Ito A, Takachi T, Aizawa J, Umita T
Department of Civil and Environmental Engineering, Iwate University, Ueda, Morioka, Japan.
Water Sci Technol. 2001;44(10):59-64.
Chemical and biological leachings of As and metals from sewage sludge were carried out using a batch reactor under an aerobic condition. Addition of phosphate to the sludge was ineffective for the elution of As from the sludge at neutral pH. Akalization of the sludge to pH 11 eluted sufficient As, whereas it was ineffective for Al, Cd, Mn and Zn. Furthermore, the effectiveness of ferric sulfate and iron oxidizing bacteria was investigated under acidic conditions. The application of ferric iron and/or iron oxidizing bacteria eluted As from the sludge more effectively than that of sulfuric acid only at pH 2. However, at pH 3, addition of ferric acid decreased significantly the amount of As eluted. It was found that the optimum pH was 2 for removing simultaneously As and metals from the sludge utilizing ferric iron or iron oxidizing bacteria.
在有氧条件下，使用间歇式反应器对污水污泥中的砷和金属进行化学和生物浸出。在中性pH值下，向污泥中添加磷酸盐对污泥中砷的洗脱无效。将污泥碱化至pH 11可洗脱足够的砷，但对铝、镉、锰和锌无效。此外，还研究了在酸性条件下硫酸铁和铁氧化细菌的效果。在pH值为2时，应用三价铁和/或铁氧化细菌比仅用硫酸更有效地从污泥中洗脱砷。然而，在pH值为3时，添加铁酸显著降低了砷的洗脱量。结果发现，利用三价铁或铁氧化细菌同时从污泥中去除砷和金属的最佳pH值为2。
