基于印迹纳米纤维的DGT技术原位连续采集环渤海近岸海水中的无机氮

Inorganic nitrogen is the main reason for coastal seawater eutrophication and has been listed as one of the strictly controlled pollution indicators. The diffusive gradients in thin films technique (DGT), an in-situ continuous passive sampling technique, has been applied in freshwaters for sampling of inorganic nitrogen. However, high background interference in coastal seawater has become one of the big issues of sampling for inorganic nitrogen using DGT technique because most existing binding phases accumulate inorganic nitrogen based on ion exchange mechanism which results in low accumulation in high background interference. The main solution of this big issue is to synthesize new binding agent which interacts with inorganic nitrogen based on covalent bond, coordinate bond, hydrogen bond, intermolecular force and volume filling. The objective of this project is to develop imprinted nanofiber complex based on imprinted technique and nanofiber, change accumulation mechanism between the binding phase and inorganic nitrogen, investigate the interaction mechanism of imprinted nanofiber and inorganic nitrogen, understand the structure-function relationship of the complex structure and its anti-interference properties, establish a new DGT method for sampling of inorganic nitrogen in high background interference environment of coastal seawater, and evaluate the validity and practicability of this new DGT method. This study can provide theoretical support for the designation of specific functional binding agent and DGT technique, and supply beneficial technical support for the prevention of red-tide alga.

无机氮是引发渤海赤潮的元凶之一，被列为环渤海地区严格控制的污染物指标之一。薄膜扩散梯度技术(DGT)是一种新型的具有分离富集作用的连续原位采集水体中污染物的被动采样技术，可以有效采集淡水中的无机氮。然而应用于海水时，海水的高背景干扰是DGT定量采集无机氮的瓶颈问题，其关键原因是现有DGT结合相与无机氮的相互作用机制主要基于离子交换，易受到高背景值的严重干扰。本项目利用印迹技术的专一性识别性能和纳米纤维的高比表面性能，通过调节和耦合共价键、配位键、氢键、分子间作用力和孔道填充等作用机制，构筑印迹纳米纤维复合材料；探明印迹纳米纤维与无机氮的作用机制，明确复合材料化学组成、结构与抗干扰能力之间的构效关系；并以此作为结合相，在方法学研究基础上，建立具有抗高背景干扰的定量采集海水中无机氮的DGT采样方法。本项目将为特定功能结合相的构筑和DGT方法的设计提供理论支撑，为海水赤潮的预警防范提供技术支持。

本项目以开发适用于高盐度水体无机氮定量采集的被动采样装置为目标，通过制备高容量结合无机氮以及抗离子干扰能力的纳米复合材料，构建以这些纳米复合材料为基础的DGT被动采样装置，探究了pH和各类离子对其定量采集无机氮的影响，旨在为为发展高背景干扰的长期连续监测装备提供有效的技术支撑。我们设计了一种基于铁氰化钴钠的新型薄膜扩散梯度(DGT)被动采样装置，将其应用于高盐度水体中铵离子的定量采集。采用双滴加法制备铁氰化钴钠，建立了以琼脂糖凝胶为扩散相、铁氰化钴钠为结合相的DGT被动采样装置，研究了采集时间、水体pH值和共存阳离子对基于铁氰化钴钠的DGT技术采集铵离子的影响。实验结果表明，使用基于铁氰化钴钠的DGT装置可以准确有效地采集高盐度水体中的铵离子。我们设计了一种基于层状双金属氢氧化物的新型薄膜扩散梯度(DGT)被动采样装置，将其应用于高盐度水体中硝酸盐的定量采集。采用水热法制备层状双金属氢氧化物，建立了以琼脂糖凝胶为扩散相、层状双金属氢氧化物为结合相的DGT被动采样装置，研究了采集时间、水体pH值和共存阴离子对基于层状双金属氢氧化物的DGT技术采集硝酸盐的影响。实验结果表明，使用基层状双金属氢氧化物的DGT装置可以准确有效地采集高盐度水体中的硝酸盐。..