CAJ | 학술논문

选取了鄱阳湖北部湖区、“五河”入湖尾闾区、湖心区共14个不同高程的表层出露沉积物样品,通过研究其总氮(TN)含量和氨氮(NH4+-N)释放热力学及动力学特征,试图揭示江湖关系变化导致的水位变化对鄱阳湖沉积物氨氮释放风险的影响.结果表明,鄱阳湖沉积物 TN 含量在377～3875mg/kg 之间；NH4+-N 吸附/解吸平衡浓度(EC0)在1.49～2.99mg/L 之间；单位沉积物 NH4+-N 的最大释放量在17.00~140.97mg/kg 之间,NH4+-N释放主要集中在0~5min时段,占最大释放量的50.84%~73.34%,TN含量、EC0浓度、NH4+-N的最大释放量及初始释放速率均随沉积物所处高程的增高而增大,由此可见近年来由于长江来水量减少,鄱阳湖与长江之间江湖关系的改变,引起鄱阳湖枯水期提前及低枯水位持续时间增加,导致沉积物出露时间延长,进而促使沉积物TN含量、EC0浓度、单位沉积物NH4+-N最大释放量及0~5min时段NH4+-N释放速率升高,进而引起沉积物 NH4+-N 释放风险增大,是导致鄱阳湖水质恶化的重要机制之一.如果此江湖关系变化持续,枯水期低枯水位持续,势必引起沉积物出露面积进一步增大及出露时间的延长,最终可导致来年丰水期鄱阳湖沉积物NH4+-N释放风险增大.
선취료파양호북부호구、“오하”입호미려구、호심구공14개불동고정적표층출로침적물양품,통과연구기총담(TN)함량화안담(NH4+-N)석방열역학급동역학특정,시도게시강호관계변화도치적수위변화대파양호침적물안담석방풍험적영향.결과표명,파양호침적물 TN 함량재377～3875mg/kg 지간；NH4+-N 흡부/해흡평형농도(EC0)재1.49～2.99mg/L 지간；단위침적물 NH4+-N 적최대석방량재17.00~140.97mg/kg 지간,NH4+-N석방주요집중재0~5min시단,점최대석방량적50.84%~73.34%,TN함량、EC0농도、NH4+-N적최대석방량급초시석방속솔균수침적물소처고정적증고이증대,유차가견근년래유우장강래수량감소,파양호여장강지간강호관계적개변,인기파양호고수기제전급저고수위지속시간증가,도치침적물출로시간연장,진이촉사침적물TN함량、EC0농도、단위침적물NH4+-N최대석방량급0~5min시단NH4+-N석방속솔승고,진이인기침적물 NH4+-N 석방풍험증대,시도치파양호수질악화적중요궤제지일.여과차강호관계변화지속,고수기저고수위지속,세필인기침적물출로면적진일보증대급출로시간적연장,최종가도치래년봉수기파양호침적물NH4+-N석방풍험증대.
The total nitrogen (TN) contents and thermodynamics/kinetics of ammonia nitrogen (NH4+-N) release characteristics of Poyang Lake surface exposed sediments were studied, tried to reveal the influence of the water level changed resulted from the relationship between Yangtze Rive and the Poyang Lake changed on the NH4+-N release risk of Poyang Lake sediments. The TN contents of Poyang Lake sediments varied from 377to 3875mg/kg; the adsorption/desorption equilibrium concentrations of NH4+-N(EC0)varied from 1.49to 2.99mg/L; the maximal release potential of NH4+-N varied from 17.00to 140.97mg/kg, the NH4+-N release process was mainly occurred within the 0~5minutes that accounted for 50.84% to 73.34% of the release amount, the TN contents, EC0 concentrations, the maximal release potential and the initial release rate of NH4+-N increased with the height increased, that’s dues to the water from Yangtze river keep reducing,resulting in the low water level advanced and the outcropped time prolonged, then caused the TN contents, EC0 concentrations, the maximal release potential and the initial release rate increased, these factors changed were the important mechanism that caused the NH4+-N release risk increased and the deterioration of water quality. With the Poyang Lake water lever keep lower, it’s bound to lead the sediments exposed area and time increased. then caused the increased of NH4+-N release risk of next year.