Small Microplastic Sampling in Water: Development of an Encapsulated Filtration Device

Robin Lenz,Matthias Labrenz

doi:10.3390/w10081055

Abstract

A variety of microplastic sampling instrumentation is currently used for water pollution studies. Plankton net-based approaches have been the most adopted techniques for water column and surface sampling. When applied to microplastics (MP) in the lower µm size range these methods, however, introduce non-negligible risks of sample contamination and loss due to instrument and procedure design. Based on the first principles of systems engineering design we have developed a mobile sampling platform for field application that fulfils the needs of producing usable MP samples with a lower size limit of 10 µm using an encapsulated flow-through filtration concept. Here, we explain the requirements, development, and construction of the device for others to replicate and improve.

Highlights

The sampling of microplastics (MP) from surface waters or in the water column is dominated by towed net sampling techniques inherited from plankton research
That Water it is,2018, important to adequately cover the lower microplastic size ranges in2surveys that estimate current pollution andthis has highlighted recent that research articles and sampling conditions, whereas levels, MP below sizebeen would necessitate by techniques appropriately reports
The They individual filter elements consist a perforated support sheet metal and a top and bottom plate which confine and hold the mesh screen without any adhesive or cementing material. They are held in place tight inside the unit by a screw pole and a stainless steel tightening cap which presses against PTFE ring seals on each side of the double open-end (DOE)

Summary

Introduction

The sampling of microplastics (MP) from surface waters or in the water column is dominated by towed net sampling techniques inherited from plankton research. That Water it is,2018, important to adequately cover the lower microplastic size ranges in2surveys that estimate current pollution andthis has highlighted recent that research articles and sampling conditions, whereas levels, MP below sizebeen would necessitate by techniques appropriately reports [10,11,14], reviews [13], and legislative policy advice [15,16,17]. Tow velocity, and depending on the mouth size and shape, as well as the net and mesh size, the Another factor, which applies to all mesh-based sampling approaches is the diminishing apparent apparent volume passing through the net can vary from what is received by the mechanical counter mesh[18,19]. Size with an advancing fill level andtoclogging of pores [20], leading to increased hydraulic head Another factor, which applies all mesh-based sampling approaches is the diminishing loss of the unit. Two resulting are the diminished volume flow and a change of the retained particle size spectrum towards smaller sizes

Technical Development

Results

Discussion and Conclusions