TITLE:
Pb and Cr Content in an Agricultural Soil Irrigated with Wastewater and Their Bioaccumulation in Alfalfa
AUTHORS:
Victor Manuel Duarte Zaragoza, Lozano-Camargo Maria Luisa, Carrasco Hernández Violeta, Pérez Hernández Victoria Sabrina
KEYWORDS:
Heavy Metals, Bioavailability, Lead, Bioaccumulation Factor
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.11 No.11,
November
28,
2023
ABSTRACT: Urban wastewater contains various pollutants, with
heavy metals being common, posing risks to the environment and public
health, especially when used for irrigation in agricultural systems. This study
aimed to assess the total and bioavailable content of Pb and Cr in agricultural
soil irrigated with wastewater and their accumulation in alfalfa crops. Five
alfalfa sites were sampled, and ten surface soil samples were collected from
the top 30 cm of each plot. Plant samples were also collected at each sampling
point. A composite sample of irrigation water from the main channels was also
collected and prepared. The concentration of heavy metals was determined using
atomic absorption spectrophotometry. The results revealed concentrations of Pb
and Cr (VI) in the irrigation water above the maximum permissible limits
according to environmental regulations. The soil had high organic matter
content, neutral pH, elevated electrical conductivity (EC), and Pb and Cr
contents of up to 103 and 89 mg/kg, respectively. In alfalfa tissues, Pb and Cr
concentrations were recorded at 26 mg/kg and 4.6 mg/kg, respectively (Cr (VI),
with lower concentrations observed in the roots. Cr (VI) was higher at all
sites, with ranges from 2.25 to 43.56, while lead (Pb) had an AR ranging from
0.64 to 27.04. The Pb presented a mean of 1.45 of the Bioaccumulation factor
values, which can be considered a metal-accumulating plant.