# Recent Strategies for Environmental Remediation of Organochlorine Pesticides
## 3 Methods for Removal of Organochlorine Pesticides from the Environment

Table 1: Pesticides removal strategies with their advantages and disadvantages. phytoaccumulation are involved in phytoremediation process. Removal of organochlorine pesticides may be via degradation occurring in the interior zone of the root or by the pesticide transformation taken place within the tissue of plants [44]. [PERSON] et al. carried out an assessment to estimate the phytoremediation potential of a tropical plant species _Ricinus communis_ for the degradation of fifteen different persistence organic pollutants including organochlorine pesticides. The evaluation carried out after sixty-six days indicated that the roots of these plants successfully reduced the concentration of these contaminants. The highest removal was observed for hexachlorocyclohexane (HCH) [27]. Another method that has been adopted is bioremediation, where specific attribute of microbes was used to degrade pesticides. The enzymes present in these microbes could attack the pesticides and convert them to fewer toxic substances. The degradation could be achieved either via in situ or ex situ approach. The ex situ method may require the use of compost on farmland, biofilter or bioreactor, whereas the in situ method may require a system for delivering liquid, biosparging, bioventing and biostimulation [45]. Irrespective of the type of bioremediation method adopted, control of environmental conditions is very crucial. One of the studies that utilized bioremediation was reported by [PERSON] et al. [28]. In the study, heptachlor, aldrin, endrin, dieldrin and HCB were successfully degraded by using anaerobic microbial strain. Although, the details of the metabolic pathways for the degradation of the pesticides was not given in the study [28; 46]. In a similar study, [PERSON] et al. utilized the aerobic bacteria _Cupriavidus_ sp. and _Burkholderia_ sp. to degrade dieldrin and endrin. The presence of 1, 2-epoxycyclohexane was found to enhance the efficiency of the degradation process [46; 47]. Incineration is another important strategy that has been utilized. This method utilizes a very high temperature, usually above 500 \({}^{\circ}\)C, and oxygen to completely degrade organochlorine pesticides to ashes. The high temperature is desirable because it leads to zero smoke generation. In addition, it prevents the production of noxious intermediate products [3]. For high organochlorine degradation efficiency, incinerators are being equipped with electrostatic filters, scrubbers, after burner and chamber as shown in Figure 3. This improves the process compared to the combustion of the pesticides in an open space, which releases enormous volume of substances such as smoke and toxic gases into the atmosphere [3; 48]. [PERSON] et al. [29] reviewed the elimination of several pesticide wastes from the environment using incineration method. Low temperature thermal desorption method is similar to incineration since they both require heat. However, low temperature thermal desorption method requires less heat energy compared to what is needed for incineration method. This method has been utilized by [PERSON] et al. [30] to remove pesticides from the clay of a manufacturing plant that was abandoned. [PERSON] et al. [31] used this method to degrade dichlorodiphenyltrichloroethane(DDT) from contaminated soil, while simultaneously monitoring polychlorinated dibenzodioxins(PCDD) formation. Figure 3: Incinerator designed for degrading municipal solid wastes (MSW) containing pesticides. Reproduced from [49]. (creative commons). adsorption process has been used to remove pesticides from water and the environment. One of the popular adsorbents that has been used is activated carbon. This adsorbent has been used for pesticides clean up and in the environment of pesticide-producing factories. [PERSON] et al. [PERSON] et al. (2018) removed pentachlorophenol pesticides from water by using chitosan as adsorbent. The removal of several pesticides from drinking water sources using activated carbon as adsorbent has also been reported by [PERSON] et al. (2018).