磷灰石-零价铁对底泥铜、铅释放的抑制效果及机理研究

以磷灰石-零价铁作为添加物,强化混凝应急处置Cu、Pb污染河道水体,并模拟构建产生沉积物,通过静态释放实验方式,研究了其对沉积物中Cu、Pb释放的影响和机理.结果表明:磷灰石复合零价铁介入应急混凝处置显著减少了沉积物中Cu、Pb的释放;45 d释放实验后,与对照组相比,添加磷灰石复合零价铁的沉积物中,Cu和Pb从生物有效性高的酸可提取态向生物有效性相对较低的可还原态、可氧化态、残渣态转化.投加磷灰石复合零价铁有利于应急混凝处置重金属产生沉积物的稳定,且零价铁掺杂比例越高,效果越好.

Effect and mechanism of apatite and zero-valent iron on inhibiting the release of copper and lead in sediment

Apatite and zero-valent iron were used to develop a composite additives for enhanced coagulation process and generating the sediments during the emergency treatment processes of river waters polluted by copper and lead. The effect and mechanism of inhibiting copper and lead release from the sediment were studied. The results of static release experiments indicate that the heavy metal released from the sediment decreased significantly with the addition of apatite and zero-valent iron. the fraction of Cu and Pb in the sediment with apatite and zero valent iron as composite additives transfer from acid exchangeable state with have high biological effectiveness to reducible, oxidizable and residual state, which have low bioavailability, in the 45 days. Compared with the control group, adding apatite and zero valent iron is beneficial to producing more stabilized sediment in an emergency coagulation treatment for river water polluted by heavy metals and the inhibiting effect increased with increasing doses of zero-valent iron.