Eco-friendly Aspects Research Articles

Advances and Applications of Hybrid Graphene-Based Materials as Sorbents for Solid Phase Microextraction Techniques.

The advancement of traditional sample preparation techniques has brought about miniaturization systems designed to scale down conventional methods and advocate for environmentally friendly analytical approaches. Although often referred to as green analytical strategies, the effectiveness of these methods is intricately linked to the properties of the sorbent utilized. Moreover, to fully embrace implementing these methods, it is crucial to innovate and develop new sorbent or solid phases that enhance the adaptability of miniaturized techniques across various matrices and analytes. Graphene-based materials exhibit remarkable versatility and modification potential, making them ideal sorbents for miniaturized strategies due to their high surface area and functional groups. Their notable adsorption capability and alignment with green synthesis approaches, such as bio-based graphene materials, enable the use of less sorbent and the creation of biodegradable materials, enhancing their eco-friendly aspects towards green analytical practices. Therefore, this study provides an overview of different types of hybrid graphene-based materials as well as their applications in crucial miniaturized techniques, focusing on offline methodologies such as stir bar sorptive extraction (SBSE), microextraction by packed sorbent (MEPS), pipette-tip solid-phase extraction (PT-SPE), disposable pipette extraction (DPX), dispersive micro-solid-phase extraction (d-µ-SPE), and magnetic solid-phase extraction (MSPE).

Towards natural fibers resistant to mold and termites thanks to fluorine

Natural materials such as fibers or wood are increasingly used in different articles due to their bio-sourced and eco-friendly aspect. However, external aggression of termites and fungi limits their use or their lifetime, because of the deterioration of the materials structure that can be caused. In addition, because of the new legislation, some of preventive products are now forbidden due to their hazardousness. Therefore, in this study, we explore the possibility to perform a direct fluorination treatment in order to protect natural product from this external aggression. In addition, we also assess the potential resistance of these material to mould growth and termites attack after the application of two other fluorination-based treatments which take benefit of the formation of NaF and fluorinated silica nanoparticles.

Efficient separation of cathode materials from aluminum foil by novel low-melting mixture solvent based on choline chloride-xylitol system

Lithium-ion batteries (LIBs) are important energy devices with significant growth and expansion that result in large amounts of metal waste. However, the separation of the cathode materials from aluminum (Al) foil during the recycling of spent LIBs is still challenging due to their strong bonding by polyvinylidene fluoride (PVDF). Herein, a novel low-melting mixture solvent (LoMMS) based on the choline chloride-xylitol system with ow-toxicity, cost-effectiveness, and environmental friendliness was developed for separating the cathode materials from Al foil in LIBs. Under the optimal treatment conditions of a molar ratio of choline chloride to xylitol of 2:1, a reaction temperature of 140 °C, a reaction time of 20 min, and solid-liquid ratio of 16 g/L separation efficiency cathode material reached a maximum of 94.92 %. The mechanistic analysis revealed that the high separation efficiency can be attributed to strong hydrogen bonding provided by choline chloride and xylitol in LoMMS, disrupted PVDF molecular bonding and resulted in deactivation and successful separation of cathode material particles from the aluminum foil. Additionally, scanning electron microscopy examination revealed no changes in the morphologies of the cathode materials, useful for their restoration and reutilization. Overall, the proposed LoMMS method with low-cost and eco-friendly aspects has great potential for recycling spent LIB cathode materials.

Comparative assessment of nano nitrogen and nano zinc nutrition on growth, yield and profitability of chilli (Capsicum annuum. L)

In contemporary agriculture, sustainability challenges like climate change, declining productivity, and nutrient deficiencies threaten food production. Judicious use of methodologies, dosages, and timing is crucial for sustainable practices. Nano-fertilizers gain importance due to their nutrient-release properties and increased use efficiencies. Chili is a commercial crop that requires high nutrients, the present field trial was carried out at AHRS, Bavikere, Shivmogga (India) during 2020 and 2021, to investigate its growth and yield responses to foliar applications of nano nitrogen (nN) and zinc (nZn) alongside conventional urea and ZnSO4. The experiment comprised combinations of recommended doses of nitrogen (RDN) (75, 100 & 125%) along with two foliar sources, nano (nN & nZn @ 0.4%) and conventional (urea @ 2% & ZnSO4@ 0.2%) against control. Foliar application of nN and nZn @0.4%+125% RDN (T3) improved growth and yield attributes & green chili yield (33.07 t ha−1), compared to RDF (T1, 23.8 t ha−1) and conventional sources (T6, 30.9 t ha−1). The utilization of nano-fertilizers in T3 resulted in a substantial enhancement of 39.0% in yield. Increments of 57.2% and 49.3% in net returns compared to conventional N and zinc sources respectively were also noted. Further, the land productivity reached $13.5 per day in T3, indicating economic viability. Application of 75% RDN with nN and nZn saved 25-50% of RDN compared to conventional sources. The results propose cutting nitrogen fertilizer by up to 50%, showcasing the eco-friendly aspect of nano-fertilizers. They boost productivity and profitability while supporting sustainable farming by reducing nitrogen usage.

Customizable cholinium-based aqueous biphasic systems as ecofriendly extraction platform for removal of pesticide from wastewaters

This study explores the use of a series of cholinium ionic liquids (ILs) or salts in combination with polypropylene glycol 400 to form aqueous biphasic systems (ABS) for extracting various polarity pesticides (dicamba, clomazone, pyraclostrobin, and deltamethrin) from water. We assessed five cholinium-based salting-out agents ([Ch][DHP], [Ch]Cl, [Ch][Ac], [Ch][Lac], and [Ch][Nic]), chosen for their structural diversity and unique properties, such as high salting-out potential and different ability to undergo specific interactions. Liquid-liquid equilibrium phase diagrams were established, and partition experiments were conducted to evaluate extraction efficiency. Different partition patterns were obtained for studied pesticides, with [Ch][DHP] demonstrating the highest efficiency exceeding 90 % for each target pesticide due to its strong salting-out ability. On the other hand, more diverse partition trends due to specific interactions were obtained for low-melting cholinium-ILs ABS. The effect of pH and temperature on the partitioning behavior in [Ch][Ac]-based ABS highlighted the cholinium ILs extraction system's customizable nature. Focusing on [Ch]Cl for its eco-friendly aspects, widespread availability and excellent extraction performance, we optimized parameters for the removal of pesticides from real samples, applying the technology to spiked agricultural wastewater with an extraction efficiency of over 99 %. Our findings demonstrate the potential of cholinium-based IL-ABS in reducing environmental pollution through efficient pesticide extraction.

A Critical Review of the Sustainable Production and Application of Methanol as a Biochemical and Bioenergy Carrier

There is a growing interest in the production of biofuels and biochemicals from renewable biomass. Biomass in the form of woody and agricultural residues, municipal solid waste and other organic refuse is becoming popular as a feedstock for biofuel and biochemical production through thermochemical and biological routes. Methanol, a widely used industrial chemical, also has clean fuel properties due to its high-octane number, low flammability, low emissions and high engine performance. This paper performs a comprehensive review of different thermochemical and biological processes able to sustainably convert waste biomass to methanol. This article also evaluates the techno-economic assessment and lifecycle analysis of different processes used for methanol production. The article discusses the effects of process parameters and biomass properties on methanol production and utilization. Finally, the article concludes with recommendations on the eco-friendly aspects of methanol for use as a clean fuel and chemical derived from renewable organic bioresources.

Green synthesis of copper nanoparticles using Citrullus colocynthis leaves extract: photocatalytic, antimicrobial and antioxidant studies

Abstract Considering the ecofriendly aspects of green synthesis, copper nanoparticles (Cu NPs) were produced using leaves extract of Citrullus colocynthis (Desert Gourd) as a reducing agent and CuSO4 as a Cu precursor. The characterization of synthesized Cu NPs was performed using various techniques including UV-Visible spectroscopy (UVS), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Energy dispersive X-ray (EDX). The tested NPs (face centered cubic) were determined to possess an average size of 17 ± 4.2 nm with spherical shape which exhibited highest absorption (λ max) at 560 nm. These NPs were assessed for their potential to function as a photocatalyst in degradation of methylene blue (MB) dye under UV light and a significant degradation (65 %) of MB dye was observed within irradiation period of 160 min. The Cu NPs displayed a promising antibacterial activity (ABA) against various bacterial cultures such as P. multocida, Botryococcus subtilis, S. aureus and Escherichia coli. While, appreciable antioxidant potential (AP) of tested nanoparticles was also revealed by various invitro antioxidant assays including total phenolic contents (TPC), total flavonoids contents (TFC) and diphenyl picrylhydrazyl (DPPH) assays. The fabrication of Cu NPs through green route, the use of C. colocynthis extract is recommended as an effective antimicrobial, antioxidant and photocatalytic agent as green route offers various advantages over chemical synthesis.

Comparative performance analysis of NMC cathodes elaborated from recovered and commercial raw materials: A low-temperature molten salt approach for extracting critical metals from end-of-life lithium-ion batteries

Recycling end-of-life (EoL) Lithium-ion batteries is crucial in maintaining the economic and ecological balance. It allows the proper management of the hazardous elements and recovering critical elements such as Li, Co, Ni, and Mn. In the study, a fully eco-friendly recycling process that utilizes a molten salt process (ammonium sulfate) to regenerate lithium, nickel, manganese and cobalt from active materials used in motorcycle batteries, obtained from a local e-mobility company, was developed. The roasting and leaching parameters of the recovered black mass were optimized in order to recover pure NixMnyCoz(OH)2 and Li2CO3. The use of (NH4)2SO4 enabled attaining high recovery yields of Li, Mn, Ni, and Co, with rates of 95.4 ± 0.3%, 94.8 ± 0.6%, 93.4 ± 0.4%, and 92.6 ± 0.5%, respectively. These recovered products were utilized in the synthesis of three different novel cathode active materials (LiNixMnyCozO2) (CAMs). Furthermore, aluminum used as the current collector was also recovered, promoting the process's eco-friendly aspect. The morphological and structural properties of the novel CAMs phases were compared to those prepared from commercial raw products, which they perfectly match. The specific discharge capacities of regenerated cathodic materials from recovered metals were benchmarked, and they were found to be approximately 180 mAh.g−1 and 135 mAh.g−1 at 0.2 C and 0.5 C, respectively, which are comparable to capacities provided by materials synthesized from commercial reagents. Through investigating the electrochemical performance of various regenerated CAMs, the feasibility of utilizing recycled precursors as an alternative to commercial reagents was established for the synthesis of multiple battery chemistries.

Is scepticism a barrier to green purchase behaviour? Testing a comprehensive model in the Indian context

PurposeThis study aims to intend to contribute to the literature by testing the effect of scepticism on green consumer behaviour through environmental concern, knowledge, value and willingness to pay more in the Indian context. Thus, the comprehensive model with new directions of antecedents of green consumer purchase behaviour and direct and indirect effects was examined using structural equation modelling.Design/methodology/approachThe study adopted the hypo-deductive research design to test the proposed structural model. Cross-sectional data were collected through a predesigned questionnaire from the households living in Visakhapatnam city using a purposive sampling method. The proposed theoretical model was tested using structural equation modelling.FindingsThe results support five antecedents’ direct and indirect effects on green purchase behavioural intentions and actual buying behaviour, except for the indirect effect of green scepticism on green purchase behaviour (GPB). Similarly, scepticism is responsible for significant variation in GPB.Practical implicationsThe present study’s findings imply the role of scepticism on GPB, and the policies of adopting green products need to be addressed. Green buying is an obscure task; however, it can be evident by adding eco-friendly aspects and persuading consumers of a win-win situation for themselves, the environment and the company.Originality/valueThis study adds to the field of knowledge by exploring and testing the factors affecting GPB, which was not emphasized earlier in the Indian context and second, by developing a theoretical consensus on testing the antecedents of GPB. The results strengthen the argument that scepticism is an antecedent that drives GPB.

A Novel Quantum Dots-Based Fluorescent Sensor for Determination of the Anticancer Dacomitinib: Application to Dosage Forms

One of the most promising drugs recently approved for the treatment of various types of cancer is dacomitinib, which belongs to the tyrosine kinase inhibitor class. The US Food and Drugs Administration (FDA) has recently approved dacomitinib as a first-line treatment for patients suffering from non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. The current study proposes the design of a novel spectrofluorimetric method for determining dacomitinib based on newly synthesized nitrogen-doped carbon quantum dots (N-CQDs) as fluorescent probes. The proposed method is simple and does not require pretreatment or preliminary procedures. Since the studied drug does not have any fluorescent properties, the importance of the current study is magnified. When excited at 325 nm, N-CQDs exhibited native fluorescence at 417 nm, which was quantitatively and selectively quenched by the increasing concentrations of dacomitinib. The developed method involved the simple and green microwave-assisted synthesis of N-CQDs, using orange juice as a carbon source and urea as a nitrogen source. The characterization of the prepared quantum dots was performed using different spectroscopic and microscopic techniques. The synthesized dots had consistently spherical shapes and a narrow size distribution and demonstrated optimal characteristics, including a high stability and a high fluorescence quantum yield (25.3%). When assessing the effectiveness of the proposed method, several optimization factors were considered. The experiments demonstrated highly linear quenching behavior across the concentration range of 1.0-20.0 μg/mL with a correlation coefficient (r) of 0.999. The recovery percentages were found to be in the range of 98.50-100.83% and the corresponding relative standard deviation (%RSD) was 0.984. The proposed method was shown to be highly sensitive with a limit of detection (LOD) as low as 0.11 μg/mL. The type of mechanism by which quenching took place was also investigated by different means and was found to be static with a complementary inner filter effect. For quality purposes, the assessment of the validation criteria adhered to the ICHQ2(R1) recommendations. Finally, the proposed method was applied to a pharmaceutical dosage form of the drug (Vizimpro® Tablets) and the obtained results were satisfactory. Considering the eco-friendly aspect of the suggested methodology, using natural materials to synthesize N-CQDs and water as a diluting solvent added to its greenness profile.

In-situ synthesis of TbAlO3/Tb3Al5O12/Tb2O3 three-component nanocomposite as a heterojunction photocatalyst with a green and eco-friendly approach

In-situ synthesis of TbAlO3 (TAP)/Tb3Al5O12 (TAG)/Tb2O3 three-component nanocomposite by sol–gel method using natural reactants and investigation of its photocatalytic activity can be considered eco-friendly aspects of this work. The bioactive components of natural compounds may play as a reductant and progress the process through auto-combustion sol–gel technique. It was found that Mulberry has more bioactive components than Capparis spinosa L., so nucleation overtook growth and produced finer particles with less agglomeration. Optical property studies represented a band gap at about 3.8 eV that is different from the amounts related to TAP and TAG. Hence, e--h+ transfers in this nanocomposite were studied by estimation of energy levels of its constituents. According to findings, these components formed a UV-active photocatalyst with Type-I configuration to degrade organic pollutants. In other words, presence of Tb2O3 helped to benefit from properties of two ferroelectric compounds, that they have large band gaps, in photocatalytic reactions. After optimizing the photocatalytic parameters, maximum yield was obtained at about 94 %. Kinetics studies showed the photocatalytic process follows zero-order kinetics. In addition, the oOH was found as the most active promoter agent.

Smart waste management perspective of COVID-19 healthy personal protective materials in concrete for decorative landscape pavements and artificial rocks

This paper presents a new method for determining the effect of healthy personal protective material (HPPM) stripes, such as surgical masks, protective suits, and overhead and foot covers, on the durability and physicomechanical characteristics of concrete for use in architectural forms. Because of the current global epidemic caused by coronavirus (COVID-19), the use of HPPM, such as surgical masks, protective suits, and overhead and foot covers, has increased considerably. COVID-19’s second and third waves are currently affecting various countries, necessitating the use of facemasks (FM). Consequently, millions of single FM have been discharged into the wild, washing up on beaches, floating beneath the seas, and ending up in hazardous locations. The effect of stripe fibers on the physicomechanical characteristics of concrete, such as the workability, Uniaxial Compressive Strength UCS, flexural strength, impact strength, spalling resistance, abrasion resistance, sorptivity, Water absorption Sw, porosity (ηe), water penetration, permeability, and economic and eco-friendly aspects, need to be determined. With a focus on HPPM, especially single-use facemasks, this study investigated an innovative way to incorporate pandemic waste into concrete structures. Scanning electron microscope and X-ray diffraction patterns were employed to analyze the microstructures and interfacial transition zones and to identify the elemental composition. The HPPM had a pore-blocking effect, which reduced the permeability and capillary porosity. Additionally, the best concentrations of HPPM, particularly of masks, were applied by volume at 0, 1, 1.5, 2.0, and 2.5%. The use of mixed fibers from different HPPMs increased the strength and overall performance of concrete samples. The tendency of growing strength began to disappear at approximately 2%. The results of this investigation showed that the stripe content had no effect on the compressive strength. However, the stripe is critical for determining the flexural strength of concrete. The UCS increased steadily between 1 and 1.5% before falling marginally at 2.5%, which indicates that incorporating HPPM into concrete had a significant impact on the UCS of the mixture. The addition of HPPM to the mixtures considerably modified the failure mode of concrete from brittle to ductile. Water absorption in hardened concrete is reduced when HPPM stripes and fibers were added separately in low-volume fractions to the concrete mixture. The concrete containing 2% HPPM fibers had the lowest water absorption and porosity percentage. The HPPM fibers were found to act as bridges across cracks, enhancing the transfer capability of the matrices. From a technological and environmental standpoint, this study found that using HPPM fibers in the production of concrete is viable.

Global distribution of microplastic contaminants in aquatic environments and their remediation strategies.

This review describes the occurrence and distribution of microplastics in freshwater and marine environments in recent years (2017-2022). Use of microplastics often results in contamination of aquatic environments, threatens biodiversity, and creates the need for environmental remediation. Such remediation strategies can involve primary, secondary, and tertiary treatments. Tertiary treatment is a frequent research subject due to its high efficiency and the possibility for advancements and enhancements. This study discusses tertiary treatments with remediation efficiencies of 95% and greater and their advantages, disadvantages, and future perspectives. Biochar-mediated remediation of microplastics is an effective method that may be able to achieve efficiencies approaching 100%. The study concludes by exploring methods of removing microplastics, including constructed wetlands and biochar, which offer high efficiency. PRACTITIONER POINTS: Tertiary treatments are an effective microplastic remediation strategy applicable succeeding secondary or primary treatments or as an individual remediation strategy. Biochar is a highly efficient adsorbent for microplastic remediation from aquatic environment with eco-friendly aspect and reusability. Modifications in tertiary treatments and enhancement in remediation efficiency are still a subject of research for future studies.

Preparation and characterization of carbon material with cellulose types as an additive in aqueous media

Cellulose has inspired great interest due to its unique nanostructure, elasticity, strong hydrogen bonding, and excellent improving durability for structure in compounds with other materials in the research over recent years. In this study, we investigated the effect of added cellulose as materials on carbon nanotubes (CNTs) which is limited by Van der Waals' force between bundles of tubes in aqueous media. Cellulose nanofibers (CNFs) produced from red algae show improved hydrophilic properties that –OH bundles were increased than cellulose nanocrystals (CNCs) in carbon nanotube (CNT) fluids. Due to the effect of the cellulose material introduced into CNTs, after result indicated improving properties at dispersion and electrical conductivity sides better than CNT particles alone. On the other hand, the thermal conductivity indicated a higher value CNT alone type. In the contact angle measurement, it can be confirmed that the size of the contant angle is decreased as the addition of cellulose types relieved the tangle between CNT bundles by the –OH surface and according to the change to hydrophilic. The composite with nanocellulose enables better properties of CNTs to be expressed. Thus, cellulose materials can enhance the limited properties of CNT dispersion in ease and eco-friendly aspects.

Sustainable Upcycling of Fisheries and Aquaculture Wastes Using Fish-Derived Cold-Adapted Proteases.

The fisheries and aquaculture industries are some of the major economic sectors in the world. However, these industries generate significant amounts of wastes that need to be properly managed to avoid serious health and environmental issues. Recent advances in marine waste valorization indicate that fish waste biomass represents an abundant source of high-value biomolecules including enzymes, functional proteins, bioactive peptides, and omega-3 rich oils. Enzyme-assisted processes, for the recovery of these value-added biomolecules, have gained interest over chemical-based processes due to their cost-effectiveness as well as their green and eco-friendly aspects. Currently, the majority of commercially available proteases that are used to recover value-added compounds from fisheries and aquaculture wastes are mesophilic and/or thermophilic that require significant energy input and can lead to unfavorable reactions (i.e., oxidation). Cold-adapted proteases extracted from cold-water fish species, on the other hand, are active at low temperatures but unstable at higher temperatures which makes them interesting from both environmental and economic points of view by upcycling fish waste as well as by offering substantial energy savings. This review provides a general overview of cold-adapted proteolytic enzymes from cold-water fish species and highlights the opportunities they offer in the valorization of fisheries and aquaculture wastes.

Effect of process parameters on pulsed laser welding of AA5083 alloy using response surface methodology and pulse shape variation

Aluminium alloys exhibit eco-friendly aspects related to global environmental issues, such as almost unlimited recyclability. Nevertheless, some intrinsic characteristics are challenges to explore all their benefits. In the welding process, the high thermal conductivity and low melt point require high control of heat input. Alternatively, the pulsed laser mode provides a sharp beam focus with precise control enabling regulating the energy delivered. In this sense, this present work analysed the effect of pulsed laser welding parameters on 3-mm-thick AA5083 aluminium alloy sheets. Trials targeted to develop sound welds with minimum defect and high penetration depth adopting statistical methods. The optimum parameter arrangement was achieved by varying peak power, spot diameter, and pulse duration. Finally, the best parameter combination was applied using different pulse shapes to mitigate crack formation and pores. As a result, the pulse shape with step-down at the end of each pulse generated crack-free spot welds.

Performance Assessment and Chip Morphology Evaluation of Austenitic Stainless Steel under Sustainable Machining Conditions

Sustainable manufacturing has received great attention in the last few decades for obtaining high quality products with minimal costs and minimal negative impacts on environment. Sustainable machining is one of the main sustainable manufacturing branches, which is concerned with improving environmental conditions, reducing power consumption, and minimizing machining costs. In the current study, the performance of three sustainable machining techniques, namely dry, compressed air cooling, and minimum quantity lubrication, is compared with conventional flood machining during the turning of austenitic stainless steel (Nitronic 60). This alloy is widely used in aerospace engine components, medical applications, gas power industries, and nuclear power systems due to its superior mechanical and thermal properties. Machining was performed using SiAlON ceramic tool with four different cutting speeds, feeds and a constant depth of cut. Consequently, various chip characteristics such as chip morphology, chip thickness, saw tooth distance and chip segmentation frequency were analyzed with both optical and scanning electron microscopes. Performance assessment was performed under the investigated cutting conditions. Our results show that the tool life under MQL machining are 138%, 72%, and 11% greater than dry, compressed air, and flooded conditions, respectively. The use of SiAlON ceramic tool results is more economically viable under the MQL environment as the overall machining cost per component is lower ($0.27) as compared to dry ($0.36), compressed air ($0.31), and flooded ($0.29) machining conditions. The minimum quantity lubrication technique outperformed the other investigated techniques in terms of eco-friendly aspects, economic feasibility, and technical viability to improve sustainability.

Metal Oxide-Based Photocatalytic Paper: A Green Alternative for Environmental Remediation

The interest in advanced photocatalytic technologies with metal oxide-based nanomaterials has been growing exponentially over the years due to their green and sustainable characteristics. Photocatalysis has been employed in several applications ranging from the degradation of pollutants to water splitting, CO2 and N2 reductions, and microorganism inactivation. However, to maintain its eco-friendly aspect, new solutions must be identified to ensure sustainability. One alternative is creating an enhanced photocatalytic paper by introducing cellulose-based materials to the process. Paper can participate as a substrate for the metal oxides, but it can also form composites or membranes, and it adds a valuable contribution as it is environmentally friendly, low-cost, flexible, recyclable, lightweight, and earth abundant. In term of photocatalysts, the use of metal oxides is widely spread, mostly since these materials display enhanced photocatalytic activities, allied to their chemical stability, non-toxicity, and earth abundance, despite being inexpensive and compatible with low-cost wet-chemical synthesis routes. This manuscript extensively reviews the recent developments of using photocatalytic papers with nanostructured metal oxides for environmental remediation. It focuses on titanium dioxide (TiO2) and zinc oxide (ZnO) in the form of nanostructures or thin films. It discusses the main characteristics of metal oxides and correlates them to their photocatalytic activity. The role of cellulose-based materials on the systems’ photocatalytic performance is extensively discussed, and the future perspective for photocatalytic papers is highlighted.

Comparative Performance Analysis Between Potassium Permanganate (KMnO<sub>4</sub>) Spray and Alternative PP (KMnO<sub>4</sub>) Spray on Various Properties of Denim Fabric

The growth of denim items in global market is rising steadily. The aesthetic appearance and design of denim are one of the causes for this increase in demand. This study was attempted to compare the performance relating to potassium permanganate spray and alternative potassium permanganate spray on denim fabric. In this research; after the application of de-sizing, stone enzyme, bleaching, neutralization processes; stretch denim fabric was all over sprayed with potassium permanganate along with alternative potassium permanganate in varying concentration. After neutralization and drying, the different features of denim fabric was explored accordingly. For comparison, industrially performed potassium permanganate concentration solution of 2%, 3%, and 5% were applied as well as alternative potassium permanganate concentration solution of 60%, 80%, and 100% were also utilized. After applying those chemicals, samples were neutralized and dried in a steam dryer. Finally, the mechanical properties like fabric tensile strength, tear strength were determined respectively. All of the tests were carried out according to ISO standards. The physical properties like color fastness to rubbing, color fastness to wash, GSM, pH values were also checked. Specially EIM (environmental impact) was also investigated; in that case, samples treated with potassium permanganate spray exhibited poor performance than the alternative potassium permanganate sprayed sample. In the case of alternative potassium permanganate spray after increasing the concentration of chemical, tensile and tear strength decreasing percentage was observed almost similar, while in the case of potassium permanganate spray, a decrease relating to tensile and tear strength properties were observed after increasing the chemical concentration respectively. On the other hand, the grading related to color-fastness to rubbing was better. But there was no significant change was observed for the grading related to color fastness to washing for samples treated with potassium permanganate and alternative potassium permanganate spray. In terms of EIM investigation, samples treated with alternative potassium permanganate spray showed satisfactory values in accordance with worker and eco-friendly aspects.

Tool wear and energy consumption optimization in EDM of chromium tool steel

The machining feasibility of high chromium tool steel using the EDM process has been studied. An attempt has been made to optimise the EDM process, concerning eco-friendly aspects like relative electrode wear ratio, process energy consumption along with machining parameter, that is process time. The four control factors: Peak current, Pulse duration, Flushing pressure and Dielectric level were selected to minimize the output responses. The Taguchi approach was used to optimise the process parameters. It was observed that the output responses were greatly influenced by the peak current and the dielectric level, but least affected by pulse duration.