The multi-stage process of wastewater cleaning ends with tertiary wastewater treatment, by eliminating inorganic substances, bacteria, viruses, and parasites. The removal of these dangerous components renders the treated water safe for reusing, recycling, or environmental release.
Take a look at the summary of what tertiary treated wastewater is, the need of tertiary wastewater treatment, as well as techniques and procedures used in the tertiary treatment of wastewater.
What is tertiary wastewater treatment?
Primary and secondary treatment together with certain additional preliminary techniques, make up the majority of wastewater treatment systems. Grit, debris, oil, grease, and certain lighter solids are removed through physical processes, such as filtration and settling during primary treatment, which typically removes 50% to 70% of the suspended solids in wastewater.
Activated sludge treatment and aeration are examples of secondary biological processes, which are used to break down suspended and dissolved biosolids, utilising beneficial microorganisms.
The addition of tertiary treatment adds a third, more challenging degree of care. Tertiary treatment such as disinfection with chlorine, UV or Ozone, or using membrane technologies such as RO Plants can accomplish degrees of water purification that makes the water suitable, for reusing in water-intensive operations.
What is the need of tertiary treatment of wastewater? What are the advantages of tertiary treatment of wastewater?
Tertiary treatment is not used in all wastewater treatment facilities. For many purposes, primary and secondary treatments are frequently sufficient. Those who do employ tertiary treatment reach higher standards of cleanliness, to adhere to the strict regulations governing water reuse, particularly in public water supplies.
It is crucial in the production of industrial pulp and paper as well as textiles and other manufacturing goods, because it removes undesired substances from wastewater more effectively than primary or secondary treatment.
Stages of wastewater treatment
Stages of treatment of wastewater
Let's quickly go over primary and secondary wastewater treatment before getting into the specifics of tertiary wastewater treatment procedures.
1: Filtration is the first step in the primary treatment of wastewater for big solid pollutants.
2: The effluent is subsequently cleaned through secondary treatment using bio-filtration, aeration, and oxidation. All of these procedures aid in the removal of silt from water.
3: Tertiary wastewater treatment is used to remove dangerous microbiological pollutants. Filtration normally comes first, then extra disinfection treatment. Other specialised treatments, like as lagoon storage, biological nutrient removal, and nitrogen and phosphorus removal, RO Plants, disinfection procedures, may also be used as part of tertiary treatment in specific circumstances.
Filtration
Tertiary treatment commonly uses sand and activated carbon, but they can also use finely woven fabric. Additionally, there are several types of filters, such as bag filters, drum filters, and disc filters.
Disinfection
There are several ways that tertiary disinfection can be done:
· Treatment with chlorine
Because it is inexpensive, simple to use, and effective, chlorine is one of the disinfectants that is most frequently used in wastewater treatment. To eliminate unwanted microorganisms like bacteria and viruses, wastewater treatment facilities might add chlorine to the wastewater.
Treatment with ultraviolet light or UV light
In tertiary wastewater treatment, ultraviolet (UV) light is frequently used as a disinfectant. The UV radiation sterilises bacteria by destroying their genetic structures, as it passes beneath banks of wastewater flowing under them. While, viruses and bacteria are often not killed by ultraviolet light, they are rendered incapable of infecting people or other living things.
However, the effluent must have undergone thorough treatment first, as any organic substance that is still there can protect the microbes from the UV rays. Additionally, the lamps need a lot of up-keep.
· Ozone treatment
An alternate option is to employ ozone, which is created by adding a third oxygen atom to regular diatomic O2, using electrical energy. Due to its high reactivity, ozone can kill the majority of microorganisms it comes in touch with.
Because, plants may produce it locally as needed rather than storing it for extended periods of time and running the risk of a harmful leak, it is safer than chlorine. Additionally, it won't produce harmful by-products in the water. However, maintaining the treatment equipment is rather expensive.
· De-chlorination
Chlorine can occasionally produce chemicals like trihalomethanes and mutagen X when it interacts with organic matter. Chlorinated wastewater must be de-chlorinated before being released into the environment, because it can affect aquatic habitats.
A substance called as sodium bisulfite is added to the wastewater to eliminate the chlorine. With the help of this chemical, chlorine ions in the water are eliminated. The treated water is now deemed safe enough to be released into the environment, once the chlorine concentration has been brought down to a safe level.
Discharge of treated wastewater
The wastewater is prepared for release back into the environment after tertiary treatment. Tertiary treatment should be adequate to meet the standards set by these governments, maintain environmental cleanliness, and protect public health. Many municipalities have special rules for the release of treated water.
Reuse of treated wastewater
Tertiary treatment is frequently used in wastewater treatment facilities in order to make water fit for human consumption. Tertiary-treated water is also suited for a wide range of processes that need clean water, including manufacturing and industrial processes, the extraction and refining of oil and gas, the cooling of utilities, and agricultural practises like irrigation.
For all your tertiary wastewater treatment needs, get in touch with Netsol water solutions
Make Netsol your go-to resource for help with your tertiary wastewater treatment system. As a full-service wastewater treatment engineering firm, we have the experience and sector knowledge to assist you in increasing the efficacy of your treatment, or ensuring that the wastewater you release complies with environmental regulations.
We are delighted to offer field services and assistance with the choice of treatment products, in addition to providing comprehensive system design and engineering. To find out more, get in touch with us at +91 9650608473 or enquiry@netsolwater.com