# Recent Strategies for Environmental Remediation of Organochlorine Pesticides
## 3 Methods for Removal of Organochlorine Pesticides from the Environment
Different organochlorine pesticides have been removed from waste water using zeolite adsorbent ([PERSON] et al., 2018) and the use of graphene oxide to adsorb pesticides from environmental samples have been reported ([PERSON] et al., 2018). An interesting technique is the use of supercritical oxidation. This involves the use of the solubility property of supercritical water. Supercritical water is prepared at high pressure and temperature. This approach also requires the introduction of an appropriate oxidizing agent such as nitrate, H\({}_{2}\)O\({}_{2}\), O\({}_{2}\) or their combination. In this process, phosphate, sulfates, nitrates, chlorides, water, carbon dioxide are derived, respectively from oxidation of phosphorus, sulfur, nitro-compound, chlorinated compounds, hydrogen and carbon. Interestingly, organic substances and gases including oxygen dissolve totally in supercritical water. Another important thing about this method is that NO\({}_{x}\) (x = 1 or 2), HCl and SO\({}_{2}\) are not part of the effluents. In fact, lower amount of CO is discharged without particulates being generated ([PERSON] et al., 2018). This strategy has been devised to degrade pesticides from wastewater at varying reaction conditions ([PERSON] et al., 2018). Reaction variables such as residence time, oxidant coefficient and reaction temperature affect the efficiency of waste water remediation. Another method that rely on oxidation process is ozonation. This involves the use of ozone, and it is usually combined with UV (ultraviolet) radiation, leading to the generation of hydrogen radicals capable of degrading the pesticides by oxidation ([PERSON] et al., 2018). Ozonation has been used to successfully degrade many pesticides present in the seed loading and wastewater ([PERSON] et al., 2018). The rate of the degradation process was observed to increase with increase in the ozone concentration. In addition, high ozonation time and the humidification of seed prior to ozonation positively increase the reaction kinetics. Chemicalochlorination method involves the removal of chlorine from organochlorine pesticides by using reductant radical which have hydrogen that could be donated or the possible use of hydrogen for the dechlorination process. With variation in the reducing agent used, direct dechlorination may occur by using base catalyzed decomposition. Similar process involving the use of alkaline polyethylene glycolate or reduction in the gas phase has also been reported ([PERSON] et al., 2018). Recently, the use of ammonia with metals were considered for the dechlorination of pesticides through solvated electron technology. A base metal, such as Na, Ca and Li was dissolved in ammonia that was free of water. This leads to the unbounding of electrons which were consumed by organochlorine compounds to release chloride due to their high affinity for electrons. The chloride in the solution then reacted with sodium ion to form NaCl without leaving noxious agents ([PERSON] et al., 2018). For instance, [PERSON] et al. (2018) remediated a soil from polychlorobiphenyls contamination using sodium and ammonia mixture. The volume of water in the soil and the concentration of the substrate were found to influence the rate of chlorine removal and amount of sodium consumed. This was also repeated in a different study using a mixture of calcium and ammonia. The efficiency with the use of calcium was observed to be greatly lower than when sodium was used. In both studies, chlorine was removed from organochlorine compounds which rendered the compound less toxic. A method, known as electrochemical oxidation, involves the utilization of electron and current movement to remove pesticides from the environment. This method has been reported as one of the efficient methods for the degradation of organochlorine pesticides. An acid solution (usually HNO\({}_{3}\)) is introduced to the anode of an electrochemical cell that liberates oxidizing species.