Cadmium Contamination in Aquatic Environments: Detoxification Mechanisms and Phytoremediation Approach

The increased presence of cadmium in the environment can lead to its increase in the food chain, particularly due to its accumulation in the consumable parts of plants. For humans, ingesting food containing high levels of Cd is a significant exposure pathway. Being a non-essential and non-metabolized element, it is harmful to microorganisms, animals, plants, and humans, even in minimal concentrations. As a result, there is a need for the remediation of both natural and urban environments. Bioremediation is a sustainable and eco-friendly technique for cleaning up the environment and reducing contamination of living organisms. This review explores the potential of phytoremediation, a bioremediation approach that utilizes plants as agents for decontamination, as a method to restore such areas. Certain plants, particularly macrophytes, are capable of remediating Cd. In response to induced stress, plants activate various tolerance mechanisms, including antioxidant enzyme systems (as peroxidase, catalase, ascorbate peroxidase, superoxide dismutase, and glutathione peroxidase) as well as non-enzymatic pathways (like phytochelatins). However, a thorough understanding of these tolerance mechanisms is essential for optimizing this method, especially for application in aquatic environments. This study will, therefore, review the existing tolerance and detoxification mechanisms for Cd, along with bioremediation strategies. The application of this eco-friendly approach is highly correlated with the three main areas required for sustainability: economic, environmental and social.