WASTEWATER TREATMENT (#appliedchemistry)(#environmentalegineering)(#wastewater)(#ipumusings)(#biotechnology)
WASTEWATER TREATMENT
Author: PALAK JAIN
India is a developing nation and one of the world’s fastest economies. However, despite its active growth as it urbanizes, its water forms are becoming toxic. According to a report, around 70% of surface water in India is inadequate for use. Almost every day, 40 million litres of wastewater contaminates the water bodies without being treated properly. In some areas, rivers and lakes are so polluted that they are catching fire. For example, in 2015, Bellandur Lake in Bangalore caught fire and carried ash onto structures up to 9.6 kilometres away. A report says that without necessary action, water conditions will continue to worsen, affecting human health, majorly decreasing food production and, consequently, delaying economic progress. [1] [2]
And therefore Wastewater Treatment is the prime solution to the above-mentioned problems. Let’s learn how it is effective.
BIOTECHNOLOGY IN WASTEWATER TREATMENT
Wastewater treatment is the method of refining the wastewater produced from households, industries, and sewages. The process removes the contaminants from water in the form of organic material.
Growing agricultural and industrial pollution has led to a more prominent need for techniques that can eliminate distinct contaminants from nature. The latest practices include aerobic, anaerobic, physical, and chemical processes under settled bed filters and bioreactors in which the elements and microorganisms are kept in a moratorium. The expenses of wastewater treatment can be decreased by the reformation of waste into useful products. Most of the anaerobic wastewater processing technology methods generate useful biogas.
Biotechnology has presented successful practices by which wastewater contaminants can be removed. A highly significant aspect of biotechnology is its ability to restore and purify wastewaters for reuse purposes, thus resulting in the sustainable use of resources. [3]
1. BIOLOGICAL WATER TREATMENT:
It is a process where microbial organisms majorly bacteria, are employed to degenerate the water components biologically. The microbe breaks down the organic substances and hence improves the quality of water. The procedure of Biological treatment makes the water fit for domestic usage. Biological water treatment is further divided into three main methods namely, aerobic method, anaerobic method and composting.
- AEROBIC METHOD: In this method, with the help of oxygen, bacteria decompose the organic material and convert them into carbon dioxide gas.
- ANAEROBIC METHOD: In this method, with the absence of oxygen, the fermentation of waste materials takes place at certain temperatures.
- COMPOSTING: In this method, the sludge is assorted with light wood particles or distinct carbon sources in the presence of oxygen to treat the wastewaters.
2. PHYSICAL WATER TREATMENT:
It comprises of the physical methods to treat wastewater.
- SEDIMENTATION: It is a process that uses gravity to separate suspended solids from wastewater. The insoluble solids settle at the base leaving behind pure water.
- FILTRATION: It is a process used to filter out insoluble particles or other substances like grease and oil from wastewater or sewage sludge. The sand filter is the most common in use.
- AERATION: It is a method in which oxygenated air is circulated through the wastewater. It eliminates the diffused gases and oxidizes the dissolved metals like hydrogen sulphide, iron, etc. present in water.
3. CHEMICAL WATER TREATMENT:
As the name suggests, this process uses chemicals to treat wastewater.
- CHLORINATION: The method of treating wastewater using chlorine is called chlorination. Chlorine acts as an oxidizing disinfectant that destroys the bacteria present in the waste. Ozone can also be used in a similar way to purify the water. Such chemicals work by prohibiting the further growth of bacteria in wastewater.
- NEUTRALIZATION: Neutralization is a unique method of treating industrial wastewater that involves altering the pH of the water to achieve a “neutral” pH of 7 (neither acid nor base). Usually, the process requires the usage of acid (pH<7) to reduce the pH of the water of basic (or alkaline) nature (pH>7), or the usage of a base (or alkali) to raise the pH of the water of acidic nature. [4]
- BIOREACTORS: 'Membrane bioreactor' (MBR) is a term used to describe wastewater treatment methods in which a semi-permeable membrane (microfiltration membrane or ultrafiltration membrane), is combined with a biological process; particularly with a suspended growth bioreactor. [5]
References
Adnan, A., 2010. Methods Of Wastewater Treatment. Available at: weblink
[1] Hirani, P. and Dimble, V., 2019. Water Pollution Is Killing Millions Of Indians. Here's How Technology And Reliable Data Can Change That
Available at: weblink
[2] UN News. 2019. ‘Invisible’ Crisis Of Water Quality Threatens Human And Environmental Well-Being: World Bank Report
Available at: weblink
[3] Fulekar, M., 2010. Environmental Biotechnology. Boca Raton [etc.]: CRC Press/Taylor & Francis Group.
Available at: weblink
[4] Tectrapro.com. n.d. Waste Neutralization- Fundamentals.
Available at: weblink
[5] The MBR Site. n.d. What Are Membrane Bioreactors?
Available at: weblink
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