Institute of Physical, Chemical and Biological Problems of Soil Science, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
J Hazard Mater. 2011 Jul 15;191(1-3):126-35. doi: 10.1016/j.jhazmat.2011.04.050. Epub 2011 Apr 19.
To mimic the role of hydroxide minerals and their humic complex derivatives on the biodegradability of pesticides in soils, synthetic Mg(R)Al Layered Double Hydroxides (LDH) and Mg(R)Al modified by Humic substances (LDH-HA) were prepared for various R values (2, 3 and 4) and fully characterized. Adsorption properties of LDH and LDH-HA toward Pseudomonas sp. strain ADP were evaluated. The adsorption kinetics were very fast (<5 min to reach equilibrium). The adsorption capacities were greater than previously reported (13.5×10(11), 41×10(11) and 45.5×10(11) cells/gLDH for Mg(2)Al, Mg(3)Al and Mg(4)Al, respectively) and varied with both surface charge and textural properties. Surface modification by HA reduced the adsorption capacities of cells by 2-6-fold. Biodegradation kinetics of atrazine by Pseudomonas sp. adsorbed on both LDHs and LDH-HA complexes were measured for various solid/liquid ratios and adsorbed cell amounts. Biodegradation activity of bacterial cells was strongly boosted after adsorption on LDHs, the effect depending on the quantity and properties of the LDH matrix. The maximum biodegradation rate was obtained in the case of a 100 mg/mL Mg(2)Al LDH suspension (26 times higher than that obtained with cells alone).
为了模拟氢氧化物矿物及其腐殖质络合衍生物在土壤中农药生物降解性方面的作用，制备了具有不同 R 值（2、3 和 4）的合成 Mg(R)Al 层状双氢氧化物（LDH）和腐殖质修饰的 Mg(R)Al 层状双氢氧化物（LDH-HA），并对其进行了全面的表征。评估了 LDH 和 LDH-HA 对假单胞菌 ADP 的吸附性能。吸附动力学非常快（<5 分钟即可达到平衡）。吸附容量大于先前报道的（Mg(2)Al、Mg(3)Al 和 Mg(4)Al 的吸附容量分别为 13.5×10(11)、41×10(11)和 45.5×10(11)个细胞/gLDH），并且与表面电荷和结构特性都有关。HA 的表面修饰使细胞的吸附容量降低了 2-6 倍。通过测定不同固液比和吸附细胞量，研究了吸附在 LDH 和 LDH-HA 复合物上的假单胞菌对莠去津的生物降解动力学。细菌细胞的生物降解活性在吸附到 LDH 后得到了强烈促进，这种作用取决于 LDH 基质的数量和性质。在 100mg/mL Mg(2)Al LDH 悬浮液的情况下，获得了最大的生物降解速率（比单独使用细胞时提高了 26 倍）。
