Centro de Investigación y Desarrollo en Criotecnología de Alimentos CCT La Plata CONICET-Fac. de Cs. Exactas, UNLP. 47 y 116 (B1900AJJ) La Plata, Argentina.
J Hazard Mater. 2010 Apr 15;176(1-3):657-65. doi: 10.1016/j.jhazmat.2009.11.082. Epub 2009 Dec 8.
The objectives of the present work were: (i) to analyze the capacity of activated sludge to reduce hexavalent chromium using different carbon sources as electron donors in batch reactors, (ii) to determine the relationship between biomass growth and the amount of Cr(VI) reduced considering the effect of the nitrogen to carbon source ratio, and (iii) to determine the effect of the Cr(VI) acclimation stage on the performance of the biological chromium reduction assessing the stability of the Cr(VI) reduction capacity of the activated sludge. The highest specific Cr(VI) removal rate (q(Cr)) was attained with cheese whey or lactose as electron donors decreasing in the following order: cheese whey approximately lactose>glucose>citrate>acetate. Batch assays with different nitrogen to carbon source ratio demonstrated that biological Cr(VI) reduction is associated to the cell multiplication phase; as a result, maximum Cr(VI) removal rates occur when there is no substrate limitation. The biomass can be acclimated to the presence of Cr(VI) and generate new cells that maintain the ability to reduce chromate. Therefore, the activated sludge process could be applied to a continuous Cr(VI) removal process.
（i）分析在批式反应器中使用不同碳源作为电子供体时活性污泥还原六价铬的能力，（ii）确定生物量增长与还原的 Cr(VI) 量之间的关系，同时考虑氮源与碳源比例的影响，以及（iii）确定 Cr(VI)驯化阶段对生物还原铬性能的影响，评估活性污泥还原 Cr(VI)能力的稳定性。当使用奶酪乳清或乳糖作为电子供体时，活性污泥对 Cr(VI)的去除率最高（q(Cr)），顺序依次为：奶酪乳清≈乳糖>葡萄糖>柠檬酸盐>乙酸盐。不同氮源与碳源比例的批式实验表明，生物 Cr(VI)还原与细胞倍增阶段有关；因此，当不存在基质限制时，会出现最大的 Cr(VI)去除率。生物量可以适应 Cr(VI)的存在并产生新的细胞，从而保持还原铬酸盐的能力。因此，活性污泥工艺可以应用于连续的 Cr(VI)去除过程。
