Abstract:
Wastewater reclamation is an important solution to alleviate water shortage problem and improve the quality of water environment. The premise is to ensure the quality of reclaimed water. In recent years, emerging trace organic contaminants (TOrCs), such as antibiotics, perfluorinated compounds, and estrogens, have been widely detected in wastewater, which poses an important threat to the quality of reclaimed water. In order to clarify the control objectives and technologies for emerging TOrCs, this study comprehensively compared the guidelines, standards, and managements for TOrCs control in the regions and countries that have rich experience of wastewater reclamation, such as the European Union, the United States, Australia. In view of the low concentration and wide variety of TOrCs, TOrCs control was conducted by classifying them into high-risk TOrCs and TOrCs indicators in many countries. The State of California in the US and Australia proposed a lists of TOrCs and the concentration limits of high-risk TOrCs and TOrCs indicators. However, the TOrCs and concentration limits have not been included in mandatory standards or regulations. In response to the needs of TOrCs risk control in reclaimed water, Switzerland and California have proposed multi-barrier approaches for wastewater reclamation. Switzerland proposes that the removal of pharmaceutical TOrCs (e.g. carbamazepine) should be higher than 80%, while California requires that the removal of 1, 4-dioxane should be higher than 69% for the reclaimed water used to augment drinking water source. In addition, TOrCs control is highly dependent on full-process safety measures such as source control of pollution (industrial wastewater blocking), unit coordination, online monitoring and feedback, and optimization. As the amount of reclaimed water in China continues to increase, there is an urgent need to formulate the objectives and technologies for wastewater reclamation, including developing the lists of high-risk and indicative TOrCs, promoting the multi-barrier approaches and technologies for wastewater reclamation, and setting the removal efficiency of TOrCs as the treatment objective.