Microplastics removal from discharge water: mitigation actions, overview and research perspectives

The increasing use of plastic materials in different industrial fields is essentially due to their unique characteristics. This spreading has brought to the dispersion of plastic materials, fragments and objects in the environment. Furthermore, an insidious kind of pollution, strictly connected to plastics, is constituted by the presence in the environment of microplastics, commonly defined as “plastic particles < 5 mm in diameter, which include particles in the nano-size range”. During the last decade, several studies have been conducted on their removal from discharge or drinking water. This topic is currently trending and even companies are showing a marked interest in this issue. The first studies conducted on possible MPs removal methods have essentially replicated the same working principles of water purification applied to solid particulates in drinking water treatment plants or in wastewater plants. At present, several new removal methods are being studied and these can be classified in chemical, physical and biological in function of their basic working principle. This work also presents mitigative actions that can be implemented on clothes fibers to avoid MPs release in water. The advantages and drawbacks of various removal mechanisms are discussed. Besides, research perspectives are presented.