A review of microplastics in wastewater treatment plants in Türkiye: Characteristics, removal efficiency, mitigation strategies for microplastic pollution and future perspective.

The effluent of WWTPs is an important source of microplastics (MP) for the aquatic environment. In this review study, MPs in wastewater treatment plants (WWTP) in Türkiye and their removal from WWTPs are reviewed for the first time. First, MP characteristics in the influent and effluent of WWTPs in Türkiye are discussed. In the next section, the abundance of MPs in the influent and effluent of WWTPs in Türkiye and the MP removal efficiency of WWTPs in Türkiye are evaluated. Then, the results of studies on MP abundance and characteristics in Türkiye's aquatic environments are presented and suggestions are made to reduce MPs released from WWTPs into the receiving environments. Strategies for reducing MPs released to the receiving environment from WWTPs of Türkiye are summarized. In the last section, research gaps regarding MPs in WWTPs in Türkiye are identified and suggestions are made for future studies. This review paper provides a comprehensive assessment of the abundance, dominant characteristics, and removal of MPs in WWTPs in Türkiye, as well as the current status and deficiencies in Türkiye. Therefore, this review can serve as a scientific guide to improve the MP removal efficiency of WWTPs in Türkiye.

A review on cigarette butts: Environmental abundance, characterization, and toxic pollutants released into water from cigarette butts.

Every year, trillions of cigarette butts (CBs) are discarded into the environment. CBs are frequently found on beaches and in urban areas worldwide due to their high resistance to physical and biological degradation. Components of CBs, such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), cellulose acetate fibers (microplastics), nicotine, aromatic amines, and BTEX (benzene, toluene, ethylbenzene, and xylene), are released into aquatic environments. Harmful components released into water from CBs cause both water pollution and toxic effects on different aquatic organisms. In the first part of this review, studies investigating the density of CBs in different environments were reviewed. In the second part, the results of studies investigating the characteristics of cigarette filters using characterization techniques were reviewed. Then, studies on heavy metals, PAHs, microplastics (microfibers), nicotine, aromatic amines and BTEX released into water from CBs were reviewed, and factors affecting the types, amounts and release conditions of compounds (pollutants) released into water from CBs were discussed. In the last section, taking into account the studies carried out to date, deficiencies in the research on pollutants released into water from CBs were identified and recommendations were made for future studies. This review highlights the environmental abundance of CBs, the characterization results of CB filters, and the release into water of some substances in CBs that are pollutants for the aquatic environment. This review may serve as a guide to elucidate the environmental abundance of CBs, the characteristics of CBs/filters, and the concentration in water of some pollutants released into water from CBs.