Utilization of sludge derived from landfill leachate treatment as a source of nutrients for the growth of Nicotiana alata L

The sludges derived from the leachate treatment (LS) represent an important environmental and operational problem in the landfill management. On the other hand, they can be utilized as an alternative source of nutrients and organic matter. The main objective of this work was to evaluate the reuse of the LS of a sanitary landfill in Santa Fe city - Argentina, as an organic amendment for the development of Nicotiana alata L. plants. Different doses of LS were applied to a soil mixture for potted seedling growth. The response surface methodology was applied, using a one-factor design. Once the phenological stage of flowering began, the plants were harvested. Physiological and biochemical determinations were made in order to evaluate the effects of the different amendments. Application of LS notably improved growth parameters such as stem height, leaf area and dry matter. Additionally, the content of proteins and photosynthetic pigments was enhanced. Through the multiple regression statistical analyses, the relationship between the response variables and the sludge content was established. The multivariate optimization analysis yielded 53% as the optimal sludge content. Our results indicate that this sludge, in appropriate doses, can be used as an organic amendment for the revegetation of sanitary landfills. •Nicotiana alata L. turned out to be a species suitable for growth in leachate sludge.•Sludge amendment improved the plant growth, proteins and photosynthetic pigments.•Leachate sludge can be used as a covering material and in revegetation activities.•Most of the variables studied had a significant correlation with the sludge content.•The optimal sludge content estimated was 53% by volume.