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This work sought to conduct the chemical association of a toxic metal (cadmium) in coal samples of various origins in Pakistan. For that purpose, a sequential extraction scheme recommended by the Community Bureau of Reference (BCR) has been carried out to know the chemical fractionation of Cd in different coal samples. Simultaneously a time saving vortex-assisted single-step extraction (VA-SSE) via the same experimental parameters conditions used in each fraction steps of BCR sequential extraction procedure (BCR-SE). The coal samples were collected from Thar coal (TCF) and Lakhra coal fields (LCF) of Sindh, Pakistan. The validity of BCR-SE and VA-SSE were checked by applying spiking standard addition procedure on real coal samples. The BCR-SE and VA-SSE were completed in 51 h and 1.0–2.0 min, respectively. In second phase determined the combustion behaviour of Cd or/amount of Cd in coal samples volatilise after heating in an electric furnace in laboratory at three temperature interim (200°C, 400°C and 900°C). The coal ash obtained at 900°C was put to three step sequential extraction method. The evaluated result showed that the total values of Cd in coal samples of block II of Thar coal field (TCF), Site I and Site II of Lakhra coal field (LCF) were found in the range of 3.42–4.43, 2.02–2.82 and 2.91–3.92 mg/kg, correspondingly. The final result indicated that the major chemical fraction of Cd was bound with organic phase of coal samples of both origins (about 40%). The evaluated data showed that 60–71% of Cd in coal samples was found in first three fractions, whilst about 29–40% of Cd was observed in residual. The extracted Cd concentrations in various chemical fractions of coal samples obtained through VA-SSE were 1.6–2.6%, higher than those values gained via BCR-SE (p < 0.04). The resulted data indicated that, after burning of coal samples at 900°C, about 63–69% of total Cd in coal samples of both mining areas was found in residual ash, while 31–34% was vaporised/volatilised out into the atmosphere. [ABSTRACT FROM AUTHOR]

An important issue to the earth's atmosphere is the volatilisation of elements such as selenium, from the burning of coal at different temperatures. In the current work, the volatilisation of selenium (Se) during combustion of coal samples at different control temperature range in an electrically controlled furnace was carried out. The coal samples were obtained from various coal fields of Sindh, Pakistan. The duplicate coal samples were combusted in controlled furnace by applying three temperature rounds (200°C, 400°C and 900°C). The ash formed following each temperature round was examined to know the volatilisation contents of Se after burning of coal samples at different temperature. The fractionation of Se in coal ash gained after combustion at 900°C was subjected to three-stage sequential extraction scheme (SES). The obtained data indicated that the total contents of Se in coal samples of block II of Thar coal field (TCF), and Site I and Site II of Lakhra coal field (LCF) were observed in the range of 7.72–14.3, 9.02–16.3 and 8.92–14.2 mg/kg, respectively. It was observed that after the burning of coal samples at 900°C, about 75–81.8% of the total Se was volatised out into atmosphere. [ABSTRACT FROM AUTHOR]

This work described a plant extract-based synthesis of titanium oxide nanoparticles (D-TiO2–NPs) using Duranta erecta leave extract, followed by the fabrication of its nanocomposite (D-TiO2–NC) with chitosan for adsorptive removal of toxic metals (TMs) cadmium (Cd) and lead (Pb) from water. D-TiO2–NPs and D-TiO2–NC were characterized by various analytical techniques. This study confirmed the porous and rough crystalline nanostructure with different functional groups of chitosan and D-TiO2–NPs of synthesized D-TiO2–NC for feasible excellent adsorptive removal of Cd and Pb. The maximum removal of Cd and Pb was achieved at pH (6), initial concentration of metal ions (30 mg L−1), the content of D-TiO2–NC (50 mg), contact time (30 min), and temperature (45 °C) with adsorption capacities of 147 and 145.5 mg g−1, respectively. The D-TiO2–NC has successfully followed the pseudo-second-order kinetics for the successful removal of Cd and Pb. However, the resulting data followed multilayer adsorption for the removal of Cd while monolayer adsorption for Pb onto the D-TiO2–NC. The findings of the thermodynamic study revealed that the D-TiO2–NC followed the endothermic and spontaneous adsorption process for the adsorption of Cd and Pb. Furthermore, D-TiO2–NC can easily be used several times after washing with diluted HNO3 for the adsorptive removal of Cd and Pb. Moreover, it is quantitatively adsorbed (> 90%) the Cd and Pb from the collected drinking water samples. [ABSTRACT FROM AUTHOR]

The aim of the current case study is to sequentially assess the heavy metals (HMs) cadmium (Cd), iron (Fe), lead (Pb) and zinc (Zn) in five products (raw juice, bagasse, mud-cake, refined sugar and molasses) along with the effluents of the selected sugar industry (SSI) Sindh, Pakistan. Estimations of daily intake and possible toxic risk of HMs by the consumption of sugar of SSI to end-user (families of SSI workers) of age group of 2.0–5.0, 6.0–15.0, 16.0–30.0 and 31.0–50.0 years were conducted. The high contents of HMs were observed in molasses followed by mud-cake and bagasse (raw waste). The raw juice of sugarcane and refined/white sugar showed the lowest levels of these HMs. The low levels of HMs in effluents of SSI might be to their separation at different stages of sugar processing and refining into the mud-cake, bagasse and molasses. The calculated daily intake of Fe and Zn from refined/white sugar to various study groups was found to be adequate based on the recommended levels by Food and Nutrition Board (FNB). The estimated weekly intake (WI) for Cd and Pb by the consumption of SSI sugar was significantly lower (2–5 times) than the provisional acceptable WI of Cd and Pb by WHO from foodstuff. The potential toxic risk study of Cd and Pb revealed that the studied subjects were not at potential toxic risk by the consumption of SSI sugar. [ABSTRACT FROM AUTHOR]

Fruits are important for human health and researcher makes it possible to learn about their nutrient composition especially essential trace and toxic elemental contents. However, due to complex matrices, the determination of elemental contents in solid and liquid food samples require acid digestion method. Therefore, the current study is designed to develop conventionally acid wet digestion method for detection of electrolytes, Calcium (Ca), Iron (Fe), Magnesium (Mg), Potassium (K), Sodium (Na), essential trace elements, Zinc (Zn) and toxic elements, cadmium (Cd) and lead (Pb) in pulp of different varieties of natural mangoes and juices collected from Hyderabad Sindh, Pakistan, prior to analyse by Atomic Absorption Spectrophotometer. The resulted data indicated that the higher value of Cd was found in a mango variety, MP2 (8.45 µg/L) and its commercially prepared juice (1.30 µg/L). Whereas, significantly higher values of Pb was observed in pulp MP6 than other mangoes sample (p < 0.05) [ABSTRACT FROM AUTHOR]