Comparative Effectiveness of Emerging and Conventional Technologies for Arsenic Removal in Drinking Water: A Systematic Review (2015–2025)

Abstract

Arsenic contamination in drinking water poses a critical global public health threat, affecting over 140 million people. Conventional technologies such as coagulation–filtration and activated alumina have been widely applied but show limited effectiveness against trivalent arsenic (As(III)) and generate hazardous waste. This study aimed to conduct a systematic comparative review of emerging and conventional technologies for arsenic removal, evaluating their effectiveness, economic feasibility, and regulatory compliance. A PRISMA-based protocol and PICOC-informed search strategy were applied to Scopus, yielding 22 eligible scientific articles published between 2015 and 2025. Results indicate that emerging technologies such as chitosan-based bioadsorption and electrocoagulation achieve removal efficiencies above 90 % for both As(III) and As(V), with operational costs ranging from 0.10 to 0.60 USD/m3, making them highly adaptable to rural and decentralized contexts. In contrast, technologies like reverse osmosis—although highly effective (>95 %)—face economic and operational limitations, particularly related to brine disposal and energy demands. Bibliometric analysis shows that India and China lead recent scientific output, with “electrocoagulation” and “bioadsorption” identified as dominant themes. The study concludes that there is no universally optimal technology; rather, selection should be context-specific, balancing technical efficiency, affordability, and long-term sustainability.