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Discarded marine plastics (DMPs) are emerging pollutants currently attracting significant attention. This present investigation focuses on the collection, characterization, and distribution analysis of DMPs collected from marine sediments followed by isolation and molecular characterization of microplastic-degrading native bacteria sequestered from Chandipur coast sediments, Bay of Bengal India. The study identified two potential microplastic-degrading strains, Exiguobacterium sp. (ON627837) and Bacillus amyloliquefacin (ON653029). The biodegradation investigation of 0.5 g of microplastic incubated under optimized conditions resulted in 4% weight loss after 30 days subject to 200 rpm constant shaking. SEM and FT-IR spectroscopy analysis of the microbial-degraded plastics' surface morphology and composition revealed uneven surfaces with residues compared with the control samples and suggested an abundance of PET (37%) which was further used for bioremediation analysis. This investigation emphasizes the significance of the biodegradation properties of the native bacterial isolates assessing the conditions and degradability of the microorganisms.

Environmental Pollution due to the unprecedented inundation of microplastics (MPs) released from various sources is a major concern for most of the environmental & material scientists in today's world. Millions of tons of microplastics are produced each year and alarmingly enter the environment and up to 14 million tons of plastic waste are thought to enter into the ocean annually. The precarious results of it show a paramount imbalance in the natural ecosystem of many living beings. Such a devastating and toxic effect on our surroundings requires a long-lasting solution to safeguard its inhabitants. Additionally, studies have shown that MPs are consumed by a variety of organisms. It is precisely the combination of ingestion and chemical interaction that lends support to the idea that MPs could potentially influence the availability and harmfulness of both naturally occurring and externally introduced co-contaminants. Microbial remediation principally by bacterial and fungal populations has been an emerging trend for improving the microplastic pollution from the environment. This review paper delves into the ecotoxicological effects of microplastic pollutants on the environment and various microbial remediation technologies used by microorganisms for the degradation. It has been proven to be a key advancement as an environmentally friendly way of decomposing MPs than that of the traditional one. Plastic degradation and bioremediation potential of these microorganisms has aroused the interest of many, in eliminating the non-biodegradable plastics from the surroundings.

The usage of face masks in various sectors of healthcare facilities dates back to years ago. However, the utilization of facial coverings experienced a rapid surge as a result of the escalating rate of COVID-19 infections witnessed across the entire globe. This culminated in an unparalleled inundation of disposed facial coverings within the surrounding ecosystem. This transforms the face mask from a potent protectant into a massive emerging solid plastic waste pollutant with long-term adverse effects on the environment and human health. The utilization of facial coverings on a worldwide scale escalated to an immensely significant 129 billion per month at the onset of the pandemic. Nanomaterial-based technologies have been integrated into mask manufacturing chains to increase performance and provide antiviral characteristics. Nanotechnology encompasses multidisciplinary aspects including artificial intelligence, chemistry, biology, material science, physical science, and medicine. Abridgment of this review aims to make discarded face masks into a sustainable solution to many environmental pollution. In addition, it culminates collaborative and well-conducted trials, done for generating sustainable greener solutions for disposed face masks with the intention that usage of face masks in an environment-friendly manner. Given the preceding, the purpose of this review is to discuss the evolution of discarded face masks from sentinel pathogens to emerging environmental pollutants over time, as well as to comprehend the effect of discarded face masks on the biosphere, human health, and the food chain, by developing scientifically validated strategies to treat discarded face masks for a sustainable future.

This work demonstrates the viability of the powder-mixed micro-electrochemical discharge machining (PMECDM) process to fabricate micro-holes on C103 niobium-based alloy for high temperature applications. Three processes are involved simultaneously i.e. spark erosion, chemical etching, and abrasive grinding for removal of material while the classical electrochemical discharge machining process involves double actions i.e. spark erosion, and chemical etching. The powder-mixed electrolyte process resulted in rapid material removal along with a better surface finish as compared to the classical micro-electrochemical discharge machining (MECDM). Further, the results are optimized through a multi-objective optimization approach and study of the surface topography of the hole wall surface obtained at optimized parameters. In the selected range of experimental parameters, PMECDM shows a higher material removal rate (MRR) and lower surface roughness (Ra) (MRR: 2.8 mg/min and Ra of 0.61 μm) as compared to the MECDM process (MRR: 2.01 mg/min and corresponding Ra of 1.11 μm). A detailed analysis of the results is presented in this paper.

Machine learning technique is extensively used to establish the relationship between non-linear data sets which cannot be described mathematically and thus an exact analytic model is either intractable or too time-consuming to develop. During hot rolling, the effect of process parameters that cannot be captured in mathematical models, such as roll dimensions and its wear, the inter-pass time between rolling passes, temperature variation has been incorporated using multivariate supervised machine learning technique for accurate prediction of roll force and torque during plate rolling of micro-alloyed steel. An ensemble method was used to combine various machine learning techniques and average them to develop one final predictive model. K-cross validation of the model was carried out to validate the results and ensure the model gets the correct pattern of data. Root mean square error of ensemble roll force model was compared with roll force calculation using Sims theory. It was found that the machine learning model can predict the roll force and torque accurately as it takes care of various non-linear process variables which cannot be accounted for mathematically. The R-value of the machine learning model was >98 %, whereas it was 92.2 % for roll force calculation using Sims theory.

The current study focuses on an alternative strategy for producing nanoparticles (NPs) using one-step electrochemical discharge process (ECDP) in different electrolyte mediums. Current and plasma discharge effects on morphology and mass output rate were examined in detail. FE-SEM and TEM results show dimensional control materials such as rod, flower and rice shapes are produced. The XRD, EDS, UV-vis and Raman characterization techniques confirm the formation of CuO-ZnO NPs with different morphology. The use of two semiconductors (n-type ZnO and p-type CuO) in combination have two different band energies may boost electrochemical performance. From the electrochemical study, the flower-shaped structure has high specific capacity (313 F/g at 2 A/g current density), with 84.1% retention capacitance after 5000 cycles. This study allows us to study the discharge-based composite formation, which could be used in supercapacitors.

Normally the word pollution states the expulsion of many elements, components, and waste products with a lot of harmful constituents into the natural surroundings in large quantities that interrupts or ruins its aptitude to support the ecosystem. Nowadays the most reported and notable pollutants are toxic metals (lead, cadmium, mercury) which are the waste products released by various industries and spent batteries. This metal can be found naturally on the outermost layer of the earth, soils, and water but in low amounts. This metal causes pollution of soil, water, and air on a global scale. Recently, it is expected that the global production of lead has increased due to the high manufacturing of automobiles, and mobile phone batteries. An additional remarkable impact of lead pollution was reported in hunting birds. To minimize these metal-related health risks to humans and harm to the environment; various routes have been available for reducing heavy metals production. Eco-technological discoveries such as tools and medications which help to clean lead from the body are known as chelation therapy. There is also limited remediation for the pollution in agricultural fields and soil such as biological remediation which is a cost-friendly and greener approach for reducing the metal in intoxicated soils. In this review, we focus on the adverse effect of lead (Pb) pollution on natural ecosystems and the distressing effect on all living beings, a detailed discussion has also been included on the methodology for the sustainable solution of lead-associated waste pollution.

Over the years, mining and metallurgical activities have rapidly influenced the human population. The manufacturing process of manganese (Mn) compounds and their use in industries increased the negative effect on the environment. Therefore, the recovery process of Mn from metal-containing wastes has become very crucial. Mn is a trace mineral found in various forms in the earth's crust and is present abundantly in terrestrial and aquatic environments. Due to the presence of high-level toxicity in surface waters, aquatic organisms exhibit a high-level toxic response. Mn is composed of many minerals such as oxides, sulfates, carbonates, etc. found naturally in the earth. Chronic exposure to this metal pollutant can result in adverse effects and various symptoms related to neurotoxicity including cognitive, Parkinson's disease, manganism, dystonia, and in plants symptoms like chlorosis in leaves and necrotic leaf spots. Mn is released into water bodies, especially through soil erosion, mining activities, and many anthropogenic activities. The toxicity depends on several aspects including the dose, route of exposure, species, and nutritional status of the individual. This element can be considered a systemic toxicant that can damage the multiple organs of humans. These microorganisms will degrade and detoxify the pollutants in the soil, water, and other environments into a non-toxic form that is not harmful to the environment. This review aims to summarize the toxicity of Mn mining pollutants in the environment as well as in humans, plants, and animals and describes the biological remediation strategies. This review also focuses on the environmental Mn pollution and the future aspects to control the Mn pollutants through biological remediation approaches.

The current study introduces a novel additive texturing method to fabricate samples with dimple and groove textures through the laser-based powder bed fusion (PBF) technique using stainless steel (SS 316L) powder. The topographical analysis shows that the additive textured samples are fabricated with periodic feature sizes less than 150 μm and within an error limit of 7%. Fine grains with an average size of 14.05 μm and 13.62 μm are formed in dimple and groove textured samples, respectively, leading to enhancement of micro-hardness up to 213%. XRD results show the formation of the face-centered cubic (FCC) austenitic phase only. Further, the wettability study indicates hydrophilic wetting behavior with contact angles in the ranges of 72.3°–60.6° for deionized (DI) water and 64.1°–39.9° for hank's balanced salt solution (HBSS). The bio-tribology test with hip-joint prosthesis condition is carried out, and the results indicate that the coefficient of friction (COF) value of 0.11 in a dry condition for groove textured, whereas for dimple textured it is 0.38 under lubricated condition. The details of the study are described in this manuscript.

Thin sheets of Ti-6Al-4V alloy of thickness 1 mm were butt welded using a pulsed Nd-YAG low-power laser setup. The goal of this research is to explore the influence of pulsation on the microstructure and mechanical properties. In addition to that, annealing at different temperatures has been performed to compare the results of pulsation and heat treatment. The results indicate that after annealing at 980 °C, the structure completely transformed into an equiaxed structure. When annealed at 1010 °C, almost the total area is composed of an equiaxed α phase, and the grains are coarse as compared to the previous. This suggests that the grain size becomes thicker when the annealing temperature is raised above 980 °C. The volume fraction of the equiaxed structure is maximum. It can be deduced that the volume–fraction is dependent on the annealing temperature. The volume fraction of the equiaxed structure increases as the annealing temperature increases. A higher tensile strength value of the sample annealed at 980 °C was found as compared with the overlapped sample (A-2). The fusion zone overlapped sample (A-2) shows high hardness with a value of 397 HV1. In the FZ sample, annealing at 980 °C has a hardness of 386 HV1. The (A-2) sample indicates higher (3–4%) hardness as compared to the annealed sample at the FZ. The β phase is increased by 16% in the XRD analysis of the overlapped samples. Hence, it is evident that the amount of β phase has increased during heating, and a complete transformation has taken place at a temperature of 958 °C.