Efficiency of the Combination of Vermicompost and Zero Valent Iron for the Remediation of Lead, Copper and Aluminum

Aims: Evaluate the efficiency of the combination of vermicompost and zero -valent iron for the remediation of two types of soil with lead, copper and aluminum.

Study Design: Observational technique and analysis of soil samples contaminated by mining.

Place and Duration of Study: It was applied in the greenhouse in the district of San Juan de Lurigancho and in the Casapalca mining industry located in the district of San Mateo, in the months of February and September 2023.

Methodology: The analysis of soil samples contaminated by mining was carried out through the addition of vermicompost amendments and zero -valent iron, seeking to observe the physicochemical changes of the soil and determine the bioavailability of lead, copper and aluminum in the soil. Using the atomic absorption spectrometer, a pH meter; the loss on ignition method, to determine organic matter; A 1.0mol L-1 ammonium acetate solution was used for the cation exchange capacity (CEC) of the soil and vermicompost and for the determination of total potassium (K) method 3050b acid digestion of sediments, sludge and soils was used.

Results: The highest efficacy for the remediation of lead, copper and aluminium contaminated soils is produced with a vermicompost dose of 3:1, with 3 kilos of soil + 60 LC and Fe ° (45 g LC + 15 Fe °); obtaining the highest reductions in Pb from 942. 6 mg/kg to 698.5 mg/kg in its final concentration, also for Cu from an initial concentration of 462.4 mg/kg, 323.8 mg/kg was obtained in its final concentration and for Al from a concentration of 9190.2 mg/kg resulted in 6823.8 mg/kg. Obtaining a maximum lead removal of 35.57%, copper 29.60% and aluminium 27.62% from the Casapalca soil. The highest efficiency of the dose of zero valent iron for the remediation of contaminated soils was at a ratio of 3:1 with a dose of 3 kg of soil + 60 Fe° and LC (45 g Fe° + 15LC). Likewise, plant uptake from 2 months after harvest of Cucumis sativus (cucumber) in the remediation of contaminated soils was efficient for all three types of metals at a dose ratio of 5:1, with Al showing a higher uptake in all cases.

Conclusion: The effectiveness of remediation of soils contaminated with heavy metals through the combination of vermicompost and zero valent iron highlights the importance of considering sustainable and ecological approaches to agricultural soil management, which could have significant implications for the protection of the environment and human health in areas with contaminated soils.