Introduction

As the population grows, so does the demand for products, which increases the industrial load, thereby putting stress on the environment. Such loads also degrade the quality of various natural resources. There are industries such as agriculture, petrochemical, tannery, and paper pulp that release pollutants in the environment. Pollutants from such industries are organic and inorganic, altering water and soil physical and chemical properties. So here comes the need for bioremediation.

Various methods or processes treat polluted water and soil, which require different treatment plants, equipment, methodologies, and high cost and energy consumption. On the other hand, the bioremediation technique is cost-effective and does not require any power consumption, heavy machinery, or equipment. It is also an eco-friendly technique.

The bioremediation method used microbes like fungi, bacteria, or other living organisms like plants, which degrade the in-situ pollutant environment and remediate the contaminated site. This bioremediation technique approaches various methods and techniques with the different microbes, increasing efficiency and broadening the remediation approach to the various pollutants.

History of Bioremediation

Bioremediation has existed since the Romans discovered it approximately 600 B.C. But it was not until the 1940s that microbiologists began studying this remediation technology. The first commercial use of bioremediation was in 1972 to clean up a solar oil pipeline accident in Amber, Pennsylvania. Dr. Ananda Mohan Chakrabarty developed the first superbug that fed on oil in 1975.

Bioremediation commercialization started in 1980 to treat soil contamination and groundwater too. After that, bioremediation was first used to treat groundwater uranium contamination in 1990 by Derek lovely and co-workers. Now currently, this technique is used for the various contaminant remediation processes.

Application of Bioremediation

1. Organic pollutant bioremediation

Oil spills, mining, agriculture, and the petroleum sector produce pollutants resistant to degradation. Several studies have shown that bacteria can break down and eliminate hazardous organic contaminants. The bio-surfactant generated by Serratia marcescens with the Ludwigia Octavalvis plant eliminates 93.5 percent of the petroleum product.

2. Metals bioremediation

Heavy metals have a higher density than other usual elements, like zinc, chromium, mercury, cadmium, silver, arsenic, and uranium released from mining or other activities and pollute the water and soil. Heavy metals can be efficiently removed from a contaminated site using the bioaugmentation procedure with the plant Spartina Maritima and Rhizobacteria.

3. PAH’s Bioremediation

PAH’s are polyaromatic hydrocarbons, polychlorinated biphenyls, and pesticides that act as persistent organic pollutants get deposited in the environment and are not easily degraded by microbes. In a study, aromatic and saturated hydrocarbon is removed 62% by use of stir tank bioreactor.

4. Rubber waste bioremediation

Waste from synthetic rubber polymer waste is non-recyclable and non-degradable. The burning of rubber also causes air pollution. In a study, fungi, Recinium bicolor, and sulfur-oxidizing or reducing microbes (Thiobacillus Ferroxidans) effectively remove rubber components from the environment.

5. Agriculture waste bioremediation

Waste from agriculture like crop residue, fertilizers, animal and human waste produce large amounts of organic waste that needs proper treatment. This waste is nutrient-rich and converted into compost by using effective microbes like earthworms by vermicomposting.

Advantages and Disadvantages of Bioremediation

Advantages

• Bioremediation is cheap, environment friendly, and aesthetic.
• This process does not require a heavy machine, equipment, or labor for implementation.
• It is effective in both onsite and in-situ environments.
• It can permanently remove the pollutant from the environment.
• The phytoremediation-like processes increase soil fertility, prevent erosion and avoid leaching.

Disadvantages

• It is a slow process that takes time to remediate.
• It is not able to work on radionuclides.
• Some microbes can produce harmful by-products.

Emerging Trends in Bioremediation

Bioremediation can be applied in both ex-situ and in-situ conditions. We can use its various procedures or strategies to remove contaminants from the environment successfully. But there is also a need to improve this technique because some pollutants remain in the environment and degrade resistance, demanding technological innovation.

An emerging trend is to treat persistent pollutants by simultaneously using two or more bioremediation methods, which is much more effective and efficient. The use of bio-surfactant obtained from microbes that degrade agricultural waste. The bioaugmentation and biostimulation together show better biodegradation using native microbes.

Biotechnology is an emerging advanced technology that improves or upgrades microbes and bioremediation processes. The new emerging technology like microbial fuel cells is inoculated with microbes that act as a potential method to degrade the polyaromatic compounds. The use of nanoparticles of nanotechnology effectively remediates the pollutants.