We studied the effects of amendment with zeolitized tuffs (ZT) in recovering nitrogen and phosphorus as potential plant nutrients in soils treated with wastewater (WW).
The surface horizon of two contrasting soils (a sandy, alkaline Entisol, and a sandy-loam, sub-acidic Alfisol), was pedotechnically managed with different ratios of Neapolitan Yellow Tuff (NYT) and a clinoptilolite bearing tuff (ZCL).
It was then exposed to repeated treatments with ‘dirty’ municipal wastewater (DMW). Results showed that the presence of ZTs had several favorable effects. As concerns the aspect connected with the investigation into the supernatant/soil solution, total N and total P decreased sharply in the supernatant as ZT content in soil/zeolite samples increased.