Microplastics Removal from Water using Fe Based Coagulant

Abstract

Microplastics (MPs), characterized as plastic particles that are less than 5 mm in diameter, have become ubiquitous pollutants in water bodies. These particles have considerable potential for bioaccumulation and can interact with numerous other contaminants. Given their durability, MPs present substantial risks to both ecological systems and human health, emphasizing the importance of developing efficient removal techniques. Research has shown that standard treatment processes, such as screening and sedimentation, can achieve removal rates of 50% to 80% for microplastics larger than 100 μm. However, traditional methods fall short in treating particles smaller than 10 μm. Advanced treatment technologies, particularly membrane filtration, show remarkable removal efficiency, reaching up to 98%, yet they are challenged by issues like membrane fouling. Coagulation has emerged as a strong and effective strategy for the removal of microplastics among alternative methods. The success of coagulation is determined by several essential parameters, including the amount of coagulant used, modifications to the coagulant's surface, pH, ionic strength, and the characteristics of the microplastics in terms of type and size. These factors together dictate the interactions between microplastics and coagulants, enabling processes such as destabilization, bridging, and hydrophobic interactions. Iron-based coagulation stands out as a promising and scalable technique for addressing the issue of microplastic pollution in aquatic environments. The key iron salts employed as coagulants are ferric chloride (FeCl3), ferrous sulfate (FeSO4), and ferric sulfate (Fe2(SO4)3). There is an urgent demand for the development of rapid, eco-friendly, and efficient iron-based coagulants. To effectively tackle microplastic contamination, it is recommended to adopt integrated coagulation strategies, such as those that merge coagulation with adsorption or photocatalytic oxidation. Utilizing these techniques in large-scale water treatment facilities presents a practical solution for decreasing microplastic pollution, elevating water quality, and ensuring the protection of ecosystems and public health.