Читать книгу Plastic and Microplastic in the Environment - Группа авторов - Страница 21

The sampling of sediment samples can be separated into the collection from the shoreline and bottom of the river or lake. For shore sediments, sampling strategies are transected sampling perpendicular, random sampling, and sampling in single squares or parallel to the water. Most studies applied the grid sampling method with depths of 2–5 cm on the surface layer (Jiang et al. 2019; Klein et al. 2018). Frame and corers are usually used to determine the sampling area. Non‐plastic tools such as scoop, trowels, or shovels, and non‐plastic sampling vessels are required (Alam et al. 2019; Jiang et al. 2019; Peng et al. 2018). Bottom sediment from the riverbed or lakebed can be carried out with grab samplers such as Ekman or Van Veen grabs or corers (Alam et al. 2019; Fan et al. 2019; Ta et al. 2020c; Wang et al. 2017). The sediment samples collected by grab methods are usually disturbed, therefore this is suitable for surface layer (top 5 cm) or bulk sampling. Conversely, sampling by cores allows determining MP depth profiles and undisturbed surface and depth layers. Nevertheless, the number of samples that can be collected is limited. According to Dris et al. (2018), river bottom sediments are mostly collected by grabs, while corers or grabs are used for lake bottom sediments. The number of MPs is usually normalized to the sediment volume or weight, and sampling area.