**6. Bioremediation prospects**

Bioremediation techniques are varied and have demonstrated effective in restoring polluted sites. Microorganisms play fundamental role in bioremediation; consequently, their diversity, abundance and community structure in polluted environments offer insight into the chance of any bioremediation technique providing other environmental factors, which can inhibit microbial activities. Advanced Molecular techniques such as 'Omics' includes genomics, proteomics, metabolomics and transcriptomics have contributed towards microbial identification, functions, metabolic and catabolic pathways, with microbial based methods. Nutrient availability, low population or absence of microbes with degradative capabilities, and pollutant bioavailability may delay the achievement of bioremediation. Since bioremediation depends on microbial process, biostimulation and bioaugmentation approaches speed up microbial activities in polluted sites. Biostimulation increase microbial activities by the addition of nutrients to a polluted sample. Microorganisms are abundantly present in different type of environmental condition, it is noticeable that pollutant degrading microbes are naturally present in polluted contaminated sites, their growth and metabolic activities may depends on pollutant type and concentration; later, we can use of agro-industrial wastes, which contains nitrogen, phosphorus and potassium as a nutrient source most polluted sites. Microbial consortium has been reported to degrade pollutants more efficiently than pure isolates [33].

This activity due to metabolic diversities of individual isolates, which potency create from their isolation source, adaptation process, pollutant composition, and synergistic effects, which may lead to complete and rapid degradation of pollutants when such isolates are mixed together [34]. Additional so, both bioaugmentation and biostimulation were effective in removing pollutant such as polyaromatic hydrocarbons (PAHs) from heavily polluted sample compared to non-amended setup (control) [35].

Although bioaugmentation has recognized effective method, it has been shown to increase the degradation of many compounds. If proper biodegrading microorganisms are not present in soil or if microbial populations decreased because of contaminant toxicity, specific microorganisms can be added as "introduced organisms" to improve the current populations and the possibility that the inoculated microorganisms may not survive in the new environment make bioaugmentation a very uncertain method. This process is known as bioaugmentation. Bioremediation technique in which natural or genetically engineered bacteria with unique metabolic profiles are used to treat sewage or contaminated water or soil. The use of alginate, agar, agarose, gelatin, gellan gum and polyurethane as carrier materials solve some of the challenges associated with bioaugmentation [36].

Biosurfactants are chemical equivalents having ecofriendly and biodegradable properties. However, high construction cost and low scalability application of biosurfactants to polluted site are uneconomical. Agro-industrial wastes combination are nutrient sources for development of biosurfactant producers during fermentation process. Application of several bioremediation techniques will help increase remediation efficiency [37].

Enhancing bioremediation ability with organized use of genetically engineered microorganisms (GEM) is a favorable approach. This is due to possibility of engineering a designer biocatalyst target pollutant including recalcitrant compounds by combining a novel and efficient metabolic pathways, widening the substrate range of existing pathways and increasing stability of catabolic activity [38].

However, parallel gene transfer and multiplication of GEM in an environmental application are encouraging approach. Bacterial containment systems, in which any GEM escaping an environment to reconstruct polluted environment.

Further, derivative pathway of genetically engineering microorganisms with a target polluted compound using biological approach could increase bioremediation efficiency. Nanomaterials decline the toxicity of pollutant to microorganisms because nanomaterials having increase surface area and lower activation energy, which reduce time and cost of bioremediation [39].

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*Bioremediation Techniques for Polluted Environment: Concept, Advantages, Limitations…*

ii.Liquids (ground water, surface water and industrial waste water

The general approaches to bioremediation are the (i) intrinsic (natural) bioremediation, (ii) biosimulation (environmental modifications, through nutrient application and aeration, and (iii) bioaugmentation (addition of microbes).

The biological community exploited for bioremediation generally consists of the native soil microflora. However, higher plants can also be manipulated to enhance toxicant removal (phytoremediation), especially for remediation of metal contami-

All bioremediation techniques have its own advantage and disadvantage because

• It is a natural process; it takes a little time, as an adequate waste treatment process for contaminated material such as soil. Microbes able to degrade the contaminant, the biodegradative populations become reduced. The treatment products are commonly harmless including cell biomass, water and carbon

• It needs a very less effort and can commonly carry out on site, regularly without disturbing normal microbial activities. This also eradicates the transport amount of waste off site and the possible threats to human health and the

• It is functional in a cost effective process as comparison to other conventional methods that are used for clean-up of toxic hazardous waste regularly for the treatment of oil contaminated sites. It also supports in complete degradation of the pollutants; many of the toxic hazardous compounds can be transformed to less harmful products and disposal of contaminated

• It does not use any dangerous chemicals. Nutrients especially fertilizers added to make active and fast microbial growth. Because of bioremediation change harmful chemicals into water and harmless gases, the harmful chemicals are

• Simple, less labor intensive and cheap due to their natural role in the

iv.Sub-surface environments (saturated and vadose zones).

Bioremediation must be considered as appropriate methods that can applied to

*DOI: http://dx.doi.org/10.5772/intechopen.90453*

**7. Bioremediation applications**

all states of matter in the environment

i.Solids (soils, sediment and sludge)

iii.Gases (industrial air emissions)

**7.1 Advantage and disadvantage**

it has its own specific applications.

*7.1.1 The advantage of bioremediation*

nated soils.

dioxide.

environment.

material.

completely destroyed.

environment.

*Bioremediation Techniques for Polluted Environment: Concept, Advantages, Limitations… DOI: http://dx.doi.org/10.5772/intechopen.90453*
