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In this work, we propose a new sensitive, selective and portable surface enhanced Raman spectroscopy (SERS) methodology for the rapid on site detection of Pb(II) pollution in water. The new method utilises aminobenzo-18-crown-6 (AB18C6) as a selective recognition molecule to form a spontaneous complex with Pb(II) ions. The formed AB18C6-Pb(II) complex was rapidly immobilised onto a nanostructured gold substrate via Au-N bond formation and reproducibly screened by SERS using a handheld Raman device. For the SERS measurements, a substrate was fabricated by electrochemical deposition of gold nanostructures onto a flat gold disc, creating multiple hotspots for ultrasensitive SERS measurements. The limit of quantification (LOQ) for Pb(II) ions by the SERS method was 2.20 pM. The limit of detection (LOD) was 0.69 pM which is five orders of magnitude lower than the maximum Pb(II) level of 72 nM allowed by the US Environmental Protection Agency. The high sensitivity of the SERS substrate is attributed to the coupling between the Surface Plasmon Polariton (SPP) of its gold surface, the localised Surface Plasmon Resonance (SPR) of the gold nanostructures and the Raman radiation from the immobilised AB18C6-Pb(II) complex. The new SERS detection method was successfully applied for the selective and rapid screening of Pb(II) ion contamination in water proving its practical application for environmental analysis.

Adsorption of iodate (IO3−) from concentrated solutions by LDH materials has been investigated in laboratory scale batch experiments. Very high iodate (IO3−) uptake (close to 100%) was observed in almost all experiments. Adsorption data was compared to the Langmuir and Freundlich adsorption isotherm models as well as the pseudo first and second order kinetic models. The data from the 3:1 Mg/Al LDH thermally activated to 500 °C was best described by the Freundlich isotherm and the pseudo second order model, suggesting that adsorption was a heterogeneous or multilayer process. HPLC data was used in an attempt to identify any conversion of iodate (IO3−) to iodide (I−) during the adsorption process, however, the residual concentration of iodide (I−) was close to or below the limit of detection of the particular analytical technique. This suggests that little or no conversion happened under experimental conditions.

Detailed knowledge of the processes that metals undergo during dry weather periods whilst deposited on urban surfaces and their environmental significance is essential to predict the potential influence of metals on stormwater quality in order to develop appropriate stormwater pollution mitigation measures. However, very limited research has been undertaken in this area. Accordingly, this study investigated the geochemical phase and particle size relationships of seven metals which are commonly associated with urban road dust, using sequential extraction in order to assess their mobility characteristics. Metals in the sequentially extracted fractions of exchangeable, reducible, oxidisable and residual were found to follow a similar trend for different land uses even though they had variable accumulation loads. The high affinity of Cd and Zn for exchangeable reactions in both, bulk and size-fractionated solid samples confirmed their high mobility, while the significant enrichment of Ni and Cr in the stable residual fraction indicated a low risk of mobility. The study results also confirmed the availability of Cu, Pb and Mn in both, stable and mobile fractions. The fine fraction of solids (

As one of the most popular beverages around world, factors influencing transfer of heavy metals from soil to tea leaves is crucial to investigate and assess health risk through tea drinking. Parent material (PM), soil and tea samples from Anhui province, typical tea producing area in China were collected in this study. To find out distribution characteristics of heavy metals in tea and soil, and influencing factors for transfer process, variables of plantation factors, soil properties and geological background were taken into account. The results showed that weathering pedogenic process could be the main release source of heavy metals in soil under the acid environment for tea growth. More than 75% of soil Cd, Hg, Pb and Zn exceeded background. However heavy metals in tea samples were below the limits of China, WHO and EU standards. Soil organic matter and redox process influenced the distribution and transfer of As, Pb, Cd and Hg in soil and tea. While geochemical behaviours of Cr, Cu, Ni and Zn were mainly related to soil pH and iron oxides in tea garden. The method of classification and regression trees (CART) showed clones of tea type, bedrock type, soil texture, soil organic and fertilizer application were identified as the main factors influencing transfer factors of heavy metals from soil to tea. The specific types of tea grown in the soil with sandy clay and bedrock of granite/granodiorite and shale should be given more monitoring. The non-carcinogenic hazard quotients (HQ) and cancer risk (Risk) through tea drinking were primarily caused by Pb and Cd respectively. To reduce the potential health risk from tea, application of organic and/or compound fertilizer were thought to be the effective management strategy for tea plantation.

The adsorption-desorption behaviour of heavy metals in aquatic environments is complex and the processes are regulated by the continuous interactions between water and sediments. This study provides a quantitative understanding of the effects of nutrients and key water and sediment properties on the adsorption-desorption behaviour of heavy metals in riverine and estuarine environments. The influence levels of the environmental factors were determined as conditional regression coefficients. The research outcomes indicate that the mineralogical composition of sediments, which influence other sediment properties, such as specific surface area and cation exchange capacity, play the most important role in the adsorption and desorption of heavy metals. It was found that particulate organic matter is the most influential nutrient in heavy metals adsorption in the riverine environment, while particulate phosphorus is more important under estuarine conditions. Dissolved nutrients do not exert a significant positive effect on the release of heavy metals in the riverine area, whilst dissolved phosphorus increases the transfer of specific metals from sediments to the overlying water under estuarine conditions. Furthermore, the positive interdependencies between marine-related ions and the release of most heavy metals in the riverine and estuarine environments indicate an increase in the mobility of heavy metals as a result of cation exchange reactions.

Earth‐abundant and environmentally friendly aluminosilicate minerals can be one of the promising alternatives to develop cost‐effective energy conversion and storage devices. Herein, in situ growth of transition metal nanoparticles is proposed to modify two commonly available feldspar minerals, albite and microcline, for promoting electrocatalytic oxygen evolution reaction activity via a one‐step thermal reduction strategy. Three types of transition metal nanoparticles, namely, Ni, Co, and Fe, are selected to modify the albite or microcline surfaces. As expected, these modified products deliver enhanced catalytic activities compared to the pristine minerals. Particularly, Co‐modified microcline (C‐KASO) demonstrates the best performance that even outperforms the commercial RuO2 catalyst. This design by coupling low‐cost aluminosilicate minerals with active transition metal nanoparticles offers a new insight into directly utilizing the natural abundant resources to address the current energy crisis.

Cyanide (CN−) is one of the most hazardous ions to humans and the environment. Therefore, sensitive, and selective sensors for CN− monitoring are highly required. A novel chemosensor based on naphthalene flanked diketopyrrolopyrrole dye (TBC-DPPN) is synthesized for the direct detection of CN− in water samples by naked eye and vibrational spectroscopy (UV–Vis and fluorescence). The electron deficient carbonyl group of the lactam ring of TBC-DPPN undergoes a nucleophilic attack by the CN− thus causing the yellow color of the dye turn to colorless, and fluorescence of the dye at 527 nm to turn-off. The mechanism of CN− sensing by the TBC-DPPN sensor is confirmed by spectral measurements and density functional theory (DFT) calculations. The TBC-DPPN sensor is utilized to determine the CN− by colorimetric and fluorescence methods in water down to 0.5 and 0.05 µm, respectively, which is well below the cut off limit of 1.9 µm that is recommended by the World Health Organization (WHO). Therefore, TBC-DPPN can act as dual channel sensor with high selectivity and sensitivity for the determination of CN− in water.

Urban road build-up solids contain toxic metals posing potential risks to human health. Management of human health risks arising from these metals is critical in urban areas. This study collected solids build-up data from 16 study sites with various land use and traffic characteristics. Source quantification was conducted using PCA/APCS receptor model. It was found that soil and asphalt wear are the largest contributors (69.43%) to risk and mainly contribute Al, Cr, Mn, Fe, Ni, Zn and Pb to build-up solids. Brake wear is the second largest contributor accounting for 17.20% and contributes Cd and Cu. Tyre wear is the third major contributor (11.38%) and it primarily contributes Ni, Zn and Cr. Mathematical equations were fitted to estimate the risk against daily traffic volume and land use fractions, and the uncertainty analysis highlighted that risk assessment should account for the variability in metal concentrations rather than a point value of concentrations at a given time and space. Based on source quantification and risk assessment, an integrated risk management model was developed to manage human health risks from toxic metals in build-up solids. This risk model provides guidance for urban planning and land use development to mitigate risk arising from urban road deposited solids.

In this article, the authors report the adsorption of iodide by Mg/Al LDHs and thermally activated LDH materials in laboratory scale batch experiments. The optimal Mg/Al cation ratio was 3:1while the percentage iodide uptake increased with increasing adsorbent dose up to 1 g/20 mL of solution. The effect of initial iodide concentration was investigated using the Langmuir and Freundlich adsorption isotherm models, while the pseudo second order kinetic model appeared to provide the best fit for the experimental data. High iodide uptake of over 80% could be achieved without completely eliminating dissolved or atmospheric carbonate and leaching of 131I from LDHs did not appear to be a significant problem over the period of 28 days investigated. These results demonstrate that LDHs, which are already commercially available in large quantities, are a technology that shows considerable promise for the removal of radioiodine from aqueous solution.

Highlights - A review of contaminants removed by clay-nZVI composite materials from aqueous solutions is made. - Reaction mechanisms of the materials with contaminants are discussed. - Excellent removal efficiencies of contaminants by composite materials are reported. - The review suggests research needs for future work. Abstract Recent industrialization and urbanization have increased the aqueous concentrations of a wide range of contaminants, which are toxic to human health and the environment. Therefore, remediation of aqueous solutions has turned into an important environmental issue. Over the last decade, growing attention has been paid to clay-supported nanoscale zero-valent iron (nZVI) composite materials as efficient and promising remediation materials in wastewater treatment and groundwater remediation technologies. This paper gives an overview of the clay minerals, zero-valent iron materials, clay-supported nZVI composites, and progress obtained during the remediation of contaminated aqueous solutions utilizing the clay-supported nZVI composites for the removal of heavy metals, nitrate, selenate, dyes, phenolic compounds, chlorinated organic compounds, nitroaromatic compounds and polybrominated diphenyl ethers. Reaction mechanisms and removal efficiencies were studied and evaluated. It was reported that the clay-supported nZVI composites have appreciable removal efficiency for different types of contaminants. This paper also reviews the use of ZVI-clay technology for the remediation of contaminated sites. Concerning clay-supported nZVI composites for future research, some recommendations are proposed and conclusions are drawn.

Highlights - Sofosbuvir metabolite was studied for the first time by Raman spectroscopy. - Cheap and disposable paper substrate was utilized for the determination of PSI-6206 by HPLC-SERS. - The use of disposable substrate eliminated the memory effect problem in the HPLC-SERS. - The SERS LOQ of PSI-6206 was 13 ng L-1 (R2 = 0.959, RSD = 5.23%), 4 orders of magnitude less than HPLC-DAD. - The HPLC-SERS method provided unique structural identification of PSI-6206 similar to HPLC-MS Abstract Sofosbuvir metabolite, 2′-deoxy-2′-fluoro-2′-C-methyluridine (PSI-6206) was studied for the first time by surface enhanced Raman spectroscopy (SERS) using the paper-based SERS substrate. The quantification limit of PSI-6206 by SERS was found to be 13 ng L−1 (R2 value = 0.959, RSD = 5.23%). For the structural and quantitative analysis of PSI-6206 in blood plasma, an interference-free HPLC-SERS method was developed and compared to HPLC-DAD and HPLC–MS methods. The SERS quantification of the drug by the paper substrate was 4 orders of magnitude more sensitive than that by the diode array detector. In addition, the SERS detection provided unique structural identification of the drug in blood plasma, similar to Mass spectroscopy detector. Due to the disposable nature of the SERS substrate, the new method does not suffer from the known “memory effect” which is known to lead to false positive identification in traditional HPLC-SERS methods. Therefore, the presented HPLC-paper SERS platform holds great potential for the sensitive and cost effective determination of drugs and their metabolites in biological fluids.

Sediment samples collected over a 3-year period from Brisbane River, Australia, were analysed for fifteen (15) polycyclic aromatic hydrocarbons (PAHs). The total PAH concentrations varied from 148 to 3079 ng/g with a mean concentration of 849±646 ng/g. The study revealed that PAH input into the river was primarily dominated by pyrogenic sources as evidenced by the predominance of the high molecular weight (HMW) PAHs. Temporal variations of PAHs can be linked to the level of urbanization, with continuous input of combustion related PAHs in the commercial area of the river. Inherent deficiencies in using a single source identification/apportionment approach were overcome by using diagnostic ratios, principal component analysis/absolute principal component scores (PCA/APCS) and positive matrix factorization (PMF). Both PCA/APCS and PMF resolved four (4) identical factors or sources of PAH, namely: gasoline emissions, diesel emissions, biomass burning and natural gas combustion. Diagnostic ratios, PCA/APCS and PMF analysis indicated that vehicular emissions were the principal sources especially within the lower section of the river while biomass burning had moderate contribution. The distribution, temporal trend and source apportionment suggest the containment of industrial-derived sources of PAH in the river. From an ecological point of view, the risk posed by PAHs in the Brisbane River sediment is low. Nevertheless, when the investigated sites were ranked using multi-criteria decision making methods (MCDM) the commercial stratum was the most contaminated. Assessment of potential risks posed by incidental dermal exposure to PAHs revealed some degree of cancer risk, especially to children.

Photochemical smog, characterized by high concentrations of ozone (O3) and fine particles (PM2.5) in the atmosphere, has become one of the top environmental concerns in China. Volatile organic compounds (VOCs), one of the key precursors of O3 and secondary organic aerosol (SOA) (an important component of PM2.5), have a critical influence on atmospheric chemistry and subsequently affect regional and global climate. Thus, VOCs have been extensively studied in many cities and regions in China, especially in the North China Plain, the Yangtze River Delta and the Pearl River Delta regions where photochemical smog pollution has become increasingly worse over recent decades. This paper reviews the main studies conducted in China on the characteristics and sources of VOCs, their relationship with O3 and SOA, and their removal technology. This paper also provides an integrated literature review on the formulation and implementation of effective control strategies of VOCs and photochemical smog, as well as suggestions for future directions of VOCs study in China.

Consumption of crops grown in cadmium-contaminated soils is an important Cd exposure route to humans. The present study utilizes statistical analysis and in vitro digestion experiments to uncover the transfer processes of Cd from soils to the human body through rice consumption. Here, a model was created to predict the levels of bioaccessible Cd in rice grains using phytoavailable Cd quantities in the soil. During the in vitro digestion, a relatively constant ratio between the total and bioaccessible Cd in rice was observed. About 14.89% of Cd in soils was found to be transferred into rice grains and up to 3.19% could be transferred from rice grains to the human body. This model was able to sufficiently predict rice grain cadmium concentrations based on CaCl2 extracted zinc and cadmium concentrations in soils (R2 = 0.862). The bioaccessible Cd concentration in rice grains was also able to be predicted using CaCl2 extracted cadmium from soil (R2 = 0.892). The models established in this study demonstrated that CaCl2 is a suitable indicator of total rice Cd concentrations and bioaccessible rice grain Cd concentrations. The chain model approach proposed in this study can be used for the fast and accurate evaluation of human Cd exposure through rice consumption based on the soil conditions in contaminated regions.

Estuarine environment is complex and receives different contaminants from numerous sources that are persistent, bioaccumulative and toxic. The distribution, source, contamination and ecological risk status of heavy metals in sediment of Brisbane River, Australia were investigated. Sediment samples were analysed for major and minor elements using LA-ICP-MS. Principal component analysis and cluster analysis identified three main sources of metals in the samples: marine sand intrusion, mixed lithogenic and sand intrusion as well as transport related. To overcome inherent deficiencies in using a single index, a range of sediment quality indices, including contamination factor, enrichment factor, index of geo-accumulation, modified degree of contamination, pollution index and modified pollution index were utilised to ascertain the sediment quality. Generally, the sediment is deemed to be "slightly" to "heavily" polluted. A further comparison with the Australian Sediment Quality Guidelines indicated that Ag, Cr, Cu, Ni, Pb and Zn had the potential to rarely cause biological effects while Hg could frequently cause biological effects. Application of potential ecological risk index (RI) revealed that the sediment poses moderate to considerable ecological risk. However, RI could not account for the complex sediment behaviour because it uses a simple contamination factor. Consequently, a modified ecological risk index (MRI) employing enrichment factor is proposed. This provides a more reliable understanding of whole sediment behaviour and classified the ecological risk of the sediment as moderate to very high. The results demonstrate the need for further investigation into heavy metal speciation and bioavailability in the sediment to ascertain the degree of toxicity.

Co-precipitation is a common method for the preparation of layered double hydroxides (LDHs) and related materials. This review article is aimed at providing newcomers to the field with some examples of the types of co-precipitation reactions that have been reported previously and to briefly investigate some of the properties of the products of these reactions. Due to the sheer volume of literature on the subject, the authors have had to limit this article to the synthesis of Mg/Al, Zn/Al and Ca/Al LDHs by co-precipitation and directly related methods. LDHs have been synthesised from various reagents including metal salts, oxides and hydroxides. Co-precipitation is also useful for the direct synthesis of LDHs with a wide range of interlayer anions and various bases have been successfully employed to prepare LDHs. Examples of other synthesis techniques including the urea method, hydrothermal synthesis and various mechanochemical methods that are undoubtedly related to co-precipitation have also been included in this review. The effect of post synthesis hydrothermal has also been summarised.

Novel heterogeneous Fenton composite materials were developed by grafting acid precursors and nano zero-valent iron particles on an acid leached diatomite, which can sequentially generate acid and ferrous ions in situ. The results show that the composite materials can potentially solve two of the biggest obstacles, which prevent the conventional Fenton reaction from being widely and practically adopted, namely: the continuous feed of ferrous ions and the maintenance of the optimum acidic pH condition during the reaction. In this study, samples were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Thermogravimetric analysis and micro organic analysis. The novel materials’ degradation capacities for bisphenol A (BPA) were evaluated and optimized. This material can be easily applied to treat wastewater via Fenton-like reaction without changing pH or adding ferrous ions. The relationships between BPA removal efficiency, the amount of grafted organosilane acid precursor and doped nZVI particles on the composite materials were investigated. It is evident from the results that the novel composite materials afford highly effective removal of BPA from water at 250 mg/g. The work thus demonstrates that the novel materials could potentially be utilized for efficient remediation of recalcitrant organic compounds from the environment.

The detection of anti-TNF-α drugs require rapid, selective and sensitive biosensors that can be easily utilised at the point of care. Herein, we demonstrate a new biosensing approach that employs target-specific nanomaterial and label free surface-enhanced Raman spectroscopy (SERS) for the selective extraction and rapid determination of Adalimumab (ADB) in human blood plasma. The new method utilises the tumour necrosis factor (TNF-α) for the fabrication of a target-specific nanomaterial for extraction of ADB. The method also uses the thiol chemistry of the purified antibody drug for its chemisorption onto a gold-coated copper oxide substrate. A handheld Raman spectrophotometer is used for the determination of ADB by label free SERS. The limits of quantification (LOQ) and detection (LOD) of the purified and reduced drug by SERS were 0.10 fM and 0.03 fM respectively. ELISA was used for the cross validation of the SERS quantification of ADB where a 98.8% agreement was found between the two methods. Many proteins have disulfide bonds in their molecular structure. Therefore, the demonstrated biosensing approach can be extended for the rapid screening of other proteins and antibody drugs by developing target-specific extractor nanomaterial and utilizing the disulfide bond structure of the purified biomolecules for their label free SERS detection.

A new benzothiazole azo dye [(E)-1-((6-methoxybenzo[d]thiazole-2-yl)diazenyl)naphthalene-2,6-diol] (also known as “BAN”), has been synthesised and used as a chemosensor for the rapid and selective detection of mercury(II) ions in water. The pink coloured chemosensor turns blue when reacted with mercury(II) ions due to the formation of a 2 : 1 coordination complex. The complex formation causes a bathochromic shift of the chemosensor's UV absorption peak from 540 to 585 nm and turns on a highly selective fluorescence emission at 425 nm. The change in the optical property of BAN upon complexation with mercury(II) was confirmed by ab initio calculations. The new chemosensor was used to quantify mercury(II) ions in water by fluorescence spectroscopy down to 5 × 10−8 M (10 ppb). The limit of detection (LOD) of Hg2+ was 9.45 nM (1.8 ppb) which satisfies the maximum allowable Hg2+ concentration in drinking water that is set by the WHO. The BAN–Hg(II) complex was used for the determination of cysteine (Cys) in aqueous solution by UV-Vis spectroscopy down to 1 × 10−7 M. The thiol-containing amino acid preferentially coordinates the mercury ions of the BAN–Hg(II) complex. This causes dissociation of the blue-coloured complex and the liberation of the pink-coloured BAN dye. The colour change of the BAN–Hg(II) complex from blue to pink was selective to the Cys biothiol while other non-thiol containing amino acids did not cause a colour change. For the in-field application, filter paper strips were loaded with the BAN–Hg(II) complex and used as a disposable sensor for the detection of cysteine (Cys) by the naked eye. Therefore, the BAN chemosensor offers a sensitive, and rapid tool for the detection of mercury(II) in water. In addition, the BAN–Hg(II) complex can be used as a simple and selective chemosensor of the screening of purified biothiols, such cysetine, homocysteine and glutathione in biology research and pharmaceutical/food industries.

Polycyclic aromatic hydrocarbons (PAHs) are prone to post-emission transformation and degradation to yield transformed PAH products (TPPs) that are potentially more hazardous than parent PAHs. This review provides a comprehensive evaluation of the potential environmental processes of PAHs such as sorption, volatilisation, photo- and bio-transformation and degradation on road surfaces, a significant accumulation point of PAHs. The review primarily evaluates key influential factors, toxicity implications, PAHs and TPPs fate and viable options for mitigating environmental and human health impacts. Photolysis was identified as the most significant transformation and degradation process due to the light absorption capacity of most PAHs. Climate conditions, physicochemical properties of road dust (sorbent), PAHs and TPPs and the existence of heavy metals such as Fe (III) are notable underlying factors for photolysis. Available data points to the predominance of carbonyl TPPs than other products such as nitro and hydroxyl TPPs with decreasing concentration trend of 9-fluorenone > 9,10-anthraquinone > benzo[a]fluorenone on road surfaces. The review recommends conducting future investigations targeting the influential factors pertaining to the fate of road deposited PAHs and TPPs. Furthermore, development of cost and time effective modern analytical methods is needed to quantify PAHs and TPPs present in minute quantities of samples. The review also identified that the unavailability of toxicity equivalency factors (TEF) for the most critical TPPs can be addressed using quantitative structure-activity relationship (QSAR) models and bioassays simultaneously. The content of this review is significant to the future work of researchers across various fields including analytical and environmental chemistry, stormwater pollution and toxicology.

Understanding the factors influencing the build-up behaviour of different pollutants accumulated on urban roads is essential for the implementation of effective stormwater pollution mitigation strategies. Even though a significant knowledge base exists on different factors influencing hydrocarbon build-up, there is a dearth of evidence on how physicochemical properties of road dust influence hydrocarbon build-up. Accordingly, this study investigated the relationships between physicochemical properties of road dust and hydrocarbons associated with different particle size fractions of road dust. Hydrocarbons with different sources of origin in all size fractions showed a significant correlation with different soil constituents of road dust, predominantly with organic matter, amorphous matter, clay minerals and clay forming minerals of feldspars. However, the physicochemical properties influencing the hydrocarbon build-up is different among different particle size fractions. The interactions identified between hydrocarbon compounds and different minerals associated with road dust will contribute to the development of effective stormwater pollution mitigation strategies.

The high pollutant loads discharged from cities pose risks to urban waterways, and in turn the estuarine environments, making it challenging to improve urban liveability. Past studies on the behaviour of pollutants in rivers have largely investigated their transport along the waterway, primarily focusing on the movement of water and sediment. However, the current approaches in pollutant transport modelling provide limited insights into how pollutant transfer between water and sediment phases influences their transport from the upstream towards the estuarine environment. This research study firstly identified typical patterns of metal loads along an urban river in a highly populated city in China. The outcomes were then used to conceptualise metal transfer between water and sediment phases. It was noted that physico-chemical characteristics of water and sediments play a key role in metal transfer between the two phases, and the dominant transfer path (sediment to water/water to sediment) is different between different metals, independent of their origin (crustal, anthropogenic or marine-related). Several scenarios were derived from the conceptualisation of metal behaviour. These in turn were then used to develop real-world scenarios of metal transport in rivers based on the field data. The conceptualisation of metal behaviour confirmed that each metal is likely to have a dominant phase of transport (sediment/water), which is influenced by the dominant transfer path of that metal between water and sediments.

Analysis of soil samples around pristine and major gold-mining areas in Ghana was carried out for heavy metals as part of a larger soil contamination and metal background study. The surface soil samples were digested using microwave digester (aqua regia) and analyzed with ICP-MS for As, Cd, Hg, Zn, Co, Cu, Mn, Fe, Al, V, Cr, and Pb. The average concentrations (mg/L) for the metals ranged from 0.01 ± 0.01 (Cd) to 86,859.36 ± 47.07 (Fe) for the pristine sites, and 0.01 ± 0.01 (Cd) to 59,006.95 ± 79.06 (Fe) for the mining sites. Mercury was below the detection limit of the analytical instrument (0.029). The concentrations of heavy metals from this study were used to assess their contamination levels, and health risks. The results showed that, the metals ranked by severity of health risks as As > Pb > Cr > Cd. Principal component analysis (PCA) and cluster analysis showed two groupings with the PCA showing metals variability explained by 79.02%. Results from the PCA and Cluster analysis indicate anthropogenic sources of the metals which may be emanating from gold-mining activities. Results from multi-criteria ranking and pattern recognition employing PROMETHEE and GAIA revealed major contribution of the metals from the mining sites with metal variability explained by 72.83%. This is the first time a multi-criteria approach is employed to characterize heavy metal contamination in Ghana, and the study nevertheless brought to light the impact of mining on human health and the environment with implications for other mineral areas around the globe.

Land use management plays a key role in mitigating urban river pollution. Past research has addressed how primary land uses influence river water and sediment quality, but has given limited attention to the subdivision of primary land uses to a secondary level, limiting the accurate identification of potential sources of pollutants. The current study, using Bayesian Networks, investigated how the hierarchical structure of land use can be employed to accurately characterise the pollution of sediments in two rivers in China and Australia. It was found that the primary land uses are a weak determinant of potential sources of metals, nutrients, and organochlorine pesticides (OCPs). However, secondary land uses provide higher accuracy in determining pollutant sources. The study highlighted that the lack of data to enable the subdivision of land uses can constrain informed decision making for the mitigation of urban water pollution.

Among urban stormwater pollutants, hydrocarbons are a significant environmental concern due to their toxicity and relatively stable chemical structure. This study focused on the identification of hydrocarbon contributing sources to urban road dust and approaches for the quantification of pollutant loads to enhance the design of source control measures. The study confirmed the validity of the use of mathematical techniques of principal component analysis (PCA) and hierarchical cluster analysis (HCA) for source identification and principal component analysis/absolute principal component scores (PCA/APCS) receptor model for pollutant load quantification. Study outcomes identified non-combusted lubrication oils, non-combusted diesel fuels and tyre and asphalt wear as the three most critical urban hydrocarbon sources. The site specific variabilities of contributions from sources were replicated using three mathematical models. The models employed predictor variables of daily traffic volume (DTV), road surface texture depth (TD), slope of the road section (SLP), effective population (EPOP) and effective impervious fraction (EIF), which can be considered as the five governing parameters of pollutant generation, deposition and redistribution. Models were developed such that they can be applicable in determining hydrocarbon contributions from urban sites enabling effective design of source control measures.

Several studies have previously demonstrated that layered double hydroxides (LDHs) show considerable potential for the adsorption of radioiodine from aqueous solution; however, few studies have demonstrated that these materials are able to store radioactive (131)I for an acceptable period. The leaching of iodide (I(-)) and iodate (IO3(-)) form Mg/Al LDHs has been carried out. Contact time appeared to be a more significant variable for the leaching of iodate (IO3(-)) compared to that of iodide (I(-)). Experimental results are fitted to the pseudo second order model, suggesting that diffusion is likely to be the rate-limiting step. The presence of carbonate in the leaching solution appeared to significantly increase the leaching of iodide (I(-)) as did the presence of chloride to a lesser extent. The maximum amount of iodate (IO3(-)) leached using ultrapure water as the leaching solution was 21% of the iodate (IO3(-)) originally present. The corresponding result for iodide (I(-)) was even lower at 3%.

The presence of radioactive iodine (radioiodine) in drinking water is a significant health hazard that originates from nuclear medicine and atomic energy industries. The application of LDHs to the removal of iodine offers potential for iodine capture and entrapment. Mg/Al and Zn/Al layered double hydroxides (LDHs) have been prepared and have been evaluated for the sorption of iodide in some small-scale batch experiments. All LDHs were prepared by the co-precipitation method and characterised by a range of techniques including powder X-ray diffraction, transmission electron microscopy and elemental analysis. Adsorption experiments were carried out at high iodide concentrations up to 1000 ppm and no control or pH or atmospheric carbonate commonly used in most studies. The highest iodide uptake of approximately 71% was observed using a 3:1 Zn/Al LDH thermally activated to 500 °C, however, a 3:1 Mg/Al LDH exhibited similar results. LDHs potentially offer a technology for the removal of iodine from aqueous media.

Inorganic-organic montmorillonites (IOMts) obtained by modifying polyhydroxy-aluminum (Al 13 )-pillared montmorillonite (AlPMt) with the cationic surfactant (C16) and zwtterionic surfactant (Z16) were investigated with the aim to remove phenol, phosphate and Cd(II) simultaneously. The structures of IOMts prepared using different surfactant doses (0.4 and 1.0CEC) strongly depended on the types and doses of the surfactants. The Al 13 contents of C16 modified AlPMts (C-AlPMts) decreased with increasing C16 loading while that of Z16 modified AlPMt (Z-AlPMts) did not. In the single adsorption system, all IOMts could efficiently remove phenol and phosphate, but not Cd(II). IOMts, however, could efficiently remove all three contaminants simultaneously in the multi-contaminant adsorption system. The adsorptions of phenol on IOMts were not affected by the other two inorganic components and vice versa. Whereas the adsorptions of phosphate and Cd(II) were significantly enhanced in the multi-contaminant system, and the adsorption of one increased with increasing initial concentration of the other one, especially the adsorption of Cd(II). The enhancements of adsorption of phosphate and Cd(II) on the IOMts with higher Al 13 content were much larger than that on IOMts with lower Al 13 content. The adsorption mechanism for phosphate and Cd(II) uptake in the multi-contaminant system possible involve the formation of phosphate-bridged ternary complexes.

Fe–montmorillonite (Fe–Mt) was prepared and tested for its potential application in the simultaneous removal of hexavalent chromium (Cr(VI)) and rhodamine B (RhB) from aqueous solution. The adsorption kinetics and capacities of Fe–Mt toward Cr(VI) and RhB were determined in relation to the initial contaminant concentration, pH of the solution and concentration of coexist contaminant. The adsorption kinetics of Cr(VI) or/and RhB in both single and simultaneous systems were investigated, which showed that an equilibrium time of a few hours was needed for the adsorption of Cr(VI) and RhB on Fe–Mt. The pseudo-second order model offers a better fit than pseudo-first order model for the Cr(VI) and RhB adsorption. Compared with the single adsorption systems, adsorption rates and quantities of Cr(VI) and RhB adsorbed on Fe–Mt were slightly enhanced in the simultaneous adsorption system. The most effective pH range for the removal of Cr(VI) and RhB was found to be 3.0–4.0. Cr(VI) adsorption isotherms were best represented by the two-site Langmuir model while RhB isotherms followed the Freundlich model. For both contaminants, the adsorption of one contaminant increases with increase in the initial concentration of the other one. Therefore, Fe–Mt could simultaneously remove Cr(VI) and RhB from water. The properties of Fe–Mt were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and thermogravimetric analysis (TG). The findings of this study provide novel information for the development of clay-based adsorbents toward dyes and heavy metals.

Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis - Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas.

Adsorption has been considered as an efficient method for the treatment of dye effluents, but proper disposal of the spent adsorbents is still a challenge. This work attempts to provide a facile method to reutilize the spent Mg/Al layered double hydroxide (Mg/Al-LDH) after the adsorption of orange II (OII). Herein, the spent hybrid was carbonized under the protection of nitrogen, and then washed with acid to obtain porous carbon materials. Thermogravimetric analysis results suggested that the carbonization could be well achieved above 600°C, as mass loss of the spent hybrid gradually stabilized. Therefore, the carbonization process was carried out at 600, 800, and 1000°C, respectively. Scanning electron microscope showed that the obtained carbon materials possessed a crooked flaky morphology. Nitrogen adsorption-desorption results showed that the carbon materials had large BET surface area and pore volume, e.g., 1426 m(2)/g and 1.67 cm(3)/g for the sample carbonized at 800°C. Moreover, the pore structure and surface chemistry compositions were tunable, as they were sensitive to the temperature. Toluene adsorption results demonstrated that the carbon materials had high efficiency in toluene removal. This work provided a facile approach for synthesizing porous carbon materials using spent Mg/Al-LDH.

2,4,6-trinitrotoluene (TNT) is one of the most commonly used nitro aromatic explosives in landmine, military and mining industry. This article demonstrates rapid and selective identification of TNT by surface-enhanced Raman spectroscopy (SERS) using 6-aminohexanethiol (AHT) as a new recognition molecule. First, Meisenheimer complex formation between AHT and TNT is confirmed by the development of pink colour and appearance of new band around 500 nm in UV-visible spectrum. Solution Raman spectroscopy study also supported the AHT:TNT complex formation by demonstrating changes in the vibrational stretching of AHT molecule between 2800-3000 cm−1. For surface enhanced Raman spectroscopy analysis, a self-assembled monolayer (SAM) of AHT is formed over the gold nanostructure (AuNS) SERS substrate in order to selectively capture TNT onto the surface. Electrochemical desorption and X-ray photoelectron studies are performed over AHT SAM modified surface to examine the presence of free amine groups with appropriate orientation for complex formation. Further, AHT and butanethiol (BT) mixed monolayer system is explored to improve the AHT:TNT complex formation efficiency. Using a 9:1 AHT:BT mixed monolayer, a very low detection limit (LOD) of 100 fM TNT was realized. The new method delivers high selectivity towards TNT over 2,4 DNT and picric acid. Finally, real sample analysis is demonstrated by the extraction and SERS detection of 302 pM of TNT from spiked.

Wet-milling protocol was employed to produce pressed powder tablets with excellent cohesion and homogeneity suitable for laser ablation (LA) analysis of volatile and refractive elements in sediment. The influence of sample preparation on analytical performance was also investigated, including sample homogeneity, accuracy and limit of detection. Milling in volatile solvent for 40 min ensured sample is well mixed and could reasonably recover both volatile (Hg) and refractive (Zr) elements. With the exception of Cr (-52%) and Nb (+26%) major, minor and trace elements in STSD-1 and MESS-3 could be analysed within ±20% of the certified values. Comparison of the method with total digestion method using HF was tested by analysing 10 different sediment samples. The laser method recovers significantly higher amounts of analytes such as Ag, Cd, Sn and Sn than the total digestion method making it a more robust method for elements across the periodic table. LA-ICP-MS also eliminates the interferences from chemical reagents as well as the health and safety risks associated with digestion processes. Therefore, it can be considered as an enhanced method for the analysis of heterogeneous matrices such as river sediments.

Meropenem (MPN), a broad spectrum β-lactam antibiotic, has been increasingly used in the treatment of moderate to severe bacterial infections. However, due to its short plasma half-life and chemical instability in solution form, it has been challenging to use in the intravenous formulation. This study aims to develop and characterize MPN dry powder inhaler (DPI) formulation for pulmonary delivery. The inhalable MPN particles (1-5µm) were prepared by micronization. Lactose, L-leucine and magnesium stearate (MgSt) were used in the powder formulation as carriers and dispersibility enhancers. The formulations were characterized by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman confocal microscopy, X-Ray powder diffraction analysis (PXRD), and differential scanning calorimetry (DSC) methods. The concentration of MPN was determined by using a validated HPLC method. The Fine Particle Fraction (FPF) of meropenem from powder mixtures was determined by a Twin Stage Impinger (TSI) at a flow rate of 60 L/min. The FPF of the original MPN was 1.91 % which was significantly increased to 37.5 % for the formulations with excipients. No physical interactions between the drug and the excipients observed. This study revealed the potential of a stable meropenem DPI formulation for pulmonary delivery.

Two-dimensional (2D) MXene, as an important member of the emerging 2D nanomaterials, has received much attention in recent years, especially in energy-related fields. Unfortunately, the controllable synthesis of high-purity MXenes in a scalable way is still a challenge, due to the usual utilization of hazardous etching agents. It is highly desired that a simple, controllable, and effective approach is available for producing MXene in a green manner. In this work, an innovative thermal reduction strategy is proposed for the fabrication of MXenes from the corresponding sulfur-containing MAX phases, in which the weakly bonded S atoms react with hydrogen to form a volatile gas and leave 2D graphene-like Ti2C nanosheets. As a promising anode material for electrochemical Li+ ion storage, the resulting MXene demonstrated satisfying initial discharge capacities of ~200 mAh g−1. Furthermore, the capacity remained at ~70 mAh g−1 over 130 cycles even at a high rate of 2.0 A g−1, indicating a good rate capability and cycling stability. This work thus offers a novel approach for MXene fabrication and enriches MXene-based electrode materials for energy devices.

As an emerging and important family of two-dimensional (2D) nanomaterials, MXene has demonstrated to be a type of promising electrode materials for energy storage devices. Hazardous fluorine-containing acids are commonly applied in exfoliation synthesis of MXenes, which bring about additional safety and environmental concerns. Herein, we proposed a novel and effective UV-induced selective etching method to fabricate fluorine-free mesoporous Mo2C MXene from Mo2Ga2C bulk ceramic in several hours. The resultant MXene exhibits a distinct 2D sheet-like structure without much contamination of impurity ions. When the as-synthesized Mo2C MXene is explored as potential anode materials for rechargeable batteries, excellent rate capability and cycling stability are achieved for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Furthermore, the assembled flexible Mo2C MXene-based batteries manifested excellent capacity retentions under bending states. Therefore, this Mo2C MXene has great potential for practical energy storage applications. This innovative approach can be further developed for fabricating other MXenes from UV-sensitive precursors.

Microplastics pose threats to aquatic environments because they serve as hard-substrate for microbial community colonization and biofilm formation due to their long-life span and hydrophobic surface which can impact on aquatic ecosystems. However, the association between microplastics and other pollutants, particularly nutrients and metals in river sediments are largely unknown. In this study, microplastics abundance and hazard scores which are the risks arising from chemical compounds used for plastics manufacture, and the correlations between microplastics and the concentrations of total carbon (TC), total nitrogen (TN), total phosphorus (TP) and metals commonly present in the urban environment such as Al, As, Cr, Co, Cu, Fe, Mg, Mn, Ni, Cd, Se, Sr, Zn, Pb, in Brisbane River sediments were investigated. The study confirmed that the risk associated with microplastics is based on their monomer composition rather than the quantities present. Sediments having relatively higher abundance of microplastics with a relatively lower hazard score result in higher nutrient concentrations. The concentrations of metals in river sediments are more dependent on their original sources rather than the concentration of microplastics. Nevertheless, leachate from plastics should be considered in risk assessment in relation to the association between metals and plastics in aquatic environments.

The direct use of natural minerals for low-cost energy storage is a promising solution toward large-scale and affordable sustainable energy supply, but it is usually impeded by their inert electrochemical activity. In this work, electrochemically inert albite mineral layered particles are activated as a promising low-cost anode material for electrochemical Li ion storage devices through a facile thermal reduction treatment technology. Via this strategy, partial SiO reduction within the albite mineral particles and a conductive carbon layer on the surface are simultaneously realized, which effectively addresses the issues of inactive lithium storage and poor electric conductivity of albite minerals. Via theoretical density functional theory calculations and molecular dynamics simulations, the activation mechanism of lithium storage achieved by silica reduction is understood. This innovatively activated albite mineral delivers a maximum specific capacity of >250 mAh g based on a dominant surface-driven capacitive storage mechanism, and demonstrates excellent capacity and cycling stability at high charging/discharging rates. This design opens a new pathway to address the current cost issue in energy devices, provides insights into producing cost-effective anodes by using silica-rich minerals, and gives an alternative solution for improving the chemical reactivity of inorganic natural minerals toward low-cost and large-scale energy storages.

Tumor necrosis factor alpha (TNF-α) is a cytokine that plays a critical role in medical conditions such cardiovascular diseases, rheumatoid arthritis, inflammatory bowel disease, Alzheimer’s and cancer. Herein, we present a new method for the determination of TNF-α by surface enhanced Raman spectroscopy (SERS). A new benzothiazole azo dye (BAN) was used as a Raman probe to detect the cytokine after its selective extraction from blood plasma using a target-specific antibody-functionalised extractor chip. The disulfide bond structure of the extracted TNF-α was reduced to generate free sulfhydryl (SH), terminal groups that adsorb preferentially onto a BAN-functionalised SERS substrate and displace the BAN Raman reporter on the substrate surface. This causes the SERS spectrum of BAN to quench proportionally with the cytokine concentration. Using this SERS quenching sensor, TNF-α was quantified down to 1 × 10−14 M (173 pg/L). The quantification of the cytokine by the SERS quenching method was cross-validated against enzyme-linked immunosorbent assay (ELISA) and the percent agreement between the two measurements was found to be 93.39 %. Since many proteins and peptides have disulfide bonds in their molecular structures, the new SERS quenching method can be extended for their ultrasensitive quantification after selective extraction from biological fluids.

The detection rates of pharmaceuticals (Ps), personal care products (PCPs), current-use pesticides (CUPs) and a food additive (FA) in Brisbane River estuary (Queensland), Sydney estuary (New South Wales) and the Yarra River estuary (Melbourne, Victoria) were: Ps: 16/25, 7/25 and 12/25, respectively, CUPs; 28/53, 5/53 and 23/53, respectively, PCPs: 1/3, 0/3 and, 1/3, respectively and FA; 1/1, 1/1 and 1/1, respectively. Diuron was measured in all estuarine samples, simazine, MCPA and 2,4 D were also commonly measured. Pharmaceuticals: carbamazepine, iopromide paracetamol tramadol and venlafaxine were also commonly measured across the estuaries. Generally, analytes were prominent in Brisbane River estuary, followed by Yarra River/Sydney estuary. Inputs of Ps are likely from leakages or effluents of WWTPs; CUPs are potentially from agricultural and parklands via surface run-off in Brisbane River estuary, while for Sydney and Yarra estuaries, which have separate stormwater and sewer systems, sources are likely to be ingression and leakage.

We demonstrate a novel method for the selective extraction and electrochemical detection of S100β disease biomarker. The protein is extracted from blood plasma using target-specific gold coated magnetic nanoparticles. This is followed by the rapid reduction of the disulfide bond structure of the purified protein using chronoamperometry and its immobilisation onto a nanostructured gold electrode. The protein concentration is quantified down to 10 pM (120 ng l−1), by electrochemical desorption using differential pulse voltammetry (DPV). The new method was used to extract and determine S100β in spiked blood plasma and the DPV quantification was cross-validated against enzyme-linked immunosorbent assay (ELISA) where the percent agreement between the two measurements was 96.54%. Therefore, this method has strong potential for the sensitive determination of S100β. In addition, 65% of proteins have similar disulfide bond structure. Therefore, the new method can be utilised for the determination of many disease biomarkers after optimizing specific extractor nanomaterial for the target biomarker.

± Sixteen significant physicochemical predictor variables for thirty PAHs and transformed PAH products (TPPs) were retrieved individually prior to collation from ChemSpider.com [1] whilst their corresponding toxicity equivalency factor (TEF) end-point was obtained from published articles by Bortey-Sam, Ikenaka [2] and Wei, Bandowe [3]. In order to achieve a 5:1 ratio of the number of observations to predictors which is vital for an effective quantitative structure-activity relationship (QSAR) modelling, factor analysis was used to reduce the data. Four fundamental predictors were obtained whilst the observations were found to cluster into two main groups of nitro-PAHs and other analytes. It is anticipated that the data presented here is highly relevant for future studies on the toxicity and health effects of the analytes in the environment. Secondly, the fate and distribution patterns of PAHs and TPPs are influenced by the parameters in the dataset. In this regard, studies on the behaviour patterns of these environmental pollutants require this information for a comprehensive evaluation and interpretation of results. Researchers across varied fields of environmental science and toxicology will find this dataset very useful. This data currently serves as supplementary information for the research article in the Journal of Hazardous Materials by Gbeddy, Egodawatta [4].

The carcinogenic human health risks (CHHR) posed by the exposure to PAHs and transformed PAH products (TPPs) are currently inconclusive due to the lack of toxicity equivalency factors (TEFs) for most TPPs although some of these pollutants are more potent carcinogens. The applicability of quantitative structure-activity relationship (QSAR) model in predicting TEF of PAHs and TPPs to holistically evaluate the CHHR posed by the exposure to these pollutants in road dust from Gold Coast, Australia was examined. Statistical evaluation via ten metrics shows that partial least-squares regression (PLSR1) model has more statistical power in predicting TEF than multiple linear regression (MLR) within relevant applicability domain. For instance, the predicted residual sum of squares (PRESS) and standard deviation of error of prediction (SDEP) for PLSR is closer to zero than that of MLR. The total cancer risk estimated using the QSAR model derived TEFs and original TEFs for outliers gives a more holistic incremental lifetime cancer risk in relation to children and adults. Potential cancer risk exists for adults with this approach whereas reliance on only the originally available TEFs lead to a negligible risk diagnosis. The application of QSAR model in assessing CHHR due to PAHs and TPPs exposures is very viable.

Plastic pollutants in aquatic ecosystems have received wide attention and research endeavours since early 1970s. However, in comparison to marine environments, the occurrence of microplastics in a tidal river system remains largely unknown, especially in river sediments. Sediment samples taken from twenty-two sampling points along Brisbane River over the four different seasons revealed relatively high concentrations of microplastics in river sediments, with abundance ranging from 0.18 to 129.20 mg kg−1, or 10 to 520 items kg−1. Unfortunately, varied methods and units used for reporting do not allow the accurate comparison between related studies. The spatial distributions of microplastics hotspots indicated that microplastics abundance is distance-dominated caused by flow velocities. Lower and higher concentrations of microplastics abundance mostly occurred in dry and wet seasons, respectively. Significant temporal variations of microplastics concentrations was observed in residential and commercial areas. Polyethylene (PE), polyamide (PA) and polypropylene (PP), were the three main polymer types found in the Brisbane River sediments. Other polymer types such as polyethylene terephthalate (PET) were also detected. The majority of the detected microplastic particles were found to be

The detection of protein biomarkers for the clinical diagnosis of diseases requires selective and sensitive methodologies and biosensors that can be easily used at pathology laboratories and points of care. An ideal methodology would be able to conduct multimode screening of low and high concentrations of proteins in biological fluids using recyclable platforms. In this work, we demonstrate a novel nanosensing methodology for the dual detection of cystatin C (CST-C), as a protein biomarker model, in blood plasma by surface-enhanced Raman spectroscopy and electrochemistry. The new methodology utilizes the thiol chemistry of biomolecules to develop a target-specific and recyclable extractor chip for the rapid isolation of protein biomarkers from blood plasma. This is followed by the rapid reduction of the disulfide bonds within the isolated protein to influence its oriented immobilization onto a conductive gold coated silicon nanopillar substrate via stable gold–sulfur (Au–S) bonds. The oriented immobilization led to reproducible surface-enhanced Raman spectroscopy (SERS) measurements of the reduced protein (RSD = 3.8%) and allowed for its direct electrochemical determination. After the SERS measurement, differential pulse voltammetry (DPV) was used to desorb the analyte from the substrate and generate a reduction current that is proportional to its concentration. CST-C was determined down to 1 pM and 62.5 nM by SERS and DPV, respectively, which satisfies the requirements for monitoring Alzheimer’s and kidney failure diseases. The new dual nanosensing methodology has strong potential for miniaturization in a lab-on-a-chip platform for the screening of many protein biomarkers that have a disulfide bond structure.

Heavy metal contamination of selected rivers in Ghana was studied as part of a bigger project aimed at setting background standard for heavy metals in the Ghanaian environment. Water samples were collected from major mining and eight pristine areas. The samples were acid digested with aqua-regia and analyzed with ICP-MS for As, Cd, Hg, Zn, Cu, Mn, Fe, Cr, Al, V, Co, Ni, and Pb. The average concentrations (mg/L) from the pristine sites ranged from 0.002 ± 0.00(As) to 0.929 ± 0.06 (Fe) and 0.002 ± 0.00 (Pb) to 20.355 ± 5.60 (Fe) from the mining sites. With the exception of Al, Fe, and Mn, the metals level were found to be within the WHO and USEPA guideline limits. Hazard quotients (HQ) for ingestion and dermal contact for pristine and mining samples ranged from 3.00E-04 (Cu) to 0.84 (Cr) and 2.40E-06 (Cu) to 7.44 (As), respectively. The carcinogenic risk (CR) for ingestion and dermal contact ranged from 5.03E-06 to 1.71E-07 (Cr) and 4.22E-08 to 1.44E-09 (Cr), respectively. Arsenic showed a CR value higher than the acceptable limit (1.8E-02) from the mining sites which poses carcinogenic health threat. Multicriteria ranking suggests Birim river (EAM) as the most contaminated. The pattern recognition and multicriteria approach in characterizing the heavy metal contamination (for the first time in the case of Ghana) from the various sites will provide fresh insights into the risk assessment of heavy metals in contaminated surface waters.

A label free electrochemical detection method for the rapid detection of recombinant human erythropoietin (rhuEPO) has been developed. In this method, we modified the rhuEPO structure for its direct sensing without using a complex signal amplification strategy. The protein was selectively extracted from blood plasma sample using target-specific magnetic beads. After releasing rhuEPO from the magnetic beads, its disulfide bonds were electrochemically reduced and the protein was spontaneously assembled onto a nanostructured gold electrode via Au-S bonds formation. For electrochemical quantification, the reduced protein was desorbed from the electrode surface using differential pulse voltammetry (DPV). The desorption current was proportional to the concentration of rhuEPO in the range 1 pM – 1000 pM. By cross-validating against ELISA, we found a 104.85 ± 3.35% agreement between the results obtained using the electrochemical biosensor and ELISA. Therefore the developed method has a strong potential for the sensitive detection of rhuEPO doping in sports as well as its rapid screening and pathology labs.

Pollution has become a serious issue in the urban water environment as stormwater runoff transports a range of pollutants to receiving water bodies, undermining water quality and posing human and ecosystem health risks. Commonly, the primary focus of stormwater quality research is on the role of pollutants directly accumulating at the ground phase. However, atmospheric phase can also exert a significant impact on stormwater quality through atmospheric deposition. Unfortunately, only limited research has focused on the linkage between atmospheric and ground phases in relation to urban stormwater quality. The study discussed in this paper characterised the four primary transport pathways, atmospheric build-up (AB), atmospheric deposition (AD) and road surface build-up (BU) and wash-off (WO) in relation to heavy metals, which is a key urban stormwater pollutant. The research outcomes confirmed the direct linkage between atmospheric phase and ground phase and in turn the significance of atmospheric heavy metals as a contributing source to stormwater runoff pollution. Zn was the most dominant heavy metal in all four pathways. For the AB pathway, atmospheric heavy metal pollution on weekdays is more serious than weekends. For the AD pathway, dry atmospheric deposition of heavy metals is positively correlated to dry days, whilst wet (bulk) deposition is related to rainfall depth. For the BU pathway, heavy-duty vehicle traffic volume was found to be the most important source. For the WO pathway, industrial and commercial areas tend to produce higher heavy metal concentrations in stormwater runoff than residential areas. The study results will contribute to the creation of effective urban stormwater pollution mitigation strategies and thereby enhancing the quality of the urban water environment.