Professor Yang Jiaxin's research group from the School of Marine Science and Engineering, Nanjing Normal University, and the Jiangsu Provincial Key Laboratory of Coastal Ocean Environment–Land Evolution and Ecological Construction, has made new progress in evaluating the ecological risk of retired lithium battery leachate using rotifers as test organisms. The relevant findings have been published in the internationally renowned journal Environmental Science & Technology (CAS Q1 Top, 2025 Impact Factor: 11.3) under the title "Generational toxicity and incomplete recovery from spent lithium-ion battery leachate in an aquatic microinvertebrate Brachionus asplanchnoidis."
With the widespread application of lithium-ion batteries and the continuous increase in large-scale retirement of new energy vehicle batteries, the potential ecological risks of their waste have drawn growing attention. Due to inadequate treatment systems, leachate may be generated from retired lithium batteries during improper disposal, long-term storage, and recycling processes, posing potential threats to aquatic environments through runoff, leakage, and infiltration. Therefore, selecting appropriate test organisms to systematically assess the ecological effects and long-term risks of retired lithium battery leachate is of great significance.
This study employed Brachionus asplanchnoidis, a common rotifer in aquatic ecosystems, as the test organism to investigate the toxic effects of retired lithium battery leachate on typical zooplankton. The results showed that both the leachate and its typical components (lithium, cobalt, nickel, naphthalene, and phenanthrene) could induce acute mortality in rotifers. At sublethal concentrations, the leachate also impaired individual physiological functions by interfering with oxidative stress and digestion/immune-related biochemical indicators, subsequently leading to abnormal population dynamics.
Rotifers exposed to leachate exhibited certain recovery capabilities. Behavioral indicators such as feeding recovered with greater resilience, while morphological, growth, and life-history traits showed slower recovery. Abnormalities in amino acid metabolism, energy supply, and immune stress pathways were important toxicity mechanisms of the leachate, whereas vitamin and protein digestion and absorption processes played key roles in rotifer recovery. The leachate also interfered with ion transport and osmoregulation in rotifers, inducing apoptosis and heavy metal detoxification processes.
The leachate exhibited multi-generational and transgenerational toxicity to rotifers. Continuous exposure to leachate increased intergenerational sensitivity, exacerbated individual decline, and ultimately led to lineage collapse. Even after the removal of stress, adverse effects persisted across multiple generations, potentially associated with toxin accumulation, reduced adaptability, and epigenetic modifications. Exogenous nutritional intervention facilitated the recovery process.
In summary, this study systematically evaluated the ecological effects of retired lithium battery leachate on the typical zooplankton Brachionus asplanchnoidis. Integrating short-term, chronic, and multi-generational dimensions, it revealed the morphological, physiological, biochemical, metabolic, and gene expression responses of rotifers under leachate exposure, as well as their recovery capacity after exposure removal. This work establishes a scientific foundation for environmental risk assessment of leachate and provides theoretical support for identifying potential threats to aquatic ecosystems and formulating regulatory policies for retired lithium batteries.
Yifan Feng, class 2025 master graduate student of Nanjing Normal University (currently pursuing a Ph.D. at the School of Marine Sciences, Sun Yat-sen University), is the first author of the paper. Yifu Xing, a 2023 Ph.D. candidate, is the co-first author. Professor Jiaxin Yang is the sole corresponding author, and Nanjing Normal University is the first affiliated institution. This research was supported by the National Natural Science Foundation of China (Grant Nos. 31772458, 32470490).