What is the Nalgonda technique?
The process comprises of addition of aluminium salt, lime and bleaching powder to the raw water followed by flocculation, sedimentation and filtration. The domestic level treatment is performed in a bucket or any plastic container. For community level, fill-and-draw type plants are used with capacity up to 400 m3/day.
Who developed Nalgonda technique?
the National Environmental Engineering Research Institute
A simple and effective process, the Nalgonda technique of difluoridation, has been developed by the National Environmental Engineering Research Institute. The process has been adapted for defluoridation öf potable water at domestic as well as community level.
What are the methods of defluoridation?
There are several different types of defluoridation method. The following are defluoridation method; bone charcoal, contact precipitation, Algona, activated alumina, ion-exchange technique, membrane filtration, nanofiltration, and clay.
What is defluoridation and explain?
Defluoridation is the downward adjustment of the level of fluoride in drinking water. Worldwide, fluoride is one of the most abundant anions present in groundwater. Fluoride is more present in groundwater than surface water mainly due to the leaching of minerals.
Why Nalgonda technique is called Nalgonda technique?
Explanation: Nalgonda Technique: This technique helps in the removal of fluoride or deflouridation along with the removal of colour, odour, turbidity, bacteria, and organic contaminants from raw supplies. Defluoridation using the Nalgonda technique used alum with prior mixing of lime (CaO) or sodium carbonate (Na2CO3).
Which coagulant is added in Nalgonda method?
The Nalgonda system uses aluminum sulfate (alum) and calcium oxide (lime) chemicals added to the reactor tanker and mixed rapidly with high fluoride concentration water.
Which of the following is removed from water using Nalgonda technique *?
fluorides
The following technologies are generally used for removing fluorides from water. Nalgonda Technique: Mainly used in rural areas, groundwater containing excess fluoride. Nalgonda technique uses aluminum salt (alum) for removing fluoride.
What is flocculation process?
Flocculation is a process by which a chemical coagulant added to the water acts to facilitate bonding between particles, creating larger aggregates which are easier to separate. The method is widely used in water treatment plants and can also be applied to sample processing for monitoring applications.
What chemical is used for flocculation?
Aluminum sulfate or alum (Al2(SO4)3), ferric chloride (FeCl3) and ferric sulfate (Fe(SO4)3) are the most widely used flocculants [1, 70]. These flocculants have a long history of use in removing colloidal particles from water and wastewater [15, 17].
What is the purpose of flocculant?
Used in a wide range of industries and applications, flocculants help to remove suspended solids from wastewater by aggregating contaminants into flakes or “flocs” that float to the surface of the water or settle at the bottom. They can also be used for lime softening, sludge thickening, and solids dehydration.
What is the principle of flocculation?
Flocculation refers to the process used to bring the coagulated particles together so that they can combine to form larger, settleable, and filterable masses of particles called floc. Zeta potential is defined and its role in coagulation described.
Does flocculant affect pH?
Because flocculants can affect the pH level, you’ll want to start out with it at about 7.0 so you can make sure your sanitizer keeps working at maximum efficiency.
What is difference between flocculation and coagulation?
Coagulation and flocculation are two separate processes, used in succession, to overcome the forces stabilising the suspended particles. While coagulation neutralises the charges on the particles, flocculation enables them to bind together, making them bigger, so that they can be more easily separated from the liquid.
How long should flocculant sit?
8 Hours
Let Pool Flocculant Sit for 8 Hours
Turn off your pump and allow the pool to sit for at least eight hours. This is easiest to do overnight. If you have an automatic timer set on your system, remember to turn it off.
Does flocculant raise pH?
What happens if you use too much flocculant?
Too much flocculant means that it will start to stick to itself over and above the bacteria and algae spores that we’re trying to clear. The issue with this happening is that it won’t sink to the bottom. It’ll stay floating in your pool and start to cause more problems, like clogging your pool filter.
What is main ingredient in flocculant?
The main ingredient in pool (or spa) flocculants is aluminum sulfate. Clarifiers are often confused with Flocculents, which is similar but works differently.