DUGi

Eficiència en l’eliminació de fòsfor d’un sistema basat en la natura a escala de laboratori

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@28662

Water resource management has been compromised by the continued increase in activities related to the primary sector, population water consumption and prolonged droughts, which they have been a new problem in our region, due to the climate change. In this context, the development and implementation of innovative and sustainable systems to manage water resources is essential. These systems should not only protect environmental and human health, they should also promote a circular economy able to reduce the growing pressure on limiting water resources. This study presents a novel nature-based solution for wastewater treatment, structured in three distinct stages. First of all, duckweed (Lemna gibba) forms a floating layer on the water surface, uptaking the first pollutants. Secondly, the water goes to the second stage which consists of an artificial riverbed where biofilm developes and is responsible of the second removal. Finally, in the final stage, a hydroponic system is used to cultivate lettuce while, simultaneously, they remove the remaining pollutants. Each stage has a two-day hydraulic retention time, resulting in a total treatment duration of six days. During 30 days, the experiment set up included 13 replicates. The first goal of our project was to assess the phosphorus removal efficiency of our system, but we also assessed carbon, nitrogen and phosphorus content in plant tissues, along with photosynthetic efficiency and biomass growth, to evaluate the physiological conditions of the plants. Water quality was determined through physicochemicals parameters (pH, temperature, electrical conductivity and dissolved oxygen) and biological indicators ( pathogen presence and nutrient content). Our results show a high removal efficiency of phosphorous (85 ± 8%), and demonstrates a strong potential as a cost-effective alternative to conventional tertiary treatment methods, which are often expensive for small-scale wastewater treatment plants. Future research should aim to optimize system performance and evaluate its scalability, considering both technical and economic viability

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