Malachite green in environmental samples: Updates on sources, fates, distribution and removal techniques

Malachite green (MG) is a synthetic triphenylmethane dye originally employed as an industrial colorant in textile, paper, and leather industries. Its subsequent application in aquaculture was driven by its demonstrated antibacterial and antiparasitic properties. However, substantial evidence has revealed its high toxicity, including carcinogenic, teratogenic, and mutagenic effects, posing severe threats to both ecological systems and human health, leading to strict regulations or outright bans in numerous countries. To address residual contamination in industrial effluents and aquaculture systems, researchers have developed various treatment approaches including advanced oxidation processes (AOPs), adsorption techniques, and bioremediation. This comprehensive review systematically summarizes the sources, fates and distribution of MG, while critically evaluating the effectiveness and limitations of existing removal technologies. The objective is to refine current methodologies and support the development of more efficient, cost-effective, and environmentally sustainable remediation strategies to mitigate their adverse environmental and biological impacts.