Removal efficiencies and environmental risk assessment of selected pharmaceuticals and metabolites at a wastewater treatment plant in Pietermaritzburg, South Africa.

This research study critically evaluates the concentrations of selected pharmaceuticals found within wastewater and at various stages within a selected wastewater treatment plant. The study further investigates the effects of seasonal variation, between wet and dry months, on the removal of target analytes. To the best of the authors' knowledge, ivermectin in wastewater has not been investigated in South Africa.

Dual functional covalent triazine framework-TiO S-scheme heterojunction for efficient sequestration of ciprofloxacin: Mechanism and degradation products.

The development of adsorbent and/or photocatalysts based on covalent triazine frameworks (CTF) is fascinating research due to their structural properties, functional groups, and active sites. Herein, a CTF-TiO heterojunction was synthesized by modifying CTF sheets with TiO particles through wet impregnation technique and adsorptive and photocatalytic activities determined for ciprofloxacin (CIP) removal. Comprehensive characterisation of the composites revealed suitable properties of the composites, such as sandwich-like CTF-TiO morphology, improved thermal stability, and better heteroatom effect (HAE).

Quantitative assessment of human health risks from chemical pollution in the uMsunduzi River, South Africa.

A quantitative chemical risk assessment was performed using published data as well as data from the official monitoring programme for the uMsunduzi River in KwaZulu-Natal, South Africa. The chemicals assessed were organochlorinated pesticides (OCPs), pharmaceuticals and personal care products (PPCPs), heavy metals, and nitrates and phosphates. The water from uMsunduzi River is used locally without treatment.

Development of gold plasmonic nanoparticles for detection of polydiallyldimethylammonium chloride at Umgeni water treatment plants: An optimised study and case application.

Background: Polydiallyldimethylammonium chloride (poly-(DADMAC) is used in many drinking water treatment plants in most parts of the world as a flocculant to remove suspended solids from raw water. However, it is very important that residual poly-(DADMAC) is monitored because it disintegrates into a carcinogenic compound known as N-nitrosodimethylamine (NDMA) during the treatment of drinking water.

Methods: In this work, the gold nanoparticle method is optimised for the detection of poly-(DADMAC), where the gold nanoparticles were stabilised with trisodium citrate and then used in quantifying poly-(DADMAC) by Ultraviolet-Visible-Near Infrared spectrophotometry.

Facile synthesis and characterization of multi-walled carbon nanotubes decorated with hydroxyapatite from cattle horns for adsorptive removal of fluoride.

Developing a new adsorbent for fluoride removal from cattle horn waste materials by a facile chemical method has shown great potential for fluoride removal. This paper reports the synthesis of multi-walled carbon nanotubes decorated with hydroxyapatite from cattle horns (MWCNT-CH) using a facile chemical method. Characterization studies using standard techniques showed that the composite is mesoporous with a rough morphology and contained MWCNTs uniformly encapsulated by the hydroxyapatite forming a crystalline MWCNT-CH composite.

Assessing the potential for nevirapine removal and its ecotoxicological effects on Coelastrella tenuitheca and Tetradesmus obliquus in aqueous environment.

Remediation of the antiretroviral (ARV) drug, nevirapine (NVP) has attracted considerable scientific attention in recent years due to its frequent detection and persistence in aquatic environments and potential hazards to living organisms. Algae-based technologies have been emerging as an environmentally friendly option for the removal of pharmaceutical compounds, but their ARV drug removal potential has not been fully explored yet. This study aimed to explore the ecotoxicity and removal potential of NVP by two microalgal species, Coelastrella tenuitheca and Tetradesmus obliquus.

Assessment of the impact of reforestation on soil, riparian sediment and river water quality based on polyaromatic hydrocarbon pollutants.

This study aimed to assess the impact of the eThekwini Municipality reforestation project on the quality of the soil within the reforestation sites, and water from the nearby rivers (White and Black Mhlasini Rivers) situated at the reforested Buffelsdraai area in KwaZulu-Natal, South Africa. This was the first evaluation of the effect of reforestation on the reduction of selected organic pollutants to be conducted in this area. The sixteen polyaromatic hydrocarbons analysed are on the Environmental Protection Agency (EPA) list of priority pollutants.

Sesquiterpene lactones from and their quorum sensing inhibitory activity.

The leaves of , with the synonym are widely used as purgative agents for gastrointestinal problems, and other members of Vernonieae have been used in African traditional medicine for decades. A new sesquiterpene lactone of the keto-hirsutinolide type, 13-acetoxy-1(4),5(6)-diepoxy-8-(senecioyloxy)-3-oxo-1,7(11)-germacradiene-12,6-olide , was isolated from the hexane extract of its leaves, in addition to the known 13-acetoxy-1,4-epoxy-8-(senecioyloxy)-3-oxo-1,5,7(11)-germacratriene-12,6-olide . Three common flavonoids (apigenin , luteolin and velutin ) were also isolated.

Covalently linked graphene oxide/reduced graphene oxide-methoxylether polyethylene glycol functionalised silica for scavenging of estrogen: Adsorption performance and mechanism.

Water pollution by pharmaceuticals is a global issue and its remediation is important. To overcome this, we synthesised super hydrophobic nanoporous 3-dimensional ordered nanomaterials with multi-functional binding chemistry for highly efficient adsorption of estrogen (17β-estradiol). Graphene oxide (GO) was synthesised via Tours method and methoxylether polyethylene glycol (mPEG) was covalently introduced onto GO surface via facile amidation mild process to give GO-mPEG.

Target, Suspect and Non-Target Screening of Silylated Derivatives of Polar Compounds Based on Single Ion Monitoring GC-MS.

There is growing interest in determining the unidentified peaks within a sample spectra besides the analytes of interest. Availability of reference standards and hyphenated instruments has been a key and limiting factor in the rapid determination of emerging pollutants in the environment. In this work, polar compounds were silylated and analyzed with gas chromatography mass spectrometry (GC-MS) to determine the abundant fragments within the single ion monitoring (SIM) mode and methodology.

Brief bibliometric analysis of "ionic liquid" applications and its review as a substitute for common adsorbent modifier for the adsorption of organic pollutants.

The importance of improving adsorbent's adsorption efficiency in organic pollutants has been reported by many researchers. Surfactant-based modified adsorbents were a tasteful choice. As a result, the use of surfactants as a modifier for removing organic pollutants has shown to play a very big role in enhancing the adsorption efficiency of different materials.

Kinetic and thermodynamic studies on partitioning of polychlorinated biphenyls (PCBs) between aqueous solution and modeled individual soil particle grain sizes.

The significance of soil mineral properties and secondary environmental conditions such as pH, temperature, ionic strength and time in the partitioning of eight selected polychlorinated biphenyl (PCB) congeners between aqueous solution and soil particles with different grain sizes was studied. The mineral properties of a model soil sample were determined, and Brunauer-Emmett-Teller (BET) adsorption-desorption isotherms were employed to observe the surface characteristics of the individual modeled soil particles. Batch adsorption experiments were conducted to determine the sorption of PCBs onto soil particles of different sizes.

Quantitative analyses of selected polychlorinated biphenyl (PCB) congeners in water, soil, and sediment during winter and spring seasons from Msunduzi River, South Africa.

The lack of information and the need for knowledge on the organic pollutants within the area of KwaZulu-Natal together with the global problem of water supply have prompted our investigation into the analyses of eight polychlorinated biphenyl (PCB) congeners in the Msunduzi River of KwaZulu-Natal, South Africa. Soil, sediment, and water samples were collected at ten different sites along the river during winter and spring seasons. Soil and sediment samples were extracted using ultra sonication with dichloromethane while water samples were liquid-liquid extracted using dichloromethane.

Theoretical and experimental adsorption studies of sulfamethoxazole and ketoprofen on synthesized ionic liquids modified CNTs.

The adsorption of sulfamethoxazole (SMZ) and ketoprofen (KET) using carbon nanotubes (CNTs) and CNTs modified with ionic liquids (ILs) was investigated. Two ionic liquids (1-benzyl, 3-hexyl imidazolium, IL1 and 1-benzyl, 3-decahexyl imidazolium, IL2) were synthesized, and characterized by nuclear magnetic resonance (H and C NMR) and high resolution-mass spectrometry (HR-MS). CNTs and modified CNTs were characterized using FT-IR, X-ray diffraction (XRD), surface area and porosity analysis, thermal gravimetric analysis (TGA), Zeta potential, Raman and scanning electron microscopy (SEM).

Application of as-synthesised MCM-41 and MCM-41 wrapped with reduced graphene oxide/graphene oxide in the remediation of acetaminophen and aspirin from aqueous system.

In this study, ASM41 (as-synthesised MCM-41), MCM-41, MCM-41 encapsulated with graphene oxide (MCM-41-GO) and reduced graphene oxide (MCM-41-G) were fabricated and utilized in the remediation of acetaminophen and aspirin from water. A surfactant template (cetyltrimethylammonium bromide) was added to ASM41 to make it more hydrophobic and its effects on the remediation of acetaminophen and aspirin from wastewater was studied. To further improve the adsorption capacity of the adsorbent, MCM-41 was encapsulated with GO and G which also aided in easy separation of the adsorbent from the aqueous solution.

Assessment of nonsteroidal anti-inflammatory drugs by ultrasonic-assisted extraction and GC-MS in Mgeni and Msunduzi river sediments, KwaZulu-Natal, South Africa.

The occurrence of eight pharmaceuticals was monitored during four seasons (spring, summer, autumn, and winter) along a 250-km stretch of the Msunduzi and Mgeni rivers in KwaZulu-Natal, South Africa. This paper describes an optimized method for the determination of nonsteroidal anti-inflammatory drugs (NSAIDs) in sediments. The method combines ultrasonic, centrifuge, and gas chromatography-mass spectrometry for the detection of these drugs in solid samples.

Detection and quantification of acidic drug residues in South African surface water using gas chromatography-mass spectrometry.

A method was optimized for derivatization, separation, detection and quantification of salicylic acid, acetylsalicylic acid, nalidixic acid, ibuprofen, phenacetin, naproxen, ketoprofen, meclofenamic acid and diclofenac in surface water using gas chromatography-mass spectrometry. For most of the acidic drugs, recovery was in the range 60-110% and the percent standard deviation was below 15% for the entire method, with limits of detection ranging from 0.041 to 1.

Quorum sensing inhibitory potential and molecular docking studies of sesquiterpene lactones from Vernonia blumeoides.

The increasing incidence of multidrug-resistant Gram-negative bacterial pathogens has focused research on the suppression of bacterial virulence via quorum sensing inhibition strategies, rather than the conventional antimicrobial approach. The anti-virulence potential of eudesmanolide sesquiterpene lactones previously isolated from Vernonia blumeoides was assessed by inhibition of quorum sensing and in silico molecular docking. Inhibition of quorum sensing-controlled violacein production in Chromobacterium violaceum was quantified using violacein inhibition assays.

Occurrence and significance of polychlorinated biphenyls in water, sediment pore water and surface sediments of Umgeni River, KwaZulu-Natal, South Africa.

The Umgeni River is one of the main sources of water in KwaZulu-Natal, South Africa; however; there is currently a lack of information on the presence and distribution of polychlorinated biphenyls (PCBs) in its sediment, sediment pore water and surface water. This study aims to determine the occurrence and significance of selected PCBs in the surface water, sediment pore water and surface sediment samples from the Umgeni River. Liquid-liquid and soxhlet extractions were used for water or pore water, and sediments, respectively.

Occurrence and distribution pattern of acidic pharmaceuticals in surface water, wastewater, and sediment of the Msunduzi River, Kwazulu-Natal, South Africa.

The paucity of information on the occurrence of pharmaceuticals in the environment in African countries led the authors to investigate 8 acidic pharmaceuticals (4 antipyretics, 3 antibiotics, and 1 lipid regulator) in wastewater, surface water, and sediments from the Msunduzi River in the province of KwaZulu-Natal, South Africa, using solid-phase extraction (SPE) and liquid chromatography-mass spectrometry (LC/MS). The method recoveries, limits of detection (LOD), and limits of quantification were determined. The method recoveries were 58.

Pharmaceutical residues in water and sediment of Msunduzi River, KwaZulu-Natal, South Africa.

The little data about pharmaceutical residue contamination in African water bodies motivated our study on the occurrence of pharmaceutical residues in the water and sediment of Msunduzi River in the KwaZulu-Natal province of South Africa; and in the Darvill wastewater treatment plant found in Msunduzi catchment. Samples collected along the River and wastewater treatment plant were extracted and analysed for pharmaceutical residues selected based on statistics of drug usage in South Africa i.e.

Novel carbapenem chalcone derivatives: synthesis, cytotoxicity and molecular docking studies.

A one-pot efficient synthetic protocol is described for the synthesis of carbapenem chalcone derivatives using AAPTMS@MCM-41 heterogeneous catalyst. Various substituted aromatic aldehydes were attached to highly chiral and reactive carbapenem using this approach. The cytotoxic activity evaluation of all synthesized compounds was performed against lung cancer cell lines (A-549) and breast cancer cell lines (MCF-7) using the MTT assay.

Occurrence of selected pharmaceuticals in water and sediment of Umgeni River, KwaZulu-Natal, South Africa.

Selected pharmaceuticals including antibiotics, antipyretics, a stimulant, an antiepileptic and an antipsychotic drug were determined in wastewater, surface water and sediment along the Umgeni River which is the main source of water to Durban City in KwaZulu-Natal, South Africa. Samples were analysed using high-performance liquid chromatography coupled to a mass spectrometer (HPLC-MS/MS) after clean up and pre-concentration by solid phase extraction (SPE). At the wastewater treatment plant outlet, the antipyretic ibuprofen was detected in concentrations up to 12.

Multicomponent one-pot synthesis of highly-functionalized pyrrole-3-carbonitriles in aqueous medium and their computational study.

A one-pot green protocol involving four-components in aqueous medium is developed to synthesize highly-functionalized pyrroles in good yields. Two of the newly synthesized compounds were subjected to in silico analysis on the Pharm Mapper web-server and the human mitogen-activated protein kinase1 (MEK1) enzyme was identified as a potential target protein for these compounds. For target validation, MEK-1 inhibition was performed with two representative compounds (5g and 5h) using docking simulations.

Sesquiterpene lactones from the aerial parts of Vernonia blumeoides growing in Nigeria.

Four eudesmanolide sesquiterpene lactones (1-4) were isolated from the aerial parts of Vernonia blumeoides used in Nigerian ethnomedicine for the treatment of diarrhea and malaria. Compound 1 demonstrated limited but interesting antibacterial activity against Bacillus, Staphylococcus and Streptococcus species. The crystal structure of 1 allowed the absolute configuration of the stereocentres in the molecule to be assigned.