缢蛏(Sinonovacula constricta)生物扰动对养殖废水处理系统中沉积物磷赋存形态垂直分布的影响

为研究缢蛏(Sinonovacula constricta)生物扰动在养殖废水生态处理系统中对沉积物不同垂直分层的各种磷形态迁移转化的影响,于2016年5—7月在养殖废水处理池的贝藻处理区采集不同缢蛏养殖密度下的实验围隔箱内的底泥,测定不同垂直方向上的磷形态、微生物活性(FDA)以及碱性磷酸酶活性(APA)。结果表明,在底栖动物缢蛏生物扰动作用下,改变了沉积物内部的微环境,促进了微生物的生长,增大了沉积物中总微生物活性以及碱性磷酸酶活性。而沉积物中有机磷(OP)含量显著减少(P0.05);非磷灰石态无机磷(NAIP)、磷灰石态无机磷(AP)和无机磷(IP)含量显著增加(P0.05),这表明在缢蛏的生物扰动下OP可能转变成为AP、NAIP等无机磷成分;总磷含量呈降低趋势。本试验结果表明,缢蛏生物扰动下对于养殖废水生态处理系统沉积物垂直方向上的磷赋存形态具有显著的影响,且高密度组的生物扰动作用对沉积物中磷形态迁移转化的影响强于低密度组。

EFFECTS OF BIOTURATION BY RAZOR CLAM SINONOVACULA CONSTRICTA ON VERTICAL DISTRIBUTION OF PHOSPHORUS FORM IN SEDIMENT IN AN AQUACULTURE WASTEWATER TREATMENT ECOSYSTEM

To study the impact of bioturbation by razor clam Sinonovacula constricta on vertical migration of phosphorus of various forms in sediment, sediment samples were collected from an aquaculture wastewater treatment pond in which different breeding densities of the clams were cultured. Phosphorus form, microbial activity, and alkaline phosphatase activity were determined in vertical direction from May to July, 2016. The results show that by bioturbation of S. constricta, the microenvironment of sediments was enhanced largely, which improved the growth of microorganisms, and increased the total microbial and alkaline phosphatase activities in sediment. The organophosphorus content in the sediment was reduced significantly (P<0.05). Non-state apatite inorganic phosphorus (NAIP), apatite state inorganic phosphorus (AP), and inorganic phosphorus were significantly increased (P<0.05), indicating that the bioturbation transformed organophosphorus into AP, NAIP and other inorganic phosphorus components, and decreased total phosphorus in sediment with an increase of density of the clams. Therefore, the bioturbation by S. constricta could affect the vertical distribution of phosphorus in different forms significantly in the sediment of aquaculture wastewater treatment, accelerated the phosphorus release from sediment, and speeded up phosphorus cycling in the whole aquatic ecosystem.