The identification and removal of pharmaceuticals from water systems have intensified as a crucial area of environmental science. For decades, the focus was on industrial pollutants, yet today, emerging contaminants like prescription medications pose a silent threat to global water quality. A critical review, titled “A critical review, and up-to-date research progress on the occurrence, and removal of antiretroviral drugs in water,” by Lawrence M. Madikizela and published in the journal Desalination and Water Treatment, systematically outlines the current knowledge gaps, challenges, and progress in addressing one specific class of these contaminants: antiretroviral drugs (ARVs).

ARVs are essential for treating and managing HIV, yet their widespread use—especially in developing countries where wastewater treatment infrastructure is often insufficient—has led to their persistent presence in aquatic environments. The review highlights the scale of this environmental contamination, noting that concentrations of ARVs in water sources have escalated over the last decade. Most notably, the drug efavirenz has been reported in wastewater effluent at concentrations as high as 33μg/L. Such concentrations, released directly into surface water, are far from benign.

The core concern is that these pharmaceutical residues possess toxic effects on aquatic organisms and plants, destabilizing ecosystems from the base of the food chain upward. Furthermore, as water scarcity drives the necessity of irrigating crops with treated or used water, the transfer of ARV contaminants from water to produce becomes a direct threat to the sustainability of high-quality vegetables and the broader food supply. The review confirms that the chemical structures of many ARVs enable them to persist through conventional wastewater treatment processes, leading to continuous release into the environment.

The author critically examines the progress made in developing remediation techniques to tackle this issue. Traditional methods are largely inadequate, leading researchers to explore advanced oxidation, membrane filtration, and adsorption technologies. Within the field of adsorption, the review specifically calls out the significant role of biochar as one of the most promising materials for ARV removal. Biochar boasts a high surface area and porous structure, making it an excellent and cost-effective adsorbent. Research is currently focused on enhancing its performance by creating biochar-based composites and other modified carbon materials that are engineered to chemically and physically attract and bind the ARV molecules from contaminated water before they can be discharged. Biochar offers a scalable and potentially economical solution, particularly for regions struggling with the high costs of conventional advanced treatment.

While removal progress is promising, the review identifies two major gaps. First, the occurrence data is heavily skewed toward developing countries, where the need for ARV treatment is high, suggesting a broader, unmeasured problem in developed nations. Second, there is a significant lack of research into the degradation products of ARVs. When ARVs break down in the environment, their resulting metabolites may retain or even increase toxicity compared to the parent compound, yet they are often overlooked in monitoring programs. Understanding these byproducts is essential for designing remediation techniques, including those using biochar, that achieve complete detoxification rather than just transforming one pollutant into another.

In summary, this critical review serves as an urgent call to action. While the medical success of ARVs is undeniable, their environmental persistence represents an emerging crisis. The documented concentrations of drugs like efavirenz at 33μg/L demand a global shift toward advanced water treatment technologies. The work confirms that materials like biochar are central to this future, offering a practical, sustainable pathway to protect aquatic health and ensure the safety of the world’s irrigated food supply.

Source: Madikizela, L. M. (2025). A critical review, and up-to-date research progress on the occurrence, and removal of antiretroviral drugs in water. Desalination and Water Treatment, 324, 101530.