硝酸钙辅助生物膜法用于污染河道原位修复

In Situ Remediation of Polluted River Using Combination of Calcium Nitrate and Biofilm Carrier

硝酸钙原位修复技术可有效抑制底泥黑臭现象,但也存在引发上覆水体有机物和TN浓度升高的可能。为此,在投加硝酸钙削减底泥污染物的同时,利用生物膜法控制底泥污染物的释放对上覆水体的影响。结果表明,联合修复的效果优于硝酸钙单独处理效果。在投加适量的生物填料条件下,上覆水体总磷的去除率为83. 9%,氨氮的去除率可达84. 8%,有机物的去除率为49. 0%,底泥酸挥发性硫化物(AVS)的去除率达92. 7%。联合修复对水体总氮浓度的控制也有积极的效果,相比单独投加硝酸钙,上覆水体总氮的含量降低了50. 0%。另外,生物填料密度对污染河道上覆水体修复效果有明显的影响。

Calcium nitrate in situ bioremediation technology can effectively inhibit the black and odor of sediment, but it may also cause the increase of organic matter and total nitrogen content in overlying water. Addition of calcium nitrate combined with biofilm carrier was applied to control the release of pollutants from sediments. The results showed that the remediation effect of combined process was better than that of dosing calcium nitrate alone. Under the condition of adding appropriate amount of carriers, the removal rates of total phosphorus, ammonia nitrogen and organic matter in the overlying water were 83.9%, 84. 8% and 49. 0%, respectively. The removal rate of acid volatile sulfide （AVS） was 92.7%. Compared with the blank group, the TN concentration was decreased by 50.0%. In addition, the density of biofilm carrier had a significant effect on the sediments remediation. The suitable density of biofilm carrier can be applied in the engineering.