Aeration is a process through which air is diffused or comes into close contact with water naturally or artificially to change the state or concentration of gases or volatile substances contain in water. Aeration have been employed to improve the quality of water supply either domestically or industrial wise by converting the chemical compounds and gases known as contaminants into a more acceptable compounds.
The process of aeration involved two principles as follows;
1. Degassing
2. Oxidation
1. Degassing is both mechanical and chemical in principle, is a process where gases are expel from water. It involves stripping of gases from water.
2. Oxidation is chemical in principle, it involves chemical reactions between the diffused oxygen and chemicals and metals in the water.
These two principles of degassing and oxidation are largely governed primarily by the ratio of the air in contact with the surface area of the water. An increase in surface area of the air and water will results in an increased in oxygen transfer rate. For this reason in the design of an aeration/ degasser tank it is very important to include enough space in the rank and to provide a means through which the incoming water are rapidly broken down into smaller units. The use of shower and poly synthetic raisin have been of help, if this is not properly achieved, then the purpose of aeration will be defeated and we will have incomplete oxidation and degassing, and there must also be an escape route for the gases expelled.
An Aerator System For Water Treatment |
Aeration will improve the quality of water by removing some of the following
1. Gases and
2. Inorganic Compounds
1. Gases
Gases such as carbon monoxide, Carbon dioxide, hydrogen sulphide, methane, ammonia e.t.c are removed through the process of aeration.
A. Carbon monoxide and Carbon dioxide; Carbon monoxide react with diffused oxygen to form carbon dioxide, this is corrosive as it create an acidic water. This occur more in a shallow wells than in deep wells, which is part of what is responsible for the corrosiveness of water.
An Aeration Tower For Water Treatment |
B. Hydrogen sulphide which is very corrosive with foul smell odour is also remove through the process of aeration at a ph of between 6-6.5. Hydrogen sulphide occur more in underground water than in surface water, this contribute to the corrosiveness of water. Hydrogen sulphide react with chlorine in water as part of chlorine demand value. Hydrogen sulphide exist in an ionized form when in an alkaline water in which the ph is above 8, in order to solve this type of problem lower the ph of the water and then aerate.
C. Methane is more prevalent in ground water than in surface water, it also add to chlorine demand value, methane can be remove from water through aeration process, thereby reducing the concentration that will be available to form trihalomethane, and disinfectant bye products(DBP)
An Aeration System For Water Treatment |
2. Inorganic compounds such as Iron and Manganese concentration are reduce through aeration, these compounds formed through oxidative reactions forms precipitates and are suspended in water but at the right ph of 6-6.5 they coagulate and flocculate and form a larger particles which are then remove by filtration or draining if the large particles that have settled down at the base of the water tank. The addition of an alkali will also help to bring about complete oxidation of iron and manganese, as the alkali optimizes the ph of the water and make use of diffused oxygen to oxidize iron and manganese. At the same time the alkali reduces the concentration of carbon dioxide in the water.
During the aeration of water we must make sure that too much of air is not pumped into the system, as over aeration is bad with corrosive water, carbon dioxide will dissolve in water to form carbonic acid.
H2O+CO2=H2CO3
An Aeration System For Water Treatment |
Aeration is one of the techniques use in treating water at the households level and also industrial level. It very cheap and reduce the cost of water treatment, and also prevent or reduce to the minimum the formation of disinfectant bye products, when chlorine is to be use as disinfectant and also the formation of monochloramine and other ammonia weak disinfectant.
Mycleanwater Nigeria is a registered business name in Nigeria, we are into water treatment and domestic water treatment plant installation and services
Kindly visit our business site for more information Click Here
To Join Mycleanwater Nigeria WhatsApp Group Click here
For Our Facebook Page Click here
Comments
Post a Comment