河流水环境及水动力条件差异对悬浮颗粒物表观特征的影响

Effects of River Water Environment and Hydrodynamic Conditions on Apparent Characteristics of Suspended Particulate Matter

为明确河流水环境及水动力条件差异对悬浮颗粒物表观特征的影响,选择海河流域的牛尾河与滦河为研究对象,通过微观形貌观测明确了不同河流悬浮颗粒物的结构特征,并采用模拟风化实验进一步探究了水环境及水动力条件差异对悬浮颗粒物表观特征的影响。结果表明:牛尾河水环境及水动力条件差,有机裹层完全包裹在悬浮颗粒物外,表观特征复杂;滦河水环境及水动力条件好,外部仅有少量有机裹层包裹,裸露内部无机矿物,表观特征简单。风化模拟实验结果表明在相同水动力条件下,较差的水环境条件能够造成牛尾河与滦河自生悬浮颗粒物有机裹层的负载量多,而较好的水环境条件造成有机裹层负载量少。牛尾河天然悬浮颗粒物在较好水质条件下,随着转速的增高其有机裹层负载量逐渐降低,当转速达到1000 r/min时,烧失量(Loss On Ignition,LOI)降低至0.12%。水环境条件及水动力条件共同塑造了悬浮颗粒物的表观特征,较差的水环境条件更易于悬浮颗粒物表面有机裹层的附着,而较强的水动力条件则不利于悬浮颗粒物表面有机裹层的附着。河流悬浮颗粒物的表观特征受到河流水环境及水动力条件的双重调控,是物理风化与化学风化共同作用的结果。本文对深入认识河流悬浮颗粒物的表观特征具有重要意义。

In order to clarify the influence of river water environment and hydrodynamic condition differences on the apparent characteristics of suspended particulate matter(SPM),Niuwei River and Luanhe River in Haihe River Basin is selected as the research object,to identify the structural characteristics of SPM in the two rivers by microscopic morphology observation.The effects of water environment and hydrodynamic conditions on the apparent characteristics of SPM are further studied by simulated weathering experiments.The results show that Niuwei River has poor water environment and hydrodynamic conditions.SPM is completely wrapped by organic coating and has complex apparent characteristics.Luanhe River has good water environment and hydrodynamic conditions,there is only a small amount of organic coating on the outside,showing inorganic minerals inside out,with simple apparent characteristics.The results of weathering simulation show that under the same hydrodynamic conditions,poor water environment conditions can cause more organic loading of autobiotically SPM in Niuwei River and Luanhe River,while better water environment conditions can cause less organic loading.Under the condition of good water quality,organic coating content of natural SPM in Niuwei River decreases gradually with the increase in rotational speed,and Loss on Ignition(LOI)decreases to 0.12%when the rotational speed reaches 1000 r/min.Water environmental conditions and hydrodynamic conditions jointly shape the apparent characteristics of SPM.Poor water environmental conditions are more likely to adhere to the surface of SPM,while strong hydrodynamic conditions are not conducive to the adhesion of the surface of SPM.The apparent characteristics of SPM in rivers are controlled by both water environment and hydrodynamic conditions,and are the result of both physical and chemical weathering.This paper is of great significance for understanding the apparent characteristics of SPM in rivers.