The pharmaceutical industry generates lots of wastewater during the production or formulation of medicines. So it is very important to convert wastewater by using various techniques. Water purification technology uses to remove solids from liquids. The impure solids may be Course, suspended, colloidal, and dissolved solids, and in purification, these are required to be removed in descending order with chain treatment.
Collection of Wastewater:
It is advised to collect the wastewater with the help of a closed pipe Line or by giving Gutter wastewater taken to the ETP side. in the open gutter, more pollutants like algae, vegetation, side Earth, leaves, papers, and plastic can enter into the effluent plant. Velocity in the closed pipe can be kept between 2.5 to 3.5 feet/second and in the case of an open Gutter 2.5 to 8 feet/second, so that solid does not normally settle out and get pushed ahead. It is very important to maintain the velocity, it should not be too high; it should not be more than 6 to 7 feet per second in the open gutter and 8 feet per second in a closed pipeline. The slope shall be provided every 50 meters for cleaning gutter and pipelines.
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Stages involve in Effluent Treatment Plant (ETP)
- Screen for ETP
- Grit chamber
- Oil grease Trap
- Equalization Tank
- Neutralization Tank
- Primary Clarifier
- Flocculation Tank
- Anaerobic Lagoons
- Aeration Tank
- Secondary Settling
- Sludge Drying bed
- Oxidation Pond
- Chlorination Tank
Screen for ETP:
The screen shall be fitted 45 to 60 degrees to the vertical if desired. The screen shall be at the right angle to the direction of flow. Screen used to remove large size particle size, cloth and plastics screen size used of 10 mm.
Grit is an inorganic pollutant and inert in nature, heavier in weight, and easily and quickly settable class.
Oil grease Trap:
It is necessary to remove oil or grease that comes through lubrication, boiler, cooling tower, and blowdown of the boiler. T-Pipe and gutter are used to avoid floating grease or oil. Then it is necessary to remove the top of the water and collected it in the waste drum. Then it should be sent to further disposal and treatment.
Water is mixed for making the homogeneous mixture with the help of air or a stirrer in an equalization Tank to remove heterogeneity.
The neutralization tank is used to adjust the pH of effluent with the help of acid (HCL) for alkali (NaOH).
To neutralize 1 mg/liter of acidity, the requirements of chemical in mg/liter are given as calcium carbonate 1.0, calcium oxide 0.56, calcium hydroxide 0.74, Sodium Hydroxide 0.8, likewise to neutralize 1 mg/liter of alkalinity the requirement of chemical in mg/liter is given as sulfuric acid 0.98, HCL 0.72, nitric acid 1.26, and carbonic acid 0.62. Water must be neutral for further treatment.
It works on the gravitational force. It separates the solids from wastewater settable under Gravity, force is dealt with in the primary sedimentation tank, settling tank, or clarifier. It is primarily because the solid that settles there is in the effluent right from the beginning, while what settles in the secondary clarifier is the Biomass solid, which gets created by secondary biological activity letter on in the same ETP it is absent.
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A flocculation tank is used in the Effluent treatment plant to dissolve the colloidal solid. These are solid, and their size is between less than suspended solids and greater than dissolved solids.
The size of them is not more than one micron. They are electrically charged because of which they do not have a settling Tendency. Alum, lime, FeSO4, and polyelectrolytes are used to settle the colloidal by Forming lamps.
Bacteria are needed for the treatment of effluent wastewater. These bacteria are classified into three categories aerobic, anaerobic, and facultative. Bacteria need Oxygen for slow combustion. This Oxygen is taken from the water. Those bacteria are aerobic.
Anaerobic bacteria form the bond by decomposing carbonate sulfate, nitrate, and facultative. These classes can use either of the sources of Oxygen and work in the presence and absence of Oxygen. Anaerobic bacteria also need or, but there is no need to fix aerators. They use Urea, and superphosphate is limited because of the earlier embankment of the tank; it is termed a lagoon.
Aeration is provided to the tank with an aerator or agitator. This technique is important for trickling filters, oxidation ponds, aerated lagoons, activated sludge, bio-disc, bio bulb, etc.
Once the completion of aeration, the micro-organism utilized the biological oxygen demand as food and grew and multiplied; as a result, the Biomass started appearing as a block patch, and this flock got separated out as sludge from liquor. A problem arises if the Biomass remains mixed in liquor, these access layers are removed from the tank to the alternative sludge bed to dry the sludge and use it as soil for land feeling. Maintained 20-30% Sludge to water.
Sludge Drying bed:
Sludge settled in the clarifier is removed in these beds and dried and used for landfill.
This is a simple system for treating effluent and stabilizing the organic impurity. Here water is getting pure from the wastewater.
Chlorination is done to kill pathogens. Chlorine is also combined with many other chemicals like Ammonia, iron, manganese, sulfide, odor, and color production material. Chlorine helps with the purification of water. The chlorine dosing depends on the stage at which wastewater is already treated.
The resident chlorine should not be less than 0.5 mg per liter and not more than 1.0 mg per liter.
Utilize dated pure water for gardening purposes after testing and release by QC.
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