# Emerging Technologies for Degradation of Dichlorvos: A Review
## 3 Physicochemical Transformation of DDVP  
Several physicochemical methods have been applied to control residual DDVP pollutant (Table 2). On the whole, these methods are efficient to a certain extent, but too expensive for developing countries that are suffering from DDVP contamination. Several researches have reported hazardous effects of DDVP exposure on aquatic animals, land mammals, and humans. Thus, removal of DDVP residue from contaminated environments is extremely urgent. The main technique for solving pesticide pollutants is chemical degradation [43]. Other common solutions for solving pesticide pollutants include chlorination, hydrodynamic cavitation, active carbon, O\({}_{2}\) plasma, metal catalysts, and H\({}_{2}\)O\({}_{2}\) and O\({}_{3}\) adsorption [14]. [PERSON] et al. [44] highlighted the urgent need and intricacy of photo-induced oxygen-mediated reactions of DDVP. DDVP is photoionized by electron transfer to dissolved oxygen, followed by superoxide radicals, and finally the HO yield. It might be the main mechanism of degradation taking place during photolysis. In addition, it has been investigated that the hydrodynamic cavitation reactor can be applied to degrade an aqueous solution of DDVP. As shown in another study, a chlorinated organophosphate compound can be effectively degraded using treatment strategies based on hydrodynamic cavitation in a large-scale operation [45]. According to this report, active carbon is an efficient substituent that absorbs DDVP residual, because powder-activated carbon shows excellent adsorption of aromatic compounds, including pesticides, herbicides, surface activators, natural pigments, and phenols [46]. Advanced oxidation processes (AOPs) containing various kinds of oxidants have been applied to remove hazardous pollutants from soil and water environments successfully. [PERSON] et al. [47] noted that the O\({}_{2}\) plasma treatment worked well in the DDVP remediation process, and the usefulness of degradation is mainly dependent on the related operating parameters and chemical structures of pesticides. Hydroxyl radicals have the ability to break the double bond in the DDVP molecule, and DDVP is further oxidized to 1,1-dichloro ethoxy dimethyl phosphate, 1,1,1-trichloro-2-hydroxyl-ethyl dimethyl phosphate, dimethyl phosphate, trimethyl phosphate, methyl phosphate, dichlor acetaldehyde, oxalic acid, CH\({}_{2}\)C\({}_{l2}\), CHC\({}_{l3}\) (parts of which are mineralized to phosphoric acid), CO\({}_{2}\), H\({}_{2}\)O, and chloridion [48]. It took only 90 min to push the elimination ration up to 98% under acidic and saturated dissolved oxygen conditions [49]. Through the known products, the reaction mechanism of DDVP oxidized by H\({}_{2}\)O\({}_{2}\) was discussed, and the conclusion was made that the main decontamination mechanism is radical chain reaction [50]. Comparatively, ozone and hydroxyl radicals are vital for DDVP abatement. The abiotic hydrolysis degradation pathway is presented in Figure 2. However, we still need more detailed studies on aqueous solutions and lower concentrations of contaminants in order to properly assess the process performance. Iron-modified ZSM-11 zeolites were applied as heterogeneous catalysts in the degradation process of DDVP water solutions. ZSM-11 zeolite matrices were synthesized by the hydrothermal method and iron was incorporated by the wet impregnation method in four concentrations. From this report, Fe/ZSM-11 with 6 wt% of incorporated iron showed the best catalytic behavior based on DDVP [51]. Removing DDVP pollutants from water is a real challenge due to the presence of the direct carbon-to-phosphorous covalent bond, which reveals its stability under chemical and thermal degradation. From recent studies, nanomaterials seem to be a possible solution for degradation. [PERSON] et al.