Castaldi Paola, Santona Laura, Melis Pietro
Dipartimento di Scienze Ambientali Agrarie e Biotecnologie Agro, Alimentari, Sez. Chimica Agraria ed Ambientale, Università di Sassari, Viale Italia 39, 07100 Sassari, Italy.
Chemosphere. 2005 Jul;60(3):365-71. doi: 10.1016/j.chemosphere.2004.11.098. Epub 2005 Jan 21.
The effects of chemical amendments (zeolite, compost and calcium hydroxide) on the solubility of Pb, Cd and Zn in a contaminated soil were determined. The polluted soil was from the Southwest Sardinia, Italy. It showed very high total concentrations of Pb (19663 mgkg(-1) d.m.), Cd (196 mgkg(-1) d.m.) and Zn (14667 mgkg(-1) d.m.). The growth and uptake of heavy metals by white lupin (Lupinus albus L., cv. Multitalia) in amended soils were also studied in a pot experiment under greenhouse conditions. Results showed that the amendments increased the residual fraction of heavy metals in the soils, and decreased the heavy metals uptake by white lupin compared with the unamended control. Among the three amendments, compost and Ca(OH)2 were the most efficient at reducing Pb and Zn uptake, while zeolite was the most efficient at reducing Cd uptake by the plants. White lupin growth was better in amended soils than in unamended control. The above ground biomass increased with a factor 1.8 (soil amended with zeolite), 3.6 (soil amended with compost) and 3.1 (soil amended with Ca(OH)2) with respect to unamended soil. The roots biomass increased with a factor 1.4 (soil amended with zeolite), 5.6 (soil amended with compost) and 4.8 (soil amended with Ca(OH)2). Results obtained suggest that the soil chemical treatment improved the performance of crops by reducing bioavailability of metals in the soils. However it would be therefore interesting to find a suitable mixture of these amendments to contemporarily immobilize the three main pollutants in the polluted soils.
测定了化学改良剂（沸石、堆肥和氢氧化钙）对污染土壤中铅、镉和锌溶解度的影响。污染土壤来自意大利撒丁岛西南部。该土壤中铅（19663 mgkg⁻¹干物质）、镉（196 mgkg⁻¹干物质）和锌（14667 mgkg⁻¹干物质）的总浓度非常高。在温室条件下的盆栽试验中，还研究了白羽扇豆（Lupinus albus L.，品种Multitalia）在改良土壤中的生长及重金属吸收情况。结果表明，与未改良的对照相比，改良剂增加了土壤中重金属的残留比例，并减少了白羽扇豆对重金属的吸收。在这三种改良剂中，堆肥和Ca(OH)₂在减少铅和锌吸收方面效率最高，而沸石在减少植物对镉的吸收方面效率最高。改良土壤中白羽扇豆的生长比未改良对照更好。与未改良土壤相比，地上生物量分别增加了1.8倍（沸石改良土壤）、3.6倍（堆肥改良土壤）和3.1倍（Ca(OH)₂改良土壤）。根系生物量分别增加了1.4倍（沸石改良土壤）、5.6倍（堆肥改良土壤）和4.8倍（Ca(OH)₂改良土壤）。所得结果表明，土壤化学处理通过降低土壤中金属的生物有效性提高了作物性能。然而，因此找到这些改良剂的合适混合物以同时固定污染土壤中的三种主要污染物将是很有趣的。
