Bioremediation of Agricultural Soils Polluted with Pesticides: a review

2021
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2. Classification of Pesticides 
The pesticides can be classified by different criteria such as chemical classes, func-
tional groups, mode of action, and toxicity. 
2.1. Classification by Origin 
The pesticides can be classified by their origin, namely chemical pesticides and bi-
opesticides. Chemical pesticides are generally organic compounds that can have natural 
sources or by chemical synthesis [7]. Biopesticides are natural substances that control 
pests by nontoxic mechanisms [25]. 
2.1.1. Classification by Chemical Composition 
With this classification, four main groups can be identified: organochlorines, organ-
ophosphates, carbamates, and pyrethrins and pyrethroids (Figure 3 and Table 2). The in-
formation on the chemical and physical characteristics of pesticides is very useful in de-
termining the mode of application, precautions that need to be taken during the applica-
tion, and the application rates [26]. 
Figure 3. 
Classification of the chemical pesticides. DDT: dichlorodiphenyltrichloroethane; DDD: dichlorodiphenyldi-
chloroethane; HETP: hexaethyl tetraphosphate.
Table 2. 
Chemical composition of the pesticides. 
Group Chemical 
Structure 
Organochlorines 
Organophasphates 
Carbamates 
Pyrethrins and pyrethroids 
Chemical pesticides
Organochlorines
E.g.: DDT, DDD, 
dieldrin, aldrin
Organophosphates
E.g.: HETP, 
parathion, 
chlorpyrifos
Carbamates
E.g.: furadan, 
sevin, fenobucarb
Pyrethrin and 
pyrethroids
E.g.: cyfluthrin, 
bifenthrin, allethrin
Carbamates
Bioengineering 
2021
, 
8
, x FOR PEER REVIEW 
4 of 29 
2. Classification of Pesticides 
The pesticides can be classified by different criteria such as chemical classes, func-
tional groups, mode of action, and toxicity. 
2.1. Classification by Origin 
The pesticides can be classified by their origin, namely chemical pesticides and bi-
opesticides. Chemical pesticides are generally organic compounds that can have natural 
sources or by chemical synthesis [7]. Biopesticides are natural substances that control 
pests by nontoxic mechanisms [25]. 
2.1.1. Classification by Chemical Composition 
With this classification, four main groups can be identified: organochlorines, organ-
ophosphates, carbamates, and pyrethrins and pyrethroids (Figure 3 and Table 2). The in-
formation on the chemical and physical characteristics of pesticides is very useful in de-
termining the mode of application, precautions that need to be taken during the applica-
tion, and the application rates [26]. 
Figure 3. 
Classification of the chemical pesticides. DDT: dichlorodiphenyltrichloroethane; DDD: dichlorodiphenyldi-
chloroethane; HETP: hexaethyl tetraphosphate.