Arsenic adsorption and plant availability in an agricultural soil irrigated with As-rich water: Effects of Fe-rich amendments and organic and inorganic fertilisers. (1st March 2018)

• Record Type: Journal Article
• Authors: Arco-Lázaro, Elena; Pardo, Tania; Clemente, Rafael; Bernal, M Pilar
• Is Part Of: Journal of environmental management. Volume 209(2018)
• Page Start: 262
• Page End: 272
• Publication Date: 2018-03-01
• Subjects: Sorption isotherms -- Plant uptake -- Iron oxides -- Red mud -- Lamination slag -- Plantox test; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2017.12.042
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: The use of As-rich water for irrigation in agricultural soils may result in As accumulation in soil and crops, with the consequent risk of its entry into the food chain. The effectiveness of three different Fe-based materials (a commercial iron oxide (Bayoxide ® ), lamination slag (a by-product of the hot rolling of steel) and a commercial red mud derivative (ViroBind™)) used as soil amendments to minimise the impact of irrigation with As-rich water in an agricultural soil-plant system was evaluated in a pot experiment. Simultaneously, the influence of organic and inorganic fertilisation (olive oil mill waste compost versus NPK fertiliser) on the effectiveness of iron oxide in As adsorption processes was also assessed. The As adsorption capacity of the amendments was determined in a preliminary batch experiment using sorption isotherms. Then, a pot experiment was carried out in a growth chamber using an agricultural soil (arenosol) from Segovia province (central Spain), amended with the different materials, in which Lactuca sativa (lettuce) was grown for two months. The As adsorption capacity was higher in the commercial iron oxide and in the red mud derivative, which fitted the Freundlich model (no saturation), than in the lamination slag, which fitted the Langmuir model (limited adsorption). All the materials decreased the pore water As concentration compared to the control (by 29–80%), but only iron oxide reduced As availability in the soil, and none of the amendments decreased the As concentration in plant leaves. The combination of iron oxide and compost did not significantly improve plant growth, but increased nutrients (N, K, Ca, Na and Mg) concentrations and availability in the soil and their concentration in the plants, relative to the other treatments and the control. Therefore, this seems to be a viable option to prevent As leaching and improve the plant nutritional status. Highlights: Iron rich materials were used to decrease As-contaminated water impact in crops. Iron oxide and red mud derivative presented the highest As adsorption capacity. Arsenic plant availability in soil was significantly reduced only by the iron oxide. Combination of iron oxide and compost improved soil and plant nutritional status. Iron oxide plus inorganic fertilisation increased As uptake and is not recommended.