Department of Soil, Plant, Environmental and Animal Production Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy.
J Environ Sci (China). 2010;22(9):1398-406. doi: 10.1016/s1001-0742(09)60266-7.
A study on variable charge soils (volcanic Italian and podzolic Scottish soils) was performed to investigate the influence of soil properties on the chemical composition of soil solution. Zinc speciation, bioavailability and toxicity in the soil solution were examined. The soils were spiked with increasing amounts of Zn (0, 100, 200, 400 and 1000 mg/kg) and the soil solutions were extracted using rhizon soil moisture samplers. The pH, total organic carbon (TOC), base cations, anions, total Zn and free Zn2+ in soil solution were analysed. A rapid bioassay with the luminescent bacterium Escherichia coli HB101 pUCD607 was performed to assess Zn toxicity. The influence of soil type and Zn treatments on the chemical composition of soil solution and on Zn toxicity was considered and discussed. Different trends of total and free Zn concentrations, base cations desorption and luminescence of E. coli HB101 pUCD607 were observed. The soil solution extracted from the volcanic soils had very low total and free Zn concentrations and showed specific Zn2+/Ca2+ exchange. The soil solution from the podzolic soil had much higher total and free Zn concentrations and showed no evidence of specific Zn2+/Ca2+ exchange. In comparison with the subalkaline volcanic soils, the acidic podzol showed enhanced levels of toxic free Zn2+ and consequently stronger effects on E. coli viability.
对变电荷土壤（意大利火山土和苏格兰灰壤）进行了研究，以调查土壤性质对土壤溶液化学组成的影响。研究了土壤溶液中锌的形态、生物可利用性和毒性。将不同量的锌（0、100、200、400 和 1000 mg/kg）添加到土壤中，并使用 rhizon 土壤水分采样器提取土壤溶液。分析了土壤溶液的 pH 值、总有机碳（TOC）、碱基阳离子、阴离子、总锌和游离 Zn2+。使用发光细菌 Escherichia coli HB101 pUCD607 进行快速生物测定，以评估 Zn 的毒性。考虑并讨论了土壤类型和 Zn 处理对土壤溶液化学组成和 Zn 毒性的影响。观察到总锌和游离锌浓度、碱基阳离子解吸和 E. coli HB101 pUCD607 发光的不同趋势。从火山土壤中提取的土壤溶液中总锌和游离锌浓度非常低，并表现出特定的 Zn2+/Ca2+交换。灰壤的土壤溶液中总锌和游离锌浓度要高得多，并且没有证据表明存在特定的 Zn2+/Ca2+交换。与弱碱性火山土壤相比，酸性灰壤显示出更高水平的有毒游离 Zn2+，因此对 E. coli 活力的影响更强。
