The Dilemmas and Challenges of Tail Water Treatment Technology for Land-Based Marine Aquaculture in China: A Review

In recent years, China’s land-based marine aquaculture industry has developed rapidly. Frequent water changes during the aquaculture process have resulted in a large amount of aquaculture tail water. The untreated tail water, containing organic waste, nutrients, and chemicals, is often discharged into the seawater, potentially causing serious environmental and ecological problems. Therefore, the tail water from land-based marine aquaculture should be treated before being reused for resource utilization or safely discharged into the environment. This can promote the sustainable development and circular economy of the marine aquaculture industry. Against this background, this article provides an in-depth understanding of the generation, composition, and hazards of aquaculture wastewater. It reviews the various technologies for marine aquaculture tail water treatment currently adopted by scholars, classifying them into three major categories: physical, chemical, and biological. The paper analyzes the advantages and disadvantages of each technology, as well as the challenges they face. Additionally, future research directions are proposed, and suggestions are provided for achieving the sustainable development of the marine aquaculture industry and transitioning to environmentally friendly aquaculture.