Investigation of the contaminant sorption of treated Romanian soils using “batch” and biological toxicity assays

To evaluate the effect of crop residue burning of agriculturally tilled soils, the soil's sorption of polycyclic aromatic hydrocarbons (PAHs) is studied using naphthalene as a representative model contaminant in the soil.Soils from agriculturally tilled fields (Dorobantu farm, Calarasi, Romania), either burned or unburned for clearance, were examined for their toxicity and sorption capacity (fields being burned for cleansing experience an increase in nanoparticles because soot particles enter the soil). The burned and unburned soils were separated into several fractions on the basis of size using membranes with different pore sizes. Batch experiments were conducted to test the impact of the following operating parameters: the initial concentration of naphthalene, initial concentration of soil, pH, soil structure and composition and soil characterization. The toxic effectiveness of the various soils was also investigated.

Graphical abstractAdsorption isotherms for naphthalene sorption on burned (soot) and not burned soils (contact time 60 min, adsorbent dosage = 5 g/L, T = 298 K and pH = 7), I% = percentage of naphthalene adsorptionFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► An original evaluation of the burning effects on some properties of the soils. ► Soot from burned soils is an effective adsorbent for naphthalene. ► No difference between the datasets of the bioassays for burned and unburned soils.