especially circular agriculture, consists of a techno-logical package divided into two techniques Horizontal sand bed that acts as slow sand filter, disposed onthe base of the permeable areas of cultivation in containers. Thissystem has been evaluated at pilot scale with satisfactory results,minimal maintenance and low cost of implementation Purification using a horizontal subsurface flow con-structed wetland (CW). CW try to emulate natural wetlands and arecomposed with shallow ponds or channels with wetland vegeta-tion, where decontamination processes occur through interactionbetween water, substrate, plants and microorganisms.Both systems are on-site technologies that should be monitored,particularly, CWs. Constructed wetlands are simple and sustainabletechniques with a low energy demand that are being used to purifydifferent effluents (Wu et al., 2014). It has been demonstrated thathorticultural leachates can be treated using CW in which denitrifi-cation process under anaerobic conditions are promoted .Previous studies have been carried out to design and setting upthe system adapted to nursery leachate characteristics containinghigh nitrate concentration. In such studies,high denitrification rates have been achieved through the use ofan appropriate carbon source dosage. Monitoring of nitrate and