Occurrence of PAHs in water samples of the Diep River, South Africa

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in freshwater may aggravate the water crisis currently being experienced in the Western Cape Province of South Africa. However, there is dearth of data on the levels of PAHs, which is necessary for effective assessment of water quality as well as remediation strategies. This study therefore assessed levels of PAHs in the Diep River freshwater system of Western Cape Province, South Africa. A liquid-liquid extraction solid-phase extraction gas chromatography flame ionisation detection (LLE-SPEGC-FID) method was developed to simultaneously determine the 16 United States Environmental Protection Agency (USEPA) listed priority PAHs in water samples. The SPE-GC-FID method allowed an acceptable linearity (R2 > 0.999) within the calibration range of 1 to 50 μg/mL. Instrument detection limits ranged between 0.02 and 0.04 μg/mL and instrument quantification limits between 0.06 and 0.13 μg/mL. Recovery study results were also acceptable (83.69–96.44%) except for naphthalene, which had recovery of 60.05% in spiked water matrix. The seasonal averages of individual PAH detected at the studied sites ranged between not detected (nd) and 72.38 ± 9.58 μg/L in water samples.Keywords: PAHs, Diep River, GC-FID, freshwate

Veterinary pharmaceuticals in aqueous systems and associated effects: an update

Environmental studies have shown that pharmaceuticals can contaminate aqueous matrices, such as groundwater, surface water, sediment as well as aquatic flora and fauna. Effluents from sewage and wastewater treatment plants, pharmaceutical industries and hospitals have been implicated in such contamination. Recent studies have however revealed significant concentrations of pharmaceuticals in wastewater from animal facilities in proximal aquatic habitats. Furthermore, epidemiological studies have shown a consistent positive correlation between exposure to some drugs of veterinary importance and increased adverse effects in aquatic biota largely due to induction of endocrine disruption, antibiotic resistance, neurotoxicity, genotoxicity and oxidative stress. The aquatic habitats and associated biota are important in the maintenance of global ecosystem and food chain. For this reason, anything that compromises the integrity and functions of the aquatic environment may lead to major upset in the world’s ecosystems. Therefore, knowledge about this route of exposure cannot be neglected and monitoring of their occurrence in the environment is required. This review focuses on scientific evidence that link the presence of pharmaceuticals in aqueous matrices to animal production facilities and presents means to reduce the occurrence of veterinary pharmaceutical residues in the aquatic habitats

Bioremediation of polycyclic aromatic hydrocarbon (PAH) compounds: (acenaphthene and fluorene) in water using indigenous bacterial species isolated from the Diep and Plankenburg rivers, Western Cape, South Africa

This study was conducted to investigate the occurrence of PAH degrading microorganisms in two river systems in the Western Cape, South Africa and their ability to degrade two PAH compounds: acenaphthene and fluorene. A total of 19 bacterial isolates were obtained from the Diep and Plankenburg rivers among which four were identified as acenaphthene and fluorene degrading isolates. In simulated batch scale experiments, the optimum temperature for efficient degradation of both compounds was determined in a shaking incubator after 14 days, testing at 25 °C, 30 °C, 35 °C, 37 °C, 38 °C, 40 °C and 45 °C followed by experiments in a Stirred Tank Bioreactor using optimum temperature profiles from the batch experiment results. All experiments were run without the addition of supplements, bulking agents, biosurfactants or any other form of biostimulants. Results showed that Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila efficiently degraded both compounds at 37 °C, 37 °C, 30 °C and 35 °C respectively. The degradation of fluorene was more efficient and rapid compared to that of acenaphthene and degradation at Stirred Tank Bioreactor scale was more efficient for all treatments. Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila degraded a mean total of 98.60%, 95.70%, 90.20% and 99.90% acenaphthene, respectively and 99.90%, 97.90%, 98.40% and 99.50% fluorene, respectively. The PAH degrading microorganisms isolated during this study significantly reduced the concentrations of acenaphthene and fluorene and may be used on a larger, commercial scale to bioremediate PAH contaminated river systems

Polycyclic aromatic hydrocarbons: A critical review of environmental occurrence and bioremediation

The degree of polycyclic aromatic hydrocarbon contamination of environmental matrices has increased over the last several years due to increase in industrial activities. Interest has surrounded the occurrence and distribution of polycyclic aromatic hydrocarbons for many decades because they pose a serious threat to the health of humans and ecosystems. The importance of the need for sustainable abatement strategies to alleviate contamination therefore cannot be overemphasised, as daily human activities continue to create pollution from polycyclic aromatic hydrocarbons and impact the natural environment. Globally, attempts have been made to design treatment schemes for the remediation and restoration of contaminated sites. Several techniques and technologies have been proposed and tested over time, the majority of which have significant limitations. This has necessitated research into environmentally friendly and cost-effective clean-up techniques. Bioremediation is an appealing option that has been extensively researched and adopted as it has been proven to be relatively cost-effective, environmentally friendly and is publicly accepted. In this review, the physicochemical properties of some priority polycyclic aromatic hydrocarbons, as well as the pathways and mechanisms through which they enter the soil, river systems, drinking water, groundwater and food are succinctly examined. Their effects on human health, other living organisms, the aquatic ecosystem, as well as soil microbiota are also elucidated. The persistence and bioavailability of polycyclic aromatic hydrocarbons are discussed as well, as they are important factors that influence the rate, efficiency and overall success of remediation. Bioremediation (aerobic and anaerobic), use of biosurfactants and bioreactors, as well as the roles of biofilms in the biological treatment of polycyclic aromatic hydrocarbons are also explored

Multi-residue method for the determination of selected veterinary pharmaceutical residues in surface water around Livestock Agricultural farms

A multi-residue method for the determination of the occurrence and prevalence levels of selected veterinary pharmaceutical residues in surface water was developed on a high performance liquid chromatography coupled to ultraviolet-visible (HPLC-UV) detector, and tested with the intent of profiling their distribution. The limit of detection (LOD) and limit of quantitation (LOQ) achieved for the selected pharmaceuticals; acetaminophen, diclofenac, salicylic acid, tetracycline, chloramphenicol, ciprofloxacin, bisphenol–A, 17β–estradiol, estriol, and ivermectin ranged between 0.06–3.45 μg L−1 and 0.17–10.35 μg L−1 respectively. Other International Conference on Harmonization (ICH) parameters for validation of analytical procedures were also evaluated and discussed. Pharmaceutical residues were recovered from surface water samples collected from around livestock farms in Cape Town, South Africa by solid phase extraction (SPE), and thereafter separated and quantified using a validated method on a HPLC-UV-detector. Most frequently detected residues were: acetaminophen (56%), diclofenac (53), tetracycline (72%), 17β–estradiol (73%); chloramphenicol (68%), and salicylic acid (67%), with significantly high (p > 0.05) spatial variability in the concentration distributions of the pharmaceuticals in the surface waters

Benzo[a]pyrene and Benzo[k]fluoranthene in Some Processed Fish and Fish Products

In this study, the concentration levels of the probable carcinogenic PAH fractions, benzo[a]pyrene (BaP) and benzo[k]fluoranthrene (BkF) in fillets of some processed fish species were investigated. Fish species comprising Merluccius poli (hake), Tyrsites atun (snoek), Seriola lalandi (yellow-tail) and Brama brama (angel fish) were bought in fish shops at Gordon’s Bay, Western Cape, South Africa. The fish were gutted, filleted and prepared for edibility by frying, grilling and boiling. Polycyclic aromatic hydrocarbons were extracted from each homogenized fish sample, cleaned-up using solid phase extraction (SPE), and analysed for the PAH fractions, BaP and BkF using a Gas Chromatograph coupled with a Flame Ionization Detector (GC-FID). The sum of the two PAHs (∑2PAH) i.e., BaP and BkF ranged between 0.56 and 1.46 µg/kg, in all boiled, grilled and fried fish species. The fried fish extracts showed significantly higher (p < 0.05) abundance of ∑2PAH, than grilled and boiled fish. Dietary safety and PAHs toxicity was also discussed

Impacts of vending practices on the microbiological quality of bread in the Ojoo Area of Ibadan, Oyo-State, Nigeria

Background: Bacterial counts in ready-to-eat foods are a key factor in assessing the microbiological quality and safety of food. Periodic assessment of the microbiological quality of food is necessary to develop a robust database and help to ensure food safety. Methods: The bacterial contamination of a total of 336 bread samples collected from two bakeries and 10 vendors in Ojoo Area of Ibadan, Oyo-State, Nigeria (December 2014 -June 2015) was evaluated. The microbiological quality of the bread loaves was investigated using standard microbiological methods (morphological, phenotypic and molecular characterization). Results: The results showed that the number of contaminated samples among the vended bread samples was higher than the bakery bread samples and can be summarized as Bacillus megaterium (4.30%), Staphylococcus arlettae (0.005%), Staphylococcus saprophyticus (2.78%), Citrobacter freundii (2.40%), Bacillus flexus (1.64%), Bacillus species (49.59%), Pseudomonas aeruginosa (4.12%), Pseudomonas fluorescens (0.92%), Pseudomonas species (0.045%), Escherichia coli (30.44%) Klebsiella sp. (0.040%) and Aeromonas hydrophila (3.72%). Conclusion: The findings demonstrate that the bread samples which become contaminated after transport and handling can be considered a potential hazard to human health in the area. More stringent adherence to food safety regulations should be encouraged and enforced by the appropriate authorities. The findings of this study may be adopted to improve the hygienic conditions of bread distribution chain in the area as well as in other regions of the World.151313

Determination of selected steroid hormones in some surface water around animal farms in Cape Town using HPLC-DAD

In this study, a method for the simultaneous determination of two steroid hormones, 17β-estradiol (E2) and estriol (E3), and a hormone mimicking polycarbonate, bisphenol-A (BPA), was developed and validated.Thiswas thereafter used for the determination of the levels of the hormones in surface water collected around some livestock farms. The sensitivity of the method allowed the LODs and LOQs of the hormones and mimic hormone in the range 1.14–2.510 and 3.42–7.53 μg/L, respectively. The results revealedwide variabilityinthe concentrations ofE2andE3, while BPAwas not detected at any of the sampling stations. The concentration of E3 ranged between <1.14 and 45.5 μg/L (N= 120) in station 2 water. The highest concentration ofE2 (15.7μg/L,N=80)wasobservedinwater from station 1. The varied concentrations may be connected with the nature and sources of release, inconsistencies in analyte distribution due to dynamics of water flow pattern and the physical/chemical properties of the receiving water bodies