A review of the occurrence, disposal, determination, toxicity and remediation technologies of the tetracycline antibiotic

Tetracycline (TC) is a group of antibiotics that includes chlorotetracycline (CTC), doxycycline (DC), and oxytetracycline (OTC). TC is the secondary most used antibiotic worldwide to treat diseases caused by bacteria. It is noteworthy that in the human and animal metabolic processes, about 60% and 17–80% of the TC dosage administered are not adsorbed and are excreted in urine and feces. Its widespread use in human and veterinary treatments is leading to the situation of environmental contamination, both in soil, surface, and underground waters. The first two sections of this review paper present an overview of the problem of water and soil contamination, and the situation on the worldwide use of TC. The third section focuses on analytical methods for detecting TC in the most diverse types of samples. Furthermore, in the following chapters it is discussed TC toxicity and the application of chemical, physical, and biological processes in removing TC in wastewater. At last, hybrid and emerging technologies for TC degradation as an environmental contaminant are presented, and some future challenges that must be faced by this research field are summarized. A critical analysis from the authors' perspective is presented at the end of each session.