Engineering Faculty, Environmental Engineering Department, Pamukkale University, Kınıklı Campus, 20160, Denizli, Turkey.
Environ Monit Assess. 2021 Mar 10;193(4):175. doi: 10.1007/s10661-021-08943-0.
Microplastics are widely detected in wastewater treatment plants. They can remove microplastics from wastewaters with a high yield, but it means that microplastics are transferred and accumulated to sewage sludge. Lately, increasing attention has been paid to microplastics in raw and treated wastewaters. However, studies about quantification and identification of microplastics in sewage sludge are very scarce and need to be further investigated. Since the sludge-based microplastics are newly studied and are a challenging matrix due to high organic content, there is limited knowledge of sampling, pre-treatment methods, identification techniques, and expression units. Besides, treated sewage sludge is mostly used for soil amendment to improve soil fertility and it gives economic advantages. This situation creates a pathway for microplastics entering the soil environment with unknown consequences. To the best of our knowledge, microplastics have a large specific surface area, small size, and hydrophobicity which makes it a good adsorbent for other pollutants. Therefore, the combined effect of microplastics with adsorbed pollutants such as heavy metals, antibiotics, and persistent organic pollutants could give serious harm to soil safety and soil organisms. Herein, new developments in the methods for sampling, pre-treatment, and identification techniques of microplastics in sewage sludge were reviewed. Then, the abundance of microplastics, major polymer types, and shapes in sewage sludge were examined. Finally, the effects and ecological risks of microplastic pollution as a result of agricultural usage of sewage sludge in the soil environment have been summarized. Also, the main points for future research were highlighted.
微塑料广泛存在于污水处理厂中。它们可以从废水中高效去除微塑料，但这意味着微塑料被转移和积累到污水污泥中。最近，人们越来越关注原水和处理废水中的微塑料。然而，关于污水污泥中微塑料的定量和鉴定研究非常匮乏，需要进一步研究。由于基于污泥的微塑料是新研究的，并且由于高有机含量而成为具有挑战性的基质，因此对于采样、预处理方法、鉴定技术和表达单位的了解有限。此外，处理后的污水污泥主要用于土壤改良以提高土壤肥力，从而带来经济优势。这种情况为微塑料进入土壤环境创造了一个未知后果的途径。据我们所知，微塑料具有较大的比表面积、较小的尺寸和疏水性，使其成为其他污染物的良好吸附剂。因此，微塑料与重金属、抗生素和持久性有机污染物等吸附污染物的联合作用可能会对土壤安全和土壤生物造成严重危害。本文综述了污水污泥中微塑料的采样、预处理和鉴定技术的新进展。然后，考察了污水污泥中微塑料的丰度、主要聚合物类型和形状。最后，总结了农业使用污水污泥在土壤环境中造成微塑料污染的影响和生态风险。并强调了未来研究的要点。
