Research progresses on phenols and ammonia nitrogen recovery and treatment methods in coal chemical wastewater (CCW)

The amount of wastewater from the coal chemical industry was large and the water quality was complex with the highest CODCr of 80,000 mg/L, ammonia nitrogen of 9000 mg/L, and phenols of 7000 mg/L. The recovery and effective treatment of ammonia nitrogen and phenols were issues that cannot be ignored for realizing the harmless treatment of CCW and the sustainable development of the coal chemical industry. This review summarized the current research status of phenols and ammonia nitrogen removal at home and abroad from three aspects: the recovery technology of phenols and ammonia nitrogen, the biochemical treatment technology of phenols and ammonia nitrogen, and the advanced treatment technology of phenols and ammonia nitrogen; Furthermore, the various technologies in terms of their advantages, disadvantages and practical application were analysed. Finally, in view of the concepts of energy saving, high efficiency, and sustainable health, the prospects of phenols and ammonia nitrogen recovery and treatment in future were discussed. The purpose of this review was to allow researchers in this field to use a more scientific approach to understand the research status and development trend of phenols and ammonia nitrogen in CCW and provide a reliable theoretical basis for the new exploration of phenol-ammonia recovery and treatment. It would be of great significance to promote the sustainable development of the coal chemical industry.