State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
Sci Total Environ. 2021 Mar 10;759:143538. doi: 10.1016/j.scitotenv.2020.143538. Epub 2020 Nov 6.
The analysis of time-series concentrations (C) is of great importance when investigating the biogeochemical processes of nutrients in aquatic environments. However, obtaining C of nutrients remains a challenge using current sampling techniques. In this study, a novel in situ sampler was constructed using reverse osmosis membrane (ROM) osmotic pumps (OP) (ROM-OP sampler), and was used to obtain the C of nutrients in surface waters. The sampler consisted of a sampling OP, sample storing coil, filter, bubble injection module, and preservative adding module. When deployed, the sampling OP continuously draws ambient water through the filter into the sample storing coil, while simultaneously the preservative adding module continuously delivers preservative (HSO solution) into the water flow. The bubble injection module periodically injects air bubbles into the sample storing coil, to segment the sample and create time stamp indicators that allow the sample age to be defined. Upon retrieval, the sample segments in the coil are sequentially pumped out of the sample storing coil and transferred into different vials for further analysis. The sampler was applied to measure the C of various nutrients, including dissolved total nitrogen, dissolved total phosphorus, dissolved reactive phosphorus, and nitrate in a river over a 20 day period and in municipal sewage treatment plant effluent for a 36 h period. Results showed that the ROM-OP sampler successfully obtained C of nutrients, capturing nutrient variations at a high temporal resolution. This sampler is relatively low-cost (~USD 300), small in size, lightweight, robust and does not require an external power source, showing high promise as an effective and efficient tool for monitoring nutrient C in aquatic environments.
当研究水生环境中营养物的生物地球化学过程时，分析时间序列浓度 (C) 非常重要。然而，使用当前的采样技术仍然难以获得营养物的 C。在这项研究中，使用反渗透膜 (ROM) 渗透泵 (OP) 构建了一种新型原位采样器 (ROM-OP 采样器)，用于获取地表水的营养物 C。采样器由采样 OP、样品储存盘管、过滤器、气泡注入模块和防腐剂添加模块组成。部署时，采样 OP 通过过滤器连续将环境水吸入样品储存盘管，同时防腐剂添加模块将防腐剂 (HSO 溶液) 连续输送到水流中。气泡注入模块定期将气泡注入样品储存盘管中，以分段样品并创建时间戳指示器，从而可以定义样品的年龄。回收时，盘管中的样品段依次从样品储存盘管中抽出并转移到不同的小瓶中进行进一步分析。该采样器用于测量河流中各种营养物的 C，包括溶解总氮、溶解总磷、溶解活性磷和硝酸盐，持续 20 天，以及城市污水处理厂废水，持续 36 小时。结果表明，ROM-OP 采样器成功地获得了营养物的 C，以高时间分辨率捕捉营养物的变化。这种采样器相对成本较低（约 300 美元）、体积小、重量轻、坚固耐用，不需要外部电源，作为监测水生环境中营养物 C 的有效工具具有很高的应用前景。
