Browsing by Autor "Juan F. Saldarriaga"

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Environmental zoning based on the distribution of potentially toxic elements, risk contamination indices, and bioindicators in three areas affected by gold mining in Antioquia, Colombia
(2024) Julián E. López; Juan F. Marín; Juan F. Saldarriaga
<title>Abstract</title> Gold mining stands out as a primary industrial operation significantly affecting the environment, underscoring the urgency of developing strategies to enhance environmental stewardship in the impacted areas. In areas directly or indirectly affected by emissions of hazardous substances like As, Cd, Pb, and Cr, these strategies are crucial for informed decision-making. Zoning the spatial distribution of these elements and using indices and pollution bioindicators can create a diagnostic and remedial tool to address pollution concerns effectively. The aim of this study is to apply environmental zoning in three gold-mining-affected municipalities in Antioquia, Colombia. The zoning considers various factors, including i) levels of potentially toxic elements, ii) contamination indices, and iii) bioindicators. Geospatial analysis was employed to create maps illustrating the distribution of potential toxic elements, along with the indices and bioindicators utilized. The results show that the concentrations of potentially toxic elements were the lowest, even below the reference values for non-contaminated soils, in the municipality of Yalí. In contrast, most samples from Puerto Berrío and Buriticá revealed amounts of potentially toxic elements higher than the standards for uncontaminated soils. In particular, the highest contamination values for the elements Cd, Pb, and Cr were found in Puerto Berrío. The correlation study shows that concentrations of potentially toxic elements, pollution indices, and bioindicators have a substantial association (P < 0.05) (r > 0.67). The municipalities can be categorized into three zones: a highly polluted area needing remediation, a moderately polluted zone requiring natural restoration monitoring, and a low-contamination region needing conservation efforts. Overall, this zoning proposal can help competent authorities enhance environmental management strategies.
Remediation of Pb-contaminated soil using Biochar-Based Slow- Release P Fertilizer and biomonitoring employing bioindicators
(Research Square (United States), 2022) María Paula Acosta Luque; Julián E. López; Nancy Henao; Juan F. Saldarriaga
Abstract Soil contamination by Pb can result from different anthropogenic sources such as lead-based paints, gasoline, pesticides, coal burning, mining, among others. This work aimed to evaluate the potential of P-loaded biochar to remediate a Pb-contaminated soil and to apply a biomonitoring alternative after soil remediation. First, rice husk-derived biochar was obtained at different temperatures (450, 500, 550, and 600 ºC). Then, part of the resulting material was activated. Later, the raw biochars and activated biochars were immersed in a saturated KH 2 PO 4 solution to produce P-loaded biochars. The ability of materials to immobilize Pb and increase the bioavailability of P in the soil was evaluated by an incubation test. The materials were incorporated into doses of 0.5, 1.0, and 2.0%. After 45 days, soil samples were taken to biomonitor the remediation process using two bioindicators: a phytotoxicity test and enzyme soil activity. Activated P-loaded biochar produced at 500 ºC has been found to present the best conditions for soil Pb remediation. This material significantly reduced the bioavailability of Pb and increased the bioavailability of P. The phytotoxicity test and the soil enzymatic activity were significantly correlated with the decrease in bioavailable Pb but not with the increase in bioavailable P. Biomonitoring using the phytotoxicity test is a promising alternative for the evaluation of soils after remediation processes.