Hot-melt pressure-sensitive adhesive (HMPSA) is an environmentally benign adhesive which is typically processed without solvent in industries. However, casting solution method is commonly used for experimental purposes in the lab for convenience. Therefore, seven types of solvent with different polarities, including toluene as the most commonly used solvent, were investigated in this work to study the feasibilities. Quick bond strength and holding power were tested with different types of solvents and different adhesive weight percent in the prepared solutions. Through viscosity measurement, thermal analysis, and compositional analysis, the correlation between the chosen solvents and adhesive performance was further explored. It was found that the differences in the obtained bond strength of HMPSA treated with a variety of solvents were due to physical reasons instead of chemical reactions, and a solvent with similar polarity to toluene (e.g., tetrachloride, octane) should be considere... [more]

Polycyclic aromatic hydrocarbons (PAHs) are reportedly toxic, ubiquitous and organic compounds that can persist in the environment and are released largely due to the incomplete combustion of fossil fuel. There is a range of microorganisms that are capable of degrading low molecular weight PAHs, such as naphthalene; however, fewer were reported to degrade higher molecular weight PAHs. Bacillus spp. has shown to be effective in neutralizing polluted streams containing hydrocarbons. Following the growing regulatory requirement to meet the PAH specification upon disposal of contaminated soil, the following study aimed to identify potential Bacillus strains that could effectively remediate low and high molecular weight PAHs from the soil. Six potential hydrocarbon-degrading strains were formulated into two prototypes and tested for the ability to remove PAHs from industry-contaminated soil. Following the dosing of each respective soil system with prototypes 1 and 2, the samples were analyz... [more]

The pollutants emission during the process of municipal solid waste management (MSWM) is of great concern due to its hazardous effect on the environment and living organisms. An assessment of the air quality of MSWM sites was made after having 16 repetitive visits at solid waste disposal sites and transfer stations of Lahore during wet and dry seasons. Pollution parameters such as fine particulate matter (PM2.5) and greenhouse gases (GHG) were measured along with meteorological parameters. PM2.5 measurement was made by using particle counter Dylos and TSI’s Dust Trak. Both of these instruments were positioned simultaneously at the source site and downwind (50 m). CH4 and meteorological parameters were measured by Aeroqual 500 series, while the Extech CO220 monitor was used to measure CO2 concentration. An assessment of air quality showed the levels of their mean values as CH4 and CO2 ranged between 1.5−13.7 ppm and 443.4−515.7 ppm, respectively. The PM2.5 ranged between 127.1 and 307.1... [more]

The paper discusses issues related to the sectors of biofuels for transport. Development directions of those sectors and factors limiting the growth rate thereof are analysed. At present, researchers’ attention is increasingly focused on development of the alternative fuels sector. Moreover, issues related to waste used in the sector of alternative fuels are now among the leading undertakings of environmental engineering. The authors have analysed the potential of biofuels sectors in Poland taking into account the EU’s legislative requirements. The paper contains a discussion of the sector of esters, liquid biofuels, sector of lignocellulose, sector of liquid bio-hydrocarbons and, additionally, pays attention to the sector of electromobility as one of the most attractive and prospective sectors in terms of emission reduction.

This work presents an advanced reactor selection strategy that combines elements of a knowledge-based expert system to reduce the number of feasible reactor configurations with elaborated and automatised process simulations to identify reactor performance parameters. Special focus was given to identify optimal catalyst loadings and favourable conditions for each configuration to enable a fair comparison. The workflow was exemplarily illustrated for the Ru/C-catalysed hydrogenation of arabinose and galactose to the corresponding sugar alcohols. The simulations were performed by using pseudo-2D reactor models implemented in Aspen Custom Modeler® and automatised by using the MS-Excel interface and VBA. The minichannel packings, namely wall-coated minichannel reactor (MCWR), minichannel reactor packed with catalytic particles (MCPR), and minichannel reactor packed with a catalytic open-celled foam (MCFR), outperform the conventional and miniaturised trickle-bed reactors (TBR and MTBR) in t... [more]

With the growing interests in non-aqueous media for diversified applications, ionic liquids (ILs) are frequently considered as green solvents. While the environmental, health, and safety assessments of the commercially developed ILs and their ‘greenness’ status are in debate, research focus is shifting towards the application of halide-free ILs for diversified applications. To clarify the situation on their greenness, and to understand if they really possess safe characteristics, we performed an initial assessment of 193 halide free ionic liquids composed of four groups of cations (imidazolium, pyridinium, pyrrodilinium, piperidinum) and 5 groups of anions (acetate, propionate, butyrate, alkanesulfonates, alkylsulfates). The ‘Technique for Order of Preference by Similarity to Ideal Solutions’ (TOPSIS), a multi-criteria decision analysis (MCDA) tool that allows ranking many alternatives is applied by carrying out the assessment against 14 criteria that includes hazard statements, precau... [more]

The link between different plastic waste pollutants and their impact on the natural aquatic environment and food chain remains a constant and growing issue. Bisphenol A (BPA), a known endocrine disruptor produced in large quantities primarily in the industry of polycarbonate plastics, can accumulate in vegetal and animal tissue, thus magnifying through trophic levels. In this study we exposed viable specimens of the aquatic plant Lemna minor under controlled conditions to 50, 100 and 200 ppm BPA levels in order to partially observe the toxic effects of BPA. Colonies ceased to form during the exposure and chlorosis was present especially in the 100 ppm group. Interestingly enough, a high density formation of non-fermenting bacteria as well as coliforms was also observed in the BPA exposed cultures but not in the control groups. The levels of Malondialdehyde (MDA) in the vegetal tissue indicated cellular insults and severe damage, results that were correlated with the HPLC BPA determined... [more]

Phosphorus, as one of the main pollutants in municipal sewage, has received increasing attention recently. Phosphorus recovery also increases the sustainable development of municipal wastewater. Since algae have the ability to effectively redirect nutrients, including phosphorus, from municipal sewage to algae biomass, municipal sewage treatments involving microalgae have piqued the interest of many researchers. The phosphorus removal depends on the potential of the microalgae to absorb, preserve, or degrade phosphorus in municipal wastewater. It is, therefore, of great interest to study the mechanisms underlying the absorption, storage, and degradation of phosphorus by microalgae to ensure the viability of this phosphorus removal process in wastewater. The objectives of this review were to summarize phosphorus metabolism in microalgae, examine key external and internal factors impacting phosphorous removal by microalgae from wastewater, and examine the status of phosphorous-metabolism... [more]

Electrochemical advanced oxidation processes (EAOP®) are promising technologies for the decentralized treatment of water and will be important elements in achieving a circular economy. To overcome the drawback of the high operational expenses of EAOP® systems, two novel reactors based on a next-generation boron-doped diamond (BDD) anode and a stainless steel cathode or a hydrogen-peroxide-generating gas diffusion electrode (GDE) are presented. This reactor design ensures the long-term stability of BDD anodes. The application potential of the novel reactors is evaluated with artificial wastewater containing phenol (COD of 2000 mg L−1); the reactors are compared to each other and to ozone and peroxone systems. The investigations show that the BDD anode can be optimized for a service life of up to 18 years, reducing the costs for EAOP® significantly. The process comparison shows a degradation efficiency for the BDD−GDE system of up to 135% in comparison to the BDD−stainless steel electrod... [more]

Applications of dual-evaporator refrigeration systems have recently gained much attention both in academia and industry due to their multiple benefits. In this study, a comprehensive thermodynamic and economic analysis is conducted to evaluate the potential of using several environmentally friendly refrigerant couples and identifies the most suitable one yielding the best economic results. To achieve this goal, a detailed parametric study is conducted, and an optimization process is performed using a particle swarm optimization (PSO) approach to minimize the unit production cost of cooling (UPCC) of the cascade refrigeration system. The results showed that among all selected 18 refrigerant pairs and for all ranges of examined operating parameters, the R170-R161 pair and R1150-R1234yf pair are identified as the best and worst pairs, respectively, from both thermodynamic and economic viewpoints. The results also confirm that R170-R161 pair has an improvement over R717-R744, used as a typ... [more]

Sulfate-reducing bacteria (SRB) are a heterogeneous group of anaerobic microorganisms that play an important role in producing hydrogen sulfide not only in the natural environment, but also in the gastrointestinal tract and oral cavity of animals and humans. The present review was written with the inclusion of 110 references including the time period from 1951 to 2021. The following databases were evaluated: Web of Science, Scopus and Google Scholar. The articles chosen to be included in the review were written mainly in the English and Czech languages. The molecular mechanisms of microbial cryoprotection differ depending on the environment where microorganisms were initially isolated. It was observed that the viability of microorganisms after cryopreservation is dependent on a number of factors, primarily colony age, amount of inoculum, cell size or rate of cooling, and their molecular inventory. Therefore, this paper is devoted to assessing the performance and suitability of various... [more]

Biofuels have many environmental and practical benefits as a transportation fuel. They are among the best alternatives to fossil fuels- thanks to their capacity for negative carbon emissions, which is vital for archiving the global ambition of a net-zero economy. However, conventional biofuel production takes place on inland sites and relies on freshwater and edible crops (or land suitable for edible crop production), which has led to the food versus fuel debate. It also suffers technical and economical barriers owing to the energy balance and the cost of production compared with fossil fuels. Establishing a coastal integrated marine biorefinery (CIMB) system for the simultaneous production of biofuels, high-value chemicals, and other co-products could be the ultimate solution. The proposed system is based on coastal sites and relies entirely on marine resources including seawater, marine biomass (seaweed), and marine microorganisms (marine yeasts and marine microalgae). The system doe... [more]

Over recent years, the food industry has striven to reduce waste, mostly because of rising awareness of the detrimental environmental impacts of food waste. While the edible oils market (mostly represented by soybean oil) is forecasted to reach 632 million tons by 2022, there is increasing interest to produce non-soybean, plant-based oils including, but not limited to, coconut, flaxseed and hemp seed. Expeller pressing and organic solvent extractions are common methods for oil extraction in the food industry. However, these two methods come with some concerns, such as lower yields for expeller pressing and environmental concerns for organic solvents. Meanwhile, supercritical CO2 and enzyme-assisted extractions are recognized as green alternatives, but their practicality and economic feasibility are questioned. Finding the right balance between oil extraction and phytochemical yields and environmental and economic impacts is challenging. This review explores the advantages and disadvant... [more]

The aim of the work was to purify model textile wastewater (MTW) using a two-stage membrane filtration process comprising nanofiltration (NF) and reverse osmosis (RO). For this purpose, a nanofiltration membrane TFC-SR3 (KOCH) and reverse osmosis membrane AG (GE Osmonics) were used. Each model wastewater contained a selected surfactant. The greatest decrease in flux in the initial phase of the process occurred for the detergents based on fatty-acid condensation products. An evident decrease in performance was observed with polysiloxane-based surfactants. No fouling effect and high flux values were observed for the wastewater containing a nonionic surfactant based on fatty alcohol ethoxylates. During RO, a significantly higher flux and lower resistance were observed for the feed that originally contained the anionic agent. For the MTW containing the nonionic surfactant, the conductivity reduction ranged from 84% to 92% depending on the concentrate ratio at the consecutive stages of RO.... [more]

The chitosan−EDTA modified magnetic biochar (E−CMBC) was successfully used as a novel adsorbent to remove heavy metals. The adsorption behaviour and mechanisms of E−CMBC to Cd2+, Cu2+ and Ni2+ were performed in single and binary system in aqueous solutions. In single−metal system, the adsorption process of Cd2+, Cu2+ and Ni2+ on E−CMBC fitted well with the Avrami fractional−order kinetics model and the Langmuir isotherm model. The measured maximum adsorption capacities were 61.08 mg g−1, 48.36 mg g−1 and 41.17 mg g−1 for Cd2+, Cu2+ and Ni2+, respectively. In binary−metal system, coexisting ions have obvious competitive adsorption behaviour on E−CMBC when the concentration of heavy meal beyond 20 mg L−1. The maximum adsorption capacities of the heavy metals were found to be lower than that in single−metal system. The order of the competitive adsorption ability was Cu2+ > Ni2+ > Cd2+. Interestingly, in Cd2+−Cu2+ system the earlier adsorbed Cd2+ could be completely replaced by Cu2+ from t... [more]

The adsorption of sodium dihydrogen phosphate (NaH2PO4) onto X- and Y-type faujasite zeolites was computationally studied using the Density Functional Theory (DFT) method. The structures were modeled using the Materials Studio software. The Si/Al ratios for the X- and Y-type zeolite models were 1.2 and 2.5, respectively. The central pore of the zeolite provided a more favorable coordination for adsorbing NaH2PO4. Full molecular optimization and adsorption energy calculations were performed using the VASP code. The adsorption was more effective on zeolite Y, with an adsorption energy of 161 kJ/mol, compared to the zeolite X system, with an adsorption energy of 31.64 kJ/mol. This calculated value for X-type faujasite was found in the interval of the adsorption energy of H2PO4− on hydrated Fe oxide (94.4 kJ/mol) and modified polyether sulfone (22.5 kJ/mol), and the calculated adsorption energy of the molecule on Y-type faujasite coincides with the reported value for this adsorbate on Mg/C... [more]

Hydrogen is mainly produced by steam reforming of natural gas, a nonrenewable resource. Alternative and renewable routes for hydrogen production play an important role in reducing dependence on oil and minimizing the emission of greenhouse gases. In this work, butanol, a model compound of bio-oil, was employed for hydrogen production by steam reforming. The reaction was evaluated for 30 h in a tubular quartz reactor at 500 °C, atmospheric pressure, GHSV of 500,000 h−1, and an aqueous solution feed of 10% v/v butanol. For this reaction, catalysts with 20 wt.% NiO were prepared by wet impregnation using three supports: γ-alumina and alumina modified with 10 wt.% of cerium and lanthanum oxides. Both promoters increased the reduction degree of the catalysts and decreased catalyst acidity, which is closely related to coke formation and deactivation. Ni/La2O3−Al2O3 presented a higher nickel dispersion (14.6%) which, combined with other properties, led to a higher stability, higher mean hydro... [more]

In this paper, various metal ions were utilized for the demulsification of spent metalworking fluids discharged from an automobile parts workshop. Five types of metal ions, i.e., Fe3+, Al3+, Fe2+, Ca2+ and Mg2+, combined with coagulant were systematically evaluated, and the synergistic effect as well as the optimum operating conditions were studied. The results indicated that the Ca2+ as well Mg2+ possessed hardly efficiency for the demulsification, on the contrary, Fe2+ reduced the yield of the by-product sludge and lowered the SV30 ratio, and Al3+ boosted the CODCr removal. Furthermore, Fe3+ and Al3+ had a significant synergistic effect to achieve a better transmittance and a higher CODCr/SV30 ratio which revealed that more CODCr was removed, as well as less by-product sludge was generated. For a better demulsification of spent metalworking fluids, the optimum operating conditions were gathered as follows: the dosage of metal ions was 0.08 mol/L with Al3+:Fe3+ ratio was 1.5:1, the re... [more]

The aim of this research was to determine whether water hyacinth can be used to remove heavy metals, such as cadmium, arsenic, lead, zinc, and copper, from industrial wastewater. Investigations of the pollution removal or prevention potential of aquatic macrophytes, such as heavy metal bio-indicators in aquatic habitats, can prove to be advanced field studies. Water hyacinth is one of the aquatic plant species that has been effectively utilized for the treatment of wastewater. It is extremely effective in removing stains, suspended solids, BOD, organic matter, and heavy metals. This research focused on the use of water hyacinth to treat wastewater from heavy metals. Water hyacinths can grow in sewage, absorbing and digesting contaminants and transforming sewage effluents into comparatively clean water in the process. As a result, the plants have the potential to be used as natural water purification systems at a fraction of the cost of a standard sewage treatment facility. The experime... [more]

The hydrocarbon compositions of shale oils, generated from two different lithological−facial Domanic deposits of the Tatarstan Republic (Russia), were studied under hydrothermal impact with 30% of water addition in a 350 °С and CO2 environment. The samples were extracted from carbonate−siliceous rocks of the Semiluky−Mendym deposits of the Berezovskaya area, and carbonate deposits of the Dankovo−Lebedyan horizon of the Zelenogorskaya area of the Romashkino oil field. The distinctive features of rocks are in the composition and content of organic matter (OM), its thermal stability, as well as the structural-group composition of the shale oil products. The hydrothermal treatment of the rock samples increased the content of saturates and decreased the content of aromatics, resins and asphaltenes in the composition of crude oil. The decomposition of the polymer-like kerogen structure and destruction processes of high-molecular compounds, such as resins and asphaltenes, are accompanied with... [more]

Industrial green technology progress is an effective way to realize high-quality economic development in China. The different competitive incentives of local governments make a difference in the intensity of environmental regulation between regions. The intensity of environmental regulation is different in different areas of the same industry, leading to the inter-regional transfer of pollution enterprises. The regional distribution of industries is different, which determines the different industries’ needs to coordinate different regions. Only when various industries realize the coordination of regional governance can they jointly promote the progress of industrial green technology. Based on data from 33 industrial sectors in China from 2001 to 2015 and considering the institutional evolution of governance synergy, this study comprehensively investigated the influence mechanism of local government environmental regulation on the industrial green technology progress using the mediatin... [more]

Drug delivery systems (DDS) are artificial devices employed to enhance drug bioavailability during administration to a human body. Among DDS, liposomes are spherical vesicles made of an aqueous core surrounded by phospholipids. Conventional production methods are characterized by several drawbacks; therefore, Supercritical assisted Liposome formation (SuperLip) has been developed to overcome these problems. Considering that the use of high pressures involves high energy cost, in this paper, sustainability indicators were calculated to quantitatively evaluate the emissions related to the attainment of liposomes containing daunorubicin (a model antibiotic drug) using the SuperLip process. The indicators were depicted using a spider diagram to raise the actual weaknesses of this technique; some variations were proposed in the process layout to solve the critical issues. According to the literature, many studies related to the pharmaceutical industry are expressed in terms of solid, liquid... [more]

In the past few decades, the role of nanotechnology has expanded into environmental remediation applications. In this regard, nanofibers have been reported for various applications in water treatment and air filtration. Nanofibers are fibers of polymeric origin with diameters in the nanometer to submicron range. Electrospinning has been the most widely used method to synthesize nanofibers with tunable properties such as high specific surface area, uniform pore size, and controlled hydrophobicity. These properties of nanofibers make them highly sought after as adsorbents, photocatalysts, electrode materials, and membranes. In this review article, a basic description of the electrospinning process is presented. Subsequently, the role of different operating parameters in the electrospinning process and precursor polymeric solution is reviewed with respect to their influence on nanofiber properties. Three key areas of nanofiber application for water treatment (desalination, heavy-metal rem... [more]

Urban roadside dust samples from Dhaka City in Bangladesh were collected from a planned residential area (PRA), spontaneous residential area (SRA), commercial area (CA), and urban green area (UGA) in winter and summer to study how season and different urban land-use categories influence the concentrations of heavy metals (Cr, Mn, Co, Ni, Cu, Zn, As, and Pb) and different pollution indices. The dust samples were fractionated into <32 μm particles, extracted by acid digestion followed by estimation of heavy metals, using ICP-MS. Pollution indices were calculated from the metal concentrations, using standard protocols. The concentrations of heavy metals in roadside dust varied significantly (all p < 0.05), due to sampling seasons and the land-use category. Higher concentrations of heavy metals (Cr, Mn, Ni, Cu, Zn, and Pb) were found in the dust sampled during the winter season than in the summer season, except for As and Co. The geo-accumulation index (Igeo) indicated that the comme... [more]

This study presents a combined process modeling—Life Cycle Assessment (LCA) approach for the evaluation of green Cr2O3 ceramic pigments production. Pigment production is associated with high calcination temperatures, achieved through the combustion of fossil fuels. Therefore, it is necessary to evaluate its environmental impact with regards to energy requirements and CO2 emissions. Initially, a process model is developed to simulate the final calcination stage of the traditional pigments production process. It is validated against titanium dioxide (TiO2) white production industrial data and adjusted for Cr2O3 production. Three alternative processes are examined: two for pigment grade (PIGM1, PIGM2) and one for metallurgical (MET) Cr2O3. Heat demand and CO2 emissions computed by the developed process models are used as input in the LCA along with upstream data from the literature using a cradle-to-gate approach. The implementation of the LCA has resulted in calculated Global Warming Pot... [more]