摘要
洞庭湖区南荻下游产业造纸行业于2019年整体退出,使得大量南荻无法被刈割利用而滞留于湖区腐解.为评估未刈割南荻残体腐解对洞庭湖水环境影响,本研究探究了沉积物湖水模拟体系内不同生物量南荻腐解过程水质变化特征.实验结果表明:在90 d腐解过程中,不同南荻生物量下(0-2 g/L)腐解体系上覆水COD、氨氮(NH 3-N)、总氮(TN)、总磷(TP)水质指标浓度均呈现“急速上升快速下降缓慢恢复”趋势,其中,COD和TP浓度均在腐解第5天时急速上升至最高值.腐解体系内南荻生物量对水质影响显著,相同腐解时间下,随着南荻投加量增加,上覆水溶解氧(DO)浓度越低,NH 3-N、TN、TP、COD水质指标浓度越高.当南荻投加量为2 g/L时,上覆水COD、NH 3-N、TN和TP水质指标浓度可分别高达46.00、4.11、6.84和1.14 mg/L,分别是空白组的2.60、1.58、1.42和8.14倍.当腐解时间为90 d时,南荻投加量为0-1 g/L条件下,腐解系统上覆水水质基本恢复至未腐解时水平;当南荻投加量增加至2 g/L,上覆水NH 3-N、TN和TP浓度仍分别为未腐解时的0.59、0.35和2倍,DO仅为初始浓度的16.6%.总体上,南荻腐解可造成短期内营养盐及有机组分浓度显著上升,且其腐解对水质的影响程度随着其生物量的增加而显著增强,以上结果可为造纸业退出后洞庭湖南荻管控提供科学依据.
All the papermaking enterprises in Lake Dongting area were closed by the government in the year of 2019.The overall withdrawal of papermaking makes Triarrhena lutarioriparia not to be cut and detained in Lake Dongting area.In order to evaluate the effects of T.lutarioriparia decomposition on the lake aquatic environment,the variations of overlying water quality during the decomposition period of T.lutarioriparia with different biomass were investigated in this study using the sediment-lake water simulation system.The experimental results showed that concentrations of the major water quality indexes,including COD,ammonia nitrogen(NH 3-N),total nitrogen(TN)and total phosphorus(TP),exhibited a trend of“sharp rise-fast decline-slow recovery”during the 90-day decomposition of T.lutarioriparia with 0-2 g/L biomass addition.Concentrations of COD and TP in overlying water rapidly rise to the highest values on the 5th day of decomposition.The quantities of T.lutarioriparia biomass involved in the decomposition exerted a significant impact on water quality.Under the same decomposing time,the more quantities of T.lutarioriparia biomass added,the concentration of DO decreased and concentrations of COD,NH 3-N,TN and TP increased.As the quantity of T.lutarioriparia biomass reached 2 g/L,the maximum concentrations of COD,NH 3-N,TN and TP in overlying water could be up to 46.00,4.11,6.84 and 1.14 mg/L,respectively,which was 2.60,1.58,1.42 and 8.14 times higher than that of the blank group without T.lutarioriparia addition.When the decomposing time got to 90 days,the overlying water quality in the decomposing system of 0-1 g/L,T.lutarioriparia was basically restored to the original level before decomposition.On the contrary,the NH 3-N,TN and TP concentrations in the overlying water of the 2 g/L-T.lutarioriparia decomposition group are still 0.59,0.35 and 2 times higher than that before decomposition,respectively,and DO was only 16.6%of the initial value.Overall,the T.lutarioriparia decomposition exerted adverse effects on quality including the depletion of DO,the increase concentrations of organic matter and nutrients,especially in rapid leaching process.Such adverse effects were significantly associated with the T.lutarioriparia biomass.Results obtained in this study provide useful references for formulating efficient strategies related to the management of T.lutarioriparia in Lake Donting wetland.
作者
赵媛媛
汤楠
李智慧
陈跃辉
许友泽
Zhao Yuanyuan;Tang Nan;Li Zhihui;Chen Yuehui;Xu Youze(Hunan Research Academy of Environmental Sciences,Changsha 410004,P.R.China;College of Environment and Resources,Xiangtan University,Xiangtan 411105,P.R.China;School of Metallurgy and Environment,Central South University,Changsha 410083,P.R.China)
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2021年第4期1188-1195,共8页
Journal of Lake Sciences
基金
湖南省重点研发计划(2018SK2023)
2019年中央水污染防治专项资金(湘财资环[2019]21号)联合资助.
关键词
洞庭湖
南荻
腐解
水质影响
Lake Dongting
Triarrhena lutarioriparia
decomposition
water quality effection
