Amezcua-Allieri Myriam A, Lead Jamie R, Rodríguez-Vázquez Refugio
Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Chemosphere. 2005 Oct;61(4):484-91. doi: 10.1016/j.chemosphere.2005.03.002. Epub 2005 Apr 14.
A fungal bioremediation method using P. frequentans removed up to 75% of phenanthrene with the addition of water and nutrients over a period of 30 d. During the bioremediation process, changes in metal behavior were monitored by an in situ technique (diffusive gradients in thin-films, DGT) and by soil solution chemistry. DGT provided absolute data on fluxes from the solid phase to the DGT device and relative trends of concentrations of the most labile metal species. DGT response indicated that bioremediation increases metal mobilization from the solid phase. Filtration provided data on the concentrations of solution phase (<0.45 microm) metal. In all case, metal fluxes and concentrations significantly increased after the bioremediation process began. Fluxes increased from <0.1 pg cm(-2)s(-1) before bioremediation to between 0.2 and 0.5 pg cm(-2)s(-1) after bioremediation. Metal concentrations in the soils solution (filtration at 0.45 microm) increased from 2 to 10 microg l(-1) (Cu), 1-4 microgl(-1) (Pb) and from 40 to 140 microg l(-1) (Ni) after bioremediation. Although over a short time period, these data strongly indicated that there was remobilization of metal from solid to solution (and thus to the DGT device) directly due to the bioremediation process. Although the mechanism was not unambiguously identified, it was shown not to be related to small changes in bulk pH over time and was attributed to the microbial action on the surface of the soil solid phase, releasing metal into solution. Additionally, differences in metal concentration and flux were observed in sterilized and non-sterilized soils and in the absence or presence of phenanthrene. The results indicated that the bioremediation of soil by P. frequentans increased the flux, lability and mobility of trace metal species and therefore the likely metal bioavailability to plants.
一种使用频繁出芽短梗霉的真菌生物修复方法，在添加水和养分的情况下，经过30天可去除高达75%的菲。在生物修复过程中，通过原位技术（薄膜扩散梯度，DGT）和土壤溶液化学来监测金属行为的变化。DGT提供了从固相到DGT装置的通量的绝对数据以及最不稳定金属物种浓度的相对趋势。DGT响应表明生物修复增加了金属从固相的活化。过滤提供了溶液相（<0.45微米）金属浓度的数据。在所有情况下，生物修复过程开始后，金属通量和浓度显著增加。通量从生物修复前的<0.1 pg cm(-2)s(-1)增加到生物修复后的0.2至0.5 pg cm(-2)s(-1)之间。生物修复后，土壤溶液（0.45微米过滤）中的金属浓度增加，铜从2微克/升增加到10微克/升，铅从1至4微克/升增加，镍从40微克/升增加到140微克/升。尽管时间较短，但这些数据有力地表明，由于生物修复过程，金属直接从固相重新活化到溶液（进而到DGT装置）。虽然机制尚未明确确定，但已表明与随时间的总体pH值小变化无关，并且归因于土壤固相表面的微生物作用，将金属释放到溶液中。此外，在灭菌和未灭菌的土壤以及有无菲的情况下，观察到了金属浓度和通量的差异。结果表明，频繁出芽短梗霉对土壤的生物修复增加了痕量金属物种的通量、活性和迁移率，因此可能增加了植物对金属的生物可利用性。
