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Valorisation involves conversion of toxic compounds into value added products. The present study has tried to evaluate the potential of vermicomposting in management of different types of toxic paper mill wastes such as primary waste (VCP) and secondary waste (VCS) using Eisenia fetida for 60 days. The procedure was performed using sundried samples of paper mill wastes, cow dung and straw in different trial sets using different ratios. The study had revealed that the trial sets (VCP1 and VCS1) using ratio of paper mill waste: Cow dung: Straw (5:4:1) were effective in maintaining physiochemical parameters and different population attributes of earthworm. The present study had also demonstrated the enzymatic enrichment of vermicompost in terms of 19 enzymes such as α-Glucosidase, lipase, leucine aminopeptidase etc. in maintenance of C/N ratio of the compost. A significant reduction of heavy metals were noticed in vermicomposting of primary waste (VCP1) as Zn (40%) ​> ​Pb (36%) ​> ​Cr (28%) ​> ​Cu (25%) and secondary waste (VCS1) as Zn (44%) ​> ​Pb (41%) ​> ​Cu (19%) ​> ​Cr (13%). Such reduction of heavy metal was highly correlated with the reduction of C/N ratio of the vermicompost. The process of bioremediation was further manifested through the regular monitoring of bioaccumulation factor (BAF) among earthworm population in vermicomposting of primary waste (VCP1) as Zn (0.40) ​> ​Cu (0.23) ​> ​Cr (0.18) ​> ​Pb (0.11) and secondary waste (VCS1) as Zn (0.47) ​> ​Cu (0.25) ​> ​Cr (0.21) ​> ​Pb (0.14). Therefore, the study concludes that the ratio of paper mill waste, cow dung and straw (5:4:1) can be an efficient formulation in qualitative enrichment of different toxic organic paper mill wastes through vermicomposting.

The generated gas bubbles in microfluidic fuel cells (MFCs) cover the active surface area of the electrode and greatly limit the cell performance. In this study, a feasible approach is proposed to effectively accelerate bubbles removal and enhance cell performance by embedding a paper separator in the middle of the microchannel. Visualization of bubble behaviors and the corresponding electrochemical measurements are performed to investigate the effect of bubbles on the cell performance. Periodical process of the bubble growth and removal leads to the fluctuation in the current density of the MFC. The rapid gas removal and the low ohmic resistance are observed after embedding a layer of filter paper in the microchannel, causing improved fuel transfer and smaller ohmic loss. Although the current density fluctuates more frequently, the fluctuation amplitude decreases and the cell performance is enhanced. Compared with the MFC without paper separator, the maximum power density and the limiting current density of the MFC with paper separator is increased by 25.2% and 130%, respectively. Moreover, the cell performance is improved with increasing the flow rate of reactant solution and the peak power density achieves 25.9 mW cm−2 under flow rate of 1500 μL min−1.

Social life cycle assessment (S-LCA) is a tool to address social impacts from a life cycle perspective. This work presents the first S-LCA of the Portuguese pulp and paper sector. It presents the social risks and the positive social impacts of the sector, which have not been extensively covered in the scientific literature. Two different approaches were used to compile the social life cycle inventory based on input-output analysis. Approach 1 was based on impact analysis of changes in added value. Approach 2 was based on structural path analysis, supporting the disaggregation by production levels (or tiers). The functional unit was the production of 1 United States Dollar in the Portuguese pulp and paper sector. In the social life cycle impact assessment, the social risk assessment was conducted using the Social Hotspots Database. The positive impacts were addressed considering indicators of employment and remuneration, namely total employment, number of employees, labor compensation, and compensation of employees. Based on Approach 1, the results of the social risks showed the Portuguese pulp and paper industry, commerce and forestry sectors, and the Spanish forestry sector as the critical sectors. Based on Approach 2, Portugal and Spain continued to be the countries having the greatest social risks. Other contributions of countries were identified at different production levels, particularly China in tier 3. In both approaches, the stakeholder category ‘worker’ was the most critical. Regarding the positive social impacts, Approach 1 showed that Portugal and Spain contribute to the highest employment level linked to the pulp and paper, commerce, and forestry sectors. Approach 2 supported the differentiation of employment and remuneration at different production levels. Tier 2 (direct suppliers) presented the highest employment level and people engaged and the lowest remuneration level. The results showed that Approach 1 provides a faster and more aggregated assessment of social risks and positive social impacts. Furthermore, Approach 2 allowed a more detailed evaluation, providing a better understanding of the social risks and positive social impacts on the supply chain. Thus, Approach 2 is encouraged for different applications since it produces a better understanding of where social risks and positive social impacts occur, providing better guidance for corrective measures and decision-making.

To develop functional honeycomb plates (HPs) with great thermal performance, This paper uses a heat flow meter to determine the equivalent thermal conductivity λ E of honeycomb plates (HPs) positioned horizontally under cold-above/hot-below conditions and combined with theoretical calculations, the influence mechanism of their geometric parameters on their heat transfer performance were investigated with different thicknesses h and cell wall lengths of 8 mm and 16 mm (HP8 and HP16, respectively). The results show that the thermal insulation performance of HPs with different cell side lengths varies with the plate thickness. HP8 presented a better thermal insulation performance when h = 40–60 mm. Based on this, the concepts of matching honeycomb structure and matching convection and the suggestions that according to the needs of a project, HP8 or HP16 can be reasonably selected, and the stacking of two kinds of plates can be optimized were first proposed. And it can be obtained that if the experimental λ E results of a HP are applied to a beetle elytron plate with the same thickness and honeycomb structure size, the heat insulation of the beetle elytron plate (BEP) would be superior to that of the HP. This paper lays a theoretical foundation for the research and development of multifunctional BEPs with heat insulation properties was verified. Finally, the internal influence mechanism of the difference in temperature distribution on the upper and lower surfaces and the three-dimensional size of the honeycomb cells on the matching honeycomb structure and matching convection.

In a circular economy, extended producer responsibility (EPR) is a regulatory approach that accounts for all environmental costs associated with a product throughout its life cycle. When considering the EPR, the regulator must (1) design an integrated framework for different stakeholders and (2) provide effective policies to create financial incentives to accelerate the circular system. Recycling funds and subsidies are the most prominent financial strategies that can either encourage or curtail the flows of recycled products. In Indonesia, a few companies provided recycling bonus s to their customers as incentives to increase the recycling rate. However, the recycling rate was not as effective as expected by the enterprise because recycling was practiced by a limited number of companies, rendering it economically unviable. The enterprises hope the government could develop a recycling fund system. In order to develop the recycling fund system, a system dynamic model was proposed and simulated to optimize the recycling funds and subsidies based on decentralized reverse supply chains. Although it is not a novelty model; however, the research show a very significant results for the government in Indonesia. This enabled a more precise, well-planned, and sustainable decision-making process for the EPR. In addition, by utilizing the system dynamic model with different scenarios in a real case study (aseptic paper packaging waste), we found that the capacity of the recycler could become the reference for the funds to be paid by the importer-producer group, wherein the recycling rate will increase with an increase in the recycling fund.

This paper presents a comprehensive approach for improved efficiency of a once-through Benson type coal boiler in a coal-fired power plant. In the method, petrographic properties, ultimate analysis and proximate analysis of coal feedstock is firstly determined. In addition, operational parameters, like O2 concentration, coal mass flow, air/fuel ratio and load were varied to establish their impact on both SO2 concentration and NOx reduction. The coal samples are led by inertinite in the range of 34.4 – 47.8 vol% afterward total vitrinite content in the range of 20.3 – 24.4 vol%. Liptinite content occurs in minor proportions of 1.8 – 4.3 vol% range. The optimum conditions for simultaneous reduction of NOx emission and SOx are achieved when the O2 concentration is 3.58% and coal mass flow of 288 tonnes/hr. Reducing coal mass flow from 331 to 288 Tonnes/hr caused high SO2 concentration to reduce from 3862 mg/Nm3 to 2232 mg/Nm3. Moreover, NOx concentration reduced from 350 mg/Nm3 to 310 mg/Nm3 when the air/fuel ratio varied from the lean side to the rich side. The optimum air/fuel ratio of 7.24 resulted in NOx reduction. The highest boiler efficiency of 90.97% was achieved at full load and the O2 concentration of 3.58%.

Rice husk is an important biomass residue derived from the production of rice. Rice husk contains silica (10–20 wt%) and lignocellulose (cellulose, 15–25 wt%; lignin, 10–20 wt%). The lignocellulose components in rice husk are potential carbon sources for functional carbon materials. In this work, we propose a general comprehensive green utilization strategy for the preparation of lignin-derived hierarchical porous carbon (LHPC) and cellulose-paper-based separator using the lignin and cellulose components inside rice husk, respectively. The obtained LHPC and cellulose paper separators were used as pivotal components for the fabrication of high-rate electrochemical zinc ion capacitors. Meanwhile, the silica and potassium sources in this comprehensive route were recycled as nano-sized SiO2 particles and pure KCl powders. This work constitutes a general route for the green utilization of rice husk biomass. This work opens a green avenue for the effective utilization of renewable biomasses to develop functional carbon materials and pivotal components of electrochemical energy storage devices.

There is growing interest in making printing inks more sustainable, and lowering the overall carbon footprint of the printing industry. A recent surge of research activity has emerged to develop “green” inks with bio-based solvents and binders, but little attention has been given to replacing the pigments that give inks their distinctive color. In this study, flexographic inks were formulated by replacing carbon black with a more sustainable biochar pigment derived from recycled paper, and fast growth cycle wood pulp. Obtained from fossil fuel sources, carbon black imparts high quality black prints, but at a significant environmental cost. Biochar, derived from recycled and renewable resources, has the potential to replace carbon black in many applications. Canceled United States currency stock was pyrolyzed at 1600 °C to produce a black biochar. Eastern White Pine (Pinus strobus) was selected for comparison, and converted to biochar at 550 °C and 1600 °C. Each biochar was functionalized and formulated into a simple ink composition optimized for flexographic printing. Prints exhibiting reflective optical densities exceeding 1.0 with excellent tone reproduction were obtained. Comparable print quality was achieved on both coated and uncoated paper substrates. Although further work would be required to fully optimize a biochar ink to match current print industry standards, a viable pathway for sustainable black ink development with good black density derived from recycled resources has been demonstrated. Our results indicate that it is possible to replace fossil fuel-based carbon black with biomass derived biochar, potentially resulting in cleaner production of flexographic printing inks.

The practice of injecting a coal/biomass blend can alleviate the pressure on carbon emissions and energy of ironmaking blast furnaces (BFs). In this paper, corn stalks treated by hydrothermal carbonization (HTC) are used as raw materials to eliminate the harm of alkali metals in the ash. The overall performance of individual behavior of the hydrochar, coal, and their blends are analyzed over the raceway with special reference to gas flow, temperature, species, and combustion efficiency. The results show that the hydrochar with higher volatile content is faster to devolatilize, showing a higher CO2 content at the nozzle tip, and reaching a higher burnout in the raceway. The addition of hydrochar to coal can improve the overall flow and combustion performance of the blends. The simulated value is higher than the calculated value, indicating the synergistic effect has existed. When the proportion of the hydrochar is 75% in blends, the synergistic effect is most obvious. The model provides an effective tool for the design of coal/biomass blends.

Environmentally friendly flame retardant chemicals are being developed in recent studies as legislation for eco-sustainable textile production becomes more stringent around the world. Utilization of waste generated by the wool spinning industry is a prime concern with present work. The extraction and modification of keratin from waste wool for flame retardant cotton has not been attempted previously. The research describes a unique method for using chemically modified keratin derived from wool waste as an environmentally acceptable nitrogen/phosphorus containing flame retardant for cotton fabrics. Melamine and sodium pyrophosphate were used as nitrogen and phosphorus sources, respectively, along with glyoxal as a cross-linking agent. The improved thermal stability of modified wool waste keratin and treated cotton fabrics was confirmed by TGA, while structural changes were established by FTIR and XRD analyses. Due to the synergistic impact of nitrogen and phosphorous, the modified wool waste keratin resulted in the formation of a continuous and intact layer of char that confers flame retardancy on treated cotton. The limiting oxygen index of cotton after application of the modified keratin showed a nearly 66.7% increase in flame retardancy compared to untreated cotton. Overall, the findings in the paper show a sustainable approach for the textile industry that combines waste utilisation from one textile sector (minimizing solid waste from the wool industry) with waste management elements to add value to another (multifunctional textile finishing agent for the cotton industry).

In lieu of the fact that modern-day research is saddled with the responsibility of replacing/supplementing fossil fuels with biodiesel for use in diesel engines, the challenge still remains the need to improve the properties of biofuels towards stimulating high engine compatibility and performance. Despite the advances made in improving biofuels such as those sourced from Juliflora with additives, none seems to have addressed the potentials that underly the use of hybrid nano-particles as property-improvers of Juliflora-biofuel for use in diesel engines. This then led to the need to harness the potential use of hybrid CeO2:CuO, MnO2:Al2O3, ZnO:TiO2, and TiO2:Al2O3 in different ratios as a means of determining the best combination for improved fuel properties, high engine performance and reduced emissions. The nanoparticles were produced via sol-gel method and ultrasonicated with the biofuel before being characterized using scanning electron microscopy/atomic force microscopy. Based on the engine-test results, the brake thermal efficiency (BTE) increased from 1.11 to 2.21% for the biodiesel mixed with nanoparticles. Furthermore, the Nitrogen oxide (NOx), hydrocarbon (HC) and carbon monoxide (CO) emissions for the admixed biofuels decreased by 16.29–23.76%, 14.07–17.32% and 5.51–8.27% respectively compared to conventional diesel, thus reducing environmental pollution.

In order to explore the feasibility of suitable drying technology of tomato-paste, four solar drying methods were employed, namely (i) Basic Solar-drying Mode (SDM), (ii) Solar-Geothermal Drying (SGD), (iii) Convective Ventilated Solar Drying (CVD), and (iv) Combination of Ventilation and Geothermal Drying (VHD) and their effect on exergy efficiency, economic and quality attributes were investigated. Results showed that the drying time using different drying methods was 10, 9, 8, and 4.5 h for SDM, SGD, CVD, and VHD, respectively. Proposed model could better describe tomato paste drying behavior among eight tested mathematical models. Highest drying efficiency and specific energy consumption were observed for VHD method as 68.27% and 3.21 kWh/kg, respectively. Highest exergy efficiency was recorded for SGD and VHD as 54%. Payback period values were 0.28, 0.325, 0.3, and 0.169 years for SDM, SGD, CVD, and VHD, respectively. Color analysis revealed that CVD method was more suitable with the lowest total color change of 22.41 and highest brightness of the red color of 1.34. SGD method preserved 73.85% and 59.42% of phenol and flavonoid compounds, respectively, while VHD method preserve the highest flavonoid compounds as 82.24% compared to fresh sample. Geothermal energy combined with ventilation is recommended as a suitable drying method for tomato paste in terms of drying time, energy, exergy efficiency, economic, and quality attribute.

To address the challenge of high water consumption, massive wastewater discharge and high pollution risk in textile industries, different countries have chosen various treatment method for textile wastewater according to the location and management of textile enterprises. It is not economical purposely to build separate wastewater treatment plants (WWTPs) for each small-scale enterprise, hence, it is common to treat the wastewater for a group of factories and then complete the treatment via a municipal wastewater treatment plant. However, the complex characteristics of textile wastewater brings some new problems for WWTPs: Textile wastewater contains over 300 mg/L COD, 100 μg/L antimony, 1000 μg/L aniline, some of which are toxic to microbes or non-biodegradable. Coagulation plays an important role in the pretreatment of textile wastewater for removing hydrophobic dyes, decreasing the SS and COD. In this paper, Poly Ferric Sulfate (PFS), Poly Aluminum Chloride (PAC) and Poly Aluminum Ferric Chloride (PAFC) were chosen to improve the biodegradability of the textile wastewater. And then, quantitatively evaluate the biodegradability of wastewater before and after coagulation treatment by analyzing the proportion of different organic pollution, which could be divided into four parts including rapid bio-treated, easy bio-treated, normal bio-treated and non-biological treatment. Results showed that the biodegradability of textile wastewater could be improved by coagulation process, and the contents of organic matter of rapid bio-treated and easy bio-treated could be maximizing when the control condition of coagulation process was optimized. Moreover, because of its characteristics of simple, easy to use, and rapidly online implement, this approach holds a great promise for applications such as investigate wastewater feature deeply, treatment technology optimization, risk control and management.

The building and construction industry is one of the leading generators of waste in the worldwide economy. Use of excessive quantities of virgin materials to manufacture building materials is a growing dilemma that needs urgent attention. With the excessive general of waste, research focus has been directed toward the use of waste to substitute and reduce the requirement for immense extraction of virgin materials. After glass and plastic, cardboard is considered as the most prominent recycled waste material that could possess potential use in mortar and concrete applications, thereby reducing virgin material extraction. The current study aims to conduct a systematic review in using cardboard waste in mortar and concrete. A bibliometric assessment of 874 research publications demonstrated that cardboard waste related studies on mortar and concrete remain seldom considered. An analysis of literature indicated kraft fibres within cardboard can be recycled into building materials. The key findings discovered matrix modification and fibre pre-treatment are essential for the enhancement of mechanical and durability properties. Researchers have developed mix designs including supplementary cementitious materials (SCM) to mitigate fibre degradation and enhance mechanical values. However, further research is required to comprehensively analyse an effective material matrix to reduce the degradation caused on the fibre. Therefore, this paper presents key findings of current trends, limitations and future research directions related to the use of recycled cardboard in concrete and cement-based materials.

Due to the growing concerns of deforestation, renewable materials as recycled cellulosic waste and non-wood fibres provide an alternative solution for partial replacement of wood resources as a reinforcement agent in building material. This study examined the effect of cellulose pulp inclusion on the physical, mechanical, and thermal performance of extruded cement stabilized earth-based matrices. Laboratory experiments of earth-based matrices reinforced with two types of fibres (bamboo pulp and recycled waste carton pulp) at varying fibre contents (0, 5, 7.5 and 10 %wt.) were performed. The results show that the inclusion of recycled waste carton pulp fibre in the soil matrix significantly improved the performance of the composites compared to matrices reinforced with bamboo pulp fibre. Addition of recycled waste carton pulp displayed improvement in flexural strength (56%), in toughness (733%), and in thermal insulation (36.35%) compared to the control sample. Inclusion of recycled waste carton pulp in earth-based matrix increases the moisture loss, the drying shrinkage and behaves as a water reservoir for earth-based materials. It has been concluded from this study that recycled waste carton pulp has the potential as a suitable reinforcement for the promotion of lightweight earthen wall block materials (reduction of bulk density up to 21% after the inclusion of 10% of recycled waste carton pulp), where flexural strength, ductility, and thermal insulation performance are the primary requirements. In addition, the successful replacement of virgin bamboo pulp fibres with recycled waste carton pulp fibres reduces the environmental footprint of the building material. Therefore, the use of this recycled waste carton pulp in the construction industry will be an attractive alternative as it will solve both energy and environmental concerns.

Torrefaction can upgrade the properties of biomass by reducing its oxygen content. In this study, the effects of torrefaction pretreatment on four different lignocellulosic biomass materials at three different temperatures (200 °C, 250 °C, and 300 °C) were studied using a Bosio EUP 6/1200 electric furnace. The results of proximate and ultimate analyses showed that the oxygen content is reduced with a higher torrefaction temperature, while the heating values increased, with 260 °C being the optimal temperature for the process. Among the torrefied products, oak waste wood (OWW, torrefied at 200 °C) had the highest solid yield, 93.2%, while the energy yield was 95.7%, fixed carbon (FC) content 11.8%, volatile matter (VM) content 80.9%, ash content 0.8%, and HHV 19.1 MJ/kg. The TGA/DTG experiments confirmed typical thermal properties for all lignocellulosic biomaterials, while the FTIR and XRD patterns for miscanthus and OWW indicate that the molecular chains of cellulose are broken (damaged) at temperatures higher than 300 °C. Porous ovals were observed at all temperatures in all biomass materials using SEM. SEM images showed that at higher temperatures the ovals started to crack, leading to materials with better grindability than the raw materials. Therefore, we conclude that solid biofuels with properties similar to coal can be produced with torrefaction.

Derived from bio-drying of municipal organic wastes (MOWs), biodried products (BPs) are normally accepted as carbon-neutral and renewable energy sources. In this study, torrefaction at different temperatures was conducted for BPs to upgrade their properties as fuels. The results indicated that high temperatures promoted formation of gases and liquids during BPs torrefaction. Among the gaseous products, the CO2 content was significantly higher than those of CO and H2. In the liquid products, including H2O, benzenes and phenols were two typical components, which coincided with organics devolatilization and lignocellulose depolymerization. Furthermore, the fuel properties of torrefied BPs were upgraded with higher fixed carbon contents (21.95%–29.25%) and heating values (15.15–17.98 MJ/kg) due to the elimination of oxygen-containing volatiles. During combustion of torrefied BPs, the devolatilization of organics was diminished, but the decomposition of lignocellulose was enhanced. Moreover, torrefaction promoted the char combustion with lower activation energy values (151.69–207.76 vs. 160.20–215.56 kJ/mol). In addition, torrefaction reduced the emissions of C O/C–O compounds and enhanced the release of CO2, CO and H2O during combustion. However, severe torrefaction decreased energy yields and the potentials of BPs for energy recovery as fuels. Moderate torrefaction (approximately 250 °C) was suggested to be more beneficial for upgrading BPs.

The article presents the results of the experimental studies of the processes of removing moisture from fairly typical and widespread forest combustible materials, and woodworking waste under conditions of their thermal preparation for combustion. Based on the results of the experiments, the main regularities of the drying processes of woody biomass under conditions of radiation-convective heating have been established. The integral characteristics (characteristic times) of the drying process of forest biomass under typical (for this technology) heating conditions have been determined. The experiments were carried out on equipment that provides a low level of error (less than 3.3%) for determining the main characteristics of the biomass dehydration process. The values of the mass rates of moisture removal (Weva) of four promising (for modern and future power engineering) and fairly common types of biomass have been established in the ambient temperature range from 333 to 393 K, which corresponds to the operating modes of the drying equipment of power plants. According to the results of the experiments, it was shown that at relatively moderate ambient temperatures (333≤ Tg ≤ 353 K), the type of wood has a rather significant effect on the characteristics and conditions of the dehumidification process. At the same time, the process of drying wood chips is much faster compared to other types of biomass. As the ambient temperature rises (at 373≤Tg ≤ 393 K), the influence of the type of biomass decreases. As a result of the experiments, a physical model of the process of removing moisture from the bulk layer of biomass was formulated. According to the results of the experiments, it was found that before burning forest biomass in boilers of thermal power plants, it is most advantageous to carry out drying in conditions of relatively moderate (at 333≤Tg ≤ 353 K) ambient temperatures. The studies carried out provide grounds for justifying the use of forest combustible material as fuel (or one of the components of the fuel mixture) at thermal power plants currently operating on coal.

Reserves of fossil fuel are being depleted, and its use to generate energy also affects the environment. Sustainable and clean energy sources, therefore, need to be produced to meet the demands. In this research, combined blended fuels were produced from cottonseed and palm oil methyl esters with petroleum diesel fuel. To achieve the benefits of palm oil biodiesel (high calorific value) and cottonseed oil biodiesel (low kinematic viscosity and acid value), the combined biodiesel blend (C05P15, C10P10, and C15P05) has been tested to assess their effect on engine performance, emissions, and tribological properties. The physicochemical properties of all fuels were measured following ASTM D6751 standard. A single-cylinder, 4-stroke, and the natural aspiration diesel engine were used for engine testing. The experimental results showed that all combined blended fuels have low brake thermal efficiency and emitted fewer hydrocarbons, carbon monoxide, and smoke opacity apart from nitrogen oxides compared with petroleum diesel fuel. Based on results, the combined blended fuel can be used as a substitute fuel in diesel engines without any engine modifications.

This study investigated the influence of torrefaction (300 °C) on the combustion performances of blends of biomass-plastic wastes (Mango branches (MBr), newspaper (Np), LDPE) using thermogravimetric analysis. The torrefied waste blends were co-combusted with coal at a blending ratio of 25 and 50 wt. % to identify possible interactions between the fuels’ components. Synergistic behaviours were noted during combustion of the torrefied MBr-Np blend and the comprehensive combustion index, Dc was 29 % higher than the predicted value. Interestingly, synergistic interactions were perceived during co-combustion of the different wastes with coal. The measured burnout temperatures (TBO) of all torrefied waste-coal blends were lowered by 6–15 %, compared to their predicted values, especially for MBr-Np-coal blends. Synergistic interactions during torrefaction of MBr-Np not only improved the combustion reactivity of the resulting char but also enhanced coal combustion in the blend compared to combustion of torrefied biomass-LDPE-coal blends. It was concluded that synergies during co-combustion of waste char with coal were governed by the waste type, its composition and the interactions that prevailed during torrefaction of the wastes.

Due to its abundance, biomass is widely used in many engineering applications such as gasification process. Using biomass as a raw material for H2-rich syngas production can not only reduce greenhouse gas emissions but also promote renewable energy utilization. In this study, a multi-stage model for H2-rich syngas production from biomass gasification was developed and studied using Aspen Plus simulator. The model is divided into four sub-models including drying sub-model, devolatilization sub-model, tar cracking sub model and gasification sub model. Performance of biomass gasifier was evaluated by predicting the gas yield, lower heating value of produced syngas, carbon conversion efficiency and cold gas efficiency. The maximum H2 content of 14.9 vol% was achived when S/B and reaction temperature were 1.0 and 1123 K, respectively. The highest CCE of 67.8 % and CGE of 37.9 % were also achieved at 1123 K. An increase in S/B from 0 to 0.5 led to a lower tar yield, which was from 133.557 g/Nm3 to 127.193 g/Nm3, and then leveled off as loading increased further from 0.5 to 1.0. The results also showed that during high S/B conditions, the gas-phase chemistry is dominated by water-gas shift (WGS) and Boudouard reactions.

The fossil fuel concerns pertaining to the cost augmentation, depletion and environmental issues needs to be supported by alternative fuel. This work reports the suitability of tri-fuel blend (diesel, ethanol and di-butyl ether) prepared in various proportions. The tri-fuel blend proportions were endorsed through the high performance thin layer chromatography using the TLC plates. The analysis of variance revealed that the measurements are within 5% of acceptable limits. In addition, the tri fuel blends were investigated on a diesel engine for its performance, emission and combustion characteristics with different engine operating conditions. The qualitative analysis and engine experimentation confirmed the superior agreement within the acceptable limit. The oxygenated fuel blend enlightens the suitability of D40 BE60 blend among the different fuel proportions. The experimentation results disclosed better fuel economy and significant reduction in NOx and smoke emissions. A substantial decrease in smoke density and NOx to the maximum of 43.2% and 17.1% respectively is observed. The D40 BE60 (DBE 45% and ethanol 15%) features an improved heat release rate and also reduced emissions in the diesel engine. Moreover, the exploit of di-butyl ether and ethanol reveals substantiate enhancements in terms of performance and reduction in emission characteristics as compared with diesel. In place of diesel, the proposed fuel blend can be employed, which would contribute less emissions to the environment.

The augmented concerns towards greenhouse emissions have stimulated the innovative technologies to reduce the carbon footprints and lessen the usage of fossil fuel by replacing them with biomass. Wheat straw is a biowaste and has a great potential for energy-production. However, the inorganic contents in the wheat straw cause operational problems such as low heat transfer and ash-deposition in combustion chamber leading to high maintenance requirements. Demineralization of wheat straw with various basic and acidic leaching reagents (NaOH, HCl, HNO3) was investigated in this study. The concentrations of leachants was varied from 0.6, 0.4 and 0.2M to study their effect on physical, chemical, thermal and kinetic behavior of the biomass. The 0.6 M HCl solution reduced the maximum ash content up to 92.71 % and raised the heating value to 3.98 % than raw wheat straw. The kinetic study of the samples treated with 0.6M HCl demonstrated the superior ignition and the activation-energy than other samples. On other hand NaOH damaged the structure of the wheat straw and had adverse effects on their physical and chemical properties. The results of the current study suggested that HCl treated wheat straw can provide a cost effective and eco-friendly solution for energy generation.

Since plants with a high biomass conversion efficiency of light energy consume less energy and require shorter cultivation periods, it is expected that plant factories can have more output with less energy. However, there have been few studies on the biomass conversion efficiency of light energy in various cultivated plants, and this agricultural engineering field is still unexplored. If the amount of energy consumed by a plant factory can be obtained from the biomass conversion efficiency of light energy, the plant types that can be grown in a plant factory and the economic efficiency of the plant factory can be clarified. In this study, we determined the amount of light energy required for plant cultivation by measuring the wavelength distribution of sunlight and plant-growing light-emitting diodes. Also, we investigated the light to biomass conversion efficiency from the amount of heat generated by the biomass of cultivated plants. The light to biomass conversion efficiency was also used to analyze the payback period of plant factories so as to estimate the profitability of various cultivated plants. The solar to biomass conversion efficiency of the tested leafy vegetables ranged from 0.03% to 0.62%, while the efficiency of the cultivation LEDs ranged from 1.21% to 20.1%. The conversion efficiency including the energy consumption of air conditioning ranged from 0.13 to 5.7%. By measuring the biomass conversion efficiency of plants, it is possible to analyze the profitability of plant factories with a high degree of accuracy.

There are world attentions to increase the share of renewable bioenergy in transportation sector to resolve problems of limited fuel reserve and polluted atmosphere. It is reasonable to produce biodiesel from non-edible vegetable oils to overcome any effect on food prices. Current study investigates the effect of castor methyl ester (CME) biodiesel blending ratio (BR) on the determined composition of diesel particulate matters (DPM). The main novelty of this study is to empirically predict the composition of DPM based on measurements of gaseous emissions and other engine parameters operated with biodiesel blends without necessity to follow expensive and time-consumed procedures. The base biodiesel is CME which is mainly mono-unsaturated fatty acids (≈87%) with 6% di-unsaturated and 7% saturated compounds. The empirical mathematical set of equation is used to estimate portions of elemental carbon (EC) and Organic carbon (OC) in DPM in addition to the total mass of emitted DPM based on measurements of gaseous emissions and engine mechanical parameters. Steady state experiments on single-cylinder engine according to ECE 96 five-mode test cycle were carried out. Results of experiments regarding effect of BR on engine performance reveled that (i) blend B10 provided best engine mechanical performance with insignificant efficiency increase, (ii) engine combustion analysis for B10 close to those for neat diesel fuel, (iii) blend B10 emit the lowest level of CO and HC emissions, while blend B30 emit the lowest exhaust opacity with slight change in NOx emissions, (iv) all blends provided DPM emissions lower than those for neat diesel fuel, (v) blend B10 provided the lowest DPM value among all other blends, and (vi) blend B30 provided the lowest EC in the emitted DPM. It can be concluded that (i) use of mathematical models to investigate the structure of DPM emissions is a useful tool, and (ii) even B10 provided the best economic and the lowest emissions with values close to those for B20, it will be more economic to increase the share of renewable energy sources and so to substitute diesel fuel with B20.

The broiler production chain (BPC) has associated environmental impacts, costs, and effects that are not compensated by the Brazilian socioeconomy. The objective of this review was to discuss BPC waste composting from a circular economy perspective. Organic solid waste is a negative externality and the agroindustry must contribute to its internalization, especially in countries with significant production, consumption, and export of chicken meat. The BPC has four main stages of significant organic waste production: reproductive poultry, hatchery, broiler growth, and broiler industry. The principal residues of this industry are reproductive poultry litter, hatchery waste, feed waste, carcasses, truck cleaning solid fraction, flotation sludge, sausage casings, charcoal, and ash. These residues have varying characteristics, such as total organic carbon (TOC) from ranging 4.4–56.22% and nitrogen from 0.2 to 9.33%. It is evident that raw materials, nutrients, and energy are misused throughout the BPC; developing countries especially cannot sustain the loss of these valuable resources. Composting has emerged as a method for mitigating the impacts of BPC waste, however, there are some obstacles. The high nitrogen concentration in BPC residues make balancing the C/N ratio complex. This deficit carbon demands residues from other sectors, such as from tree pruning, cotton residues, raw glycerin, and Napier grass. The produced BPC compost has favorable attributes to be reincorporated into the supply chain as an agricultural input. However, little research has been conducted on the short, medium, and long-term impacts of BPC compost application on different crop and soil types. Cultivations close to BPC facilities which grow broiler feed components (e.g., corn) are attractive for a closed cycle strategy and for approaching the principles of the circular economy.

Blended fuels of run-of-mine (ROM) coal and untreated rice straw (RS) have not yet been used for fuel applications due to their poor fuel performance and the release of pollutants during combustion. Combining co-hydrothermal carbonization (co-HTC) with oxidative acid/alkaline solvents could be useful as a single-pot approach for effectively upgrading ROM coal/RS blended fuels. However, the determination of optimal co-HTC conditions is critical to achieve maximal performance of ROM coal/RS hydrochars. In this study, the Taguchi method was used to investigate optimal co-HTC conditions for the production of hydrochars with desired fuel properties. Characterization of produced hydrochars was performed by elemental analysis, proximate analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and thermogravimetric analysis. Based on calculations of S/N ratios, hydrochar with the best combustibility was produced using the lowest reaction temperature (180 °C) and residence time (4 h), hence minimizing energy consumption. Hydrochars produced under the optimal conditions for the best fuel ratio (FR) and proximate analysis (PA) indices had superior high heating values (HHVs) of 29.4 and 29.0 MJ kg−1, respectively. In addition, synergistic effects from the optimal conditions resulted in lower contents of sulfur and post-combustion ash of the hydrochars.

Anaerobic biotechnology is promising for the recovery of biomethane from organic wastes to mitigate greenhouse gas (GHG). This study aims to evaluate the performance of a domestic pilot biodigester (DPBD) designed for methane production/optimization for use in schools and households besides pollution control. Unpretreated and pretreated chicken manure (CM), waste food, and sewage sludge (SwS) both single and at various ratios were characterised and used to assess the DPBD efficiency. At 21 days retention time, 25rpm stirring, 100 kg single untreated and pretreated substrates and in the ratios of 1:1:0, 1:1:1, 3:1:0, and 3:1:1 was digested. Scrubbing with Fe2O3 chips, activated carbon and water removed H2S and CO2. The average pH of 6.8, the temperature of 25.4 °C yielded 2.7 m3 methane from CM single pretreated substrate. The pretreated 3:1:1 produced an average of 5.94 m3 methane at pH 6.9 and temperature 27.2 °C. Substrates produced low methane in the absence of SwS, while inclusion increased methane. The 40.81 m3 DPBD showed a high biomethane production performance when substrates are co-digested, pretreated with NaOH, neutral pH and mixed with inoculum (SwS). DPBD exhibits the characteristic sustainability of renewable energy synthesis and reduction of compost emissions. The slurry is a rich fertiliser due to high optimum values of NPK nutrients. Kinetic and mathematical modelling of the DPBD biomethane production can be a future study.

Coal preparation plants are increasingly turning to alternative sources of water to reduce their consumption of fresh water, including recycled water. Some of these sources can vary greatly in inorganic electrolyte content. In this study, standard flotation tests were conducted with varying water chemistry. The concentrations of collector, frother and salt, which reflect the water quality, were varied to study the main effect of the reagents with water of varying purity as well as their interactions. The concentration of frother was clearly the most influencing factor for the yield, water recovery and ash. However, it was found that ionic content (or water quality) also had a profound effect. In particular, a higher concentration of salt tended to produce flotation products with a higher ash content. Thus, as regulation of coal preparation plants becomes more stringent and water of varying quality such as process water is used in flotation, the quality of the coal concentrates deteriorate. Thus, the environmentally beneficial practice of recycling water can lead to increased air pollution and waste generation due to an inferior product.

Co-hydrothermal carbonization (co-HTC) has emerged recently as a promising thermochemical technique that can transfer organic solid residue (e.g., biomass, sewage sludge, plastic, livestock manure) into value-added products (i.e., hydrochar). This advanced mechanism conceals the weakness of hydrochars derived from the hydrothermal carbonization (HTC) of a single feedstock. The co-HTC of various feedstock blends used for hydrochar is reviewed in this article. Biomass/sludge, biomass/plastic, biomass/coal, biomass/manure were the most common feedstock blends. Many studies have found that co-HTC, compared to single feedstock, enhances the yield, ultimate and proximate properties, higher heating value (HHV), thermal behaviors, and overall quality of hydrochars. The synergistic effects of feedstock types, blending ratio, temperature, and residence time are also discussed. The feedstock mixing ratio emerges as the most important variable, followed by feedstock types, temperature, and reaction time. Thermogravimetric (TG) and derivative thermogravimetric (DTG) analyses have made it possible to better understand the thermal decomposition characteristics of hydrochars. In most papers on this subject, the range of combustion temperature and comprehensive combustion index (CCI) has increased. Overall, the physicochemical and thermal behaviors of hydrochar derived from co-HTC make it energy-efficient and environmentally sound by reducing the waste load and avoiding pollution issues. Additionally, several important suggestions have been recommended for future advances being made in co-HTC of feedstocks and its comprehensive application.

In this paper, we report on the economic and environmental issues associated with a pyrolysis plant for processing sugarcane residues. The analyses consider four scenarios: (i) raw sugarcane bagasse (SCB), (ii) raw sugarcane trash (SCT) and acid-leached (iii) sugarcane bagasse (L-SCB) and (iv) sugarcane trash (L-SCT). The systems were studied by integrating a comprehensive mathematical model and experimental data. The environmental impact assessment was performed using the Life Cycle Assessment (LCA) methodology, including agriculture and sugar industry stages into the system boundaries. The results demonstrate that the process economy heavily depends on the bio-oil composition, yield, feedstock cost, and leaching conditions. Bio-oil from L-SCT and L-SCB contained more than 30 wt%. levoglucosan, which made it a candidate to produce fermentable sugars or other valuable chemicals instead of being burnt in low-efficiency boilers. The unitary cost of bio-oil produced from L-SCT (0.89 USD/L) and L-SCB (0.75 USD/L) was below that obtained for raw biomass, even when the Total Investment Costs behaved differently. The environmental impacts, expressed in damage categories, associated with L-SCB and L-SCT, were nearly 86% higher than for SCB and SCT. The highest impact could be attributed to the citric acid (CA) production chain, biomass transport, and harvesting operations.

In this work, an integrated conversion system of coal to ammonia (NH3) is developed with the objectives of total energy efficiency maximization and process simplification. The system integrates drying, chemical looping hydrogen production, cryogenic nitrogen separation, NH3 synthesis, and power generation. Due to this integration, the total exergy destruction from each individual process, as well as the whole system, can be reduced significantly, leading to high energy efficiency. Several operating parameters, including mass fraction of oxygen carrier, reduction temperature, oxidation temperature, operating pressure, and conversion per pass during NH3 synthesis are evaluated. Low-rank coal with a flowrate of 100 t h−1 (moisture content of 65.5 wt% wb) is used as the feedstock, while Fe2O3 is adopted as an oxygen carrier. From the results, the system shows high total energy efficiency (NH3 production and total energy efficiencies of 58% and 60%, respectively) and significant system simplification. Higher Fe2O3 mass fraction lowers the total flowrate of circulated material in the chemical looping module. Moreover, lower reduction temperature and higher combustion temperature are preferred due to lower amount of circulated material in the chemical looping module. Conversion per pass of 40% during NH3 synthesis leads to largest NH3 production amount, which is 40 t h−1.

Ultrasonication lysis-cryptic growth is an efficient, green method for the source reduction of excess sludge. However, the commonly used high-intensity ultrasound (HIU) suffers from high energy consumption and poor effluent quality. We explored the feasibility of low-intensity ultrasound (LIU) for sludge yield reduction. Batch activity assays indicated that an ultrasound specific energy (Es) of 2000 kJ/kg dry sludge (DS) could increase the dehydrogenase activity of the sonicated sludge by 30%. Further testing of the ultrasonic stimulus using a sequential batch reactor (SBR) showed that LIU reduced the sludge yield rate by 21.53% when the proportion of sonicated sludge (SP) was 20%, without affecting sludge dehydrogenase activity, effluent quality and sedimentation performance. Compared with that obtained with HIU, the sludge reduction rate obtained with LIU was reduced by half, but its energy consumption efficiency (EE) was 4 times higher (0.0606 kg DS/kWh). Repeated ultrasonic experiments confirmed that dehydrogenase activity reached a maximum of 60% after the sludge was sonicated once and decreased rapidly after two or more repeated ultrasonic irradiation cycles. Therefore, LIU application to a portion of the sludge achieved a balance between sludge activity and destruction, thereby promoting sludge reduction without effluent deterioration.

International audience; In Normandy, the marine macroalgae become a large problem when the retreat of the tide leaves large quantities of stranded seaweed on coast. These stranded seaweeds can be toxic during their degradation in addition to creating odor problems. Consequently, their elimination has become a major problem and their recovery an emergency. In this work, we proposed to use the stranded seaweed in the building construction at a large scale. We investigated in particular the performance of insulated walls based on lightened earth incorporating reed and stranded Laminaria digitata seaweed at different substitution level. The compressive strength and the hygrothermal properties of the earth insulated walls specimens were carried out. Our results show that the incorporation of seaweed in lightened earth improves both its heat storage capacity and its level of insulation without compromising its compressive strength. The most efficient seaweed content for improving the thermal insulation of the material seems to be 20%. Indeed, the addition of 20% of Laminaria digitata decreased the thermal conductivity by 34% at 20 °C in comparison with standard cob. For this mixture, the specific heat capacity value is around 800 J.kg−1.K−1 at 20 °C, which are very high compared to that of the only earth-fiber specimen (400 J.kg−1.K−1). These increases in mechanical and hygrothermal performance of insulating cob material incorporating seaweed will lead to a reduction of the cob walls thickness and therefore to the development of sustainable energy efficient building materials with a low environmental impact.

The disposal of coal slime has attracted increasing attention due to its increasing production and consequent environmental pollution. The co-combustion with biomass is a promising method for the treatment of coal slime. However, there are only a few studies on coal slime and biomass co-combustion. This study investigated the co-combustion characteristics and gaseous pollutant emissions of coal slime with camphor wood and wheat straw. The results showed that there are significant interactions between biomass and coal slime during the co-combustion process. The addition of biomass reduced the ignition and burnout temperature and enhanced the combustion stability of the blends. Meanwhile, the addition of biomass inhibited the emission of NO and SO2 from the blends. Moreover, the kinetic analysis showed that the activation energies of biomass char and coal slime combustion stage decreased with increasing biomass content, indicating that biomass's addition improved the combustion reactivity of the blended fuel. The results provide basic knowledge regarding the thermal behaviour and emission characteristics of coal slime and biomass co-combustion. It was established that co-firing is beneficial for the clean and efficient utilisation of coal slime.

In this study, bituminous coal and two aquatic biomasses, Ulva lactuca and Hydrilla verticillate, were selected as the raw materials for studying the ash slagging behavior. Furthermore, Ulva lactuca was pretreated by washing with water and acid; the influence of pretreatment on ash transformation was subsequently studied. Co-firing tests were performed in a drop tube furnace and the SO2 content in the flue gas was determined using a flue gas analyzer. The chemical compositions and mineral phase properties of the collected ash were studied using several analytical techniques, including ICP, XRF, SEM-EDS, and XRD, as well as thermochemical software Factsage 7.2. The results indicated that the most extreme agglomeration of coal co-fired with Ulva lactuca was due to the increased content of alkali metals, especially K. Pretreatment can effectively reduce the slagging trend of co-fired ash. Acid washing had a higher removal rate of S and alkali and alkaline earth metals but did not show a lower slagging tendency when co-firing with coal. The SO2 emissions during co-firing were less than the value calculated by linear interpolation but much higher than the SO2 emissions when coal was burned alone.

In this work, 138 datapoints, including elemental composition and ultimate analysis of various types of sewage sludge, and the hydrothermal carbonization reaction conditions, are used to develop a prediction model for the nitrogen content of the hydrochar. The results suggested that a two-layer feedforward neural network with five (05) neurons in the hidden layer can accurately predict the nitrogen content of the hydrochar based on the reaction temperature and the contents of nitrogen, carbon, volatiles and fixed carbon in the feedstock. Over 100 runs, the R2 and RMSE are in [87.547–99.097%] and [0.243–1.431] wt.% (db), respectively. Moreover, a statistical and regression analysis revealed that the sewage sludge-N is the main contributor to the hydrochar-N. Mostly, 40–70% of sewage sludge-N goes to hydrochar-N. The results are consistent with previous experimental reports, and this model can be used to predict the sewage sludge-derived hydrochar-N.

Microbial fuel cell (MFC) technology allows renewable energy production from the decomposition of organic matter present in wastewater. This technology, however, poses challenges that hinder scaling up of its usage in practical implementation. Also, resource recovery from the available waste sources is attracting attention due to the immense amount of valuable nutrients present in the wastewater. Herein, the present study focuses on investigating high-performance anodes, that is, using a stainless-steel brush (SSB) and carbon brush (CB) to accommodate the MFC in terms of energy production, leading to transformation into a microbial nutrient recovery system (MNRS) for nutrients’ recovery from wastewater. The present novel SSB anode system generated a stable voltage of ∼0.4V and a maximum power density of ∼400 mW/m2 whereas CB anode system produced the voltage and maximum power density of ∼0.5 V and ∼800 mW/m2, respectively. Besides, using the MNRS process, recovery of nutrients in terms of PO43− (80–83.4% for CB-MNRS and 60–69.5% for SSB-MNRS when using feed PO43− concentration of 10–20 ppm) and NH4+ (63–80.64% for the CB-MNRS and 52–70% for the SSB-MNRS when using feed NH4+ with a concentration of 10–20 ppm) was achieved.

Bioconversion technology has paved the way for solving the contradiction between population growth, food production reduction, and global environmental degradation because of its ability to convert organic waste into high-value products (including plant biostimulants) and stabilize organic materials. However, the current literature review and reference framework of biostimulants in bioconversion compost of organic waste have not yet surfaced. With the great advantages of bioconversion technology, this review focuses on combing and summarizing the biostimulants components (represented by betaines, chitin, humic substances, protein hydrolysates, and beneficial microorganisms) in bioconversion compost (larvae bioconversion compost and vermicompost) and their agricultural application. In addition, the complexity of the action mode of plant biostimulants produced in bioconversion compost, as well as the existing knowledge gaps, challenges, and opportunities, were also discussed in order to give full play to the potential and agricultural application value of bioconversion technology in the future.

Increasing global energy demands requires a versatile approach, prompting many researchers to focus on renewable biofuel from sustainable resources, especially second-generation lignocellulosic biomass. The utilization of lignocellulosic biomass for biofuel production requires proper pre-treatment in biorefinery to increase the reaction rate in the subsequent enzymatic hydrolysis step. Consequently, operational cost, enzymes and other chemical agents consumed and amount of waste produced are reduced. In this review, the latest trends in green pre-treatment methods of lignocellulosic biomass are presented and discussed, spanning the years from 2018 to 2021 and every terrestrial biomass type. Green pre-treatment methods such as ozonolysis, ionic liquids, deep eutectic solvents (DES), organosolv and steam explosion are scrutinized for their optimal process parameters that maximize lignin degradation, hydrolysis sugar yield, as well as minimize reaction time, reagent consumption and energy consumption. The potential of green biofuel production by applying green pre-treatment methods are elaborated, and future perspectives for the utilization of green pre-treatment technology at industrial scale are also presented.

Clean dyeing technologies for polyester textiles, particularly waterless dyeing, have been studied extensively in recent decades. In the present work, a new waterless dyeing technology, the silicone medium dyeing, for polyester textiles had been investigated. The dyeing process of polyester textile in the silicone medium was optimized by determining the dyeing temperature, holding time, type and dosage of dye accelerator. The dye uptake of disperse dye and the fastness properties of the dyed polyester were equivalent to those of conventional water-bathed dyeing. After dyeing, polyester textile had a better color levelness. From the TGA and XRD results, it can be proved that silicone medium has no adverse effects on the fiber and can be used as a dyeing medium. The influence of the increase of halogen in the diazotized component on the affinity, dye uptake, diffusion coefficient, and other parameters was obtained by analyzing the dye uptake of C.I. Disperse Orange 44 and C.I. Disperse Yellow 163. These parameters formulate guidelines for the selection of disperse dyes for silicone medium dyeing system. To verify the feasibility of industrialization, pilot-scale dyeing was carried out. The results showed that, as compared to aqueous dyeing, higher colorfastness and better color levelness were obtained from silicone media. Therefore, this eco-friendly dyeing technology has considerable potential to become a mainstream dyeing method in the foreseeable future.

Wastewater treatment plants play a key role in preserving the resources of the environment, as well as human health. The applied technological system of a wastewater treatment plant determines the efficiency of wastewater and sewage sludge treatment, but also energy efficiency and operating costs. The aim of the presented work is to analyse the technological unconventional system of a small wastewater treatment plant with some modifications generating ecological profits, mainly the fertiliser, biomass or peat substitution ("biosolids factory" concept). The modification of the technological system consists in the application of sewage microfiltration, conditioning of sewage and sludge with cellulose material and application of short-term thermo-composting (Bionor technology). The use of a belt filter for suspension separation reduces the load on activated sludge bioreactors and aerobic stabilisation. The basic modification is the use of thermo-composting of separated sewage sludge with the addition of a structure-forming agent (straw pellet). Importantly, no precipitating or flocculating chemical substances or agents are used in this technology. The technology used enables the processing of sewage sludge into biomass with high fertilising and energy potential. In the following work, the Life Cycle Assessment (LCA) of a wastewater (and sewage sludge) treatment plants was made, comparing different possible concepts of sewage sludge management. The LCA was performed on five applied sewage sludge treatment scenarios: incineration of biomass (S1); biomass as a fertiliser product - "fertiliser substitution" (S2); biomass as a soil addition - "peat substitution" (S3); biomass as both fertiliser and a soil addition - "fertiliser and peat substitution" (S4); and biomass as a filling without any substitution benefits - "no specific use" (S5). The LCA analyses of the Bionor sludge technology applied in the wastewater and sewage sludge treatment plant confirm the environmental benefits and minimise the environmental impact with conventional solutions. The fertiliser and peat substitution scenario cause the least impact on climate change. This scenario was found as beneficial for avoiding net CO2 emissions (-5.8 kg CO2 eq/1 m(3) wastewater) and eutrophication potential (-1.7 to -2.0 kg N2O eq/1 m 3 wastewater, -2.78 to -3.0 PO4 eq/1 m(3) wastewater). The eco-toxicity study also showed low impact potentials for a land application scenario. Incineration of biomass yields higher environmental impacts than any application scenario (13.8 kg CO2 eq/1 m(3) wastewater). The LCA analysis confirmed that the peat substitution scenario was found as the most valuable. Web of Science 319 art. no. 128655

Biochar is biomass that has undergone pyrolysis and contains many pores; therefore, it can effectively be used as a building material. This experiment aims to improve the thermal performance of artificial stone finishes used as interior veneers. A phase change material (PCM) with a high latent heat performance and biochar, an eco-friendly material, were used in the experiment. n-Octadecane was incorporated into lightweight aggregates; spruce tree, rise husk, and miscanthus straw biochars were utilized. The strength performance of specimens using biochar was found to be slightly degraded when 6% biochar was incorporated, and biochar use within 4% was found to yield similar or higher strength results. Moreover, the thermal conductivity decreased as the amount of biochar in the mixture increased; these thermal conductivity characteristics depended on the pore characteristics of the biochar type. It was demonstrated that the use of 6% biochar reduced the peak temperature of the specimen by 4–5 °C. Using biochar that reuses waste can have environmental benefits; biochar can facilitate efficient use of thermal energy and indoor temperature control when used in combination with PCM.

Perfluorinated compounds (PFCs) are largely used in textile auxiliaries for the water/oil repellent finishing and have been listed as substances of very high concerns globally. Quantifying the generations and emissions of PFCs from textile and dyeing enterprises is of great significance to realizing the cleaner production management. In this study, congener- and isomer-specific PFCs were measured in regulation tank influent and final effluent from 48 textile plants in the Yangtze River Delta, China. The median ∑17 PFC concentrations in influent and effluent were 428.5 and 268.0 ng/L, respectively. Short- and medium-chain homologues accounted for three-quarters of the total PFCAs in these wastewater samples. Isomeric fingerprints showed an overwhelming occurrence of linear isomers rather than branched ones for PFOA, PFOS and PFHxS. This implied that PFCs in textile wastewater might not be exclusively from a 3M electrochemical fluorination (ECF) source. Raw materials played an important role in PFCs distributions since significantly higher levels of PFHpA, PFHxA, PFNA, PFDA, PFUnDA and PFTrDA were found in wastewater from chemical fibre manufacturing than from manufacturing of other materials. There was no significant discrepancy in PFCs removal rates between different treatments techniques. Although ecological risk assessment revealed an absent health risks of PFCs from effluent in the short term, the implement of textile cleaner production warrants concern due to the high volumes of water per unit fabric for processing. The widespread PFCs occurrence in textile wastewater highlighted the urgency of PFCs removal and disposal. We also encouraged the replacement of synthetic substances with natural materials, adoptions of technical improvements, and innovations such as life cycle analysis or cluster process management in the development of the textile industry.

In recent years, the evaluation of aging behavior of different types of asphalt mixture has become an important research field in pavement engineering. The short-term and long-term aging properties of reclaimed asphalt concrete (RAC) under the effects of vegetable/mineral oil rejuvenators are introduced in this research. Eighteen specimens of reclaimed asphalt binders classified by rejuvenator contents and types were evaluated. The viscosity of aged/unaged reclaimed asphalt binder was measured at different temperature. The results proved that the type and content of rejuvenators have significant impacts on the viscosity values of the reclaimed asphalt binder. The reclaimed asphalt binders with vegetable oil rejuvenators have lower viscosity, which also demonstrated a less increase than that with a conventional mineral rejuvenator. Less weight loss, lower complex modulus G* and lower increase rates were also found in the reclaimed binders with vegetable oil rejuvenators than that with mineral oil rejuvenators. Less weight loss, lower complex modulus G*, and lower increase rates were also found in the reclaimed binders with vegetable oil rejuvenators than that with mineral oil rejuvenators. With various RAC were determined by the Marshall design method, the results of indirect tensile strength test (ITST) displayed that the aging procedure increased the ITS of RAC. Furthermore, the results of resilient modulus test, indicated that aging did not significantly increase the resilient modulus for RAC with vegetable oil rejuvenators.

Due to growing environmental concerns mainly related to non-renewable fuels and high added-value chemicals, new solutions should reduce greenhouse gas emissions. Biorefineries, which use lignocellulosic biomass as raw material, emerges as a promising alternative to replace fossil fuels and to avoid competition between food and fuel production for arable land and drinking water. Sugarcane is one of the most harvested crops in the world, mainly in the equatorial zone. One tonne of processed cane generates between 300 and 400 kg of bagasse. This work proposes a biorefinery configuration for the co-production of ethanol, xylitol, lignin, and cellulose acetate, analyzing two different scenarios in the context of low sugarcane availability. The analysis included the determination of mass, total capital investment, total manufacturing costs, CO2 footprint, and water consumption. The cellulose acetate, ethanol, and xylitol production were economically viable only if lignin is considered a product. Positive net income, with return on investment in at least ten years, was achieved. Based on the environmental assessment, the carbon capture capacity is about 400 kg per tonne of sugarcane included in the process was determined.

This study evaluated the potential of ultrasonic enhanced Fenton-based advanced oxidation to reduce toxicity, total phenol (TPh) and organic matter (COD) from olive mill wastewater (OMW). Emphasis was also placed on suggesting a sustainable treatment strategy in the light of accumulated scientific evidence, indicating the role of Fenton-based oxidation in the suggested scheme. Fenton oxidation and Fenton-like oxidation (with Fe2+ and Fe3+) were tested as selected advanced oxidation methods. The experiments were conducted in such a way that the individual removal efficiencies of ultrasonication and advanced oxidation processes be evaluated separately and in sequence. The impact on toxicity removal was tested by means of a standard respirometric method, also currently used to assess biodegradation in wastewaters. Response Surface Methodology (RSM) involving central composite design (CCD) was implemented to assess the optimum conditions. Results highlighted the merit of Fenton-based oxidation with an 80% TPh reduction and a decrease of toxicity down to the narrow margin of 13–17%, together with a COD reduction of 20–26%, all quite meaningful for the following step of biological treatment. The ultrasonic pretreatment also proved to be quite useful as it secured up to 40% of particulate COD dissolution. Studies on particle size distribution of the OMW clearly showed that preliminary treatment including advanced oxidation would leave behind the bulk of soluble COD accumulated below the size of 3 nm. Accordingly, co-treatment of OMW diluted with municipal sewage was recommended after a pretreatment sequence of holding/plain settling; chemical treatment and Fenton-based oxidation. For OMWs with low particulate COD (VSS) content, Fenton-based oxidation enhanced by ultrasonic pretreatment would be a viable option in the view of effective particulate COD dissolution achieved in this study when coupled with ultrafiltration, prior to joint biological treatment with sewage. The study highlighted advanced oxidation as an indispensable step in the treatment of olive mill wastewaters.

Livestock waste products have been shown to be a viable source of biofuel. Although research have shown that animal excreta may be used to produce bioethanol, there are scanty of reports on the use of piggery (Sus scrofa) excreta for bioethanol production. The goal of this study was to produce bioethanol on a modest scale from pig excreta using a conventional anaerobically fermentation technique with Saccharomyces cervices. Using piggery excreta, we were able to produce 0.765–1.02 gm/200 mL of 89.59 percent pure bioethanol. Gas chromatography (GC) was used to evaluate the single distilled solvent generated from the pretreated (with 4% H2SO4) and fermented pig excreta, which indicated 89.59 percent purity and a retention time of 4.104 min that was closer to absolute ethanol values. The signal peaks indicating the CH3, OH, and CH2 groups of ethyl alcohol were detected employing proton nuclear magnetic resonance (1H NMR) analysis of the fermented distilled colourless from pig excreta. The antibacterial activity of bioethanol was also evaluated against several gram positive and negative pathogens, and the minimum inhibitory concentration (MIC) was found to be between 11 and 25 g/mL. The potential of piggery excreta as an alternative source of bioethanol production and antibacterial agents were identified in this early investigation. In view of public health concerns as well as pollution prevention, pig manure disposal is a critical concern. In developing countries, industrialized small-scale pig farming has exploded, but the environmental issues that come with it have yet to be fully recognized. This research might lead to a more inventive and intelligent method for piggery waste/excreta disposal. As a result, policymakers may wish to consider adopting this approach for piggery farm waste/excreta management in the future, resulting in cleaner production and improved environmental conditions.

Furfural is an organic compound that is widely used in the chemical industry for manufacturing various products, such as pharmaceuticals, pesticides, and solvents. Furfural production from biomass feedstocks can be achieved through various conversion pathways (e.g., pyrolysis or hydrolysis), however, it requires further investigation to reduce the total cost and meet the market needs. This study proposes a multi-objective decision making framework to compare techno-economic and environmental aspects of pyrolysis and hydrolysis technologies for furfural production from sugar beet pulp. Life cycle assessment method is applied for investigating the environmental impacts of converting organic materials to intermediate bioproducts (e.g., bio-oil) on-site, near collection area, using a portable refinery unit. The techno-economic assessment employs an optimization model for minimizing the upstream and midstream costs (e.g., collection, transportation, and production). Sustainability assessments are conducted on a real case study in southern Idaho, USA, to evaluate and verify the methodology and demonstrate the application of this study. The results show that the total cost for furfural production, using pyrolysis and hydrolysis, are approximately $846 and $980 per metric ton, and total emission is 267 and 1095 kg CO2 eq. per metric ton, respectively. Therefore, the pyrolysis pathway results in lower emissions and costs due to the high-water demand and low energy-density feedstock transportation associated with the hydrolysis pathway. It is concluded that portable operations near collection sites can reduce the total costs and emissions, and consequently stimulate sustainable furfural production by addressing upstream and midstream challenges.

Mercury pollution from artisanal gold mining causes severe environmental and health problems, especially to operators and people living around the processing facilities. Over 2000 tonnes/a of mercury is released to the environment by the artisanal miners which is the largest man-made source of mercury pollution. Here we present a novel method using a local plant, cassava, common in many artisanal mining areas in Latin America, Africa, and Asia, to dissolve gold from ores. In our experiments, we used a liquid by-product of cassava flour manufacturing, “manipueira” to leach gold from the gold ore. It contains hydrogen cyanide, generating from the hydrolysis of cyanogenic glycosides in the cassava plant. The results were very promising to replace the use of mercury, as approximately 50% of the gold content was extracted from the ore in 24 h.