Some of the applications of biotechnology in environmental management are briefly described below.
Effluents from factories and mines
Effluents from factories and mines cause environmental pollution. Cyanide, lead, mercury, copper, and zinc emitted from factories are highly toxic and chronic pollutants. Various microorganisms grow in the effluents from the factories and break down the waste materials into simpler substances. In France, Japan, Taiwan, and India, a type of bacteria grow in the effluents of petroleum factories and is used as a single-cell protein for animal and human food. Lactic acid is produced from the waste (whey) of dairy factories with the help of microorganisms. The pulp and paper industry waste material grows a yeast called Torula, which contains a lot of meat. Saccharomyces cerevisiae and Torula utilis grow in the waste material. Amino acids are obtained from them.
Chlorine is used to bleach raw materials in the paper industry. The environment can be quickly freed from this chlorine pollution by using various fungi. Cellulosic wastes from jute, textile and sugar industries can also be converted into useful simple products by various bacteria and fungi, thus, on the one hand, the environment is free from pollution, and on the other hand, the necessary profitable products are obtained, such as various organic acids (acetic acid, citric acid, lactic acid, tartaric acid). Acid etc.), ethanol, proteins, vitamins, amino acids, acetone, glycerin, butanol, etc.
Oil spills in the sea
The pollution caused by oil in the sea through various means, accidental or intentional (pollution), can occur, and its consequences are dire. Since oil is insoluble and lighter than water, it floats on water and creates a glossy layer. This layer of oil causes severe damage to various plants and animals living in the sea. But the hydrocarbon oxidizing microorganisms that live in the ocean grow in number by attaching to the insoluble oil grains and, in the presence of oxygen, break the oil down into simpler components and free the oil from contamination. However, if oil somehow gets to the bottom of the ocean, it remains unchanged for years. Because these microorganisms do not work in the absence of oxygen. Pseudomonas, Nocardia, Mycobacteria, and certain types of yeasts and molds act as hydrocarbon-oxidizing microorganisms.
Using the process of genetic engineering technology, a new strain of Pseudomonas bacteria has been developed that can rapidly degrade oil and hydrocarbons to clean the environment.
Wastewater or sewage assimilation
The excreta and waste released from houses, villages, or farms are sewage or sewage. Sometimes stormwater runoff also flows through underground drains and becomes sewage. Sewage consists of organic and inorganic matter, including disease-causing parasites. Mechanical and chemical methods separate inorganic materials such as mud, sand, and other waste materials. Organic matter is one of the causes of water pollution. Therefore, in developed countries, biological treatment prevents sewage water from mixing with food or drinking water. Algae, fungi, and protozoa, along with aerobic or anaerobic bacteria, participate in this process, and they break down organic matter into CO2 and CH. CH can be used as a fuel and is first released into the atmosphere in gaseous form. After the biological reaction, the water should be purified and discharged into the river or sea.
Some selected microorganisms' starter cultures have been developed to facilitate sewage assimilation. Apart from this, some sewage assimilation plants have also been invented. These innovations make sewage assimilation easier.
Currently, all over the world, activated sludge is used to purify sewage and release it into rivers or lakes. It is a simple biological process; thus, the environment is free from pollution. This method uses two tanks called an aeration tank and a sedimentation tank. The first tank is rich in various microorganisms (bacteria, fungi, etc.) that break down the organic matter into CO and water. In the second tank, the water is stabilized so that the bottom collects and the top contains purified water, which is discharged into a river or lake. The bottom is used as fertilizer. A notable bacterium used in this work is Zooglea ramigera.