Thirty years of experience in water pollution control in Taihu Lake: A review

Taihu Lake has suffered from eutrophication and algal blooms for decades, primarily due to increasing anthropogenic pollutants from human activities. Extensive research and widespread implementation of water pollution control measures have significantly contributed to the improvement of water quality of Taihu Lake. However, the relevant experience of Taihu Lake pollution control has not been well summarized to provide insight for future lake restoration. This review article seeks to address this gap by first providing a comprehensive overview of Taihu Lake's water quality dynamics over the past thirty years, characterized by two distinct stages: (I) water quality deterioration (1990s–2007); and (II) water total nitrogen (TN) improvement but total phosphorus (TP) fluctuation (2007–current). Subsequently, we conducted a thorough review of the experiences and challenges associated with water pollution control during these two stages. Generally, pollution control practices emphasized point source control but overlooked non-point sources before 2007, possibly due to point sources being easier to identify and manage. Accordingly, the focus shifted from industrial point sources to a combination of industrial point and agricultural non-point sources after 2007 to control water pollution in the Taihu Lake Basin. Numerous studies have delved into non-point source pollution control, including source control, transport intercept, in-lake measures, and the integration of these technologies. Taken together, this paper provides suggestions based on the needs and opportunities of this region. Further research is needed to better understand and model the underlying pollution processes, as well as to increase public participation and improve policy and law implementation, which will assist decision-makers in formulating better water management in Taihu Lake.