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Woody and agricultural wastes are important fuels in many countries, and have the potential of being even more important in the future. The main problems of plant biomass combustion are low ash melting temperatures and increased emissions. The most widely used treatment to solve the problem of low ash melting point is blending a fuel with an additive. In this work, pellets were produced from wheat straw containing wood sawdust and paper sludge in the following proportions 40:40:20 and 45:45:10 (straw/sawdust/paper sludge). The purpose of this work was to study the influence of sludge and dendromass on the straw pellet parameters and combustion process. The highest calorific value of 15.71 MJ kg&minus, 1 was registered for a sample with a 10% paper sludge concentration. The effectiveness of paper sludge was proved, and the ash melting temperature was increased from 1025 to 1328 &deg, C for the same sample.

This paper deals with the valorization of waste paper fly ash (WPFA) as a binder for soil stabilization. The mineralogical characterization shows the presence of free lime, as well as some non-reactive and cementitious phases. The hydration of lime is an expansive reaction and can be problematic in soil stabilization. Therefore, to study its effect on stabilized soil, an in-house experimental set-up is proposed to measure the possible expansion. Furthermore, to study the effect of water reduction and delay time on strength, unconfined compressive strength with different mixes is conducted. The obtained results showed that using WPFA causes expansion in stabilized soil, but a delay time of 30 min, after mixing the material with water and then compacting it, can decrease the expansion. Additionally, decreasing the water content by a point of Proctor can be essential for improving the strength in soil samples, even reaching the same strength values as control samples cured at 7 days. Finally, all the results obtained in this study have shown that WPFA is a suitable material for use as a binder for soil stabilization while reducing its optimum water content, adding a proper delay time, and taking into consideration WPFA&rsquo, s expansive behavior at the moment of its use.

Paper and pulp industries produce effluents with high phosphorus concentrations, which need to be treated before their discharge in watercourses. The use of microalgae for this purpose has attracted the attention of researchers because: (i) microalgae can assimilate phosphorus (one of the main nutrients for their growth), and (ii) growing on effluents can significantly reduce the costs and environmental impact of microalgal biomass production. This study evaluated the growth and ability of Chlorella vulgaris to remove the phosphorus from a secondary-treated effluent of a Portuguese paper company. Batch experiments were performed for 11 days using different dilutions of the effluent to evaluate its inhibitory effect on microalgae. Results showed that the non-diluted effluent inhibited microalgal growth, indicating that this bioremediation process is possible after a previous dilution of the effluent. Regarding phosphorus removal, promising results were achieved, especially in the experiments conducted with the most diluted effluent: removal efficiencies obtained in these conditions were (54 &plusmn, 1)%. Another interesting finding of this study was microalgal growth in flakes&rsquo, form (mainly due to the compounds present in the effluent and to the pH values achieved), which can be an important economic advantage for biomass recovery after the remediation step.

A hybrid montmorillonite (Mt)-rich/chitosan composite (MCC) with high adsorption performance was synthesized for the decolorization of water used in the joss paper process. The performance was reported in terms of the dye removal. The composite expressed higher performance than chitosan or Mt-rich clay, respectively. The optimum condition for complete dye removal was achieved when using at least 0.6 g of the composite over a wide pH range (3&ndash, 10) and initial dye concentration (10&ndash, 100 mg L&minus, 1). The composite showed good reusability without the requirement of regeneration, adsorbing the dye completely for up to eight successive cycles of adsorption (&gt, 1.33 gdye gMCC&minus, 1). Thermodynamic analyses revealed the degree of spontaneity and the endothermic adsorption process. From the isotherm studies, the Koble&ndash, Corrigan isotherm model fitted very well to the experimental data, revealing that the composite had a heterogeneous surface with various active sites to adsorb the dye molecules. This also evidenced the synergistic electrostatic attraction and hydrophobic interaction between the dye and the composite. The pseudo-second-order model best explained the kinetic rate of adsorption. From evaluation of the adsorption process using the Webber and Morris equation and Boyd model, the rate-limiting step consisted of film diffusion and intra-particle diffusion.

Cyber Physical Systems (CPSs) are systems that are developed by seamlessly integrating computational algorithms and physical components, and they are a result of the technological advancement in the embedded systems and distributed systems domains, as well as the availability of sophisticated networking technology. Many industrial CPSs are subject to timing predictability, security and functional safety requirements, due to which the developers of these systems are required to verify these requirements during the their development. This position paper starts by exploring the state of the art with respect to developing timing predictable and secure embedded systems. Thereafter, the paper extends the discussion to time-critical and secure CPSs and highlights the key issues that are faced when verifying the timing predictability requirements during the development of these systems. In this context, the paper takes the position to advocate paramount importance of security as a prerequisite for timing predictability, as well as both security and timing predictability as prerequisites for functional safety. Moreover, the paper identifies the gaps in the existing frameworks and techniques for the development of time- and safety-critical CPSs and describes our viewpoint on ensuring timing predictability and security in these systems. Finally, the paper emphasises the opportunities that artificial intelligence can provide in the development of these systems.

The surface charge and space charge accumulation in paper used in oil&ndash, paper insulation system may distort electric field distribution and lead to the flashover and breakdown of insulation system. In this paper, the effect of gas-phase fluorination on the surface charge and space charge characteristics of oil-impregnated Nomex paper was investigated. Nomex T410 was fluorinated at 25 &deg, C using F2/N2 mixtures with 20% F2 in volume at 0.05 MPa for 15, 30 and 45 min. Fourier Transform Infrared Spectroscopy (FTIR) proved that the molecular chain scission and cleavage occurred during gas-phase fluorination. Furthermore, the surface charge and space charge characteristic of the original and fluorinated oil-impregnated paper were measured using an electrostatic voltmeter and Pulsed Electroacoustic (PEA) equipment respectively. Furthermore, the hole and electron trap distribution of the samples were obtained by Isothermal Surface Potential Decay (ISPD) model. The results showed that both the positive and negative charge decay rates were accelerated by gas-phase fluorination and the hole, electron trap energy and density of the fluorinated samples were reduced by fluorination. It is suggested that the space charge dissipation was also accelerated by fluorination, indicating that gas-phase fluorination is an effective approach to modify the charge dynamics of oil-impregnated Nomex paper.

Global energy consumption is increasing every year, and, despite their many negative impacts, fossil fuels are a major source of energy, but their reserves are gradually depleting. One of the promising but underutilized resources is plant biomass (phytomass). The main problem of plant biomass combustion is the low melting temperature of ash, but there are also problems with corrosion of heat exchangers and clogging of heat-exchanging surfaces. This work is concerned with the production of straw pellets in order to increase the melting temperature of ash by adding an additive. The paper sludge contains substances that can increase the melting point of ash and was therefore added to the pellet samples. This additive was mixed with straw in ratios from 90:10, 80:20 and 70:30 (straw/paper sludge). The use of paper sludge showed positive effects on increasing the melting temperature of the ash samples. The deformation temperature of the ash has already risen from 1020 to 1260 &deg, C after the addition of 10% sludge, which is comparable to wood pellets.

Defects related to degradation were observed in an ancient book paperboard cover through nuclear magnetic resonance relaxometry and infrared thermography. Data collected with this combined method allowed identifying areas with moisture content and thermal diffusivity anomalies within the front board, corresponding to the different conservation status of the cellulose-based material. Non-destructive testing analytical procedures provide comprehensive knowledge for preserving precious library archives.

In this article, we report a facile method to fabricate free-standing reduced graphene oxide paper (rGOP) by vacuum filtration. Pt nanoparticles were electrodeposited on reduced graphene oxide paper to construct a sensitive and flexible hydrogen peroxide (H2O2) sensor. The properties of Pt/rGOP were characterized by scanning electron microscopy, energy dispersive X-ray, X-ray photoelectron spectroscopy and Raman spectroscopy. The electrochemical characterizations of the resulting sensor were carried out by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The Pt/rGOP hybrid electrode had an excellent electrochemical property, with superb electrocatalytic activity, a large electrochemical active surface area, flexibility and high stability. The linear ranges of the as-prepared sensor for H2O2 detection were divided into two linear sections: 0.2 μmol/L to 2.0 mmol/L and 2.0 to 8.5 mmol/L, with a detection limit of 100 nmol/L (S/N = 3) and a response time of less than 5 s. The proposed sensor has great potential to become a reliable and flexible tool in biosensor and point-of-care medical devices.

The purpose of this study is to make geopolymers using burned joss paper ash (BJPA)&mdash, which is used in traditional Chinese festivals&mdash, and ground-granulated blast-furnace slag (GGBFS). GGBFS-based geopolymers were replaced by BJPA, by mass, at levels of 0%, 20%, 40%, 60%, 80% and 100% and the liquid-to-solid ratios (L/Ss) were 0.3, 0.4 and 0.5. The properties of fresh, hardening, durability and microscopic analysis were examined to determine the effect of BJPA-substitution ratios and L/S on the engineering properties of composite geopolymers. The results show that among the fresh properties, as the amount of BJPA replacement increases, the setting time tended to increase, but the fluidity slowed down. The maximum compressive strength reached 81.1 MPa. As the amount of BJPA replacement increased, the elastic modulus of the geopolymer increased and the brittleness decreased. However, in the dry shrinkage test, it was found that an increase in BJPA helped reduce the dry shrinkage of the geopolymer. X-ray diffraction analysis revealed that a rise in the BJPA-substitution ratio increased the peak value of calcium carbonate. Scanning electron microscope images showed that microcrack size decreased with an increase in the BJPA-substitution ratio, with maximum and minimum crack sizes of 5.80 &mu, m and 176.8 nm, respectively. This was because BJPA was unable to undergo complete polymerization and therefore was able to fill the cracks produced during the polymerization. In conclusion, BJPA may be used for waste recycling in the production of geopolymers.

In this perspective article, some of the latest paper and fiber-based bio-analytical platforms are summarized, along with their fabrication strategies, the processing behind the product development, and the embedded systems in which paper or fiber materials were integrated. The article also reviews bio-recognition applications of paper/fiber-based devices, the detected analytes of interest, applied detection techniques, the related evaluation parameters, the type and duration of the assays, as well as the advantages and disadvantages of each technique. Moreover, some of the existing challenges of utilizing paper and/or fiber materials are discussed. These include control over the physical characteristics (porosity, permeability, wettability) and the chemical properties (surface functionality) of paper/fiber materials are discussed. Other aspects of the review focus on shelf life, the multi-functionality of the platforms, readout strategies, and other challenges that have to be addressed in order to obtain reliable detection outcomes. Keywords: paper-based bio-analytical devices; shelf life; equipment-free bio-recognition; flow rate; readout strategies; multi-functional platforms

This Special Issue on “Selected Papers from IEEE ICASI 2018” includes excellent papers presented at the IEEE ICASI 2018 regarding the “applied system innovation” topic. Mechanical engineering and design innovations are both academic and practical engineering fields, which involve systematic technological materialization through scientific principles and engineering designs. Technological innovations in mechanical engineering include IT-based intelligent mechanical systems, mechanics and design innovations, and applied materials in nanosciences and nanotechnology. The aim is to encourage the attendees at the IEEE ICASI 2018 to publish their experimental and theoretical research relating to applied system innovation.

MDPI´s Applied Sciences reached a remarkable milestone in 2020 when the 10th volume of the journal was published and an impact factor of 2 [...]

Recent advances in the production and development of two-dimensional transition metal dichalcogenides (2D TMDs) allow applications of these materials, with a structure similar to that of graphene, in a series of devices as promising technologies for optoelectronic applications. In this work, molybdenum disulfide (MoS2) nanostructures were grown directly on paper substrates through a microwave-assisted hydrothermal synthesis. The synthesized samples were subjected to morphological, structural, and optical analysis, using techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman. The variation of synthesis parameters, as temperature and synthesis time, allowed the manipulation of these nanostructures during the growth process, with alteration of the metallic (1T) and semiconductor (2H) phases. By using this synthesis method, two-dimensional MoS2 nanostructures were directly grown on paper substrates. The MoS2 nanostructures were used as the active layer, to produce low-cost near-infrared photodetectors. The set of results indicates that the interdigital MoS2 photodetector with the best characteristics (responsivity of 290 mA/W, detectivity of 1.8 &times, 109 Jones and external quantum efficiency of 37%) was obtained using photoactive MoS2 nanosheets synthesized at 200 &deg, C for 120 min.

One of the main issues in a paper mill is the minimization of trim loss when cutting master reels and stocked reels into reels of smaller required widths. The losses produced in trimming at a paper mill are reprocessed by using different chemicals which contributes to significant discharge of effluent to surface water and causes environmental damage. This paper presents a real-world industrial problem of production planning and cutting optimization of reels at a paper mill and differs from other cutting stock problems by considering production and cutting of master reels of flexible widths and cutting already stocked over-produced and useable leftover reels of smaller widths. The cutting process of reels is performed with a limited number of cutting knives at the winder. The problem is formulated as a linear programming model where the generation of all feasible cutting patterns determines the columns of the constraint matrix. The model is solved optimally using simplex algorithm with the objective of trim loss minimization while satisfying a set of constraints. The solution obtained is rounded in a post-optimization procedure in order to satisfy integer constraints. When tested on data from the paper mill, the results of the proposed model showed a significant reduction in trim loss and outperformed traditional exact approaches. The cutting optimization resulted in minimum losses in paper trimming and a lesser amount of paper is reprocessed to make new reels which reduced the discharge of effluent to the environment.

The disc-cutter is a finishing tool for the ultrasonic-cutting of paper honeycomb-core material. The cutting state directly affects the machining accuracy and surface quality of the workpiece. The cutting force is an important physical quantity and the cause of ultrasonic cutting defects of the honeycomb-core material. Due to differences in the mechanical properties and cutting performance of honeycomb-core materials and commonly used metal materials, existing metal-cutting-force models cannot be applied to the calculation of ultrasonic cutting forces in the processing of honeycomb-core materials. In response to this problem&mdash, combined with actual working conditions using the ABAQUS finite element analysis software&mdash, a finite element simulation model of the ultrasonic vibration-assisted cutting force of the disc-cutter on the honeycomb-core material was established, and the cutting curves and values were obtained. The experiment of ultrasonic vibration cutting of the disc-cutter proves that from the surface morphology of the honeycomb core, the milling-width has the greatest influence on the cutting force, and the cutting-depth has the smallest influence on the cutting force. The maximum error between the cutting force experimental results and the finite element simulation results under the same cutting conditions was 13.2%, which means that the established cutting-force finite element model is more accurate and can be used to predict the cutting in honeycomb ultrasonic vibration-assisted cutting-force value. Finally, based on the response surface method, a three-dimensional cutting force prediction model of the ultrasonic cutting honeycomb core of the disc-cutter was established by using the simulation model data. The results of this study can provide a useful basis for the improvement of cutting performance and processing efficiency in the processing of paper honeycomb-core materials.

Although good field emission from graphene has been demonstrated from a wide variety of different microfabricated structures, very few of them can be used to improve the design of cold field emitters for electron microscopy applications. Most of them consist of densely packed nano-emitters, which produce a large array of defocused overlapping electron beams, and therefore cannot be subsequently focused down to a single nanometer electron probe. This paper reviews the kind of single-tip cathode structures suitable in cold field emission guns for instruments such as scanning electron microscopy, transmission electron microscope or scanning transmission electron microscopy, and reviews progress in fabricating them from graphene-based materials.

The fifth IEEE International Conference on Applied System Innovation 2019 (IEEE ICASI 2019, https://2019.icasi-conf.net/), which was held in Fukuoka, Japan, on April 11–15, 2019, provided a unified communication platform for a wide range of topics.[...]

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funded by the "Innovative Microfluidic Platform for Analysis of myeloid Leukemia blasts" project (030782). co-funded by FCT and the ERDF through COMPETE2020, the CANCER project (NORTE-01-0145-FEDER-000029) funded through the NORTE-45-2015-02 program. Surface-enhanced Raman scattering (SERS) spectroscopy stands out due to its sensitivity, selectivity, and multiplex ability. The development of ready-to-use, simple, and low-cost SERS substrates is one of the main challenges of the field. In this paper, the intrinsic reproducibility of microfluidics technology was used for the fabrication of self-assembled nanoparticle structures over a paper film. The paper SERS substrates were fabricated by assembling anisotropic particles, gold nanostars (GNSs), and nanorods (NRs) onto paper to offer an extra enhancement to reach ultra-sensitive detection limits. A polydimethylsiloxane PDMS-paper hybrid device was used to control the drying kinetics of the nanoparticles over the paper substrate. This method allowed a high reproducibility and homogeneity of the fabrication of SERS substrates that reach limits of detection down to the picomolar range. This simple and low-cost fabrication of a paper-based sensing device was tested for the discrimination of different cell lineages. publishersversion published

The manufacturing of Portland cement is responsible for a big amount of energy and greenhouse gas (GHG) emission. Therefore, to date, it is imperative to find alternative materials to replace a major part of cement for sustainable concrete constructions. The present study forms a part of an on-going research project on the application of new cementitious matrices produced using different types of recycled materials. In particular, it focuses on the use of pulp and waste paper to partially replace Portland cement at varying percentages for producing a new lightweight mortar, frequently named papercrete. The development of this economical and eco-friendly material may permit of recycling a big amount of waste paper leading to lower housing costs with also ecological benefits. To this scope, an experimental campaign in the laboratory is carried out to characterize this new innovative material from a physical and mechanical point of view. The preliminary results of this on-going experimental campaign are illustrated and commented on in this paper. The obtained results confirm the possibility of applying this partially-recycled material as a possible alternative for strengthening existing panels of masonry.

The results of research on the efficiency and technological reliability of domestic wastewater purification in two household wastewater treatment plants (WWTPs) with activated sludge are presented in this paper. The studied facilities were located in the territory of the Roztocze National Park (Poland). The mean wastewater flow rate in the WWTPs was 1.0 and 1.6 m3/day. In 2017–2019, 20 series of analyses were done, and 40 wastewater samples were taken. On the basis of the received results, the efficiency of basic pollutant removal was determined. The technological reliability of the tested facilities was specified using the Weibull method. The average removal efficiencies for the biochemical oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD) were 66–83% and 62–65%, respectively. Much lower effects were obtained for total suspended solids (TSS) and amounted to 17–48%, while the efficiency of total phosphorus (TP) and total nitrogen (TN) removal did not exceed 34%. The analyzed systems were characterized by the reliability of TSS, BOD5, and COD removal at the level of 76–96%. However, the reliability of TN and TP elimination was less than 5%. Thus, in the case of biogenic compounds, the analyzed systems did not guarantee that the quality of treated wastewater would meet the requirements of the Polish law during any period of operation. This disqualifies the discussed technological solution in terms of its wide application in protected areas and near lakes, where the requirements for nitrogen and phosphorus removal are high.

An increasing number of industrial plants integrate the anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) with a subsequent composting phase. To improve the plant productivity, a fraction of OFMSW digestate can be converted into a carbonaceous material, called hydrocar (HC), through Hydrothermal Carbonization (HTC), and then composted together with the OFMSW digestate itself, to produce “hydrochar co-compost”. The aim of this paper is to present the design and assembly of batch bioreactors, built in-house to investigate the co-composting process of OFMSW digestate and its HC, and to provide some preliminary results. The OFMSW digestate from an industrial plant was carbonized at 200 °C for 3 h in a 2 L HTC reactor, to produce wet HC after filtration. The ratio of OFMSW digestate and green waste (1:1) used as bulking medium was reproduced in four bioreactors with an increasing percentage of HC substituting the OFMSW digestate (0, 25, 50, 75%). The bioreactors managed to effectively compost the solid wet biomasses in a wet environment with temperature and oxygen control, while measuring online the oxygen consumption and thus the dynamic respirometric index (DRI). The DRI24,max measured with AIR-nl solid respirometer (standardized offline measurement) started from values above 800 mg O2 kgVS−1 h−1 before composting and dropped at the end of the process to values in the range 124–340 mg O2 kgVS−1 h−1 for the four mixes, well below the recommended limit of 500 mg O2 kgVS−1 h−1 for high-quality compost stability. These offline DRI values were confirmed by the online DRI measurements. This research is part of the international C2Land Project funded by the European Institute of Innovation and Technology Climate Knowledge and Innovation Community (EIT Climate-KIC), which is greatly acknowledged.

A pre-hydrolysate is an aqueous stream obtained during the production of hardwood kraft dissolving pulp. It is rich in sugars and contains dissolved organic matters. The purpose of this study is to investigate the optimization of lignin recovery from wood pre-hydrolysates and to characterize the extracted lignin. The optimal conditions for lignin extraction have been determined to be (a) a filtration temperature of 40 &deg, C, (b) a sulfuric acid concentration of 8.5 kg.m&minus, 3, and (c) a coagulation time of 180 min. Using these conditions, high filtration rates have been obtained and the extracted lignin has a low content of impurities (8.3%), a low molecular weight (1270 Da), and a very low polydispersity (Mw/Mn = 1.22). Compared to kraft lignin, the pre-hydrolysate lignin has a much lower molecular weight and could be a potential candidate for niche applications. A high lignin recovery rate is possible (52% of the total lignin content in the pre-hydrolysate).

In this study, the influence of physio-chemical properties of four printing substrates, fibrous papers (filter, bulky, recycled), and polymer film (synthetic paper) on the size of the thermochromic (TC) prints microcapsules was investigated. Results indicate that interaction between thermochromic ink and printing substrate determine the print morphology, i.e., porosity and roughness of printing substrate affect dimensions of TC microcapsules of resulting prints, while ink adhesion affects dimensional changes during heating&ndash, cooling cycle. Atomic force microscopy (AFM) analysis showed that microcapsules of the prints, on the surface of the smoothest synthetic paper, possess the smallest diameter and height, while, on the most porous and the most roughened surface of F paper, the microcapsules of the prints possess the highest diameter and height. By increasing the temperature to 40 &deg, C, the biggest changes in the shape of the microcapsules (increase in height and decrease in diameter) were obtained using the surface of the hydrophilic filter paper. While using the recycled paper surface, the situation is opposite, the height and diameter of the microcapsules are reduced, and the microcapsules penetrate deeper into the paper structure (due to optimum adhesion). On the bulky paper surfaces, which are more hydrophobic than recycled paper (higher interfacial tension), the increase of temperature does not cause any significant changes in the shape and position of the microcapsules. The same behavior is observed using hydrophobic non-porous synthetic paper.

In the development of packaging products, the considerations are not limited to the food shelf-life, safety, and practicality, but also environmental sustainability. This paper reports a life cycle assessment (LCA) analysis of a proposed natural fiber-reinforced biopolymer composite takeout food container. The study focuses on the damage assessment of the whole product system, including disposal scenarios of the thermoformed sugar palm fiber (SPF)-reinforced sago starch composite takeout food container. The analysis performed was to anticipate the environmental impact of the cradle-to-grave approach. The results exhibited the total human health damage of 2.63 &times, 10&minus, 5 DALY and ecosystem damage of 9.46 &times, 8 species.year per kg of containers. The main contributor was the carbon dioxide emission from fossil fuel combustion for energy generation that contributed to climate change and caused human health and the ecosystem damages with low-level metrics of 1.3 &times, 5 DALY and 7.39 &times, 8 species.yr per kg of containers, respectively. The most contributed substances in the &lsquo, Particulate matter formation&rsquo, impact categories that caused respiratory diseases were from air/nitrogen oxides, air/particulates, &lt, 2.5 &micro, m, and air/sulphur dioxide with the metrics of 2.93 &times, 6 DALY, 2.75 &times, 6 DALY, and 1.9 &times, 6 DALY per kg containers, correspondingly. Whereas, for the &lsquo, Agricultural land occupation&rsquo, which contributed to ecosystem damage, almost the total contributions came from raw/occupation, forest, intensive with the metric of 1.93 &times, 9 species.yr per kg of containers. Nevertheless, from the results, all impact categories impacted below than 0.0001 DALY for the Human Health damage category and below 0.00001 species.yr for the ecosystem damage category. These results would provide important insights to companies and manufacturers in commercializing the fully biobased takeout food containers.

The sugarcane industry has assumed an increasingly important role at a global level, with countries such as Brazil and India dominating the field. However, this causes environmental problems, since the industry produces large amounts of waste, such as sugarcane bagasse. This by-product, which is energetically partially recovered in sugar mills and in the pulp and paper industry, can make a significant contribution to the general use of biomass energy, if the usual disadvantages associated with products with low density and a high moisture content are overcome. From this perspective, thermochemical conversion technologies, especially torrefaction, are assumed to be capable of improving the fuel properties of this material, making it more appealing for potential export and use in far-off destinations. In this work, sugarcane samples were acquired, and the process of obtaining bagasse was simulated. Subsequently, the bagasse was dried and heat-treated at 200 and 300 &deg, C to simulate the over-drying and torrefaction process. Afterward, product characterization was performed, including thermogravimetric analysis, elemental analysis, calorimetry, and energy densification. The results showed significant improvements in the energy content, from 18.17 to 33.36 MJ&middot, kg&minus, 1 from dried bagasse to torrefied bagasse at 300 &deg, C, showing that despite high mass loss, there is potential for a future value added chain for this waste form, since the increment in energy density could enhance its transportation and use in locations far off the production site.

Fluorite is an important industrial mineral composed of calcium and fluorine (CaF2). This mineral is widely distributed through different deposits. However, in most cases, fluorite is tightly associated with gangue, such as calcite and quartz. In this paper, different depressants are tested in the flotation of fluorite in two different laboratory configurations&mdash, cell and column. Quebracho tree (QT) was tested as the main depressant in combination with white dextrin (WD), potato starch (PT), carboxymethyl cellulose (CMC), and sodium hexametaphosphate (SHMP). The optimum pulp pH of the flotation of fluorite was determined as approximately 9.5&ndash, 10. The best results are obtained using a combination of quebracho and white dextrin as depressants, reaching 74% of fluorite grade for modified column flotation and 70.5% for cell flotation. Additionally, the metallurgical recovery obtained higher values when the flotation was carried out in the modified column and using the same combination of depressant agents&mdash, 75% for modified column flotation and 60% for flotation cell.

This paper presents the combustion and emissions characteristics including volatile organic compound (VOC) of a common rail direct injection diesel engine fueled with palm oil biodiesel blends contained 0%, 10%, 30%, and 100% (by volume) biodiesel at low idle speed, i.e., 750 rpm. The nitrogen oxide (NOx) emissions of biodiesel blends were lower than that of pure diesel and NOx tended to decrease as the blending ratio increased. Soot opacity and hydrocarbon (HC) were reduced with an increasing blend ratio. Carbon monoxide (CO) varied with the engine load conditions. Under low load, CO emissions tended to decrease with increasing blending ratio and increased under high load. Alkane and aromatic VOCs were mostly emitted. Benzene and tetrahydrofuran accounted for the largest percentage of total detected VOCs in all test conditions. Benzene, toluene, ethylbenzene, xylene (BTEX, toxic aromatic VOCs) were detected for all tests. Among BTEX, benzene has the highest emission ratio, followed by xylene, toluene, and ethylbenzene. Benzene increased for all tests. At low engine load, toluene, ethylbenzene, and xylene decreased with increasing blend ratio. However, these increased at high engine load. When pure palm oil biodiesel was applied at high engine load, benzene decreased.

Microalgal harvesting is one of the most challenging processes in the development of algal research and development. Several methods, such as centrifugation, flocculation and filtration, are available at the laboratory scale. However, the requirement for expensive pieces of equipment and the possibility of biomass contamination are recurring gaps that hinder the development of microalgae R&amp, D (research and development) in different parts of the world. Recently, electroflotation has been proved to be a suitable method for the harvesting of different species of microalgae and cyanobacteria. To this day, there are no companies that sell laboratory-scale electroflotation equipment, this is mainly due to the gap in the knowledge of which factors (time, mixing rate, number of electrodes and others) will affect the efficiency of concentration without reducing the biomass quality. This paper aims to build an innovative, low-cost electroflotation system for under 300 USD (United States dollar) with cheap and resistant materials. To achieve our goal, we tested the interaction of three variables (time, mixing rate and amount of electrodes). Results showed that an efficiency closer to 100% could be achieved in under 20 min using &gt, 10 electrodes and 150 rpm (round per minute). We hope this innovative approach can be used by different researchers to improve our knowledge of the concentration and harvesting of algae and cyanobacteria.

This paper describes an organosolv pretreatment of corncob waste to improve its anaerobic digestion for biogas production. Through a thermochemical process based on the use of ethanol and acetic acid, it was possible to separate the fractions of lignin, considered to be a natural inhibitor of anaerobic digestion processes. In addition, with this organosolv pretreatment, the available sugars in the carbohydrates present as monosaccharides, or simple sugars, were depolymerised, facilitating the digestion process. The obtained results include the chemical characterisation of the corncob, the hydrolysate, and the mixture with cow manure, finding that these substrates have potential to be used in anaerobic digestion. The total reducing sugars consumed were 96.8%, and total sugars were 85.75%. It was clearly observed that with the use of pretreatment with organosolv, the production of biogas was superior, because 484 NmL/gVS was obtained compared to the other reported treatments. It was also observed that adding the hydrolysate organosolv increased the production because the values of the control without hydrolysate were 120 NmL/gVS in the bottle experiment. When the experiment was scaled to the 5L reactor, the total volumes of biogas that were accumulated in 15 days of production were 5050 NmL/gVS and 1212 NmL/gVS with and without hydrolysate, respectively. This indicates that the organosolv pretreatment of corncob waste is effective in improving biogas production.

This paper studies a new convenient method to prepare microfibrillated cellulose from a bleached eucalyptus kraft pulp. First, the wood pulp was reacted with urea to produce cellulose carbamate (CC), and then the CC was treated with colloid mill in an acidic medium. A feasible preparation process for CC was to soak the pulp with the urea solution, and then the cellulose pulp was dewatered, dried, and reacted with urea at high temperatures above the melting point of urea. The Kjeldahl method, infrared spectroscopy, and solid 13C NMR were used to confirm the effectiveness of the reaction. On the basis of CC with the degree of substitution, DS = 0.123, the aqueous suspension with 2% content of CC at pH values of 1, 3, or 7 was severally ground by a colloid milling. After centrifugation, the nanocellulose carbamate fiber (CCNF) in the supernatant was obtained. X-ray diffraction showed that CC and CCNF had the same crystal form as the cellulose pulp, but the crystallinity decreased successively. The nanometer diameter of the CCNF fiber was observed with scanning electron microscopy. Results showed that when the pH value of the CC suspension decreased during the colloid milling, the crystallinity of the CCNF decreased along with the decrease of fiber diameter, and the zeta potential of the supernatant increased. This indicated that carbamate side groups of CC were protonated at low pHs and the cation repulsion between cellulose molecular chains enhanced the driving force of the pulp separation to CCNF. Interestingly, the thermal stability of CCNF is comparable to that of the original cellulose, and the enhancement effect of CCNF on starch can be clearly observed even at a relatively low loading of CCNF.

The AHP–GTMA (analytic hierarchy process and graph theory and matrix approach) has been applied to select the best paper shredder before a company was making a bulk purchase order. However, there is a question as to whether one such relatively recent approach is effective to aid the selection decision problems in industrial/commercial practice. In this paper, a novel multi-measure, rank-based comparative research flow is proposed. The real decision problem case mentioned above is solved using the AHP–GTMA and the AHP–TOPSIS methods, respectively, with relevant datasets sourced. Several measures in the proposed flow, i.e., the arithmetical, geometrical, or even statistical ones, are multiplexed and used to validate the similarity between the rank order vectors (ROVs) (and thus between the final preferential orders determined over the alternatives) that are obtained using these two different methods. While AHP–TOPSIS is a confident multi-attribute decision-making (MADM) approach which has been successfully applied to many other fields, the similarity validated between these individual results using the proposed method is used to confirm the efficacy of the AHP–GTMA approach and to determine its applicability in practice. In addition, along with this study, some contributable points are also rendered for implementing the decision models, e.g., the optimized recursive implementation in R to compute the permanent value of a square ASAM (alternative selection attribute matrix, which is the computational basis required by AHP–GTMA) of any dimension. The proposed methodological flow to confirm the similarity based on the ordinal rank information is not only convenient in operational practice with ubiquitous tool supports (e.g., the vector-based R statistical platform), but also generalizable (to verify between another pair of results obtained using any other MADM methods). This gives options for future research.

The corn crop is one of the most important crops worldwide. However, the management of the residues generated is not efficient enough, which diminishes the competitiveness of this crop. An interesting option for the valorization of these wastes is their thermal use. In order to make the management of this residue as much efficient as possible, it is vital to know the different processes related to a corn harvest, and try to adapt the use of this waste depending on its characteristics. Thus, in this work, and on the basis of a conventional corn harvest, a differentiated analysis of the residue generated was carried out, including its characterization and assessing its behavior during pyrolysis and combustion. The results pointed out the importance of collecting residue immediately after its generation and avoiding its contact with the soil as this factor tends to worsen its thermal properties and ash content. Concerning the selective collection, it is highly advisable if the subsequent thermal use is going to be a pyrolytic process. In the case of combustion, even though the samples that contain corn stalk showed better combustion properties, this improvement did not outweigh the adverse effects related to the increase in ash content, especially for its pelletizing.

Torrefaction is a thermal pretreatment technique usually adopted for improving biomass properties to be on par with that of coal for energy production. In this study, the torrefaction characteristics of blended fuel of sewage sludge (SS) and sugarcane bagasse (BG) biomass were investigated for the purpose of gasification. The thermal degradation behavior of the blended biomass sample was tested in an inert atmosphere from ambient temperature to 900 °C using thermogravimetric analysis (TGA). The obtained TGA data aided in the determination of thermochemical parameters that are of necessity in gasification. Morphological changes in the blended torrefied samples were examined through scanning electron microscopy. Further changes in the chemical structure of the samples were investigated through Fourier-transform infrared analysis. The blend ratio of 75% SS + 25% BG torrefied at 350 °C gave the highest energy value (HHV) of 23.62 MJ/kg, fixed carbon of 51.37 wt % and fuel ratio of 1.70. The obtained fuel ratio is comparable to that required for optimum combustion performance of coal. The morphological structure of the samples showed that there was an aggregation of the biomass particles into small lumps at higher torrefaction temperature for 50% SS + 50% BG and 75% SS + 25% BG blend indicating a better grind ability of the biomass material. Thus, it can be concluded that the blend and torrefaction enhanced the properties of the biomass materials.

Multiple recycling of waste concrete has attracted widespread attention. This study presented the carbonation behavior of repeatedly recycled aggregate concrete (RRAC) used in a micro-frozen region. The effects of freeze–thaw cycles on the carbonation depth of three generations of RRAC with 25%, 75%, and 100% of replacement rate were evaluated. All RRAC specimens after different numbers of freeze–thaw cycles were rapidly carbonated for 28 d indoors to test the carbonation resistance of concrete. The results suggested that the carbonation depth of RRAC subjected to freeze–thaw cycles is higher than that in the non-freeze–thaw condition. This is because the freeze–thaw damages cause the internal structure of RRAC to become porous and and prone to cracking, thus providing convenient channels for CO2 to react with the alkali in the cementitious materials. With the growth of replacement rate or recycling number, RRAC reveals serious freeze–thaw damage and inferior carbonation resistance, which is due to the continuous deterioration repeatedly recycled concrete aggregate (RRCA) quality. However, when the replacement rate was 25%, the carbonation depth for the third generation of RAC was comparable to the second generation of RAC at a 75% replacement rate, and even the first generation of 100% RAC. To ensure better carbonation resistance durability of multiple recycling RAC, the low replacement rate of RRCA should be considered. For the third generation of RAC with the 100% replacement rate, its highest carbonation depth after freeze–thaw cycles was 9.16 mm, which still met the design requirements for structural use in a micro-frozen region. This indicates that it is feasible for three generations of RRAC to be used in the micro-frozen environment and that RRAC has great engineering application potential and promotional value.

Animal waste is generated at an increased rate, and its disposal is attracting wide public attention. Anaerobic digestion is considered the most promising option for reducing this waste, and simultaneously, it produces renewable energy. Lignin contained in lignocellulosic biomass is hardly biodegradable, thus pre-treatment has to be considered prior to digestion. The possibility of biological pre-treatment of chicken manure with sawdust using Pleurotus ostreatus fungi was investigated in our study. This animal waste was used as a substrate for further biogas production. To provide a better nutrient balance, we added two different co-substrates, wheat straw and Miscanthus. Mixtures with different mass ratios of chicken manure with sawdust/ordinary wheat straw, as well as chicken manure with sawdust/pre-treated wheat straw were incubated for 30 d. The same experiments were performed with Miscanthus. During incubation, samples were taken at predetermined time intervals, and the concentration of acid-insoluble lignin was determined. Additionally, concentrations of glucose and xylose in the filtrate taken at the end of the Klasson procedure were determined in the initial samples and in the samples after 30 d of incubation. Despite our expectations, almost no lignin degradation was observed. Insignificant decreases in glucose and xylose concentrations after 30 d is attributed to fungi ingestion. Obtained results show that Pleurotus ostreatus, as a white-rot fungi with a unique enzymatic system and as generally preferred organisms for lignin degradation, is, therefore, not suitable for delignification of this particular animal waste.

Carbonation of cementitious binders implies gradual capture of CO2 and significant compensation for the abundant cement-related CO2 emissions. Therefore, one should always look at the CO2-sequestration-to-emission ratio (CO2SP/EM). Here, this was done for High-Volume Fly Ash (HVFA) mortar (versus two commercial cement mortars). Regarding their CO2 sequestration potential, effects of accelerated testing (at 1–10% CO2) on as such estimated natural carbonation degrees and rates were studied. Production related CO2 emissions were evaluated using life cycle assessment with no/economic allocation for fly ash. Natural carbonation rates estimated from accelerated tests significantly underestimate actual natural carbonation rates (with 29–59% for HVFA mortar) while corresponding carbonation degrees are significantly overestimated (67–74% as opposed to the actual 58% for HVFA mortar). It is advised to stick with the more time-consuming natural tests. Even then, CO2SP/EM values can vary considerably depending on whether economic allocation coefficients (Ce) were considered. This approach imposes significant portions of the CO2 emissions of coal-fired electricity production onto fly ash originating from Germany, China, UK, US and Canada. Ce values of ≥0.50% lower the potential CO2SP/EM values up to a point that it seems no longer environmentally worthwhile to aim at high-volume replacement of Portland cement/clinker by fly ash.

This study evaluates the anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) and digested sewage sludge (DSS) at lowered temperatures. AD batch tests for CH4 yield determination were carried out with DSS as inoculum between 23 and 40 °C. All results were related to organic dry matter and calculated for standard conditions (1013 hPa, 0 °C). The AD experiments at 40 °C and at 35 °C delivered specific CH4 yields of 325 ± 6 mL/g and 268 ± 27 mL/g for OFMSW alone. At lower temperatures, specific CH4 yields of 364 ± 25 mL/g (25 °C) and 172 ± 21 mL/g (23 °C) were reached. AD at 25 °C could be beneficial regarding energy input (heating costs) and energy output (CH4 yield). Plant operators could increase AD efficiencies by avoiding heating costs. The co-digestion of OFMSW together with DSS could lead to further synergies such as better exploitation of the energy potentials of DSS, but the digestate utilization could become problematic due to hygienic requirements. Efficiency potentials through lowered operating temperatures are limited. In further research, lowered process temperatures could be applied in the AD of energy crops due to large numbers of existing plants.

The development of intensive aquaculture is facing the challenge of the sustainable management of effluents. The reproductive sectors (i.e., hatcheries) mainly use water recirculation systems (RAS), which discharge a portion of wastewater. Anaerobic digestion (AD) could reduce the environmental impact of this waste stream while producing biogas. The study is focused on the biochemical methane potential (BMP) of brackish fish hatchery sludges. Wastewater was concentrated by microfiltration and sedimentation and thickened sludges were treated in a BMP system with different inoculum/substrate (I/S) volatile solids ratios (from 50:1 to no inoculum). The highest I/S ratio showed the highest BMP (564.2 NmL CH4/g VS), while different I/S ratios showed a decreasing trend (319.4 and 127.7 NmL CH4/g VS, for I/S = 30 and I/S = 3). In absence of inoculum BMP resulted of 62.2 NmL CH4/g VS. The kinetic analysis (modified Gompertz model) showed a good correlation with the experimental data, but with a long lag-phase duration (from 14.0 to 5.5 days) in particular with the highest I/S. AD applied to brackish water sludges can be a promising treatment with interesting methane productions. For a continuous, full-scale application further investigation on biomass adaptation to salinity and on retention times is needed. Further experimental tests are ongoing.

Spinning disc (SD) technology has been successfully applied, for the first time, in real textile wastewater treatment with no other additional processing. The SD efficiency was investigated using real textile effluents to study the color and suspended solids removals at different effluent-supplying flowrates (10&ndash, 30 L/h) and different disc rotational speeds (100&ndash, 1500 rpm) with good experimental results, thus, it can minimize the polluting loads within a short time period. Furthermore, within this study, process modeling and its classical optimization were applied to SD technology for wastewater treatment. The experiments were organized according to an active central composite rotatable 23 order design, considering as independent variables the wastewater flowrate, rotational speed, and operating time and, as optimization criteria, the suspended solids removal and discoloration degree. Overall, this novel study proved that the SD technology applied in textile effluent treatment is a suitable alternative to a primary mechanical step.

In Spain, the winery industry exerts a great influence on the national economy. Proportional to the scale of production, a significant volume of waste is generated, estimated at 2 million tons per year. In this work, a laboratory-scale reactor was used to study the feasibility of the energetic valorization of winery effluents into hydrogen by means of dark fermentation and its subsequent conversion into electrical energy using fuel cells. First, winery wastewater was characterized, identifying and determining the concentration of the main organic substrates contained within it. To achieve this, a synthetic winery effluent was prepared according to the composition of the winery wastewater studied. This effluent was fermented anaerobically at 26 &deg, C and pH = 5.0 to produce hydrogen. The acidogenic fermentation generated a gas effluent composed of CO2 and H2, with the percentage of hydrogen being about 55% and the hydrogen yield being about 1.5 L of hydrogen at standard conditions per liter of wastewater fermented. A gas effluent with the same composition was fed into a fuel cell and the electrical current generated was monitored, obtaining a power generation of 1 W&middot, h L&minus, 1 of winery wastewater. These results indicate that it is feasible to transform winery wastewater into electricity by means of acidogenic fermentation and the subsequent oxidation of the bio-hydrogen generated in a fuel cell.

In this study, a synthetic phenol solution of water and raw olive mill wastewater (OMW) were considered to achieve purification of the aqueous streams from pollutants. Only OMW was initially submitted to a coagulation/flocculation process, to reduce the turbidity, phenols, and chemical oxygen demand (COD). This first treatment appeared to be mandatory in order to remove solids from wastewater, allowing the successive use of laboratory-made core-shell nanocomposites. In detail, the optimal coagulant concentration, i.e., chitosan, was 500 mg/L, allowing a reduction of the turbidity and the COD value by 90% and 33%, respectively. After this, phenol wastewater was tested for photocatalysis and then OMW was treated by employing the laboratory-made nanocomposites in a photoreactor equipped with visible light sources and using optimal catalyst concentrations, which allowed for an additional 45% reduction of the COD of the OMW. In addition to this, the effect of the operating temperature was investigated on the photocatalytic process, and suitable kinetic models proposed.

Carbohydrates from vegetal biomass (wood and agricultural biomass) are the focus of biorefinery strategies [...]

In this study, indigenous acidophilic bacteria living in mine drainage and hot acidic spring were collected and used for bioleaching experiments. The incubated indigenous acidophilic bacteria were inoculated on various minerals. The changes in pH, Eh, and heavy metal concentrations were examined with uninoculated controls to study bioleaching over time. As a result, the aspects of bioleaching varied greatly depending on the origin of microorganisms, the type of minerals, the temperature conditions, etc. We applied an ANN model to express and predict these complex bioleaching trends. Through the application of an ANN model, we developed the ANN models that can predict the changes in concentration of pH, Eh, and heavy metal ion concentrations and further evaluated predictability. Through this, the predictability of bioleaching using the ANN models can be confirmed. However, we also identified limitations, showing that further testing and application of the ANN models in more diverse experimental conditions are needed to improve the predictability of the ANN models.

In recent years, production of biohydrogen and biomethane (or a mixture of these; biohythane) from organic wastes using two-stage bioreactor have been implemented by developing countries such as Germany, USA and the United Kingdom using the anaerobic digestion (AD) process. In Thailand, biohythane production in a two-stage process has been widely studied. However, in Malaysia, treating organic and agricultural wastes using an integrated system of dark fermentation (DF) coupled with anaerobic digestion (AD) is scarce. For instance, in most oil palm mills, palm oil mill effluent (POME) is treated using a conventional open-ponding system or closed-digester tank for biogas capture. This paper reviewed relevant literature studies on treating POME and other organic wastes using integrated bioreactor implementing DF and/or AD process for biohydrogen and/or biomethane production. Although the number of papers that have been published in this area is increasing, a further review is needed to reveal current technology used and its benefits, especially in Malaysia, since Malaysia is the second-largest oil palm producer in the world.

In this study, a method was suggested to produce dried powder from red mud (RM) sludge with 40%&ndash, 60% water content without heating. The RM sludge is discharged from the Bayer process, which is used to produce alumina from bauxite ores. Nonthermally treated RM (NTRM) powder was produced by mixing RM sludge (50%), paper sludge ash (PSA, 35%), and high-calcium fly ash (HCFA, 15%). The physicochemical properties of NTRM were investigated by analyzing its water content, X-ray fluorescence spectra, X-ray diffraction patterns, and particle size. Moreover, to examine the applicability of NTRM as a construction material, slag cement mortar in which 20 wt% of the binder was replaced with NTRM was produced, and the compressive strength, porosity, and water absorption rate of the mortar were evaluated. Results indicated that NTRM of acceptable quality was produced when the water content in RM sludge decreased and CaO contained in PSA and HCFA reacted with moisture and formed portlandite. The NTRM-mixed mortar requires further examination in terms of durability because of the increased capillary voids and high water absorption rate, but its compressive strength is sufficient to enable its use in sidewalks, bike roads, and parking lots.

Bio-oil hydrogenation upgrading process is a method that can convert crude bio-oil into high-quality bio-fuel oil, which includes two stages of mild and deep hydrogenation. However, coking in the hydrogenation process is the key issue which negatively affects the catalyst activity and consequently the degree of hydrogenation in both stages. In this paper, an Aspen Plus process simulation model was developed for the two-stage bio-oil hydrogenation demonstration plant which was used to evaluate the effect of catalyst coking on the bio-oil upgrading process and the economic performance of the process. The model was also used to investigate the effect of catalyst deactivation caused by coke deposition in the mild stage. Three reaction temperatures in the mild stage (250 &deg, C, 280 &deg, C, and 300 &deg, C) were considered. The simulation results show that 45% yield of final product is obtained at the optimal reaction condition which is 280 &deg, C for the mild stage and 400 &deg, C for the deep stage. Economic analysis shows that the capital cost of industrial production is $15.2 million for a bio-oil upgrading plant at a scale of 107 thousand tons per year. The operating costs are predicted to be $1024.27 per ton of final product.

A brief technical and economic insight into producing the water-soluble yellow colorant limocitrol 3-O-6&Prime, [3-hydroxyl-3-methylglutaryl)])-&beta, d-glucopyranoside from waste lemon peel via simple solid&ndash, liquid extraction in aqueous ethanol or via hydrodynamic cavitation of waste lemon peel in water shows that the biocolorant can be obtained with multiple technical and economic advantages. Coupled with the simplicity and sustainability of the extraction processes suggested, the high chemical and physical stability of this polymethoxylated flavonol and the health benefits of citrus flavonoids support industrialization of this new bioeconomy production.

The need for biomass as an alternative source for energy purposes points toward oil palm fruit residues (Elaeis guineensis Jacq.) as an attractive solution. Oil palm industry residue, such as oil palm empty fruit bunch (EFB) composites and mesocarp fiber (PMF), have a high gross calorific value and could help countries meet their energy demands. However, information concerning physical, mechanical, and energy characteristics of agro-pellets made from mixtures of oil palm residue with pine sawdust, is not available. In this research, oil palm residues were mixed at ratios of 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 with pine sawdust, and were chemically analyzed. Agro-pellets from mixtures were tested on their physical and mechanical properties, and the relationship of these properties with the chemical composition of oil palm residue mixtures was determined. Normality distribution tests of the variables were performed using the Kolmogorov&ndash, Smirnov test. Normal variables were analyzed through one-way ANOVA tests. When differences were found, they were validated using the Tukey&rsquo, s honestly significant difference (HSD) test and were considered statistically significant at p &le, 0.05. Data not normally distributed were analyzed by the Kruskal&ndash, Wallis test. Bulk density, particle density, and gross calorific value of agro-pellets (from mixing 80:20 oil palm residues with pine sawdust) were statistically higher (p &lt, 0.05) to agro-pellets of 100% oil palm residues. Adding pine sawdust to oil palm residues increases some mechanical agro-pellet properties. Addition of pine sawdust to oil palm residues acts to increase some mechanical properties of agro-pellets.