Recently, Laurent from the French National Academy of Sciences? Serant and his team published a research result in the journal Biology Letters of the British Society: after microplastics enter the ocean, their direct biological interference effect will eventually suppress the behavioral response of intertidal gastropods, thereby increasing their vulnerability to predation.



With the successive reports of microplastic pollution caused by contact lenses and cosmetics in recent years, the already alarming problem of white pollution has further received social attention. According to statistics, the known sources of microplastic pollution currently include cosmetics, detergents, microscopes, agricultural tools, paints, etc., the vast majority of which flow into the ocean through sewers.

As early as the beginning of this year, the Environmental Planning Agency mentioned microplastic pollution and referred to it as a major environmental problem alongside warming, ozone holes, and ocean acidification. So how should we deal with microplastic pollution?

To some extent, in order to address microplastic pollution, water quality monitoring is a long and arduous task. However, water quality monitoring is not just about measuring the content of microplastics in water. The reason why microplastics are known as PM2.5 in water is not only because they are small particles, spread quickly, and difficult to capture like PM2.5, but also because of their large specific surface area, which makes them a breeding ground and transmission medium for viruses, bacteria, and harmful substances, and can spread them to marine organisms or cause disasters in the natural environment. In other words, in order to control microplastics through water quality monitoring, water temperature, turbidity, suspended solids content, organic matter content, water acidity and alkalinity, and inorganic matter indicators cannot be omitted.

Let's first talk about microbial indicators. Generally speaking, microbial indicators are intuitive indicators that can reflect the water quality status, and due to the very small volume of bacteria and viruses, it is difficult to directly test them. Conventional water quality bacterial detection requires the use of fungal culture. After sampling the water, nutrient agar medium is used for cultivation. After cultivation, the number of bacterial colonies is observed with the naked eye and any omissions are checked with a magnifying glass. It should be noted that some bacteria have very small volumes that are difficult to capture with ordinary optical microscopes. Therefore, in order to determine the types of bacteria in liquids, instruments such as electron microscopes may also be needed.

In addition, with the integration and intelligent development of instruments, portability has gradually become one of the development directions of instruments. While ensuring accuracy, portable instruments can often bring a lot of convenience to field testing. In the field of water quality testing, basic data such as water temperature, water pressure, turbidity, acidity and alkalinity, total nitrogen, and total chromium can be quickly analyzed on site with the help of portable water quality multi parameter analyzers.

Another important point to note is that due to the complex sources of microplastics that pollute the water environment, their components are also different. Therefore, for microplastic pollution detection in water quality monitoring, it is also important to test the composition of microplastics themselves. Generally speaking, the detection of microplastics, a water pollutant, requires separation and analysis. The purpose of separation is to eliminate the influence of solid impurities other than microplastics on the inspection results. Generally, density separation combined with filtration method is used to achieve this.

The composition detection of microplastics generally adopts environmental scanning electron microscopy energy dispersive X-ray spectroscopy (ESEM-EDS) and infrared spectroscopy analysis technology. The principle of ESEM-EDS analysis is that the production of microplastics is generally due to environmental forces such as biodegradation, photodegradation, chemical weathering, etc., which may cause certain cracks. In other words, surface analysis of microplastics using ESEM-EDS can be used to analyze their elemental composition. In addition, microplastics should be transparent and lightweight enough to ensure infrared penetration, so Fourier transform infrared spectroscopy can effectively identify the high polymer chemical components of microplastics.

It is worth mentioning that in-depth analysis of microplastics is not only beneficial for relevant personnel to understand the water quality situation, but also provides certain assistance for the treatment of microplastics.