Wastewater must be made safe, and disinfection is a crucial step in accomplishing this. Water is treated with disinfectants to eliminate pathogenic germs.
What are 3 disinfection processes in wastewater treatment?
Chlorine is a very powerful way to get rid of practically all pathogenic germs, from water. It has both primary and secondary disinfecting use. As it is so hazardous, it cannot be used in a residential system. It is fatal at concentrations as low as 0.1% air by volume.
All the elements of water, including chemicals, small animals, microbes, plant matter, scents, colours, and tastes, readily combine with chlorine. To meet the need for chlorine in the water and provide residual disinfection, a sufficient amount of chlorine is required.
The chlorine that remains after it has been combined with other elements of water, is known as residual (free) chlorine. The breakpoint is the point at which free chlorine is continuously accessible for disinfection. An ideal system would have free chlorine delivered, at a concentration of 0.3 to 0.5 mg/l.
Advantages of using chlorine as a disinfectant
· Compared to UV or ozone disinfection, chlorination is a less expensive source for treating water.
· It works well against a variety of harmful germs.
· Due to their flexibility, dosing rates are simple to regulate.
· Even after initial treatment, the chlorine leftovers in the wastewater effluent can lengthen the disinfection process. They can also be utilized to assess the efficacy.
In order to create ozone, three oxygen molecules are joined to form an allotrope (unstable) new molecule. It breaks down fast, producing free radicals that are extremely reactive.
The oxidation potential of ozone (2.7 V) is higher than that of hypochlorite ion (1.49) and chlorine (1.36), two common oxidants used in wastewater treatment. The hydroxyl radical (•OH) and fluoride are the two substances that can oxidize more than ozone.
Ozone is created from an oxygen-containing gas (usually ambient air or pure oxygen). After that, a gas is run through an electric field. To ensure that the air is dry and free of dust particles, it is treated.
Ozone is created when oxygen is exposed to an electrical field. After that, the ozone is fed into the contact tank, where it is dissolved by water to continue the disinfection process.
Advantages of ozonation
When ozone is used to treat water, the benefits are as follows:
· Ozone has a potent oxidizing power.
· In order to destroy germs (including viruses) in a matter of seconds, quick reaction time is required.
· Taste and color remain unchanged.
· Does not require chemicals.
· Removes and destroys algae.
· Oxidizes manganese and iron.
· Eliminates all organic stuff after reacting with it.
3: Ultraviolet radiation (UV)
Aquaculture, drinking water, and wastewater can all be treated with UV light. The biological components of bacteria are altered by the UV radiation, notably the chemical connections in DNA, RNA, and proteins are broken.
The structure is very straightforward and comprises of a UV light source, which is encased in a clear protective sleeve. The light source is positioned to allow water to flow through a flow chamber, allowing UV rays to enter the stream and be absorbed there.
An advantage of this procedure is that flavour and color are not altered. Because, these beams quickly eradicate the dangerous microorganisms, the contact period is likewise quite brief.
Advantages of UV light
· It prevents an increase in the concentration of biodegradable or assimilable organic carbon (AOC), by limiting the regeneration potential within the distribution system.
· There are no issues with interactions with pipe material.
· There are no by-products produced, including acetaldehydes related with haemoglobin, trihalomethanes, aldehydes, ketoacidosis, and bromate.
· Giardia and Cryptosporidium can be effectively inactivated with UV light, at a lower cost than with chlorine dioxide or ozone.
· There is no evidence of the development of chlorinated disinfection by-products (DBP), when used in conjunction with chloramines.
What do we offer?
Since, effluent composition varies, specialized wastewater management is required. Every project is different, and our experts at Netsol Water will assist you in selecting the most effective technique, such as an effluent treatment plant for treating effluent in the best way.
Netsol combines cutting-edge technology with years of experience, to handle the most challenging water treatment or wastewater treatment requirements of a wide range of clients, including small enterprises, corporations, and regional government agencies.