Effects of Fertigation with Untreated and Treated Leachates from Municipal Solid Waste on the Microelement Status and Biometric Parameters of Viola × wittrockiana

Blanca María Plaza,Alberto Pardossi,Silvia Jiménez-Becker,Cecilia Diara,Giulia Carmassi,María Teresa Lao

doi:10.3390/agronomy11010186

Blanca María Plaza, Alberto Pardossi + Show 4 more

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https://doi.org/10.3390/agronomy11010186

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Abstract

Landfill leachate can release pollutants into the environment. Nevertheless, it can be treated using a phytodepuration system via constructed wetlands to reduce contaminants. Moreover, this leachate can also increase the availability of macro and micronutrients in soil and water. In this trial, the reuse of untreated and treated wastewater from municipal solid waste (MSW) for fertigation was assessed. Plantlets of Viola × wittrockiana (pansy) were grown in a greenhouse and five fertigation treatments were applied: W9.0 (pure wastewater, EC 9.0 dS m−1), W4.5 (diluted wastewater, EC 4.5 dS m−1), DW4.5 (depurated wastewater, EC 4.5 dS m−1), PW4.5 (phytodepurated wastewater, EC 4.5 dS m−1), and T (tap water, control, EC 1.5 dS m−1). The treatment with untreated wastewater had a negative effect on plant dry weight, leaf size, specific leaf area, water content, and the number of closed and open flowers, due to the high concentration of SO42− in the fertigation water. It also reduced the content of Cu, Mn, Fe, and Zn with respect to the control, because of the dry biomass diminution. Conversely, fertigation with phytodepurated wastewater enhanced root and shoot dry weight, water content, and the number of closed and open flowers. Cu and Mn contents in flowers surpassed the content detected in plants fertigated with untreated leachates. These findings demonstrate that phytodepurated wastewater obtained from MSW can be employed for the fertigation of this species.

Highlights

Leachate is a black or brown, foul smelling liquid produced during landfilling, composting, incineration, treating of municipal solid waste (MSW), etc. [1]
It is generally known that landfills of MSW release numerous pollutants into the environment via landfill leachate or landfill gas (CO2, CH4, CO, H2S, etc.), which present a major threat to the environment and human health, causing permanent deterioration of environmental quality [5,6,7,8]
In the fertigation waters tested (Table 1), the highest pH was found in W9.0 (9.34), followed by W4.5 (9.17), PW4.5 (9.11), DW4.5 (8.99), and T (8.58)

Summary

Introduction

Leachate is a black or brown, foul smelling liquid produced during landfilling, composting, incineration, treating of municipal solid waste (MSW), etc. [1]. Leachate is a black or brown, foul smelling liquid produced during landfilling, composting, incineration, treating of municipal solid waste (MSW), etc. Landfill leachate is the product of water that has percolated through waste deposits which have undergone aerobic and anaerobic microbial decomposition [2,3]. There are large amounts of organic matter, inorganic salts, ammoniacal nitrogen, and metal ions in this leachate [9]. For this reason, MSWs and their leachate increase the availability of both macro- (N, P, and K) and micro-nutrients (Fe, Mn, Zn, and Ni) in the soil, which subsequently enhance soil productivity and crop yield [10,11,12]

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