Non-polluting Method Research Articles

Optimization Mechanism of Mechanical Properties of Basalt Fiber-Epoxy Resin Composites by Interfacially Enriched Distribution of Nano-Starch Crystals

Fibre reinforced polymer composites have become a new generation of structural materials due to their unique advantages such as high specific strength, designability, good dimensional stability and ease of large-area monolithic forming. However, the problem of interfacial bonding between the resin matrix and the fibres limits the direct use of reinforcing fibres and has become a central difficulty in the development of basalt fibre-epoxy composites. This paper proposes a solution for enhancing the strength of the fibre-resin interface using maize starch nanocrystals, which are highly yield and eco-friendly. Firstly, in this paper, corn starch nanocrystals (SNC) were prepared by hydrolysis, and were deposited on the surface of basalt fibers by electrostatic adsorption. After that, in order to maximize the modification effect of nano-starch crystals on the interface, the basalt fiber-epoxy resin composite samples were prepared by mixing in a pressureless molding method. The test results shown that the addition of basalt fibers alone led to a reduction in the strength of the sample. Deposition of 0.1 wt% SNC on the surface of basalt fibers can make the strength consistent with pure epoxy resin. When the adsorption amount of SNC reached 0.5 wt%, the tensile strength of the samples was 23.7% higher than that of pure epoxy resin. This is due to the formation of ether bond homopolymers between the SNC at the fibre-epoxy interface and the epoxy resin, which distorts the originally smooth interface, leading to increased stress concentration and the development of cracks. This enhances the binding of basalt fibers. The conclusions of this paper can provide an effective, simple, low-cost and non-polluting method of interfacial enhancement modification.

An efficient and eco-friendly method for removing sericin using microwave-assisted steam degumming

Silk is a promising textile resource, but its degumming treatment still lacks efficient and non-polluting methods. In this paper, an innovative silk degumming process combining microwave pre-treatment and steam degumming is introduced. When the technical parameters of microwave-steam synergistic degumming were 10 min of microwave, 120 ℃ of steam temperature, and 30 min of steam time, the degumming efficiency of the specimen was three times of the traditional Na2CO3 degumming method, and the energy consumption was only one-half of the traditional method. In terms of time efficiency, the traditional Na2CO3 degumming took 2.75 h, while this novel method took only 0.75 h. Among the samples, the mechanical properties of the specimens treated with microwave for 10 min were the best, with the warp breaking strength of 542.20 N and the weft breaking strength of 356.19 N. Meanwhile, the hygroscopicity and air permeability were also the best compared to the traditional treating samples. This indicates that microwave-steam synergistic degumming technology is a clean technology with the advantages of high sericin degumming rate, short degumming time, low energy consumption, and no use of any chemicals. This method is conducive to achieving better and faster sustainable development.

Friction Reduction Achieved by Ultraviolet Illumination on TiO2 Surface.

Controlling friction by light field is a low-cost, low-energy, non-polluting method. By applying ultraviolet light on the surface of photosensitive materials, the properties of the friction pairs or lubricant can be influenced, thus achieving the purpose of reducing friction. In this study, TiO2, an inorganic photosensitive material, was selected to investigate the modulating effect of light fields on friction lubrication when using polyalphaolefin (PAO) base oil as a lubricant, and the modulation law of light fields on the friction lubrication behavior was investigated under different loads (1-8 N), different speeds (20-380 mm/s), and different viscosities (10.1-108.6 mPa·s) of PAO base oil. The experimental results showed that light treatment could reduce the friction coefficient of PAO4 base oil lubrication from 0.034 to 0.016, with a reduction of 52.9% under conditions of 3 N-load and 56.5 mm/s-speed, and the best regulation effect could be achieved under the mixed lubrication condition. After TiO2 was treated with ultraviolet light, due to its photocatalytic property, PAO molecules were oxidized and adsorbed on the TiO2 surface to form an adsorption layer, which avoided the direct contact of rough peaks and thus reduced the friction coefficient. This study combines photosensitivity, photocatalysis, and friction, presenting a method to reduce the friction coefficient by applying a light field without changing the friction pairs or lubricants, which provides a new direction for friction modulation and gives new ideas for practical applications.

Isolation and Characterization of Bacterial Gut Symbionts from Irradiated, Wild and Lab Reared Males of Melon Fly, Zeugodacus cucurbitae (Coquillett)

The melon fly, Bactrocera cucurbitae is of serious concern inflicting heavy losses to the horticultural industry. It attacks cucurbits right from the primordial stages of the crop up to harvest and causing yield loss of 30 to 100%. The Sterile Insect Technique is a species-specific and environmentally non-polluting method of insect control that relies on sterilization of males using gamma rays and systemic release of sterile males in wild environment. Male pupae of Zeugodacus cucurbitae were exposed to gamma radiation at 50 Gy using Cobalt-60 source. Bacterial gut symbionts from sterile males, wild males of field collected population and laboratory reared males of melon fly were isolated and characterized based on morphological characteristics (viz., colour, size, shape, opacity, margin, elevation and viscosity), gram staining, morphology and arrangement of bacterial cells in culture media. Ten adult flies from sterile, wild and laboratory reared males were used for isolation of gut symbionts. The most dominant phylum of bacteria found among the sterile, wild and lab reared male flies was Proteobacteria followed by the phylum Firmicutes. Different genera of bacteria isolated from sterile males were Enterobacter, Providencia and Bacillus. From wild males; Enterobacter, Providencia, Morganella, Klebsiella and Bacillus were identified. Bacterial genera obtained from lab reared males were Enterobacter, Providencia, Klebsiella and Bacillus. Among the entire bacterial genus, Enterobacter, Providencia and Bacillus were the common bacterial genera isolated from sterile, wild and lab reared male flies. Irradiation had resulted in loss of endosymbiotic bacteria in sterile males.

Submerged Photosynthesis of Molybdenum–Tungsten Nanostructures for Supercapacitor Application

Research on electrochemical energy storage devices aims to produce supercapacitors via a facile and nonpolluting method. Because of unnecessary elemental doping and disordered morphologies of nano-oxides, impurities in raw materials during the conventional fabrication process would reduce the pseudocapacitance. Herein, we propose a submerged photosynthesis crystalline method for synthesizing oxygen vacancy (Vo)-enriched Mo–W oxide hydrates and Mo-doped tungsten oxide hydrate nanocomposites at 55 °C and normal pressure. In addition, this study describes the impact of Vos on pseudocapacitance using ab initio calculations based on density functional theory. Doping the WO3·0.33H2O lattice with Mo and Vos brings the conduction band closer to the Fermi energy level. The comparison of the ultraviolet–visible–near-infrared (UV–vis–NIR) irradiation spectrum and absorption coefficient calculation suggests that Mo and Vo doping is responsible for the NIR absorption. This study concludes that enriched Vos result in the highest specific capacitance and pseudocapacitive behavior of MoxW1–xO3·0.33H2O.

Nickel nanoparticle decorated silicon carbide as a thermal filler in thermal conductive aramid nanofiber-based composite films for heat dissipation applications.

Aramid nanofibers (ANFs) have shown potential applications in the fields of nanocomposite reinforcement, battery separators, thermal insulation and flexible electronics. However, the inherent low thermal conductivity limits the application of ANFs, currently, to ensure long lifetime in electronics. In this work, new nickel (Ni) nanoparticles were employed to decorate the silicon carbide (SiC) filler by a rapid and non-polluting method, in which nickel acetate tetrahydrate (Ni(CH3COO)2·4H2O) and SiC were mixed and heated under an inert atmosphere. The composites as thermal fillers were applied to prepare an aramid nanofiber (ANF)-based composite film. Our results showed that the decoration of SiC by an appropriate amount of Ni nanoparticles played an important role in improving the thermal conductivity, hydrophobicity, thermal stability, and puncture resistance of the ANF composite film. After adjusting the balling time at 10 h, the optimized content of 10 mol% Ni nanoparticles improved the thermal conductivity to 0.502 W m-1 K-1, 298.4% higher than that of the original ANF film. Moreover, increasing the content of thermal fillers to 30 wt% realized a high thermal conductivity of 0.937 W m-1 K-1, which is 643.7% higher than that of the pristine ANF film. Moreover, the compatibility between thermal fillers and ANFs and thermal stability were improved for the ANF-composite films. The effective heat transfer function of our composite films was further confirmed using a LED lamp and thermoelectric device. In addition, the obtained composite films show certain mechanical properties and better hydrophobicity; these results exhibit their great potential applications in electronic devices.

Molecular and physiological mechanisms of strigolactones-mediated drought stress in crab apple (Malus hupehensis Rehd.) seedlings

Drought stress severely affects apple growth and yield. Therefore, it is urgent to identify an efficient and nonpolluting method to cope with drought stress. Strigolactones (SLs), a class of carotenoid-derived phytohormones, play an important role in regulating plant responses to abiotic stresses. However, the role of SLs in apple seedlings in response to drought stress remains unknown. In the present study, the ameliorative effects and underlying mechanism of exogenous GR24 (a synthetic SL analog) on apple seedlings under drought stress were studied. The results indicated that drought stress inhibited the growth of apple seedlings, whereas exogenous GR24 significantly ameliorated the damage caused by drought stress. Compared with drought treatment alone, GR24+drought treatment improved leaf chlorophyll contents, photosynthetic parameters and antioxidant capacity and inhibited the production of reactive oxygen species (ROS) and malondialdehyde (MDA) in apple seedlings. RNA sequencing (RNA-seq) analysis showed that 6490 genes (2753 upregulated and 3737 downregulated) were differentially expressed between the drought treatment (D) and the drought treatment with GR24 (DSL). Further analysis showed that these differentially expressed genes (DEGs) are mainly associated with stress response, antioxidant enzyme metabolism, calcium signaling and plant hormone signaling. In addition, several transcription factor families, such as WRKY, AP2/ERF, and NAC, are also activated by exogenous GR24. Taken together, our physiological and transcriptomic data revealed the mechanisms by which SLs alleviate drought stress, which may contribute to improving apple yield and quality under drought stress.

Efficient electrocatalytic degradation of doxycycline hydrochloride in wastewater by Ni/MWCNTs-OH on modified Ti

The abuse of doxycycline hydrochloride (DOX) in animal husbandry and its incomplete treatment have led to serious environmental problems, especially the risk of bacterial resistance. As an efficient, simple, and non-polluting method of catalysis, electrocatalysis has many advantages, which has attracted extensive attention in the removal of antibiotic pollutants in wastewater. Hence, the Ni/MWCNTs-OH/Ti composite electrode was prepared by galvanostatic electrodeposition to electrocatalyze DOX, and then the electrode was observed and analyzed by SEM, XRD and XPS. The optimal conditions (MWCNTs-OH was 0.10 mg/L, the concentration of NiSO4 was 75 mmol/L, the degradation current was 15 mA, NaCl was present at a concentration of 0.20 mol/L, and pH value of 4) for degradation of 30 mg/L DOX within 60 min were determined by controlling variables. The degradation process of DOX followed Langmuir-Hinshelwood quasi-first-order reaction kinetics. As a result of stable the electrode, DOX removal rate was consistently above 70 % after 10 continuous uses, which showed good stability and reusability. The composite electrode electrocatalyzed DOX under the synergistic effect of cathode and anode. To identify the main intermediates involved in the electrochemical degradation of DOX, LC-MS was used. The toxicity of the intermediate products and final products was compared and analyzed by microbial culture experiment. And then Ecosar 2.2 was used to predict the biotoxicity of main intermediates to fish, daphnid, and green algae. This work provides a new material for the environmental remediation of antibiotic pollution.

Green method for improving performance attributes of wool fibres using immobilized proteolytic thermozyme

Wool has the tendency to turn into felt during agitation in washing machines. Thus, a benign non-polluting method for the production of machine-washable wool was developed herein. Initially, a proteolytic bacteria was isolated from hot region soil. The bacterial isolate was identified as Bacillus safensis FO-36bMZ836779 according to the 16S rRNA gene sequencing. Afterwards, the extracellular protease produced by this isolate was covalently immobilized in order to enhance its stability under non-ambient conditions which are usually adopted in industrial sectors like textile industries. Sericin, which is usually discharged into degumming effluent of natural silk, was utilized to prepare the immobilization carrier. Box–Behnken design was adopted in order to hone the preparation of the sericin–polyethylene–imine–glutaraldehyde activated agar carrier. The pH and temperature profiles of the free and immobilized proteases were compared. Later, wool fibres were bio-treated with both the free and the immobilized enzymes. The effect of process conditions on the resistance of the bio-finished wool to felting was investigated. The alteration in the fibre morphology was monitored using SEM. Amino acid analysis and alkali solubility tests were adopted to assign any change in the chemical structure of the bio-treated wool. The influence of bio-treatment of wool on its inherent properties was assigned. Results revealed that bio-treatment of wool with the said enzyme led to production of machine-washable wool without severe deterioration in the fibres’ properties. In an energy- and water-consuming process, the hot solution from bio-treatment bath was used successfully in dyeing of wool.

Yield loss assessment and control of fruit bat (Pteropus giganteus) in litchi orchards using the artificial light method

Litchi (Litchi chinensis) is an important subtropical evergreen fruit crop of Punjab and is considerably damaged by the fruit bat (Pteropus giganteus). Since no study has been done in Punjab to assess fruit damage and control of fruit bats in litchi crop, present study was conducted in litchi orchards at two different locations (six sites) Gurdaspur [Regional Research Station (PAU), villages Ranjit Bagh and Tibar] and Pathankot (villages Sujanpur, Balusa and Malikpur) each having three replications, during 2018 and 2019. Our results reported that yield loss (%) to litchi fruits by P. giganteus was in the range from 6.85 to 8.93% and damage 5.59 kg/tree having average yield of 74.09 kg/tree. The average economic litchi fruit loss was calculated to be Rs. 32,232.0/acre. This damage to litchi fruit crop was minimized by using lighting, a non-lethal and non-polluting method (LED bulbs), with one-time installation cost. It is concluded that after installation of 16 LED bulbs/acre of 30 watts at a distance of 50 feet from each other in an upward position at the height of 8 feet above tree canopy in an orchard having 72 trees planted at a distance of 25×25 feet, we can reduce fruit bat damage to a lower level and can give a net economic return of Rs. 13448.0/acre to litchi fruit growers which will increase their farm income and help in conservation of fruit bats.

Eco‐friendly method for rearing sea cucumber ( Apostichopus japonicus ) larvae

Seed production plays an important role in aquaculture. The sea cucumber Apostichopus japonicus is an important marine aquaculture species in many Asian countries. By 2020, the annual total seed production of A. japonicus reached 551 billion individuals in China. However, the traditional method of culturing A. japonicus larvae is cost intensive and causes environmental pollution. In this study, we developed an eco-friendly method for rearing sea cucumber larvae. We designed a cage system to provide a suitable living environment for larvae in open-air outdoor ponds, and then, we identified 0.2 larvae per ml as the optimal stocking density for larval rearing. We also found that substrates made of oyster and scallop shells were optimal for larval settlement. A. japonicus larvae showed good survival, growth, development and settlement when cultured using this low-cost and non-polluting method. Our results can be applied to support sustainable development of the sea cucumber industry.

BIOLOGICAL ACTIVITY OF RICE STRAW-DERIVED MATERIALS: AN OVERVIEW

RS (RS) waste has been the most widely recognised pollutant in the world for several years. Therefore, it is critical to develop a simple process for converting rice straw (RS) into a useful products. RS is a rich source of phenolic acids (PAs), lignin, condensed tannins, flavonoids, and momilactone that can be extracted using conventional and environmentally friendly methods. These bioactive components of RS have various biological activities such as antibacterial, antifungal, pesticide, antioxidant, etc. Recently, RS-derived fluorescent nitrogen-doped carbon dots (NCDs) were developed for the detection and monitoring of diabetic ketoacidosis in diabetic patients. Herein, various straightforward and non-polluting method for reprocessing RS into value-added materials are discussed.

Nitrogen-rich carbon quantum dots (N-CQDs) based on natural deep eutectic solvents: Simultaneous detection and treatment of trace Co2+ under saline conditions

Trace Co2+, when present in large quantities, is harmful to the environment and therefore cannot be ignored. Inductively coupled plasma mass spectrometry (ICP-MS) is a standard method used to detect metal ions, however, detecting trace Co2+ under high saline conditions can be challenging. Similarly, existing Co2+ treatment methods are prone to secondary pollution and have high energy consumption. Therefore, it is necessary to find an efficient and non-polluting method for Co2+ detection and treatment. This study successfully synthesized nitrogen-rich carbon quantum dots (N-CQDs) based on natural deep eutectic solvents (NADES) using a one-step solvothermal method. The prepared N-CQDs exhibited excellent fluorescence and high salt tolerance. The simultaneous detection and treatment of trace Co2+ in water under high salinity conditions were achieved for the first time. The response of the N-CQDs to Co2+ under saline condition was linear in the range of 5–250 μM with a limit of detection (LOD) of 1.2269 μM. Feasibility of practical application was assessed by quantitative detection of Co2+ in real water samples. Furthermore, the N-CQDs can treat Co2+, and the removal rate was 99.98%.

A non-polluting method for rapidly purifying uranium-containing wastewater and efficiently recovering uranium through electrochemical mineralization and oxidative roasting

Iron-based materials have been widely used for treating uranium-containing wastewater. However, the iron-uranium solids originating by treating radioactive water through pollutant transfer methods has become a new uncontrolled source of persistent radioactive pollution. The safe disposal of such hazardous waste is not yet well-resolved. The electrochemical mineralization method was developed to rapidly purify uranium-containing wastewater through lattice doping in magnetite and recover uranium without generating any pollutants. An unexpected isolation of U3O8 from uranium-doped magnetite was discovered through in-situ XRD with a temperature variation from 300 °C to 700 °C. Through HRTEM and DFT calculation, it was confirmed that the destruction of the inverse spinel crystal structure during the gradual transformation of magnetite into γ-Fe2O3 and α-Fe2O3 promoted the migration, aggregation, and isolation of uranium atoms. Uniquely generated U3O8 and Fe2O3 were easily separated and over 80% uranium and 99.5% iron could be recovered. These results demonstrate a new strategy for uranium utilization and the environmentally friendly treatment of uranium-containing wastewater.

Effect of two‐dimensional zeolitic imidazolate frameworks‐L on flame retardant property of thermoplastic polyurethane elastomers

In this study, three kinds of two‐dimensional nanoplates consisting of zinc zeolite imidazole frameworks‐L (Zn‐ZIF‐L), cobalt zeolite imidazole frameworks‐L (Co‐ZIF‐L), and Zinc‐Cobalt hybrid zeolite imidazole frameworks‐L (Zn&Co‐ZIF‐L), were prepared by a green and nonpolluting method. Each of the three nanoplates was added to thermoplastic polyurethane elastomers (TPU) at 3 wt% to investigate their performance in flame retardancy and smoke suppression of TPU. Compared with pure TPU, the limiting oxygen index values of Zn‐ZIF‐L/TPU, Co‐ZIF‐L/TPU, and Zn&Co‐ZIF‐L/TPU increased from 23.2% for pure TPU to 25.3, 26.0, and 25.7%, respectively; the total heat release of these three composite materials decreased by 7.8, 11.4, and 9.3%, their peak heat release rate decreased by 28.8, 42.8, and 43.8% and their peak smoke production rate reduced by 50, 45, and 51.5%, respectively. All three nanoplates showed good flame retardancy and smoke suppression properties. In addition, through thermogravimetric/Fourier transform infrared spectroscopy (TG‐FTIR) analysis of the TPU composite and the X‐ray diffraction analysis of residual char, the specific flame‐retardant mechanisms and smoke suppression mechanisms were explored.

Synthesis of Hydroxylatopillar[6]arene-Controlled Gold Nanoparticles-Cellulose Nanocrystals and Their Applications.

In this work, two macrocyclic hosts, named hydroxylatopillar[6]arene and dihydroxylatopillar[6]arene (HP6, 2HP6), are proposed. We found that the reduction of Au3+ to Au0 can success by using HP6 or 2HP6 as a reductant and stabilizing agent. At the end of HP6/2HP6, hydroxyl (-OH) groups were used as a reductant to reduce Au3+ to Au0. At the same time, -OH on HP6/2HP6 was oxidized to -COOH, and then the formed -COOH can be used as the stabilizer to prevent the infinite growth of AuNPs. The cellulose nanocrystals (CNCs) prepared by a clean and nonpolluting method were used as carriers to load AuNPs on them. The CNCs were applied for the adsorption of methylene blue (MB), and then the MB was catalytically degraded by HP6/2HP6-AuNPs-CNC. Besides, the HP6/2HP6-AuNPs-CNC showed remarkable catalytic performance for reducing nitro to the amino group in 4-nitrophenol. The advantages of clean and green synthesis make the HP6/2HP6-AuNPs-CNC a hybrid material and its application sustainable.

Application of clay minerals in remediation of heavy metal pollution in soil

In modern times where heavy metal pollution in soil is becoming more and more serious, the new natural non-polluting remediation methods represented by clay mineral materials have attracted more and more attention in the industry.In this paper, the research progress on the types and basic characteristics of clay mineral materials, the effect and mechanism of remediation of heavy metal pollution in soil at home and abroad was comprehensively discussed. The deficiencies of relevant studies were also summarized, and the future research trend was predicted.

O-cresol Concentration Online Measurement Based On Near Infrared Spectroscopy Via Partial Least Square Regression.

Unlike macroscopic process variables, near-infrared spectroscopy provides process information at the molecular level and can significantly improve the prediction of the components in industrial processes. The ability to record spectra for solid and liquid samples without any pretreatment is advantageous and the method is widely used. However, the disadvantages of analyzing high-dimensional near-infrared spectral data include information redundancy and multicollinearity of the spectral data. Thus, we propose to use partial least squares regression method, which has traditionally been used to reduce the data dimensionality and eliminate the collinearity between the original features. We implement the method for predicting the o-cresol concentration during the production of polyphenylene ether. The proposed approach offers the following advantages over component regression prediction methods: 1) partial least squares regression solves the multicollinearity problem of the independent variables and effectively avoids overfitting, which occurs in a regression analysis due to the high correlation between the independent variables; 2) the use of the near-infrared spectra results in high accuracy because it is a non-destructive and non-polluting method to obtain information at microscopic and molecular scales.

Should All Cars Be Electric by 2025? The Electric Car Debate in Europe

The car is still the most common mode of transport in Western countries, particularly so across the European Union, as it accounts for about two-thirds of daily commuting. So far, measures aiming to reduce automobile traffic and incentives for the modal shift to public transport and non-polluting methods of travel (walking, cycling, etc.) have had little effect. Moreover, the car lies at the core of a very complex system that has proven to be difficult to unlock. In light of these challenges, using new types of engine power may appear to be a solution. Electric vehicles have the potential to improve the efficiency, affordability, and sustainability of the transport system. However, there remains much uncertainty as to how such a transition from one type of engine to another may unfold, and where it could take place within the European context. In June 2017, the H2020 project SHAPE-ENERGY launched an online debate on the Debating Europe platform with the question: “Should all cars be electric by 2025?”. The aim of the debate was to elicit citizens views on whether the goal could be reached, how and with which consequences. The diversity of the vantage points that have appeared in the subsequent discussion generated by the strands of debate allows us to bring into discussion the viewpoints and arguments that are not often addressed in the literature on the adoption of electric cars in a comprehensive way. The article sheds light on those debates across Europe, in order to bring new insights to European policymakers that are seeking to promote the market for electric vehicles. It also broadens the scope and offers important contributions to scholarly debates on the diffusion and adoption of such vehicles.

Core-shell magnetic nano-powders with an excellent decolorization effect on dye wastewater.

In recent years, zero-valent nano-iron (nZVI) has received extensive attention due to its excellent decolorization effect on dye wastewater. In this paper, zero-valent nano-iron-nickel (nZVIN) powders were prepared by a simple, efficient and non-polluting method. The powder has a unique core–shell structure and excellent oxidation resistance. Hence the problem that nZVI powders are easily oxidized and difficult to store is solved. Due to the addition of Ni, the magnetic properties of the nZVIN powders are enhanced, which facilitates the recycling of the powders using a magnetic field after sewage treatment. In the decolorization treatment of dye wastewater simulated with Congo red (CR) dye, nZVIN powders can maintain a removal rate of more than 90% for CR solutions with different pH values (7.0–11.5) and an initial dye concentration (50–200 mg L−1). The research results show that nZVIN powders have broad application prospects in the treatment of azo dye wastewater.