Occurrence of pharmaceuticals in aquatic environments: A review and potential impacts in South Africa

Environmental impact and source-controlled approaches for emerging micropollutants: Current status and future prospects

Emerging micropollutants, originating from diverse sources, including pharmaceutical, pesticides, and industrial effluents, are a serious environmental concern. Their presence in natural water bodies has negative effects on ecosystems and human health. To address this issue, the importance of a source-controlled approach has grown, highlighting the use of advanced technologies such as oxidation processes, membrane filtration, and adsorption to prevent micropollutants from entering the environment. Therefore, this review provides a comprehensive overview of emerging micropollutants, their analytical detection methods, and their environmental impacts, with a focus on aquatic ecosystems, human health, and terrestrial environments. It also highlights the importance of using a source-controlled approach and provides insights into the benefits and drawbacks of this strategy. The primary micropollutants identified in this review were erythromycin, ibuprofen, and triclocarban, originating from the pharmaceutical industries for their use as antibiotics, analgesic, and antibacterial drugs. The primary analytical methods used for detection involved hybrid techniques that integrate chromatography with spectroscopy. Thus, this review emphasizes the source-controlled approach's benefits and drawbacks, focusing on emerging micropollutants, their detection, and impacts on ecosystems and health.

Emerging contaminants as unintentional substances in paper and board: A case of unexpected pharmaceuticals detection in the paper recycling chain

The contamination of paper products by various chemicals has been reported on a global level, but to date, no published research has investigated pharmaceutical contamination of paper-based products. In this study, pharmaceutical analysis was conducted on 42 samples collected from various points of the recycled paper value chain in Cape Town, South Africa, which included the various grades that may be included in the manufacturing of recycled paperboard. The analysis was achieved by ultrasonic-assisted extraction of paper samples before detection by UHPLC-Q Orbitrap. Quantification limits ranged from 1.15 pg/g for ketoprofen to 46.07 pg/g for methocarbamol. Pharmaceuticals identified in newspaper samples were dexamethasone, ketoprofen, and 17β-estradiol. The latter was also detected in paper shopping bags (up to 697.49 ng/g), infant bathtub packaging (280.62 ng/g), battery packaging (137.43 ng/g), and an egg carton (170.47 ng/g). Carbamazepine was also prominent with its concentration reaching 13.02 ng/g in a vegetable box. Suspect screening tentatively identified 14 additional pharmaceuticals in paper samples, with minocycline, prazepam, and anabolic steroids appearing more prominently. This pioneering study indicated that unintentional pharmaceutical exposure had expanded beyond environmental media to consumer products.

Pharmaceuticals in the Water: The Need for Environmental Bioethics

Pharmaceuticals are present in various water sources used by wildlife and as drinking water for humans. Research shows that certain pharmaceuticals, sold over the counter and by prescription only, can harm wildlife. Moreover, the human ingestion of water contaminated by polypharmacy presents a potential cause for concern for human health. Despite the wide scope of this problem, environmental bioethics has not adequately engaged with this topic and, instead, has concerned itself with healthcare waste products more generally. The present essay calls for more ethical investigation on the topic.

Evaluation of Photocatalytic Performance of Nano-Sized Sr0.9La0.1TiO3 and Sr0.25Ca0.25Na0.25Pr0.25TiO3 Ceramic Powders for Water Purification

Water pollution is a significant issue nowadays. Among the many different technologies for water purification, photocatalysis is a very promising and environment-friendly approach. In this study, the photocatalytic activity of Sr_0.9La_0.1TiO₃ (SLTO) and Sr_0.25Ca_0.25Na_0.25Pr_0.25TiO₃ (SCNPTO) nano-sized powders were evaluated by degradation of pindolol in water. Pindolol is almost entirely insoluble in water due to its lipophilic properties. The synthesis of the SCNPTO was performed using the reverse co-precipitation method using nitrate precursors, whereas the SLTO was produced by spray pyrolysis (CerPoTech, Trondheim Norway). The phase purity of the synthesized powders was validated by XRD, while HR-SEM revealed particle sizes between 50 and 70 nm. The obtained SLTO and SCNPTO powders were agglomerated but had relatively similar specific surface areas of about 27.6 m² g^-1 and 34.0 m² g^-1, respectively. The energy band gaps of the SCNPTO and SLTO were calculated (DFT) to be about 2.69 eV and 3.05 eV, respectively. The photocatalytic performances of the materials were examined by removing the pindolol from the polluted water under simulated solar irradiation (SSI), UV-LED irradiation, and UV irradiation. Ultra-fast liquid chromatography was used to monitor the kinetics of the pindolol degradation with diode array detection (UFLC-DAD). The SLTO removed 68%, 94%, and 100% of the pindolol after 240 min under SSI, UV-LED, and UV irradiation, respectively. A similar but slightly lower photocatalytic activity was obtained with the SCNPTO under identical conditions, resulting in 65%, 84%, and 93% degradation of the pindolol, respectively. Chemical oxygen demand measurements showed high mineralization of the investigated mixtures under UV-LED and UV irradiation.

Microalgae, a current option for the bioremediation of pharmaceuticals: a review

In this review, research on the use of microalgae as an option for bioremediation purposes of pharmaceutical compounds is reported and discussed thoroughly. Pharmaceuticals have been detected in water bodies around the world, attracting attention towards the increasing potential risks to humans and aquatic biota. Unfortunately, pharmaceuticals have no regulatory standards for safe disposal in many countries. Despite the advances in new analytical techniques, the current wastewater treatment facilities in many countries are ineffective to remove the whole presence of pharmaceutical compounds and their metabolites. Though new methods are substantially effective, removal rates of drugs from wastewater make the cost-effectiveness ratio a not viable option. Therefore, the necessity for investigating and developing more adequate removal treatments with a higher efficiency rate and at a lower cost is mandatory. The present review highlights the algae-based removal strategies for bioremediation purposes, considering their pathway as well as the removal rate and efficiency of the microalgae species used in assays. We have critically reviewed both application of living and non-living microalgae biomass for bioremediation purposes considering the most commonly used microalgae species. In addition, the use of modified and immobilized microalgae biomass for the removal of pharmaceutical compounds from water was discussed. Furthermore, research considering various microalgal species and their potential use to detoxify organic and inorganic toxic compounds were well evaluated in the review. Further research is required to exploit the potential use of microalgae species as an option for the bioremediation of pharmaceuticals in water.

Antiretroviral Drugs in African Surface Waters: Prevalence, Analysis, and Potential Remediation

The sources, ecotoxicological impact, and potential remediation strategies of antiretroviral drugs (ARVDs) as emerging contaminants in surface waters are reviewed based on recent literature. The occurrence of ARVDs in water bodies raises concern because many communities in Africa depend on rivers for water resources. Southern Africa is a potential hotspot regarding ARVD contamination due to relatively high therapeutic application and detection thereof in water bodies. Efavirenz and nevirapine are the most persistent in effluents and are prevalent in surface water based on environmental concentrations. Whereas the highest concentration of efavirenz reported in Kenya was 12.4 µg L^-1 , concentrations as high as 119 and 140 µg L^-1 have been reported in Zambia and South Africa, respectively. Concentrations of ARVDs ranging from 670 to 34 000 ng L^-1 (influents) and 540 to 34 000 ng L^-1 (effluents) were determined in wastewater treatment plants in South Africa, compared with Europe, where reported concentrations range from less than limit of detection (LOD) to 32 ng L^-1 (influents) and less than LOD to 22 ng L^-1 (effluents). The present African-based review suggests the need for comprehensive toxicological and risk assessment of these emerging pollutants in Africa, with the intent of averting environmental hazards and the development of sustainable remediation strategies. Environ Toxicol Chem 2022;41:247-262. © 2021 SETAC.

Medicines as an emergent contaminant: the review of microbial biodegration potential

Emerging environmental contaminants, such as medicine waste, are of great concern to the scientific community and to the local environmental and health departments because of their potential long-term effects and ecotoxicological risk. Besides the prolonged use of medicines for the development of modern society, the elucidation of their effect on the ecosystem is relatively recent. Medicine waste and its metabolites can, for instance, cause alterations in microbial dynamics and disturb fish behavior. Bioremediation is an efficient and eco-friendly technology that appears as a suitable alternative to conventional methods of water waste and sludge treatment and has the capacity to remove or reduce the presence of emerging contaminants. Thus, this review has the objective of compiling information on environmental contamination by common medicines and their microbial biodegradation, focusing on five therapeutic classes: analgesics, antibiotics, antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs), and contraceptives. Their effects in the environment will also be analyzed, as well as the possible routes of degradation by microorganisms.

Occurrence and Effects of Antimicrobials Drugs in Aquatic Ecosystems

Currently, thanks to the development of sensitive analytical techniques, the presence of different emerging pollutants in aquatic ecosystems has been evidenced; however, most of them have not been submitted to any regulation so far. Among emerging contaminants, antimicrobials have received particular attention in recent decades, mainly due to the concerning development of antibiotic resistance observed in bacteria, but little is known about the toxicological and ecological impact that antimicrobials can have on aquatic ecosystems. Their high consumption in human and veterinary medicine, food-producing animals and aquaculture, as well as persistence and poor absorption have caused antimicrobials to be discharged into receiving waters, with or without prior treatment, where they have been detected at ng-mg L−1 levels with the potential to cause effects on the various organisms living within aquatic systems. This review presents the current knowledge on the occurrence of antimicrobials in aquatic ecosystems, emphasizing their occurrence in different environmental matrixes and the effects on aquatic organisms (cyanobacteria, microalgae, invertebrates and vertebrates).

Sulfidogenic fluidized-bed bioreactor kinetics for co-treatment of hospital wastewater and acid mine drainage

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Bioremediation process for acidic mine water co-treatment with hospital wastewater.

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Metal precipitation reached 98% and soluble concentrations of Fe and Zn were less than 0.1 mg/l.

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SO₄²⁻ removal was above 90% in the sulfidogenic bioreactor.

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Naproxen, ibuprofen, ketoprofen, and diclofenac partially removed during the co-treatment process.

A passive co-treatment of acid mine drainage and hospital wastewater previously demonstrated a promising bioremediation viable approach for both toxic streams. The study of inhibition kinetics and microbial communities is essential to understand better the diverse species and the reaction mechanisms within the system. The kinetics and microbiology diversity in the sulfidogenic fluidized-bed reactor (at 30 °C) for co-treatment of hospital wastewater and metal-containing acidic water were examined. The alkalinity from organic oxidation raised the pH of the effluent from 2.3 to 6.1–8.2. Michaelis-Menten modeling yielded (K_m =7.3 mg/l, V_max = 0.12 mg/l min⁻¹) in the batch bioreactor treatment using sulfate-reducing bacteria. For COD oxidation, the dissolved sulfide inhibition constant (K_i) was 3.6 mg/l, and the K_i value for H₂S was 9 mg/l. The dominant species in the treatment process belong to the Proteobacteria group (especially Deltaproteobacteria). The ibuprofen and diclofenac compounds achieved the highest removal rates in the bioreactor of 58.6% and 52.3%, respectively; while, ketoprofen and naproxen of 41.9% and 46.6%, respectively. The findings in COD kinetics, sulfate-reducing bacteria abundance, and selected pharmaceutical concentration reduction provide insight into this co-treatment process's capability.

Predicting the Adsorption of Amoxicillin and Ibuprofen on Chitosan and Graphene Oxide Materials: A Density Functional Theory Study

The occurrence, persistence, and accumulation of antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) represent a new environmental problem due to their harmful effects on human and aquatic life. A suitable absorbent for a particular type of pollutant does not necessarily absorb other types of compounds, so knowing the compatibility between a particular pollutant and a potential absorbent before experimentation seems to be fundamental. In this work, the molecular interactions between some pharmaceuticals (amoxicillin, ibuprofen, and tetracycline derivatives) with two potential absorbers, chitosan and graphene oxide models (pyrene, GO-1, and coronene, GO-2), were studied using the ωB97X-D/6-311G(2d,p) level of theory. The energetic interaction order found was amoxicillin/chitosan > amoxicillin/GO-1 > amoxicillin/GO-2 > ibuprofen/chitosan > ibuprofen/GO-2 > ibuprofen/GO-1, the negative sign for the interaction energy in all complex formations confirms good compatibility, while the size of Eint between 24-34 kcal/mol indicates physisorption processes. Moreover, the free energies of complex formation were negative, confirming the spontaneity of the processes. The larger interaction of amoxicillin Gos, compared to ibuprofen Gos, is consistent with previously reported experimental results, demonstrating the exceptional predictability of these methods. The second-order perturbation theory analysis shows that the amoxicillin complexes are mainly driven by hydrogen bonds, while van der Waals interactions with chitosan and hydrophobic interactions with graphene oxides are modelled for the ibuprofen complexes. Energy decomposition analysis (EDA) shows that electrostatic energy is a major contributor to the stabilization energy in all cases. The results obtained in this work promote the use of graphene oxides and chitosan as potential adsorbents for the removal of these emerging pollutants from water.