东平湖菹草腐烂分解过程中营养元素和重金属的动态释放及其环境效应  

Dynamics of nutrient and heavy metal release and environmental effect during the decomposition of Potamogeton crispus Linn in Dongping Lake

作　　者：刘浩志 邓焕广 鲁长娟 张菊 吴金甲 LIU Haozhi;DENG Huanguang;LU Changjuan;ZHANG Jü;WU Jinjia(College of Geography and Environment,Liaocheng University,Liaocheng 252059,China;Research Institute of the Yellow River Science,Liaocheng University,Liaocheng 252059,China;Dezhou Natural Resources Bureau,Dezhou 253000,China;The Great Canal Research Institute,Liaocheng University,Liaocheng 252059,China)

机构地区：[1]聊城大学地理与环境学院,聊城252059 [2]聊城大学黄河学研究院,聊城252059 [3]德州市自然资源局,德州253000 [4]聊城大学运河学研究院,聊城252059

出　　处：《应用与环境生物学报》2024年第3期544-549,共6页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(41401563);聊城大学科研启动基金项目(318011909,318012019)资助。

摘　　要：东平湖是南水北调东线工程的调蓄湖库和山东省西水东输的重要水源地,其优势沉水植物菹草(Potamogeton crispus Linn)对水体生态系统具有重要影响.为揭示菹草腐烂分解过程及营养元素(C、N和P)、重金属(Hg、As、Cd、Cu、Cr和Zn)含量的动态变化,采用分解网袋法开展了为期170 d的现场分解试验,并采用元素积累指数(accumulation index,AI)分析其动态释放或积累并评估其环境效应.结果表明,菹草腐烂分解过程中干物质残留率(dry mass residue rate,DRR)符合二次指数模型W_(t)/W_(0)=0.474e^(-0.081t)+0.526e^(-0.001t)(R^(2)=0.889),0-32 d为其快速分解阶段.分解残留物中C含量在0-32 d略有增加后下降,N含量在0-4 d略有降低后显著升高,P含量在0-4 d显著下降,随后呈缓慢增加趋势,各重金属元素含量均有显著增加.菹草腐烂分解过程中C、N和P均表现为释放,各重金属除Zn外则主要表现为富集.C、N和P的积累指数与残留率呈显著正相关(P<0.01),而各重金属元素的积累指数与残留率无显著相关关系(P>0.05),吸附作用和微生物活动可能是残留物富集重金属的主要原因.综上所述,东平湖菹草腐烂分解将增加水体富营养化和重金属内源性污染的风险.Dongping Lake is an important reservoir on the eastern route of the South-to-North Water Diversion Project and is a significant water source for the West-to-East Water Transfer Project in Shandong Province.Potamogeton crispus Linn.,the dominant submerged plant in Dongping Lake,plays a crucial role in aquatic ecosystems.To reveal the dynamic changes in nutrient elements(C,N,and P)and heavy metals(Hg,As,Cd,Cu,Cr,and Zn)in the litter,a 170-day decomposition experiment was conducted in situ using the litterbag method.The dynamic release/accumulation of nutrient elements and heavy metals was analyzed,and their environmental effects were assessed using the element accumulation index(AI).The results showed that the residual ratio of dry mass during the decomposition of P.crispus could be simulated using the double exponential model,W_(t)/W_(0)=0.474e^(-0.081t)+0.526e^(-0.001t)(R^(2)=0.889),and P.crispus decomposed rapidly during the initial 32 days.The C content in the litter increased slightly from days 0-32 and then decreased,whereas the N content decreased slightly from days 0-4 and then increased significantly.The P content decreased significantly from days 0-4 and then slowly increased,and the content of all heavy metals in the litter increased significantly.During the decomposition of P.crispus C,N,and P were released into the water,whereas heavy metals,except Zn,were enriched in the litter.The AI values of C,N,and P were significantly and positively correlated with the residual ratio(P<0.01),whereas no significant correlations were found between the AI values of heavy metals and the residual ratio(P>0.05).Adsorption and microbial activity may be the main causes of heavy metal accumulation in litter.These results indicate that the decomposition of P.crispus in Dongping Lake increases the risk of water eutrophication and endogenous heavy metal pollution.

关 键 词：东平湖 菹草 腐烂分解 营养元素 重金属 动态释放 环境效应 

分 类 号：X524[环境科学与工程—环境工程] X173