Green Way Research Articles

New method for green extraction of ginsenosides based on mechanochemically-assisted extraction and deep eutectic solvents

Ginsenosides are the main active ingredients in ginseng. Studies have shown that ginsenosides have anti-virus, anti-tumor, anti-aging, nootropic, cardiovascular diseases-protecting, and other pharmacological activities. Thus, the development and utilization of ginsenosides have persistently attracted much attention. At present, the extraction of ginsenosides is mainly based on organic solvents, and there are relatively few studies on their green extraction. In this study, different deep eutectic solvents(DESs) were synthesized by heating and stirring method, combined with an emerging technology, mechanochemically-assisted extraction(MCAE), to extract ginsenosides in a green way. Six parameters that might affect the extraction effect were optimized to determine the optimal conditions, and the method validation was conducted. The new established method was compared with a commonly used extraction method(ultrasound-assisted extraction using 70% ethanol) to evaluate its extraction efficiency. The results revealed that the optimal extraction conditions of DES-MCAE were that the volume ratio of DES3(choline chloride∶urea 1∶2) and water in the extraction solvent was 6∶4, and the liquid ratio and the linear vibration speed were 0.05 g·mL~(-1) and 4.0 m·s~(-1); the extraction was performed twice, 40 s each. With only 80 s extraction, the extraction rate of this method was 36.22% higher than that of ultrasoun-dassisted extraction using 70% ethanol. In this study, a DESs-based pretreatment method for ginsenosides was established and its rapid, green and efficient extraction was realized, which provided new ideas and methods for further research on green extraction of other active ingredients from Chinese medicine.

Identified necessary skills to establish a center of excellence in vocational education for green innovation

Innovation is critical for any organization to maintain sustainability and to grow. In today's world, where environmental concerns are constantly increasing, companies must adopt greener innovation strategies. These greener ways of innovating promote the monitoring and preserving of our now endangered environment. Current literature lacks data concerning the necessary skills to ease the implementation of green innovations in certain regions, one of them the Vaasa region in Finland. The aim of this study is therefore to identify those skills that can be diffused through necessary educational programs and training. Such necessary skills can be disseminated through the establishment of a Center of Vocational Excellence (CoVE) in a country or region, being this a suitable way by which educational programs and training can be offered. The skills needed for green innovation in the Vaasa region in Finland were collected through two extensive workshops, a series of semi-structured interviews, and a set of questionnaire surveys. This study adopted both qualitative and quantitative methods to meet the expected goals. From the study results, it is noticed that establishing a CoVE can be a good source for the regional companies to get a skilled workforce, which is ultimately essential to adopt a green and sustainable innovation mindset in their products and services development processes. The study is concluded with further research directions. • Digital solutions are preferred over sustainable products and services. • Collaboration is perceived as the most relevant skill for green innovation. • New content should be added to existing educational programs. • The most benefit to organizations is expected when they cooperate with the industry. • Organizations are more willing to offer internships than case study examples.

Electrospraying poly(lactic acid) microcapsules loaded with n-hexadecane for thermal energy storage systems

Poly(lactic acid) (PLA) with good thermomechanical stability and biodegradability is selected as the shell for achieving the electro-microencapsulation of phase change materials. And, a series of n-hexadecane/PLA solutions with different compositions are electrosprayed into phase change microcapsules (mPCMs) in a green and high-efficiency way. The effects of PLA concentration and n-hexadecane addition in electrospraying solution on the microencapsulation process of n-hexadecane as well as the structures and properties of mPCMs are investigated. Experimental results indicate that spherical mPCMs with a mono-dispersed size distribution are obtained regardless of the variations in PLA concentrations and n-hexadecane additions. Encapsulated n-hexadecane tends to be randomly in the form of a poly-nuclear distribution. With increasing n-hexadecane addition, although both the mean diameter and the loading content of n-hexadecane in mPCMs increase gradually, the corresponding encapsulation efficiency of n-hexadecane decreases. And, higher loading content and higher encapsulation efficiency of n-hexadecane are obtained from higher PLA concentration solutions. When 5 wt% PLA/chloroform solution is used as matrix liquid to encapsulate n-hexadecane, the encapsulation efficiency of n-hexadecane in the mixture of 50 w/t% n-hexadecane and 50 wt% PLA can reach about 100%. Correspondingly, the phase-transition enthalpy also reaches 97 J/g. Meanwhile, because of the PLA matrix's protection, the phase-transition enthalpy of encapsulated n-hexadecane remains stable even after multiple heating-cooling processes. In addition, the cooperation of the PLA matrix with n-hexadecane chains also improves the mobility of PLA chains, resulting in a higher crystallization degree of the PLA matrix. This green, biodegradable, and durable n-hexadecane/PLA electrosprayed microcapsule can offer a new choice for the fields of thermal management and energy storage.

Enhanced hydrogen generation in a combined hybrid cycle using aluminum and cooper oxide nanomaterial based on biomass and vanadium chloride cycle: Optimization based on deep learning techniques and Environmental appraisal

The usage of Nanofluid to enhance heat transfer has been investigated by many researchers in small-scale heat transfers; however, in large-scale power plants, it has not been taken care of. In this research paper, a newly proposed energy system for hydrogen generation based on renewable sources is proposed and analyzed in detail. Unlike other power input systems, the vanadium chloride system generates hydrogen because it uses waste heat. In this regard, the nanoparticles of Al2O3 and CuO are utilized in the main heat exchanger to enhance the heat transfer to the reactor of VCLC to generate more hydrogen. Also, the compound system has the gasifier-based internally fired gas turbine as the main system and can generate hydrogen in a more green way. The optimization based on deep learning methods is applied to seek the highest point of operation by the system. The results exhibit that Al2O3 causes more heat transfer and efficiency enhancement, thus in hydrogen production, causing an increase of 18.5% compared to base fluid and 8.3% compared to CuO in H2 Generation In circumstances when it is optimal, the values for exergetic efficiency and total hydrogen production are 64.5% and 4.5 kg/s respectively. In addition, using a nanofluid heat exchanger and biomass energy reduces CO2 emissions to 0.91 kg/kWh.

Numerical investigation on preparation of expanded polymer beads using supercritical CO2 in a spouted bed

The bead foaming process in a spouted bed is a green way to manufacture expanded beads. A CFD-DEM model has been established to investigate the hydrodynamics behavior in the spouted bed. The simulation results have showed that the establishment of the particle fountain during saturation can effectively disperse the polymer particles and avoid their aggregation. During depressurization, the flow field in the main part of the spouted bed is relatively uniform. Therefore, particles confined within the spouted bed experience similar depressurization profiles, which is beneficial to the uniformity of the expanded beads. Based on the depressurization profiles provided by the CFD-DEM simulation, a bubble evolution model has been built to investigate the effects of operating parameters on the bead foaming results. The simulation results indicate that expanded beads with a narrower cell size distribution can be prepared at a higher saturation pressure rather than a higher pressure release rate.

Evaluating Pedestrian Environment Using DeepLab Models Based on Street Walkability in Small and Medium-Sized Cities: Case Study in Gaoping, China

In small and medium-sized cities of China, walking plays an important role as a green and healthy way to travel. However, the intensification of motorized travel and poor planning of pedestrian transportation systems have resulted in poor travel experiences for residents. To encourage residents to change their mode of travel from motorized transport to greener modes, it is necessary to consider the characteristics of walking travel, design good walking street environments, and increase the advantages of walking in the downtown areas of small and medium-sized cities. In this study, a spatial environment model of a pedestrian street was constructed based on the walking score. Visual perception elements, street function elements, and walking scale elements were acquired by semantic segmentation of Baidu street view images obtained with the DeepLab model. Points of interest (POI) were obtained based on surveys, measurements, and the space syntax. Considering walking distances for small and medium-sized cities, the attenuation coefficient of a reasonable facility distance was adopted to modify the walking score. Based on the comprehensive score obtained, walking paths were divided into four categories: functionally preferred, visually preferred, scale preferred, and environmentally balanced. This categorization provides theoretical support for the design of pedestrian street space environments. Taking the pedestrian street in the city center of Gaoping in Shanxi Province, China as an example, the feasibility of the method and model was verified.

Selective absorption and efficient biodegradation of petroleum pollutants by oleophilic porous activated sludge loading with microorganism

Efficient elimination of organic pollutants from wastewater is of great importance for sustainable human development. In this work, we report the fabrication of oleophilic porous activated sludge loading with microorganism (OPAS-M), which was prepared through multi-step doping of the microorganism into the as-prepared porous network of activated sludge (AS) followed by a hydrophobic surface modification, so that it has selective adsorption properties to achieve oil-water separation in oily wastewater and high effective degradation organic pollutions. Thanks to its abundantly porous structure and oleophilic wettability, the petroleum pollutants in wastewater (using n-hexadecane as model compound) can be selectively absorbed inside the OPAS-M and then could be biodegraded by the loaded microorganism. Compared with that of free microbial and porous activated sludge loading with microorganism (PSA-M) which has a degradation efficiency of 58.80% and 74.37%, respectively, the OPAS-M possesses a higher removal efficiency of 84.7%. The degradation kinetics of free microorganism, PAS-M and OPAS-M all fit well with the first-order kinetic equation, their degradation half-life is measured to be 7.44 d, 3.56 d, and 2.23 d, respectively. In addition, OPAS-M has good stability and tolerance, and the degradation efficiency can reach more than 50% in a poor environment. The degradation mechanism of n-hexadecane was studied by GC-MS. The results showed that n-hexadecane was selectively adsorbed to the interior of OPAS-M, and it was be degraded by enzymes in microorganism into n-hexadecanol、n-hexadecaldehyde and n-hexadecanoic acid in turn, and finally converted to water and carbon dioxide. The combination of selective absorption and biodegradable OPAS-M may open up a green and efficient way in the biological remediation of organic pollutants.

Sustainable Fly Ash Based Geopolymer Binders: A Review on Compressive Strength and Microstructure Properties

As a result of global warming, the pursuance of low-carbon, sustainable building materials has been prioritized. The development of geopolymer/cement-less binders can be considered an innovative and green way forward to minimize carbon footprint and tackle industrial waste material utilization. However, the chemical composition and properties of industrial waste-derived geopolymer binders varies considerably based on the chemical compositions of the source materials. This review paper presents a comprehensive understanding of the role of different chemical compositions (namely SiO2, Al2O3, CaO, Fe2O, and MgO) available in contemporary industrial wastes and the development of geopolymer binders. Subsequently, the compressive and microstructure properties of various FA-based geopolymer binders have been discussed to exhibit the feasibility of FA as a reliable source material. Significant findings and research gaps have been considered to aid future research works. Indeed, they provide guidelines for the commercial implementation of FA-based geopolymer binders as a low-carbon alternative to Portland cement.

Study on Efficient Adsorption Mechanism of Pb2+ by Magnetic Coconut Biochar.

Lead ion (Pb2+) in wastewater cannot be biodegraded and destroyed. It can easily be enriched in living organisms, which causes serious harm to the environment and human health. Among the existing treatment technologies, adsorption is a green and efficient way to treat heavy metal contamination. Novel KMnO4-treated magnetic biochar (KFBC) was successfully synthesized by the addition of Fe(NO3)3 and KMnO4 treatment during carbonization following Pb2+ adsorption. SEM-EDS, XPS, and ICP-OES were used to evaluate the KFBC and magnetic biochar (FBC) on the surface morphology, surface chemistry characteristics, surface functional groups, and Pb2+ adsorption behavior. The effects of pH on the Pb2+ solution, initial concentration of Pb2+, adsorption time, and influencing ions on the adsorption amount of Pb2+ were examined, and the adsorption mechanisms of FBC and KFBC on Pb2+ were investigated. The results showed that pH had a strong influence on the adsorption of KFBC and the optimum adsorption pH was 5. The saturation adsorption capacity fitted by the model was 170.668 mg/g. The successful loading of manganese oxides and the enhanced oxygen functional groups, as evidenced by XPS and FTIR data, improved KFBC for heavy metal adsorption. Mineral precipitation, functional group complexation, and π-electron interactions were the primary adsorption processes.

Enhanced lignin degradation of paddy straw and pine needle biomass by combinatorial approach of chemical treatment and fungal enzymes for pulp making

Paddy straw (PS) and pine needles (PN) are one of the challenging biomasses in terms of disposal and compost making due to their high silica and tannin contents. Particulate air pollution, loss of biodiversity and respiratory impairments are some of disastrous outcomes caused by burning. However, high percentage of cellulose and hemicellulose makes them potential substrate for paper and pulp industries. The main aim of work was to study and utilize a combinatorial approach of weak chemical treatment and lignin degrading fungal species as agents of effective production of lignin modifying enzymes (LME’s) for lignin depolymerisation from the biomasses. Phanerochaete chrysosporium was found to be the best degrader of lignin (47.11 % in PS + PN in 28 days) with maximum LME’s production between 10th–17th days. Efficient lignin degradation in the PS and PN biomass will aid further application in pulp production supporting the transition to a circular economy in a greener way.

Green synthesis of nanostructures from rice straw food waste to improve the antimicrobial efficiency: New insight

Applications for nanotechnology, which is constantly gaining prominence, have been found in a variety of industrial applications. Due to the multiple benefits associated with it, including an eco-friendly, pollution-free, cost-effective, and non-toxic synthesis method, the green way to synthesize nanostructures utilizing waste biomasses has become one of the key focuses of the current researches globally. Additionally, lignocellulasic biomass (LCB), which is a waste of the food crops, can be used as one of the potential substrates for the synthesis of a variety of nanostructures. Among different types of LCB, rice straw is a potential food waste biomass and can be efficiently employed during the synthesis of different types of nanostructures for a range of technological applications. Here, diverse phenolic compounds found in rice straw as well as reducing sugars can be used as natural reducing and capping agents to prepare a range of nanostructures. Based on the aforementioned facts, the objective of this review is to investigate the viability of using rice straw to produce nanostructured materials using rice straw as a renewable biosource following an environmentally friendly method. Additionally, it is noted that various organic compounds present on the surface of nanostructures produced using rice straw extract/hydrolyzate through a green approach may be more successful in terms of antibacterial efficacy, which might be of considerable interest for a variety of biomedical applications. Based on the possibility of enhancing the antimicrobial activity of developed nanostructures, the review also provides overview on the feasibility, characteristics, and availability of using rice straw extract in the synthesis of nanostructures. Additionally, the constraints of the present and potential futures of the green synthesis methods using rice straw wastes have been explored.

Environmental Benefit of Eco-Industrial Development: Effective Approach of Europe to Climate Change and Mitigation

Recent rapid progress in industrialization and urbanization has made scientists to explore a green development so that environmental bodies should not be contaminated and living things should not face health threat. Even though industries not related to environmental concern should also develop a green way in their production. Eco-Industrial Parks are evaluated in several comparative studies, generally in advanced countries. An important message is that EIPs concurrently need advances in business relations, among several such as corporations, and resource flows. The profits for all are comprised enterprises, who take steps for reduction in the net waste production and/or resource consumption. The implementation of advanced technologies is required towards resource conservation. Another important matter is the manufacturing of new products and the urbanized zoned should be provided the environmental services. Concerning these all things, this paper deals with benefits of eco-industrial parks and sustainable development in the future. This paper also deals with how eco-industrial parks are beneficial for Europe and developing countries. Findings from previously published literature demonstrated that eco-industrial parks play significant role for eco-environment friendly sustainable development.

The effect of mild CO2 treatment on thermal properties of poly(l-lactic acid): An experimental study

The influence of mild CO2 treatment on thermal properties of poly(l-lactic acid) (PLLA) is discussed in this article. A slowly crystallizing PLLA with 4% d-isomer was treated with CO2 at room temperature and moderate pressures (up to 6.0 MPa) for short times, not longer than 20 min. These mild treatments are sufficient to develop ε-form (PLLA/CO2 complex), which evolves to α"-mesophase after desorption of CO2. The amount of mesophase depends on the pressure of CO2 and the sorption times, and significantly affects the thermal properties of PLLA. Although the mesophase melts immediately above the glass transition, it affects subsequent cold crystallization. The influence of CO2 sorption time and pressure on the cold crystallization kinetics of PLLA is quantified here, and it is found that only a few minutes of treatment with low-pressure CO2 is sufficient to enhance the crystallization rate. After longer exposure to CO2, α-crystals also develop, especially under high CO2 pressure, hence proper adjustment of these parameters can allow tuning the structure and thermal properties of PLLA. The results demonstrate the possibility of producing CO2-induced mesophase at room temperature using very short sorption times, thus introducing a fast, green and cost-effective way to tailor the crystallization kinetics of PLLA.

Green Advertising on Social Media: A Systematic Literature Review

Consumer interest in environmental protection has grown in recent decades, alongside a shift in companies’ strategies to embrace a greener way of doing business. Green advertising is rapidly expanding and gaining popularity. With more and more consumers being actively involved in social media searching and purchasing products, social media advertising is transformed into a principal way of communication. Although prior research has addressed green marketing and advertising, their presence in social media has been largely neglected. Based on a systematic review approach, the present study addresses recent trends and developments in green advertising on social media. We used PRISMA for the systematic review of eighty-one articles published between 2011 and 2022. Green advertising content, and greenwashing in particular have attracted significant research interest. Green skepticism and the role of generations are gaining popularity. The descriptive analysis provides article, author, and journal-related information (i.e., citations, year of publications, journals, etc.). This systematic literature review reports the trends in the topic, highlights existing research gaps, and suggests future research avenues. Research and managerial implications are discussed.

Transglutaminase crosslinked sodium caseinate/starch/tri calcium phosphate based flexible sponge grafts

• Green way of crosslinking of natural polymers. • A new method to crosslink water soluble proteins. • Formable, flexible bone scaffolds. In this study, sodium caseinate/starch/ tri-calcium phosphate (TCP) base scaffolds were fabricated and cross-linked with microbial transglutaminase. A Maillard reaction was carried out to stabilize the blend of sodium caseinate (8% w/w) and starch (8% w/w) solutions. The dynamics of enzymatic cross-linking activity were assessed with different TCP concentrations. Freeze-dry method was used to extract water from the gel system to acquire a porous, spongy structure. Apart from many other enzymes, microbial transglutaminase has the capability to be active even below freezing temperatures. Keeping at −50 °C for 12 h, enzymes were still active to complete the post-crosslinking process. 0.5% TCP case resulted in 690 kPa ultimate tensile strength at dried state. Cell activity and characterization tests were elucidated and observed that those scaffolds can have very promising applications in bone tissue engineering.

Has China’s pilot emission trading system promoted technological progress in industrial subsectors?

Under the ‘dual carbon’ goal, the key to environmental-friendly economic development is to increase total factor productivity (TFP) in a greener way. However, as a key market-based emission reduction mechanism, the exploration related to whether the emission trading system (ETS) promotes green TFP (GTFP) is not deep enough, especially for secondary decomposition of this technical index and for specific industrial subsectors. In this study, combining biennial Malmquist-Luenberger productivity index with multi-period difference in differences model, we assess the technological progress of China’s pilot ETS dynamically. The results show that the pilot ETS promoted GTFP significantly in the industrial subsectors, by 8.5%. The technology change index increased by 17.5%, which is the key action path to increasing GTFP. Furtherly, the mechanism test confirms that the policy works mainly through innovation channel. This study implied that the governance toward carbon-zero economies could be accelerated much more effectively by technological innovation of green.

Energy, exergy and ecology performance prediction of a novel SOFC-AMTEC-TEG power system

• A novel triple-cycle power system is proposed. • Energy, exergy and ecology performance are analyzed. • Effectiveness and generic performance characteristics are demonstrated. • There is an optimum thermoelectric element number to optimize performance. In order to realize the cascade utilization of the waste heat for the solid oxide fuel cell, a novel triple-cycle system including a solid oxide fuel cell, an alkali metal thermal electric converter and a thermoelectric generator is proposed. In this system, the alkali metal thermal electric converter powered by the waste heat of the solid oxide fuel cell can drive the thermoelectric generator. The proposed system can efficiently generate electricity in a green and noiseless way, and Thomson effect is considered in the thermoelectric generator model. The results show that improving the number of the thermoelectric generator stages is not conducive to the improvement of the system performance. The maximum power density and ecology function density can result in 42.0% and 53.5% improvement over those of the sole solid oxide fuel cell system, respectively. Further sensitivity analysis confirms that there is an optimum element number of the thermoelectric generator to optimize the performance of the triple-cycle system. This work proves the feasibility of the triple-cycle system, and hints the broad prospect of high-grade heat recovery through an alkali metal thermal electric converter-thermoelectric generator unit.

Green Synthesis and Characterization of Silver Nanoparticles Synthesized Using Leaf Extract of Passiflora Foetida Linn

The silver nanoparticles (SNPs) are applied in nanomedicine, health, food safety and other applications. The topical methods are based on chemicals that are toxic in nature, thus to minimize the hazardous effects the natural sources need to be explored forsynthesizing SNPs. The contemporary work reports the greener way of silver nanoparticles (SNPs) fabrication using phytochemical, functional groups and secondary metabolites from Passifloraaqueous leaf extract. The optimized condition for SNPs synthesis was 1 mM AgNO3 95ml + leaf extract 5 ml at alkaline pH 11 yields stable NPs. Various parameters such as temperature, pH, sunlight, dark, different concentration of AgNO3were evaluated. The UV-spectroscopic analysis confirms SNPs synthesis at 420 nm for sunlight based, 428 nm at room temperature and 425 nm for microwave-based conditions. The FTIR determines alkanes, alkyne, amines, aliphatic amine, carboxylic acid; nitro-compound from the leaf extract have been used for reducing silver nitrate for SNPs synthesis. The SEM and TEM analysis confirms the 14.96 nm size SNPs under sun light condition shows antimicrobial activity against E. coliand S. aureouspathogens at 50 ug/ml concentration, which may have applicability to raised SNPs based green sustainable products in treating pathogens.

Oxygen mediated oxidative couplings of flavones in alkaline water

Catalyzed oxidative C-C bond coupling reactions play an important role in the chemical synthesis of complex natural products of medicinal importance. However, the poor functional group tolerance renders them unfit for the synthesis of naturally occurring polyphenolic flavones. We find that molecular oxygen in alkaline water acts as a hydrogen atom acceptor and oxidant in catalyst-free (without added catalyst) oxidative coupling of luteolin and other flavones. By this facile method, we achieve the synthesis of a small collection of flavone dimers and trimers including naturally occurring dicranolomin, philonotisflavone, dehydrohegoflavone, distichumtriluteolin, and cyclodistichumtriluteolin. Mechanistic studies using both experimental and computational chemistry uncover the underlying reasons for optimal pH, oxygen availability, and counter-cations that define the success of the reaction. We expect our reaction opens up a green and sustainable way to synthesize flavonoid dimers and oligomers using the readily available monomeric flavonoids isolated from biomass and exploiting their use for health care products and treatment of diseases.

Rational design of silver NPs-incorporated quaternized chitin nanomicelle with combinational antibacterial capability for infected wound healing

Bacterial and biofilm infections are prevalent, photothermal antibacterial therapy exploiting Ag NPs was an alternative. However, various matrix materials including polysaccharides used to stabilize Ag NPs are not efficiently utilized. In this study, catechol functionalized quaternized chitin (DQC) is first synthesized, then Ag+ is in situ reduced to small Ag NPs stabilized and well-dispersed by DQC to form Ag NPs-incorporated quaternized chitin (DQCA) nanomicelle in a green and simple way. The photothermal conversion efficiency of the DQCA was up to be 65 %, which was much higher than that of many reported systems. The rationally designed DQCA takes full advantage of each component, specifically, DQCA is endowed with bacterial targeting, sterilization effects of cationic groups and Ag NPs, and superior photothermal combinational bactericidal and antibiofilm activities. The in vitro antibacterial rate of DQCA with NIR laser irradiation was >95 % in 10 min (99.5 % for E. coli and 95.7 % for S. aureus, respectively), and the eradication efficiency against both of the E. coli and S. aureus biofilms reached up to 99.9 %. Moreover, full-thickness S. aureus biofilms-infected wound healing test in the mouse model demonstrates that the combinational effect of DQCA nanomicelle could significantly accelerate the wound healing, by simultaneously reducing inflammation, enhancing re-epithelialization and promoting collagen deposition. And the wound treated with DQCA plus NIR irradiation at day 15 possessed the smallest open wound (2.5 %). Collectively, these features indicate facilely fabricated DQCA nanomicelle gets the most use of each component, and could serve as an excellent alternative for bacterial infection therapy.