利用大型海藻净化养殖牡蛎体内重金属的研究

Removing Heavy Metals in Cultured Oysters with Macroalgae

为有效地对牡蛎体内重金属进行净化,在室内水泥池中将葡萄牙牡蛎(也称福建牡蛎)与大型海藻(龙须菜)、大型海藻加壳聚糖、大型海藻加维生素C多聚磷酸酯用砂滤海水暂养14天,并以砂滤海水为对照组,通过测定比较不同净化组牡蛎体内的Cu2+、Cd+、Pb2+含量,来评估大型海藻对养殖牡蛎体内重金属的净化效果。结果表明,大型海藻能够显著降低牡蛎体内的重金属含量(P<0.05),但就3种净化方法相比,大型海藻加壳聚糖的净化效果最佳,14天后,牡蛎体内的Cu2+、Cd+、Pb2+含量(mg/kg,湿重)分别为1.93、0.58、0.33,皆低于GB 2762—2012中制定的标准。因此,在室内采用大型海藻与壳聚糖结合方法来净化养殖牡蛎重金属是完全可行的。

To effectively remove the heavy metals in cultured oysters, we separately cultured oyster（Crassostrea angulate） in concrete tanks indoors with sand-filtered seawater（control）, macroalga（Gracilaria lemaneiformis）, macroalga ＋ chitosan, and macroalga ＋ ascorbyl polyphosphate for 14 days. The oysters weresampled on day 0, day 7 and day 14 for determining concentrations of Cu2＋, Cd2＋and Pb2＋. Data were analyzedand compared to evaluate the macroalga ability of removing heavy metals in oysters. The results showed thatthree treatments of macroalga, macroalga＋chitosan, and macroalga＋ascorbyl polyphosphate all significantlydecreased the concentrations of heavy metals in oysters（P〈0.05）. Macroalga ＋ chitosan showed the bestremoving effect, and the concentrations of Cu2 ＋, Cd2 ＋and Pb2 ＋were respectively 1.93, 0.58, 0.33 mg/kg（wetweight） on day 14, which were all lower than the limits in GB 2762-2012. Therefore, it is completely feasibleto remove the heavy metals in cultured oysters by employing the method of combining macroalgae with chitosan.