Sustainable sludge management - its use for remediation of degraded lands

Abstract

The sludge resulted from the urban wastewater treatment plants, can be used, from a circular economy, as a fertilizer for agricultural and degraded lands, for horticulture and forestry. This paper aims to propose an alternative for the use of this type of sludge in a sustainable way, with a low impact on the environment. The study consisted of experiments done to recover the stabilized sludge from the urban wastewater treatment plants in the process of degraded land rehabilitation, using the energetic Willow, Salix sp. The experimental results showed that the use of stabilized sludge as fertilizer for naturally and anthropogenic degraded lands determined the improvement of nutritional characteristics of the lands cultivated with Salix sp., and allowed the growth, development, and maintenance of this plant. Taking into consideration the characteristics of the cultures and the quantities of metals accumulated by Salix sp., it can be concluded that these plants were adapted to the environmental conditions and the substrate toxically composition. The results obtained on two degraded lands indicate that Salix sp. can be used for its introduction in the economic circuit, both for salty soils and ash dumps.