86

6 Bioremediation of Pesticides Containing Soil and Water

important for the degradation process that involves microbes. But, the anionic

moieties in the pesticides hinder the degradation. Concentration of contaminants,

soil density, and size of the contaminated area will act as the deciding factors for the

duration of the bioremediation which might vary from few months to several years.

Advantages of bioremediation comprise of:

●Transfer of contaminants to a different environment does not occur since complete

breakdown of impurities to nontoxic compounds is achievable [15].

●In comparison to other removal/degradation techniques, the equipments involved

are extremely minimal, thus making it cost-effective.

●Either of the techniques, in situ or ex situ approaches, can be conducted based on

the parameters.

●Bioremediation is more of a natural process that is publicly accepted and the cost

involved per unit volume of ground water or soil is low.

Disadvantages of bioremediation comprise of:

●Toxic byproducts can be obtained in case of partial degradation of the process

involving organic pollutants.

●Precise parameters like temperature and pH are mandatory for the microbial

activity to sustain and carry out the sensitive process which involves toxins.

●Volatile organic compounds (VOCs) are difficult to regulate during ex situ

methods.

●In comparison with other techniques, it is time-consuming.

●Uncertain performance regulations are observed since there is no distinct level of

“clean” site.

6.5

Methods Used in Bioremediation Process

Bioremediation is a novel method to overcome the problem of contamination of soil

and water due to various kinds of contaminants. During the intrinsic bioremedia-

tion where microbes that already exist is not adequate to degrade the quantity of

pesticides used, it requires a processed bioremediation method where new natural

or engineered microbes are added for the effective action [1]. The mechanism usu-

ally utilizes microorganisms like fungi, bacteria, actinomycetes, and cyanobacteria

to degrade or eradicate noxious pollutants [19]. These microorganisms are naturally

appearing and they assimilate the contaminants from the surrounding environment,

leading to a province which is nearly contaminant-free. Usually, the pesticides are

absorbed within the organism [25], while organic constituents are digested. Meth-

ods involved in bioremediation are natural, as they promote the growth and repro-

duction of these organisms that can successfully eradicate precise contaminants by

converting them to nontoxic byproducts. Notably, bioremediation can also be com-

bined with an extensive range of long-established chemical and physical methods to

augment their ability [26].