Antiretroviral drugs for the treatment of human immunodeficiency virus (HIV) and other viral infections are among the emerging contaminants considered for ecological risk assessment. These compounds have been reported to be widely distributed in water bodies and other aquatic environments, while data concerning the risk they may pose to unintended non-target species in a different ecosystem (environment) is scanty. In South Africa and other developing countries, lamivudine is one of the common antiretrovirals applied. Despite this, little is known about its environmental impacts as an emerging contaminant. The present study employed a battery of ecotoxicity bioassays to assess the environmental threat lamivudine poses to aquatic fauna and flora. Daphnia magna (filter feeders), the Ames bacterial mutagenicity test, Lactuca sativa (lettuce) germination test, and the Allium cepa root tip assay were conducted, testing lamivudine at two concentrations (10 and 100 µg/L), with environmental relevance. The Daphnia magna toxicity test revealed a statistically significant response (p << 0.05) with a mortality rate of 85% on exposure to 100 µg/L lamivudine in freshwater, which increased to 100% at 48-h exposure. At lower concentrations of 10 µg/L lamivudine, 90% and 55% survival rates were observed at 24 h and 48 h, respectively. No potential mutagenic effects were observed from the Ames test at both concentrations of lamivudine. Allium cepa bioassays revealed a noticeable adverse impact on the root lengths on exposure to 100 µg/L lamivudine. This impact was further investigated through microscopic examination, revealing some chromosomal aberration in the exposed Allium cepa root tips. The Lactuca sativa bioassay showed a slight adverse impact on both the germination rate of the seeds and their respective hypocotyl lengths compared to the control. Overall, this indicates that lamivudine poses an ecological health risk at different trophic levels, to both flora and fauna, at concentrations previously found in the environment.

The intensive use of antibiotics (for human, veterinary, and agricultural purposes) has steadily increased over the last 30 years. Large amounts of antibiotic residues are released into aquatic systems, mostly due to inefficient wastewater treatment. Conventional wastewater treatments are not designed to remove emerging contaminants (such as antibiotics) from wastewater. Therefore, algae treatment (phycoremediation) has emerged as a promising choice for cost-effective, eco-friendly, and sustainable wastewater treatment. For this reason, we investigated the removal performance of a well-established algal consortia (Chlorella protothecoides and Chlorella vulgaris) used in passive wastewater treatment ponds (Mosselbay, South Africa). Five antibiotics (sulfamethoxazole, amoxicillin, trimethoprim, ofloxacin, and clarithromycin) were selected for their ubiquity and/or low removal efficiency in conventional wastewater treatment plants (WWTPs). For each antibiotic, two concentrations were used: one environmentally relevant (10 ppb) and another 10 times higher (100 ppb), tested in triplicate and collected at two-time points (7 and 10 days). The algae remained viable over the exposure period (which is similar to the retention time within maturation ponds) and exhibited the capacity to remove sulfamethoxazole (77.3% ± 3.0 and 46.5% ± 5.3) and ofloxacin (43.5% ± 18.9 and 55.1% ± 12.0) from samples spiked with 10 and 100 ppb, respectively. This study demonstrates the potential and innovation of algal remediation for contaminants in a developing country context, where minimal infrastructure is available.

Industrialisation, population growth, and concomitant demand for fresh water have immensely impacted water quality and scarcity. In particular, wastewater generated from industries generally produces high amounts of nutrients, heavy metals, and chemicals that degrade the environment. Several algal species have been studied and utilized for their role in the treatment of various types of wastewater. Conventional wastewater treatment options are often expensive and energy-demanding, and generally ineffective at completely removing contaminants. Conversely, phycoremediation technology is an emerging green approach used to remove various types of pollutants from the environment while producing valuable compounds. Compared to conventional methods, phycoremediation presents as an eco-friendly and economically attractive alternative. This paper serves as a review of an algal-based treatment technology in wastewater remediation for industry, describing the most common microalgal consortia used for this purpose. Phycoremediation challenges and strategies to urgently accelerate steps towards achieving a clean and safe environment are presented, while examples of applications in industries are also provided.