GPCB Norms For Potable Water

 Potable water is one type of drinking water. 

The norms are follows;

1.) It should be sparking clear and odour. 

2.) It should be pleasant in taste. 

3.) It should be perfectly cool. 

4.) It's turbidity should not exceed 10 ppm( parts per million). 

5.) It should be reasonable soft. 

6.) It total dissolve solid should be less than 500 ppm. 

7.) It should be free from Objectionable dissolve gases like Hydrogen sulfide H2S. 

8.) It should be free from objectionable mineral such as lead, arsenic, chromium.

9.) It's pH should be about 8.

10.) It should be free from disease producing micro-organisms. 

BOD, COD, Dissolve Solid, Dissolve oxygen

Dissolve oxygen:-Dissolve oxygen is the amount of oxygen in its dissolve state in the waste water. 

Generally waste water doesn't have any dissolve oxygen. 

Biological oxygen demand:-BOD may defined as the oxygen required for micro organism to carry out the biological decomposition of dissolved solid or organic matter in the waste water under aerobic condition at standard temperature. 

Chemical oxygen demand:-COD measure oxygen require equivalent of organic matter presence in waste water sample for oxidation by strong chemical oxidant

Chemical oxidant means oxidizing agent. 

Dissolve solid:-It is measure content of all inorganic and organic substance in liquid or waste water sample. 

Methods Of Waste Disposal

1.Open dumping:-Open dumping of solid waste is practiced extensively in india because it is cheap and require no planning. 

Generally low lying area, village and out skirts of town and cities are used for same purpose. 

The open dumping caused health problem by encouraging the mosquito rates and other pest. 

2.Composting:-Composting is the biological reclamation of organics material by natural decomposition process. 

For example decay of falling leave, dead animal and it's excreta. 

3.Sanitary Land Fill:-It is method of disposing waste on the land by covering of solid waste inside the land by using soil as shown in fig. 

4.Incineration:-It is the process of burning of solid waste by heating at high temperature about 850 °C.

5.Reuse,Recycle,Recover:-This process is most widely used nowadays, because it reduce the solid waste and indirectly pollution. 

Solid waste generated from industry ,household and other field contain significant amount of valuable material like steel, copper, iron, plastic and other material if they are recovered and reused would reduce the volume of the waste. 

Difference Between Drop wise and Film Wise Condensation

Drop-wise Condensation :

1.When a saturated vapour comes into contact with a cold surface (a surface at a lower temperature), it condenses and if condensate does not wet the surface, the droplets formed on the surface. These droplets grow and ultimately fall down the surface in a random fashion under the influence of gravity leaving behind the bare metal surface on which further condensation takes place. The condensation occurring by this mechanism is known as drop- wise condensation.

2.Heat transfer coefficients are very high as the heat does not have to flow through a film by conduction.

                                            

                            

3.Oily or greasy surfaces seem to tend towards drop-wise condensation.
4.Drop-wise condensation is very difficult to achieve.
5.Drop-wise condensation is unstable and difficult to maintain, uncommon and so not desired industrially.
6.Heat transfer coefficients and heat transfer rates are very high.