Experimental design and multiple response optimization of batch leaching tests of volcanic ashes

NICOLAS KARIM VALLEJO-AZAR; LUIS ARIEL ESCUDERO; JOSE LUIS FERNANDEZ-TURIEL; RAUL ANDRES GIL

JOURNAL OF ENVIRONMENTAL SCIENCES

Elsevier's

Año: 2024

0022-0906

Volcanic eruptions are natural phenomena during which tephra, lava, and variousgases are expelled from a vent. Eruptions often attract attention due to theirmagnitude, energy, and consequences for life and the environment. Among the mostdocumented and sometimes dramatic effects of volcanic ashes are those linked to theinput of diverse elements in the environment, which are released as a consequence ofash weathering. Laboratory studies have been conducted to investigate and predict theenvironmental input of chemical elements from volcanic ashea. This research paperdescribes the optimization of batch leaching tests used to investigate the release ofions from ashes collected in the Andes Cordillera after the eruption of the Puyehuevolcano in 2011. Chemometric multivariate strategies were employed to evaluate theinfluence of variables affecting the leaching of volcanic ash. The effects of the mainvariables, namely contact time, the acidity of the leaching agent, the solid/liquid ratio,the particle size, and the stirring speed, were studied in leaching tests. To determinethe optimal conditions for selected metal determinations, we employ Darringer´sdesirability function, which allows for the simultaneous optimization of the selectedresponses (element concentrations during the leaching process). A series ofmultielemental determinations were conducted following the dilution of leachingsolutions by ICP-MS. The results of these determinations were used to establish theexperimental conditions necessary to conduct studies of volcanic ash as a source ofchemical elements to the environment.