will not be oxidized.
		biological contactor (RBC).
		It is suitable for smaller capacities and does	Total Suspended Solids
		not require skilled labour to handle. The	Ø Total suspended solids(TSS) include all particles suspended in water which will pass through a filter.
		quality of treatment is good.
		e) Fluidized bio-bed reactor (FBBR) — In this	Ø As levels of TSS increase, a water body begins to lose its ability to support a diversity of aquatic life.
		process,  cells  are  immobilized  in  small	Suspended solids absorb heat from sunlight, which increases water temperature and subsequently decreases levels of dissolved oxygen(warmer water holds less oxygen than cooler water
		particles which move with the fluid. The small
		particles create a large surface area for cells	Components of Sewage Treatment
		to stick and enable a high rate of transfer of	Plants
		oxygen and nutrients to the cells. It is also	•           Pumping of Sewage
		known as moving bed bio reactor (MBBR). It	•           Primary Treatment
		is suitable for all type of communities, does	•           Secondary treatment
		not require skilled labour and requires less	•           Tertiary Treatment
		space. It can be installed for all capacities and
		the quality of treatment is good.	Pumping Station
			•        Receiving Chamber
		f) Submerged  aerobic  fixed  film  reactor	•        Coarse Screening
		(SAFF) — It is a combined growth process in	•        Wet Well (Raw Sewage Sump)
		allowed to grow on media, which has air	•        Pump House
		supply from below.	•        Raw Sewage Pumps
		It does not require skilled labour. Supporting
		structure for media should be anti-corrosive
		to enable media fixing.
		g) Trickling filters — It is an attached growth
		process where media is used to grow bacteria
		by trickling sewage over the media. It is an
		old concept and is not now widely used.
		h) Oxidation ponds/lagoons  Oxidation ponds,
		also called lagoons or stabilization ponds are
		large  shallow  ponds  designed  to  treat
		wastewater through the interaction of sunlight,
		bacteria, and algae.
	What is biological treatment of wastewater?	Biological treatments rely on bacteria, nematodes, or other small organisms to break down organic wastes using normal cellular processes. Wastewater typically contains a buffet of organic matter, such as garbage, wastes, and partially digested foods. It may also contain pathogenic organisms, heavy metals, and toxins	Step by Step Wastewater Treatment Process
	What do sewage treatment plants do?	Sewage treatment is the process of removing contaminants from wastewater and household sewage water. Click here for our range of sewage treatment plants. ... Its aim is to produce an environmentally safe sewage water, called effluent, and a solid waste, called sludge or biosolids, suitable for disposal or reuse.	1. Wastewater Collection
	What are the 3 stages of sewage treatment?	Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment. Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface	This is the first step in waste water treatment process. Collection systems are put in place by municipal administration, home owners as well as business owners to ensure that all the wastewater is collected and directed to a central point. This water is then directed to a treatment plant using underground drainage systems or by exhauster tracks owned and operated by business people. The transportation of wastewater should however be done under hygienic conditions. The pipes or tracks should be leak proof and the people offering the exhausting services should wear protective clothing.
	What are the steps of wastewater treatment plant?	Treatment Steps	2. Odor Control
		Step 1: Screening and Pumping. ...	At the treatment plant, odor control is very important. Wastewater contains a lot of dirty substances that cause a foul smell over time. To ensure that the surrounding areas are free of the foul smell, odor treatment processes are initiated at the treatment plant. All odor sources are contained and treated using chemicals to neutralize the foul smell producing elements. It is the first wastewater treatment plant process and it’s very important.
		Step 2: Grit Removal. ...	3. Screening
		Step 3: Primary Settling. ...	This is the next step in wastewater treatment process. Screening involves the removal of large objects for example nappies, cotton buds, plastics, diapers, rags, sanitary items, nappies, face wipes, broken bottles or bottle tops that in one way or another may damage the equipment. Failure to observe this step, results in constant machine and equipment problems. Specially designed equipment is used to get rid of grit that is usually washed down into the sewer lines by rainwater. The solid wastes removed from the wastewater are then transported and disposed off in landfills.
		Step 4: Aeration / Activated Sludge. ...	4. Primary Treatment
		Step 5: Secondary Settling. ...	This process involves the separation of macrobiotic solid matter from the wastewater. Primary treatment is done by pouring the wastewater into big tanks for the solid matter to settle at the surface of the tanks. The sludge, the solid waste that settles at the surface of the tanks, is removed by large scrappers and is pushed to the center of the cylindrical tanks and later pumped out of the tanks for further treatment. The remaining water is then pumped for secondary treatment.
		Step 6: Filtration. ...	5. Secondary Treatment
		Step 7: Disinfection. ...	Also known as the activated sludge process, the secondary treatment stage involves adding seed sludge to the wastewater to ensure that is broken down further. Air is first pumped into huge aeration tanks which mix the wastewater with the seed sludge which is basically small amount of sludge, which fuels the growth of bacteria that uses oxygen and the growth of other small microorganisms that consume the remaining organic matter. This process leads to the production of large particles that settle down at the bottom of the huge tanks. The wastewater passes through the large tanks for a period of 3-6 hours
		Step 8: Oxygen Uptake.	6. Bio-solids handling
	What is wastewater treatment definition?	Links. Sewage Treatment, Or Domestic Wastewater Treatment:: Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater, both runoff (effluents) and domestic. It includes physical, chemical and biological processes to remove physical, chemical and biological contaminants	The solid matter that settle out after the primary and secondary treatment stages are directed to digesters. The digesters are heated at room temperature. The solid wastes are then treated for a month where they undergo anaerobic digestion. During this process, methane gases are produced and there is a formation of nutrient rich bio-solids which are recycled and dewatered into local firms. The methane gas formed is usually used as a source of energy at the treatment plants. It can be used to produce electricity in engines or to simply drive plant equipment. This gas can also be used in boilers to generate heat for digesters.
	What are types of wastewater?	Types and sources of wastewater. Wastewater comes in three main types namely Blackwater, Graywater and Yellow water. This is wastewater that originates from toilet fixtures, dishwashers, and food preparation sinks. It is made up of all the things that you can imagine going down the toilets, bath and sink drains	7. Tertiary treatment
			This stage is similar to the one used by drinking water treatment plants which clean raw water for drinking purposes. The tertiary treatment stage has the ability to remove up to 99 percent of the impurities from the wastewater. This produces effluent water that is close to drinking water quality. Unfortunately, this process tends to be a bit expensive as it requires special equipment, well trained and highly skilled equipment operators, chemicals and a steady energy supply. All these are not readily available.
			8. Disinfection
			After the primary treatment stage and the secondary treatment process, there are still some diseases causing organisms in the remaining treated wastewater. To eliminate them, the wastewater must be disinfected for at least 20-25 minutes in tanks that contain a mixture of chlorine and sodium hypochlorite. The disinfection process is an integral part of the treatment process because it guards the health of the animals and the local people who use the water for other purposes. The effluent (treated waste water) is later released into the environment through the local water ways.
			9. Sludge Treatment
			The sludge that is produced and collected during the primary and secondary treatment processes requires concentration and thickening to enable further processing. It is put into thickening tanks that allow it to settle down and later separates from the water. This process can take up to 24 hours. The remaining water is collected and sent back to the huge aeration tanks for further treatment. The sludge is then treated and sent back into the environment and can be used for agricultural use.
			Wastewater treatment has a number of benefits. For example, wastewater treatment ensures that the environment is kept clean, there is no water pollution, makes use of the most important natural resource; water, the treated water can be used for cooling machines in factories and industries, prevents the outbreak of waterborne diseases and most importantly, it ensures that there is adequate water for other purposes like irrigation.
			Conclusion
			In summary, wastewater treatment process is one of the most important environmental conservation processes that should be encouraged worldwide. Most wastewater treatment plants treat wastewater from homes and business places. Industrial plant, refineries and manufacturing plants wastewater is usually treated at the onsite facilities. These facilities are designed to ensure that the wastewater is treated before it can be released to the local environment. Some of the water is used for cooling the machines within the plants and treated again. They try to ensure that nothing is lost. It illegal for disposing untreated wastewater into rivers, lakes, oceans or into the environment and if found culpable one can be prosecuted.