especially circular agriculture, consists of a techno-logical package divided into two techniques Horizontal sand bed that acts as slow sand filter, disposed on the base of the permeable areas of cultivation in containers. This system has been evaluated at pilot scale with satisfactory results,minimal maintenance and low cost of implementation Purification using a horizontal subsurface flow constructed wetland . CW try to emulate natural wetlands and are composed with shallow ponds or channels with wetland vegetation, where decontamination processes occur through interaction between water, substrate, plants and microorganisms.Both systems are onsite technologies that should be monitored,particularly, CWs. Constructed wetlands are simple and sustainable techniques with a low energy demand that are being used to purify different effluents . It has been demonstrated that horticultural leachates can be treated using CW in which denitrification process under anaerobic conditions are promoted .Previous studies have been carried out to design and setting up the system adapted to nursery leachate characteristics containing high nitrate concentration. In such studies,high denitrification rates have been achieved through the use ofan appropriate carbon source dosage. Monitoring of nitrate and