Industrial waste water treatment. 


The first stage of purification of industrial waste water usually removes floating solids, flavors and odors and colors. In addition

The pH is also neutralized at this stage of purification. This stage of refining is usually done with the help of the following methods

Industrial waste water is purified.


(i) Screening

(ii) Neutralization

(iii) Equalization

(iv) Sedimentation

(v) Coagulation

(vi) Precipitation

(vii) Co-precipitation

The second stage of industrial wastewater treatment is the organic method. This method uses bacteria for oxidation

Is done. Bacteria use the organic matter present in the wastewater as food and in a short time the wastewater becomes organic.

The substance is free. Among the methods used at this stage are the following:

(i) Trickling filter

(ii) Anaerobic digestion

(iii) Oxidation ditch

(iv) Aerated lagoon

(v) Activated sludge process

(vi) Oxidation pond.

Activated sludge process of industrial wastewater treatment

waste water treatment):

The activated sludge method is an important organic oxidation method. In this way the waste is floating from the water

(Suspended) and Colloidal solids can be removed. In addition, the organic oxygen demand (BOD) of water is low

By In this method the ongoing decomposition of the organic matter present in the waste water by microorganisms is carried out. The decomposition of organic matter is a

Is done in the tank and the tank is mechanically supplied with oxygen. Sludge deposited in the form of sediment inside the tank

Remains and some waste water goes back into the decomposition process.

The efficiency of the activated sludge system depends on the following factors.

(i) pH value

(ii) Temperature

(iii) Volume of tank

(iv) Nature of organic matter

(v) Velocity of water flow

(vi) Oxidation and Reduction potential of Sludge.

The microorganisms active in the activated sludge process are bacteria, fungi, protozoa, nematodes and rotifiers.

The nutrients nitrogen and phosphorus are supplied to the tank as food for the microorganisms. Usually nitrogen and

Urea, mono-ammonium or di-ammonium hydrogen phosphate are supplied as phosphorus. 10% per day

Requires 2% nitrogen and ammonium. Actual demand depends on the amount of sludge. Activated

In the sludge method the pH value is kept from 7.5 to 9.0. This is because bacteria do not work well when the pH is less than 7.5 and 9.0

If more, the speed of digestion process decreases.

Some chemists propose the following modification of the activated sludge method

(i) Contact stabilization

(ii) High rate aerobic treatment

(iii) Stepped aeration

(iv) Extended aeration

(v) Taper aeration.

Of the above aeration methods the extended aeration method is more acceptable, where the aeration method is 10845 hours.

f goes. If the aeration of waste water is done in different steps in different tanks, it is called stepped aeration.

And if the supply of oxygen gradually decreases, then it is called tapered aeration. Currently

The modified activated sludge method is called high rate aerobic treatment.

Theoretical

Trickling filter method of industrial waste

water treatment):

Trickling filter is a round or quadrangular bed made by advanced means. Its depth is 1

M to 3 m. Broken stone as medium, PVC, coal, rock coal, synthetic, resin

(Resin), Grave. Etc. are used. They range in size from 40 mm to 150 mm. Rotating device attached to the nozzle

The water is sprinkled in such a way that water falls on all the beds. So in this method the waste water is through the medium

It flows in drops. The filta ring arrangement is done in such a way that air can enter from the bottom. That is wind

And the water flows in opposite directions. Gelatinous membrane on the surface of the bed with a combination of bacteria and microorganisms

Is created. This screen is called Zooglea. Organic contaminants get stuck in this adhesive screen and present bacteria and microorganisms

Is oxidized by. If the screen becomes too thick, some part is cleaned, which is of flowing water

Is flowing with. In the trickling filter method the accumulated material starts to accumulate in one place and is removed through charge neutralization. The trickling filter method can be divided into aerobic and anaerobic. Spores in aerobic bacteria

Productive bacteria and Bacillus bacteria are notable. Desulfo vibrio in anaerobic bacteria

Notable. Aerobic bacteria located at the top of the filter bed and anaerobic bacteria at the top of the rock

Microorganisms

The screen created by is very sensitive to temperature. Exists in the water flowing through the filter

The decomposition of organic matter is proportional to temperature. Thus the effectiveness of the trickling filter decreases in winter.