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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.

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.

The work presented details the manufacturing of a low-cost hybrid inkjet-printed paper-based potentiostat, with the aim of creating a low-cost sensing system for rapid water quality monitoring. Potentiostats exhibit high sensitivities and can be used for a variety of applications. The results highlight the functionality of a paper-based potentiostat compared to a potentiostat manufactured on a printed circuit board (PCB), an LMP91000EVM development board and a laboratory-based Metrohm Autolab potentiostat. Cyclic voltammetry was performed using an 80 &micro, L sample of 5 mM ferri-ferrocyanide dropped onto a commercial screen-printed electrode from DropSens. The miniaturized paper-based potentiostat is small enough to be stored in a wallet and therefore easy to transport. Furthermore, a cost analysis shows that the potentiostat is 10 times lower in cost than the commercially available handheld potentiostat, taking the costs of man hours into account. This technology enables electrochemistry experiments to be performed on-site using the portable, disposable and low-cost solution and can be applied to a variety of fields including healthcare, wearables and environmental monitoring.

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.

In the munitions industry, there have been considerable efforts spent to develop low-cost, simply fabricated, easily wearable, and biocompatible bulletproof armors. Recently, long fiber-reinforced composites and shear thickening fluids (STFs) were inceptively utilized to improve bulletproof performance with solid or fabric materials. In this study, Hanji, a cornstarch suspension, Korean traditional long fiber paper, and a well-known STF, respectively, were examined for bulletproof applications to evaluate their own effects on bulletproof performance, tests were carried out in the field and finite element analysis (FEA) was performed to evaluate the behavior of materials regarding with perforated clay areas from in-field tests. It was found that both Hanji and STF influenced the bullet penetration by two factors, namely the momentum of bullet and stress propagation. The cornstarch suspension, rather than Hanji, showed outstanding performance in decreasing the linear velocity of the bullet and minimized the stress propagation to the protecting object. Thus, although STF performed a key role in bulletproof performance, Hanji also proved to be a suitable material as an exterior covering for absorbing the initial impact stress and maintaining the durability and stability of the armor itself.

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

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 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 recent years, reversible data hiding (RDH) has become a research hotspot in the field of multimedia security that has aroused more and more researchers&rsquo, attention. Most of the existing RDH algorithms are aiming at continuous-tone images. For RDH in encrypted halftone images (RDH-EH), the original cover image cannot be recovered losslessly after the watermark is extracted. For some application scenarios such as medical or military images sharing, reversibility is critical. In this paper, a reversible data hiding scheme in encrypted color halftone images (RDH-ECH) is proposed. In the watermark embedding procedure, the cover image is copied into two identical images to increase redundancy. We use wet paper code to embed the watermark into the image blocks. Thus, the receiver only needs to process the image blocks by the check matrices in order to extract the watermarks. To increase embedding capacity, we embed three layers in the embedding procedure and combine the resulting images into one image for convenience of transmission. From the experimental results, it can be concluded that the original image can be restored entirely after the watermarks are extracted. Besides, for marked color halftone images, our algorithm can implement high embedding capacity and moderate visual quality.

The smart, rapid, and customizable detection of chemical warfare agents is a huge issue for taking the proper countermeasures in a timely fashion. The printing techniques have established the main pillar to develop miniaturized electrochemical biosensors for onsite and fast detection of nerve and mustard agents, allowing for a lab on a chip in the chemical warfare agent sector. In the fast growth of novel technologies, the combination of miniaturized electrochemical biosensors with flexible electronics allowed for the delivery of useful wearable sensors capable of fast detection of chemical warfare agents. The wearable microneedle sensor array for minimally invasive continuous electrochemical detection of organophosphorus nerve agents, as well as the wearable paper-based origami functionalized with nanomaterials for mustard agents in the gas phase, represent two examples of the forefront devices developed in the chemical warfare agent detection field. This review will highlight the most promising electrochemical biosensors developed by exploiting nanomaterials and cross-cutting technologies for the fabrication of smart and sensitive electrochemical biosensors for the detection of chemical warfare agents.

We have had high expectations for using algae biodiesel for many years, but the quantities of biodiesel currently produced from algae are tiny compared to the quantities of conventional diesel oil. Furthermore, no comprehensive analysis of the impact of all factors on the market production of algal biodiesel has been made so far. This paper aims to analyze the strengths, weaknesses, opportunities, and threats associated with algal biodiesel, to evaluate its production prospects for the biofuels market. The results of the analysis show that it is possible to increase the efficiency of algae biomass production further. However, because the production of this biodiesel is an energy-intensive process, the price of biodiesel is high. Opportunities for more economical production of algal biodiesel are seen in integration with other processes, such as wastewater treatment, but this does not ensure large-scale production. The impact of state policies and laws is significant in the future of algal biodiesel production. With increasingly stringent environmental requirements, electric cars are a significant threat to biodiesel production. By considering all the influencing factors, it is not expected that algal biodiesel will gain an essential place in the fuel market.

The environmental pollution and high energy consumption caused by the coal-dominated energy structure in China have been the focus of attention for a long time. The co-firing of biomass with coal can save coal resources and realize effective utilization of biomass. In this paper, brewery wastewater sludge (SD) and bituminous coal (BC) were blended for an experimental study which aimed to provide basic experimental data and operational guidance as a reference for practical application in power plants. The co-firing characteristics of sludge and bituminous coal were studied. The results show that the burnout temperature and ignition temperature decrease with an increase in the sludge blending ratio. The Comprehensive Combustion Index (CCI) first rises, then decreases, reaching a maximum at about 15%. Compared with the atmosphere with 79% N2/21% O2, under the 79% CO2/21% O2 atmosphere, ignition is delayed and the burnout temperature is higher. Under an O2/CO2 atmosphere, as the O2 concentration improves, the thermo-gravimetric (TG) curve shifts to the low-temperature region, the burnout temperature drops significantly, and the comprehensive combustion characteristics are improved. With an increment of the heating rate, the curve of TG analysis shifts to the high-temperature region and the CCI increases. This study could provide helpful information on practical blending in coal-fired power plants for energy savings and emission reductions.

Natural dyes have been used from ancient times for multiple purposes, most importantly in the field of textile dying. The increasing demand and excessive costs of natural dye extraction engendered the discovery of synthetic dyes from petrochemical compounds. Nowadays, they are dominating the textile market, with nearly 8 × 105 tons produced per year due to their wide range of color pigments and consistent coloration. Textile industries consume huge amounts of water in the dyeing processes, making it hard to treat the enormous quantities of this hazardous wastewater. Thus, they have harmful impacts when discharged in non-treated or partially treated forms in the environment (air, soil, plants and water), causing several human diseases. In the present work we focused on synthetic dyes. We started by studying their classification which depended on the nature of the manufactured fiber (cellulose, protein and synthetic fiber dyes). Then, we mentioned the characteristics of synthetic dyes, however, we focused more on their negative impacts on the ecosystem (soil, plants, water and air) and on humans. Lastly, we discussed the applied physical, chemical and biological strategies solely or in combination for textile dye wastewater treatments. Additionally, we described the newly established nanotechnology which achieves complete discharge decontamination.

This paper presents a review of the expectations and challenges of using biomass in the prevention and slowing of paraffin wax deposition that takes place during the crude oil production process. The inhibition of the deposition process involves the use of solvents from biomass that are generally available around the crude oil production field. The processes used to scale down the precipitation of wax include mixing crude oil with the manufacturer’s solvent composed of toluene and xylene. The goal is to assess solvents sourced from biomass that are capable to slow down the wax deposition process. Wax appearance temperature is an important characteristic to evaluate the possible wax precipitation of a given fluid. Wax precipitation can be reduced by using some chemical additives, often called the pour point depressant. This additive is expected to be produced from local biomass which can compete with solvents currently produced on the market.

The organic fraction of municipal solid waste (OFMSW) is recognized as a suitable substrate for the anaerobic digestion (AD) process and is currently considered a mature technology. A promising strategy to enhance biogas yield and productivity is the co-digestion of OFMSW with other organic biomass, such as green waste (GW), a mixture of leaves, grass, and woody materials originated from private yards and public greenspace management. The main limitation to the use of GW for biogas production is the high percentage of the lignocellulosic fraction, which makes necessary a pretreatment of delignification to dissolve the recalcitrant structure. In this study, a new strategy of sustainable bio-delignification using the white-rot fungi Bjerkandera adusta (BA) in comparison with other chemical pretreatments were investigated. Untreated and treated GW were, respectively, submitted to anaerobic co-digestion with OFMSW. AD processes were carried out in a lab-scale plant for 30 days in thermophilic conditions (55 °C). Biogas cumulative production was increased by about 100% in the case of treated GW compared with that of just OFMSW, from 145 to 289 Nm3 CH4/ton SV, and productivity almost doubled from 145 to 283 Nm3/ton FM * day. The measured average methane content values in the cumulative biogas were 55% from OFMSW and 54% from GW. Moreover, over 95% of the biogas was produced in 20 days, showing the potential opportunity to reduce the AD time.

The aim of the study was to verify two morphological forms (“angel hair” and “scraps”) of xylit as a trickling filter material. The study was carried out on two types of polluted media: septic tank effluent (STE) and seminatural greywater (GW). The basic wastewater quality indicators, namely, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), ammonium nitrogen (NNH4), and total phosphorus (Ptot) were used as the indicators of treatment efficiency. Filtering columns filled with the investigated material acted as conventional trickling filters at a hydraulic load of 376–472 cm3/d during the preliminary stage, 198–245 cm3/d during stage I, and 184–223 cm3/d during stage II. The removal efficiency of the two morphological forms of xylit did not differ significantly. The average efficiencies of treatment were as follows: for COD, over 70, 80, and 85% for preliminary stage, stage I and stage II, respectively, for BOD5, 77–79% (preliminary stage), for TSS, 42% and 70% during the preliminary stage, and 88, 91, and 65% during stage I, for NNH4, 97–99% for stage I and 36–49% for stage II, for Ptot, 51–54% for stage I and 52–56% for stage II. The study demonstrated that xylit was a material highly effective in wastewater quality indicators removal, even during the initial period of its use.

11 p., [EN] Mine tailing storage represents an important environmental issue. The generation and dispersal of dust from mine tailings can contaminate air and surrounding soils. In addition, metals and soluble salts present in these wastes could pollute groundwater and surface water. The recovery of metals from mine tailings can contribute to minimize the environmental risk and to achieve a circular economy model. The main objective of the present work is to study the use of two carbon-based materials, a commercial activated carbon (AC) and a commercial charcoal (VC) in the leaching of zinc and copper from low-grade tailing waste. Experimental results obtained show that it is possible to achieve the recovery of more than 87 wt% of Zn after 6 h of leaching with different sulfuric acid solutions. The addition of carbon-based materials increases the extraction of Zn at high sulfuric acid concentrations (1 M) from 89% to 99%. The addition of VC significantly increases the extraction of Cu in leaching solution with high sulfuric acid concentration (1 M), from 41 to 61%. Future research will be necessary to optimize the properties of carbon-based materials and their recovery after leaching experiments in order to assess their potential for industrial application, This research was funded by Ministerio de Ciencia e Innovación (Spain), grant number RTI2018-096695-B-C31.

Intensive swine farming causes strong local environmental impacts by generating effluents rich in solids, organic matter, nitrogen, phosphorus, and pathogenic bacteria. Insufficient treatment of hog farm effluents has been reported for common technologies, and vermifiltration is considered a promising treatment alternative that, however, requires additional processes to remove nitrate and phosphorus. This work aimed to study the use of vermifiltration with a downstream hydroponic culture to treat hog farm effluents. A treatment system comprising a vermifilter and a downstream deep-water culture hydroponic unit was built. The treated effluent was reused to dilute raw wastewater. Electrical conductivity, pH, and changes in BOD5, ammonia, nitrite, nitrate, phosphorus, and coliform bacteria were assessed. Plants were monitored throughout the experiment. Electrical conductivity increased due to vermifiltration, pH stayed within a neutral to mild alkaline range. Vermifiltration removed 83% of BOD5, 99% of ammonia and nitrite, and increased nitrate by 11%. Hydroponic treatment removed BOD5 (63%), ammonia (100%), nitrite (66%), nitrate (27%), and phosphorus (47% total and 44% dissolved) from vermifiltered water. Coliforms were reduced by vermifiltration but recovered in the hydroponic unit. Plants showed the ability to grow on vermifiltered wastewater, although requiring nutrient supplementation. Vermifiltration combined with hydroponics is a promising treatment for swine wastewater, although optimization will be needed for a sustainable real-scale implementation.

Residual biomass from various industries represents an important source of valuable compounds, used as raw materials for the production of a wide range of new products and also in various treatment and valorization processes or/and sanitation services, thus responding to the principles of sustainable development, waste recovery, and a green and circular economy. The aim of this work is to make use of residual Bacillus sp. biomass (resulting from a process of removing fatty acids from municipal wastewater) immobilized in alginate that, although it results in large quantities from biotechnological processes, is not reported to be valorized in dye biosorption processes, except in few specific applications. The biosorption potential of residual Bacillus sp. biomass in the reactive Brilliant Red HE-3B textile dye removal from aqueous systems was studied in a fixed-bed column. The effects of various experimental operating parameters, such as bed depth (h), flow rate (Fv), were investigated, and the modeling of experimental data based on Thomas and Yoon–Nelson kinetic models was satisfactorily achieved. The obtained results reconfirm that the studied residual biomass can be also considered as a good biosorbent in dynamic operating system, and can be beneficially used in the treatment of wastewater containing small quantities of organic dyes.

In this study, semi-continuous anaerobic digestion of lignin-rich steam-exploded Ludwigia grandiflora (Lignin = 25.22% ± 4.6% total solids) was performed to understand better the effect of steam explosion on the substrate solubilisation and inhibitors formation during the process. Steam explosion pretreatment was performed at 180 °C for 30 min at a severity factor of 3.8 to enhance the biogas yield of the lignocellulosic biomass. The semi-continuous anaerobic digestion was performed in a continuously stirred tank reactor for 98 days at an initial hydraulic retention time of 30 days and an organic loading rate of 0.9 g-VS L−1 day−1. The performed steam explosion pretreatment caused biomass solubilisation, resulting in enhanced biogas production during the process. During the anaerobic digestion process, the average biogas yield was 265 mL g-VS−1, and the pH throughout the operation was in the optimum range of 6.5–8.2. Due to fluctuations in the biogas yield, the hydraulic retention time and organic loading rate were changed on day 42 (50 days and 0.5 g-VS L−1 day−1) and on day 49 (40 days and 0.7 g-VS L−1 day−1), and 1 M of NaOH was added to the liquid fraction of the steam-exploded L. grandiflora during the latter part of the operation to maintain the stability in the reactor. Therefore, the steam explosion pretreatment helped in the degradation of L. grandiflora by breaking the lignocellulose structure. In addition, changes in the operating conditions of the anaerobic digestion led to an increase in the biogas production towards the end of the process, leading to the stability in the CSTR.

A hybrid anaerobic reactor was operated under the complementary effluents concept to reduce the unbalanced/inhibitory capacity of the provided piggery effluent. Brewery wastewater was chosen to complement piggery effluent (60:40% v/v, respectively). The HRT reduction from 6.7 to 3.0 days allowed the testing of an organic load increase from 4.5 to 10.0 g COD/L·d, which resulted in the almost doubling of biogas production. Biogas volumes (1.2 and 2.1 L/L·d, respectively) associated with its quality (&gt, 77% CH4) revealed that the hybrid anaerobic reactor responded positively to the operational changes and that piggery effluent can be advantageously digested using the brewery wastewater as the complementary effluent. The unit bottom and the packing bed were the main functional sections recognized in the hybrid. At the beginning of anaerobic digestion, bacterial populations belonged mostly to Bacteroidales (33%) and Clostridiales (35%). The process stability and the biogas quality at 3-d HRT were related to a change in the structure composition, since Flavobacteriales (18%), Bacillales (7%), Pseudomonadales (11%) and members of the Alcaligenaceae family (5%) also integrated the microbial communities. An evident change had also occurred in archaeal populations at this phase. Methanosaeta became the dominant genus (95%), confirming that acetoclastic methanogenesis was the main way for methane production.

Energy consumption, because of population development, is progressively increasing. For this reason, new sources of energy are being developed, such as that produced from the combustion of biomass. However, this type of renewable energy has one main disadvantage, the production of waste. Biomass bottom ash is a residue of this industry that currently has not much use. For this reason, this research evaluates its use as a filler in bituminous mixtures, since this sector also has a significant impact on the environment, as it requires large quantities of raw materials. With this objective, first, the physical and chemical properties of biomass bottom ashes were evaluated, verifying their characteristics for their use as filler. Subsequently, bituminous mixtures were conformed with biomass bottom ash as filler, and their physical and mechanical properties were analyzed through particle loss and Marshall tests. The results of these tests were compared with those obtained with the same type of mixture but with conventional and ophite aggregates. This study confirmed that biomass bottom ash was viable for use as a filler, creating mixtures with a higher percentage of bitumen, better mechanical behavior, and similar physical properties. In short, more sustainable material for roads was obtained with waste currently condemned to landfill.

Poultry is a crucial global protein source.However, processing creates sizable quantities of feathers as a by-product. Identifying suitable uses for these feathers poses a major challenge. One possible use would be as an extender in medium density fiberboards (MDF). At the same time, feathers might also modify the inherent fire resistance of the resulting panels, suggesting the need for additives to enhance fire performance. The potential for using feathers to supplement wood in MDF panels was evaluated in conjunction with the addition of wollastonite. The effects of using 5% or 10% feathers with or without 10% wollastonite were investigated. Adding 5% feathers did affect properties. However, simultaneous addition of 10% wollastonite resulted in panels with improved fire performance properties and increased the ability of panels to dissipate heat. The results suggest that feathers could be a resource for extending timber supplies for MDF production, especially with wollastonite to improve fire performance.

The present study evaluates the digestion of cork boiling wastewater (CBW) through a biochemical methane potential (BMP) test. BMP assays were carried out with a working volume of 600 mL at a constant mesophilic temperature (35 °C). The experiment bottles contained CBW and inoculum (digested sludge from a wastewater treatment plant (WWTP)), with a ratio of inoculum/substrate (Ino/CBW) of 1:1 and 2:1 on the basis of volatile solids (VSs), the codigestion with food waste (FW) had a ratio of 2/0.7:0.3 (Ino/CBW:FW) and the codigestion with cow manure (CM) had a ratio of 2/0.5:0.5 (Ino/CBW:CM). Biogas and methane production was proportional to the inoculum substrate ratio (ISR) used. BMP tests have proved to be valuable for inferring the adequacy of anaerobic digestion to treat wastewater from the cork industry. The results indicate that the biomethane potential of CBWs for Ino/CBW ratios 1:1 and 2:1 is very low compared to other organic substrates. For the codigestion tests, the test with the Ino/CBW:CM ratio of 2/0.7:0.3 showed better biomethane yields, being in the expected values. This demonstrated that it is possible to perform the anaerobic digestion (AD) of CBW using a cosubstrate to increase biogas production and biomethane and to improve the quality of the final digestate.

We hypothesized that the type of wood, in combination with the grit size of sandpapers, would affect sanding efficiency. Fixed factors were used in the experiment (a belt sander with pressure p = 3828 Pa, and a belt speed of vs = 14.5 m/s) as well as variable factors (three sand belts (P60, P120, P180), six hardwood species (beech, oak, ash, hornbeam, alder, walnut) and three softwood species (pine, spruce, larch)). The masses of the test samples were measured until they were completely sanded. The sanding efficiency of hardwood species is less variable than for softwood species. Maximum sanding efficiency for the softwood ranged from 1 to 2 min, while for the hardwood species, it ranged from 2 to 4.5 min at the start of sanding and then decreased. The average time for complete sanding of the softwood samples was: 87 s (P60), 150 s (P120), and 188 s (P180). For hardwood, these times were 2.4, 1.5, and 1.8 times longer. The results indicate that the factors determining sanding efficiency are the type of wood, and, secondly, the grit size of sanding belts. In the first phase of blunting with the sanding belts, the sanding processes of hardwood and softwood are significantly different. In the second phase of blunting, sanding belts with higher grit numbers (P120 and P180) behaved similarly while sanding hardwood and softwood.

To realize energy-saving and efficient industrial grain drying, the present work studied the variable-temperature drying process of corn drying in a novel industrial corn-drying system with a heat recycling and self-adaptive control function. The drying kinetics, thermal performance, heat-loss characteristics and the heat-recycling performance of the drying system under different allocations between flue gas and hot air were investigated, and the optimized drying process was proposed and compared with two constant drying processes. The results showed that the optimized drying process exhibited better drying kinetic and thermal performance than the two constant drying processes. More specifically, the total heat loss, total energy consumption and specific energy consumption of the optimized drying process were ascertained to be 36,132.85 MJ, 48,803.99 MJ and 7290.27 kJ/kg, respectively, which were lower than those of the other two processes. On the other hand, the thermal efficiency of the drying chamber for the optimized drying process was ascertained to be varied within the range of 6.81–41.71%. Overall, the validation results showed that the optimized drying process can significantly improve the drying performance of the drying system.

Based on a “filter press backwash–chemical precipitation–gaseous membrane absorption” process, treatment of harmless cyanide tailings was conducted using cyanide tailings from a gold smelting enterprises (Yunnan Province, China) as the research object. The effects of air-drying time, backwash water parameters, initial pH of acidification, NaHS dosage, cyanide-containing water flow rate, and gaseous membrane stages on the process were investigated. Chemical composition, X-ray diffraction, and X-ray photoelectron spectroscopy analyses of the copper products were carried out. Results showed that the copper content in the copper product was 54.56%, and the chemical composition was mainly CuSCN, CuS, Cu2S, and CaSO4. Five cycles of experiments were carried out under optimal conditions, the results showed that the process can make the treated cyanide tailings meet the requirements of the technical specification for pollution control of cyanide leaching residue in the gold industry (TSPC) standard for storage in a tailings pond and a have certain stability. The average recovery rate of copper and total cyanide in elution water was 97.8% and 99.89%, respectively, and the average removal rate of thiocyanate was 94.09%.

The presence of microorganisms, specifically the Escherichia coli, in drinking water is of global concern. This is mainly due to the health implications of these pathogens. Several conventional methods have been developed for their removal; however, this pathogen is still found in most drinking water. In the continuous quest for a more effective removal approach, photocatalysis has been considered as an alternative method for the elimination of pathogens including E. coli from water. Photocatalysis has many advantages compared to the conventional methods. It offers the advantage of non-toxicity and utilizes the energy from sunlight, thereby making it a completely green route. Since most photocatalysts could only be active in the ultraviolet region of the solar spectrum, which is less than 5% of the entire spectrum, the challenge associated with photocatalysis is the design of a system for the effective harvest and complete utilization of the solar energy for the photocatalytic process. In this review, different photocatalysts for effective inactivation of E. coli and the mechanism involved in the process were reviewed. Various strategies that have been adopted in order to modulate the band gap energy of these photocatalysts have been explored. In addition, different methods of estimating and detecting E. coli in drinking water were presented. Furthermore, different photocatalytic reactor designs for photocatalytic inactivation of E. coli were examined. Finally, the kinetics of E. coli inactivation was discussed.

This research focused on the obtainment of sustainable lightweight aggregates (LWAs) for agronomic application. The cleaner production is based on saving matter through the valorization of waste available in industry as a substitute of clays into the formulation of the lightweight aggregates (LWAs). Three different types of clays (white, black, and red) and alternative raw materials were blended. Cattle bone flour ash (CBA) and a fertilizer glass (FG) were used to introduce K and P into the mixture in amounts suitable for fertilizer application, and a sewage sludge from a brewery wastewater treatment plant was used as pore forming agent. For the production of the LWAs, we mixed different percentage of waste in two different clay mixtures, which were thermally treated at 1000 &deg, C for 1 h. Technological parameters such as loose bulk and oven dry density, total porosity, water absorption capacity, pH, and electrical conductivity were determined to evaluate the potential use of LWAs as a growing media. Moreover, scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) techniques were used, and leaching tests were performed to complete the samples&rsquo, characterization. The results indicated the potential for manufacturing high-quality LWAs for the agronomic field by using energy-saving and matter-processing involving low temperatures with respect to the conventional process.

Algal/cyanobacterial biofilm photobioreactors provide an alternative technology to conventional photosynthetic systems for wastewater treatment based on high biomass production and easy biomass harvesting at low cost. This study introduces a novel cyanobacteria-based biofilm photobioreactor and assesses its performance in post-treatment of brewery wastewater and biomass production. Two different supporting materials (glass/polyurethane) were tested to investigate the effect of surface hydrophobicity on biomass attachment and overall reactor performance. The reactor exhibited high removal efficiency (over 65%) of the wastewater&rsquo, s pollutants (chemical oxygen demand, nitrate, nitrite, ammonium, orthophosphate, and total Kjeldahl nitrogen), while biomass per reactor surface reached 13.1 and 12.8 g&middot, m&minus, 2 corresponding to 406 and 392 mg&middot, L&minus, 1 for glass and polyurethane, respectively, after 15 days of cultivation. The hydrophilic glass surface favored initial biomass adhesion, although eventually both materials yielded complete biomass attachment, highlighting that cell-to-cell interactions are the dominant adhesion mechanism in mature biofilms. It was also found that the biofilm accumulated up to 61% of its dry weight in carbohydrates at the end of cultivation, thus making the produced biomass a suitable feedstock for bioethanol production.

Microalgae are an excellent source of bioactive compounds for the production of a wide range of vital consumer products in the biofuel, pharmaceutical, food, cosmetics, and agricultural industries, in addition to huge upstream benefits relating to carbon dioxide biosequestration and wastewater treatment. However, energy-efficient, cost-effective, and scalable microalgal technologies for commercial-scale applications are limited, and this has significantly impacted the full-scale implementation of microalgal biosystems for bioproduct development, phycoremediation, and biorefinery applications. Microalgae culture dewatering continues to be a major challenge to large-scale biomass generation, and this is primarily due to the low cell densities of microalgal cultures and the small hydrodynamic size of microalgal cells. With such biophysical characteristics, energy-intensive solid–liquid separation processes such as centrifugation and filtration are generally used for continuous generation of biomass in large-scale settings, making dewatering a major contributor to the microalgae bioprocess economics. This article analyzes the potential of electroflotation as a cost-effective dewatering process that can be integrated into microalgae bioprocesses for continuous biomass production. Electroflotation hinges on the generation of fine bubbles at the surface of an electrode system to entrain microalgal particulates to the surface. A modification of electroflotation, which combines electrocoagulation to catalyze the coalescence of microalgae cells before gaseous entrainment, is also discussed. A technoeconomic appraisal of the prospects of electroflotation compared with other dewatering technologies is presented.

The avocado (Persea americana Mill.) is a tree native to Mexico and Guatemala. Avocado consumption, fresh or in the form of processed products, is growing everywhere and it has caused a large number of countries to invest heavily in avocado production. The industrialization of avocado gives as a result a huge amount of waste, not only the peel and stone but also that waste generated by the pruning practices and oil extraction. These biomasses could be converted into raw materials to obtain different types of co-products, but this implies changes in the use of these resources, the design of efficient production systems, and integration to take full advantage of them, e.g., by developing biorefinery models. Therefore, this review firstly gives a snapshot of those residues generated in the avocado industry and provides their chemical composition. Secondly, this review presents updated information about the valorization ways of avocado-derived biomass to obtain bioenergy, biofuels, and other marketable products (starch, protein, phenolic compounds, and biosorbents, among others) using a single process or integrated processes within a biorefinery context. Green technologies to obtain these products are also covered, e.g., based on the application of microwaves, ultrasound, supercritical fluids, etc. As a conclusion, there is a variety of ways to valorize avocado waste in single processes, but it would be promising to develop biorefinery schemes. This would enable the avocado sector to move towards the zero-waste principle.

Providing anaerobic digestion is a prospective technology for utilizing organic waste, however, for waste with a high content of nitrogen such as manure, dilution is necessary to decrease the ammonia inhibition effect which leads to the production of a huge effluent amount which is difficult to use. Dry anaerobic digestion has some advantages such as reduced reactor volume, higher volumetric methane yield, lower energy consumption for heating, less wastewater production, and lower logistic costs for fertilizers. These factors generate interest in using it for treatment of even high-nitrogen substrates. The purpose of this work was to analyze different dry anaerobic digestion technologies, the features of dry anaerobic digestion, laboratory studies on chicken manure dry anaerobic digestion, and methods of reducing inhibitors’ effects. Nowadays, there are no dry anaerobic industrial plants working on chicken manure. However, studies on dry anaerobic digestion of chicken manure have proven the possibility of methane production under fermentation of chicken manure with high total solids content, but the process has been described as being unstable. Co-fermentation, ammonium/ammonia removal, and adaptation of the microbial consortium have been used to decrease the effect of ammonia inhibition. A prospective way for ammonia concentration control is absorption using a non-volatile sorbent located in the reactor. It decreases ammonia content during wet anaerobic digestion by 33% and it is characterized by having a positive economic effect. Therefore, dry anaerobic fermentation of chicken manure is possible, but there is still no efficient way to provide it. The results of this article should be helpful in the selection of anaerobic digestion technology for treating chicken manure.

Large-scale eco-efficient production of polyoxymethylene dimethyl ethers (PODEn) has garnered wide attention as environmental-friendly diesel additives. Among the various PODEn research studies, the effect of water on the PODEn process is one of the most important research fields. In this work, the effects of water content in feedstock on the reboiler duty of the PODEn process were analyzed by rigorous simulation. To ensure the accuracy of the model, vapor&ndash, liquid equilibria (VLE) data of PODE2-H2O were measured and the model was regressed by using the experimental data. Furthermore, the production process consisting of raw material preparation section and PODEn synthesis section was evaluated by comparing it with the various water contents (0, 0.05, 0.10 and 0.15 g/g) in feedstock. We found the reboiler duty in the case of 0.10 g/g water in feedstock was lowest (77.99 MJ/kg), which is even lower than anhydrous case (100.24 MJ/kg). The results suggest that the water can be appropriately allowed in the production, which can reduce the reboiler duty of the PODEn.

Wheat straw is an easily affordable, cost-effective and natural source of antioxidants and cellulose, but its full potential is not yet utilized. In the present investigation, an auto-hydrolytic process was applied to recover both antioxidant phenolic compounds and cellulose from wheat straw. Two three-step acid/alkaline fractionation processes were applied differing for the first step: a conventional mild acid hydrolysis or an auto-hydrolysis. The liquors from the first step were analyzed for the recovery of antioxidants, while the final residues from the whole process were analyzed for cellulose yield and purity. The auto-hydrolysis process led to a higher yield in antioxidants but also in sugars (glucose and xylose) and sugar degradation products (5-HMF, 5-MF, furfural) than the acid hydrolysis process. The overall cellulose recovery (about 45% g/100 gcellulose wheat straw dm) and purity was comparable in the two processes, therefore, the auto-hydrolysis-based process could be recommended as a potentially more environmentally friendly process to recover antioxidants and cellulose from wheat straw for different applications. Finally, a first study on the optimization of hydrolysis step was provided from the point of view of improving the cellulose yield, monitoring the sugars release during both the acid hydrolysis and the auto-hydrolysis process.

Intensive agriculture has led to the increasing application of pesticides, such as malathion, thus generating large volumes of untreated cropland wastewater (CropWW). In this work, a hybrid system constructed wetlands (CW) coupled in continuous with an optimized UV/H2O2 pretreatment was evaluated for the efficient removal of malathion contained in CropWW. In the first stage, 90 min UV irradiation time (UV IR) and 65 mM hydrogen peroxide (H2O2) were identified as optimal operation parameters through a central composite design. The second stage consisted of CW planted with Phragmites australis collected from the agricultural discharge area and operated as a piston flow reactor. Furthermore, CW hydraulic residence times (HRT) of 1, 2 and 3 days, including hydraulic coupling, were evaluated. The removal efficiencies obtained in the first stage (UV/H2O2) were 94 &plusmn, 2.5% of malathion and 45 &plusmn, 2.5% of total organic carbon (TOC). In stage two (CW) 65 &plusmn, 9.6% TOC removal was achieved during the first 17 days, from which around 24% was associated to the biosorption of malathion byproducts. Subsequently, and until the operation ends, CW removed about 80% of TOC for 2 and 3 days HRT, with no significant differences (p &gt, 0.2), which is higher than those reported in several studies involving only advanced oxidation processes (AOP) with UV IR times above 240 min and even for systems using catalysts. The results obtained indicate that the system UV/H2O2-CW is a technically suitable option for the treatment of CropWW with a high content of malathion mainly found in developing countries. Moreover, the hybrid system proposed also represent significant reduction in the size of the treatment plant.

Biodiesel constitutes an attractive source of energy because it is renewable, biodegradable, and non-polluting. Up to 20% biodiesel can be blended with fossil diesel and is being produced and used in many countries. Animal fat waste represents nearly 6% of total feedstock used to produce biodiesel through alkaline catalysis transesterification after its pretreatment. Lipase transesterification has some advantages such as the need of mild conditions, absence of pretreatment, no soap formation, simple downstream purification process and generation of high quality biodiesel. A few companies are using liquid lipase formulations and, in some cases, immobilized lipases for industrial biodiesel production, but the efficiency of the process can be further improved. Recent developments on immobilization support materials such as nanoparticles and magnetic nanomaterials have demonstrated high efficiency and potential for industrial applications. This manuscript reviews the latest advances on lipase transesterification and key operational variables for an efficient biodiesel production from animal fat waste.

The main goal of this work was to measure the total alkaloid content (TALC) from pulp, peel, seed, and columella of soursop fruit (Annona muricata L.) by ultrasound-assisted extraction (UAE) and to obtain the best conditions of the UAE with the response surface methodology (RSM). We evaluated the effect of amplitude (40%, 70%, and 100%), time (5, 10, and 15 min) and pulse-cycles (0.4, 0.7, and 1 s) and compared the best UAE conditions of alkaloids with a conventional extraction (maceration). The structural characterization of the raw material with the highest TALC was developed using nuclear magnetic resonance (NMR) techniques [1H, 13C, heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), and homonuclear correlation spectroscopy (COSY)]. According to the RSM, the best conditions in the UAE for extracting alkaloids varied depending on the type of plant tissue. It took 5 min with an amplitude of 70% and pulse-cycles of 1, 0.4, and 1 s, respectively, to extract the highest TALC in peel, seed, and columella while the optimal conditions for extracting the largest amount of alkaloids from the pulp were obtained at 5 min in UAE with pulse-cycles of 0.55 s and 100% amplitude. The TALC was highest in the peel (7.48 mg/g), which was followed by the seed (2.31 mg/g), the pulp (1.20 mg/g), and the columella (0.79 mg/g) and was positively correlated (R2 = 0.98&ndash, 0.88) with the predicted values. In addition, the extraction alkaloids from the peel, pulp, seed, and columella using the UAE was 56.31, 5.45, 3.06, and 2.96 times higher, respectively, than the extraction by maceration. The alkaloids identified in the peel have not been reported and were nornuciferin, assimilobin, anonaine, and isolaureline. This study showed that the soursop fruit peel can be a source of alkaloids and that UAE has an important potential for extracting these compounds.

Fly ash and steel slag both have a good adsorption performance and many researchers have mixed the two to make effective adsorbents. Based on previous knowledge, activated clay is added in this study. In order to deep dephosphorize wastewater, two different industrial wastes (steel slag, fly ash) are blended into activated clay as adsorption substrates, supplemented with a binder and foaming agent to prepare a Residue and Soil Phosphorus Removal Composite (RSPRC). This is prepared to carry out experimental research on the decolorization effect and phosphorus removal characteristics of RSPRC. Meanwhile, a self-developed concentric circular diversion wall adsorption reactor is implemented to study the effect of phosphorus removal. It is found that the addition of activated clay can significantly improve the phosphorus removal performance. The results suggest that the phosphorus concentration in the effluent from the reactor can be stably reduced to below 0.10 mg/L. The concentric circular diversion wall adsorption reactor and RSPRC will have broad application prospects in phosphorus removal.

Biochar as a stable carbon-rich material shows incredible potential to handle water/wastewater contaminants. Its application is gaining increasing interest due to the availability of feedstock, the simplicity of the preparation methods, and their enhanced physico-chemical properties. The efficacy of biochar to remove organic and inorganic pollutants depends on its surface area, pore size distribution, surface functional groups, and the size of the molecules to be removed, while the physical architecture and surface properties of biochar depend on the nature of feedstock and the preparation method/conditions. For instance, pyrolysis at high temperatures generally produces hydrophobic biochars with higher surface area and micropore volume, allowing it to be more suitable for organic contaminants sorption, whereas biochars produced at low temperatures own smaller pore size, lower surface area, and higher oxygen-containing functional groups and are more suitable to remove inorganic contaminants. In the field of water/wastewater treatment, biochar can have extensive application prospects. Biochar have been widely used as an additive/support media during anaerobic digestion and as filter media for the removal of suspended matter, heavy metals and pathogens. Biochar was also tested for its efficiency as a support-based catalyst for the degradation of dyes and recalcitrant contaminants. The current review discusses on the different methods for biochar production and provides an overview of current applications of biochar in wastewater treatment.

© 2020 by the authors. The ubiquitous presence of organic micropollutants (OMPs) in the environment as a result of continuous discharge from wastewater treatment plants (WWTPs) into water matrices-even at trace concentrations (ng/L)-is of great concern, both in the public and environmental health domains. This fact essentially warrants developing and implementing energy-efficient, economical, sustainable and easy to handle technologies to meet stringent legislative requirements. Membrane-based processes-both stand-alone or integration of membrane processes-are an attractive option for the removal of OMPs because of their high reliability compared with conventional process, least chemical consumption and smaller footprint. This review summarizes recent research (mainly 2015-present) on the application of conventional aerobic and anaerobic membrane bioreactors used for the removal of organic micropollutants (OMP) from wastewater. Integration and hybridization of membrane processes with other physicochemical processes are becoming promising options for OMP removal. Recent studies on high retention membrane bioreactors (HRMBRs) such as osmotic membrane bioreactor (OMBRs) and membrane distillation bioreactors (MDBRs) are discussed. Future prospects of membrane bioreactors (MBRs) and HRMBRs for improving OMP removal from wastewater are also proposed.

The significant amount of excess sewage sludge (ESS) generated on a daily basis by wastewater treatment plants (WWTPs) is mainly subjected to biogas production, as for other organic waste streams such as food waste slurry (FWS). However, these organic wastes can be further valorized by production of volatile fatty acids (VFAs) that have various applications such as the application as an external carbon source for the denitrification stage at a WWTP. In this study, an immersed membrane bioreactor set-up was proposed for the stable production and in situ recovery of clarified VFAs from ESS and FWS. The VFAs yields from ESS and FWS reached 0.38 and 0.34 gVFA/gVSadded, respectively, during a three-month operation period without pH control. The average flux during the stable VFAs production phase with the ESS was 5.53 L/m2/h while 16.18 L/m2/h was attained with FWS. Moreover, minimal flux deterioration was observed even during operation at maximum suspended solids concentration of 32 g/L, implying that the membrane bioreactors could potentially guarantee the required volumetric productivities. In addition, the techno-economic assessment of retrofitting the membrane-assisted VFAs production process in an actual WWTP estimated savings of up to 140 &euro, /h for replacing 300 kg/h of methanol with VFAs.

This study describes the exploitation of wood waste (Pinus spp.) in the form of sawdust and shavings generated during the production of furniture and artisanal items in a community in the state of Michoac&aacute, n, western Mexico. A process is described to densifying this raw material, to produce solid-type biofuel briquettes that can be used to satisfy the need to generate low-power heat for residential sectors. Briquette production involved six stages: (a) gathering samples of sawdust and shavings from artisanal workshops in the community, (b) proximal characterization of the samples, (c) elaborating the briquettes, (d) physicochemical characterization of the briquettes, (e) evaluation of the physical-thermal combustion of the briquettes, and (f) an economic evaluation of briquette production to determine viability. Finally, we performed a comparative analysis of the energy, economic, and environmental indicators of the briquettes produced and conventional pine and oak firewood (Pinus spp., Quercus spp.) in the study community. The results show the viability of using biomass residues to make briquettes, which are efficient, economic and easy to make and use.

The present study deals with the experimental research findings for the characteristics of ignition (ignition delay times, minimum ignition temperature) and combustion (maximum combustion temperature, concentration of anthropogenic emission), as well as theoretical calculations of integral environmental, economic, and energy performance indicators of fuel compositions based on coal processing waste with the most typical types of biomass (sawdust, leaves, straw, oil-containing waste, and rapeseed oil). Based on the results of the experiments, involving the co-combustion of biomass (10% mass) with coal processing waste (90% mass) as part of slurry fuels, we establish differences in the concentrations of NOx and SOx in the gaseous combustion products. They make up from 36 to 218 ppm when analyzing the flue gases of coal and fuel slurries. Additionally, the values of relative environmental, economic, and energy performance indicators were calculated for a group of biomass-containing fuel compositions. The calculation results for equal weight coefficients are presented. It was shown that the efficiency of slurry fuels with biomass is 10%&ndash, 24% better than that of coal and 2%&ndash, 8% better than that of filter-cake without additives. Much lower anthropogenic emissions (NOx by 25%&ndash, 62% and SOx by 61%&ndash, 88%) are confirmed when solid fossil fuels are partly or completely replaced with slurry fuels.

Low temperature fluidity and oxidation stability are important indicators for the measurement of the performance of biodiesel, which are currently two major issues in association with the use of biodiesel on diesel engines. In the current work, actors affecting the low temperature fluidity and oxidation stability of biodiesel, such as adding reagents, changing the blending ratio, were studied separately. Then, the influencing factors were comprehensively analyzed to simultaneously improve the low temperature fluidity and oxidation stability of biodiesel through adjusting the proportion of fatty acid methyl esters (FAMEs). The results show that the cold fluidity improver (CFI) exerts the greatest influence on the biodiesel blending oil B10. When the CFI is added to 0.6%, the cold filter plugging point (CFPP) of B10 is reduced to a minimum of &minus, 17 &deg, C. Additionally, blending ratio also has a great influence on the CFPP of biodiesel blended fuel. When the amount of biodiesel added is 5%, the CFPP of biodiesel blended fuel is equivalent to the CFPP of 0 petrol diesel (0PD). When the amount of biodiesel added exceeds 50%, the oxidation induction time (OIT) of biodiesel with different blending ratios can be made greater than 6 h by adding butylated hydroxyanisole (BHA) with a ratio of 0.1%. The CFPP and OIT of the blended fuel increase with the increasing of PME addition ratio. When the blending ratio of palm oil methyl ester (PME) and rapeseed oil methyl ester (RME) is R60P40, the CFPP is 0 &deg, C, and the OIT is 5.9 h.

The hardest obstacle to make use of lignocellulosic biomass by using green technology is the existence of lignin. It can hinder enzyme reactions with cellulose or hemicellulose as a substrate. Oil palm empty fruit bunches (OPEFBs) consist of hemicellulose with xylan as the main component. Xylitol production via fermentation could use this xylan since it can be converted into xylose. Several pretreatment processes were explored to increase sugar recovery from lignocellulosic biomass. Considering that hemicellulose is more susceptible to heat than cellulose, the hydrothermal process was applied to OPEFB before it was hydrolyzed enzymatically. The purpose of this study was to investigate the effect of temperature, solid loading, and pretreatment time on the OPEFB hydrothermal process. The xylose concentration in OPEFB hydrolysate was analyzed using high-performance liquid chromatography (HPLC). The results indicated that temperature was more important than pretreatment time and solid loading for OPEFB sugar recovery. The optimum temperature, solid loading, and pretreatment time for maximum xylose recovery from pretreated OPEFB were 165 &deg, C, 7%, and 60 min, respectively, giving a xylose recovery of 0.061 g/g of pretreated OPEFB (35% of OPEFB xylan was recovered).