Recent advances in nanoscience and nanotechnology have also led to the development of novel nanomaterials, which ultimately increase potential health and environmental hazards. Interest in developing environmentally benign procedures for the synthesis of metallic nanoparticles has been increased. The purpose is to minimize the negative impacts of synthetic procedures, their accompanying chemicals and derivative compounds. The exploitation of different biomaterials for the synthesis of nanoparticles is considered a valuable approach in green nanotechnology. Biological resources such as bacteria, algae fungi and plants have been used for the production of low-cost, energy-efficient, and nontoxic environmental friendly metallic nanoparticles. This review provides an overview of various reports of green synthesised zero valent metallic iron (ZVMI) and iron oxide (Fe2O3/Fe3O4) nanoparticles (NPs) and highlights their substantial applications in environmental pollution control. This review also summarizes the ecotoxicological impacts of green synthesised iron nanoparticles opposed to non-green synthesised iron nanoparticles.

Research on green production methods for metal oxide nanoparticles (NPs) is growing, with the objective to overcome the potential hazards of these chemicals for a safer environment. In this study, facile, ecofriendly synthesis of copper oxide (CuO) nanoparticles was successfully achieved using aqueous extract of Pterospermum acerifolium leaves. P. acerifolium-fabricated CuO nanoparticles were further characterized by UV-Visible spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and dynamic light scattering (DLS). Plant-mediated CuO nanoparticles were found to be oval shaped and well dispersed in suspension. XPS confirmed the elemental composition of P. acerifolium-mediated copper nanoparticles as comprised purely of copper and oxygen. DLS measurements and ion release profile showed that P. acerifolium-mediated copper nanoparticles were more stable than the engineered CuO NPs. Copper oxide nanoparticles are used in many applications; therefore, their potential toxicity cannot be ignored. A comparative study was performed to investigate the bio-toxic impacts of plant-synthesized and engineered CuO nanoparticles on water flea Daphnia. Experiments were conducted to investigate the 48-h acute toxicity of engineered CuO NPs and plant-synthesized nanoparticles. Lower EC50 value 0.102 ± 0.019 mg/L was observed for engineered CuO NPs, while 0.69 ± 0.226 mg/L was observed for plant-synthesized CuO NPs. Additionally, ion release from CuO nanoparticles and 48-h accumulation of these nano CuOs in daphnids were also calculated. Our findings thus suggest that the contribution of released ions from nanoparticles and particles/ions accumulation in Daphnia needs to be interpreted with care.

Background: Cold storage facilities are the most common workplaces that produce artificially cold work environments and are associated with different adverse effects on human health, work productivity and the occurrence of accidents and injuries. The aim of this study was to measure the antagonistic health effects on workers, so that common factors causing abnormal symptoms could be determined, and to gather basic information to monitor the associated health risks from the exposure to cold work environments. Material and Methods: A cross-sectional analytical study was conducted to investigate the occurrence of cold-related adverse health effects, musculoskeletal symptoms, skin problems, injuries, respiratory illnesses, general hygiene and occupational environment related to cold indoor workplaces, using the Standardized Nordic Questionnaire. A total of 200 subjects took part in this study, including 100 exposed and 100 unexposed to cold environments. A 1-way analysis of variance (ANOVA) and a t-test were applied to measure statistical differences and to differentiate the cases where variations occurred, using SPSS 16. Results: The study revealed that a longer and constant exposure to extremely cold indoor work environments significantly increased (p < 0.001) the cold-related symptoms and musculoskeletal disorders which ultimately reduced (p < 0.01) the efficiency, effectiveness, performance and work ability of the exposed workers. Conclusions: The study disclosed various adverse cold-related complaints of the studied subjects who were exposed to extreme cold conditions during a maximum number of working hours. The most consistent problems were related to musculoskeletal discomfort, skin problems and respiratory abnormalities.

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The title compound, C14H10BrN3O3S, crystallizes as two concomitant polymorphs that differ in colour (one yellow and one colourless). Only the structure of the colourless form could be determined. The mol­ecule exists in the thio­amide form with an intra­molecular N—H⋯O=C hydrogen bond across the thio­urea system. Mol­ecules are linked into layers parallel to (120) by Br⋯Onitro contacts [3.103 (1) Å], classical hydrogen bonds from the other NH function to the S atom and Nnitro⋯O=C contacts. The layers are linked by weak C—H⋯Onitro hydrogen bonds to produce the observed three-dimensional network.

With the ever-increasing demand of plastics in the world and their consequent disastrous effects on environment, a suitable environmental-friendly substitute like bioplastics/biodegradable plastics is the need time. This study centers on green-production of a variety of bioplastic samples from (1) banana peel starch (BPP) and (2) a composite of banana peel starch, cornstarch and rice starch (COM) with varying amounts of potato peel powder and wood dust powder as fillers, respectively. Two different plasticizers – Glycerol and Sorbitol – have been utilized separately and in a 1:1 combination. A total of 12 samples of each of two types of bioplastics were made using multiple amounts and combinations of the fillers and plasticizers, to test the differences in the physical and chemical characteristics (moisture content, absorption of water, solubility in water, solubility in alcohol, biodegradation in soil, tensile strength, Young’s modulus and FT-IR) of the produced samples due to their different compositions. The differences in the properties of the bioplastic samples produced make them suitable for usage in many different applications. All 24 of the samples produced were synthesized using natural and environmentally safe raw material and showed biodegradation, thus proving to be a good alternative to the conventional plastics.

The xylanase gene (xynA) of Bacillus licheniformis 9945A was cloned and expressed in Escherichia coli BL21(DE3) using pET-22b(+) as an expression vector. The recombinant xylanase enzyme was purified by ammonium sulfate precipitation, followed by single-step immobilized metal ion affinity chromatography with a 57.58-fold purification having 138.2 U/mg specific activity and recovery of 70.08 %. Molecular weight of the purified xylanase, 23 kDa, was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was stable for up to 70 °C with a broad pH range of 4-9 pH units. The enzyme activity was increased in the presence of metal ions especially Ca(+2) and decreased in the presence of EDTA, indicating that the xylanase was a metalloenzyme. However, an addition of 1-4 % Tween 80, β-mercaptoethanol, and DTT resulted in the increase of enzyme activity by 51, 52, and 5 %, respectively. Organic solvents with a concentration of 10-40 % slightly decreased the enzyme activity. The xylanase enzyme possesses the ability of bioconversion of plant biomasses like wheat straw, rice straw, and sugarcane bagasse. Among the different tested biomasses, the highest saccharification percentage was observed with 1 % sugarcane bagasse after 72 h of incubation at 50 °C with 20 units of enzyme. The results suggest that recombinant xylanase can be used in the bioconversion of natural biomasses into simple sugars which could be further used for the production of biofuel.