Biowaste-Based Solutions to Water Pollution: Dragon Fruit Peel as a Green Adsorbent

Water pollution has become an escalating global threat, driven by industrialization, agricultural runoff, and improper waste disposal. Contaminants such as heavy metals, synthetic dyes, and organic pollutants are increasingly polluting freshwater sources, posing serious risks to ecosystems and human health. There is an urgent need for eco-friendly and cost-effective solutions to mitigate this issue. One sustainable approach gaining attention is the valorization of agricultural waste, particularly from fruit crops like dragon fruit (Hylocereus spp.), to develop natural adsorbents for water purification. This review explores the potential of dragon fruit peel and other waste parts as bio-adsorbents for treating polluted water. Rich in cellulose, pectin, hemicellulose, and phenolic compounds, dragon fruit peel exhibits high surface area and active functional groups capable of binding and removing various pollutants. Studies have shown its efficiency in adsorbing heavy metals like lead (Pb²⁺), cadmium (Cd²⁺), and chromium (Cr⁶⁺), as well as synthetic dyes such as methylene blue and malachite green, through mechanisms including ion exchange, hydrogen bonding, and surface complexation. By converting agricultural waste into a valuable resource for water remediation, dragon fruit waste offers an environmentally sustainable and low-cost solution. This approach supports circular economy practices while reducing dependency on synthetic and non-biodegradable adsorbents. In conclusion, dragon fruit waste has significant potential in reducing water pollution, and further research into optimization, scalability, and real-world applications can enhance its role in sustainable water management systems.