修复方式对滩涂贝类养殖底质TN、TP及TOC影响的室内模拟实验

通过室内模拟实验方法,探讨了物理修复方式(翻耕、压沙加翻耕)和投放双齿围沙蚕(Perinereis aibuhitensis)的生物修复方式下滩涂文蛤(Meretrix meretrix)养殖区底质中TN、TP及TOC含量的变化特征.结果表明,物理修复组中,翻耕20 cm组底质TN、TOC的去除效果及翻耕30cm和翻耕加压沙组底质TN、TP及TOC的去除效果较对照组均达到了显著水平(p0.05),且不同修复组对3种指标的去除率大小顺序一致,均表现为翻耕加压沙组最佳,翻耕30 cm组次之,翻耕20 cm组最差;生物修复组中,双齿围沙蚕对底质修复效果明显,0.28 kg·m-2密度组对TN、TP的去除效果及0.14 kg·m-2、0.21 kg·m-2密度组对TN、TP及TOC的去除效果均较对照组达到了显著水平(p0.05),其中,0.21 kg·m-2密度组对TN、TP及TOC的修复效果均最佳,而较高密度的0.28 kg·m-2组的修复效果反而降低,说明沙蚕总体修复效果并不完全随投放密度的增加而增强.

Simulation experiments on TN, TP and TOC concentrations in sediment of the clam (Meretrix meretrix) culture areas influenced by different remediation methods

This study investigated the removal efficiencies of the total nitrogen (TN), total phosphorus (TP) and total organic carbon (TOC) in sediment of the clam culture areas by physical (ploughing the soil to 20cm or 30cm in depth, both covering sand and beach ploughing) and biological remediation (add the polychaetes Perinereis aibuhitensis at the densities of 0.07 kg·m^-2, 0.14 kg·m^-2, 0.21 kg·m^-2 and 0.28 kg·m^-2, respectively) methods through simulated experiments. The results showed that the TN, TP and TOC concentrations in sediment at two physical remediation groups (ploughing 30 cm in depth, both covering sand and beach ploughing) were significantly lower than those in the control (p<0.05). Their removal percentages were ranked as: both covering and beach ploughing>ploughing 30 cm in depth>ploughing 20 cm in depth. Three biological remediation groups (0.14 kg·m^-2, 0.21 kg·m^-2 and 0.28kg·m^-2) significantly decreased the TN, TP and TOC concentrations in sediment compared to the control (p<0.05). The results also indicated greater remediation effect for the group at 0.21 kg·m^-2 than that at 0.28 kg·m^-2. This provided evidence that the effects of Perinereis aibuhitensis were not completely amplified with density.