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The global cement industry produces over four billion tonnes annually. In recent years, the quest for increasing energy efficiency has led this industry to test and use “waste” materials as alternative fuels (AF). The objective of this study was to examine the use, as alternative fuel, of the shredded non-recycled plastics and paper residue (NRPP) of a materials recovery facility at the Balcones plant in San Antonio, Texas; this material has a Lower Heating Value (LHV) of about 17 MJ/kg and is called “engineered fuel” (EF). The results showed that EF consists of mostly paper fiber, a biogenic material, so its use helps to decrease CO2 emissions from cement production. In the US, on an average about 4.3 MJ of thermal energy are used to dry, decompose, and sinter the carbonate minerals to produce one kg of “clinker” that is then ground to cement powder and mixed with other compounds. If the maximum amount of EF that can be used by the U.S. cement industry (83 million tonnes of cement per year) were to be separated at Material Recovery Facilities and used as alternative fuel in cement kilns, the diversion of non-recycled paper and plastics from landfills would amount to 17.7 million tonnes of EF. The general methodology used for the Life Cycle Assessment (LCA) is Eco-indicators 99 that uses the SimaPro database and four scenarios were assessed. The corresponding chemical structure of the EF was calculated and the associated emissions during combustion were determined. The laboratory analyses determined the average makeup of the sampled fuels consisted of 20% fossil based carbon and 80% biogenic. The use of EF in the cement industry reduces greenhouse gas emission by up to 3 tonnes of CO2 per tonne of EF used in place of a high-quality coal. The study also found that use of EF in cement production has no adverse effect on the stack emissions of cement plants, nor on the quality of cement produced. The mercury concentration in the stack gas of U.S. cement kilns is well below the U.S. standard and the total dioxin emissions of all cement plants amount to only 0.05% of the dioxins emitted by all U.S. sources. Furthermore, the cement process incorporates the residual ash in the EF into the final clinker, thus resulting in both energy and materials recovery.

Sustainability measurement in economics includes assessment of environmental and economic effects in an integrated manner. In this study, system level economic data are integrated with environmental impacts determined from a life cycle assessment (LCA) of a common product. We adopt a costing methodology that captures conventional costs, but additionally incorporates externality costs to present a convenient, easily interpretable metric. Green Net Value Added (GNVA) is a type of full cost accounting that incorporates total revenue, the cost of production, depreciation, and environmental externalities. We present externality costs disaggregated by upstream sectors, full cost of production, and GNVA to evaluate the relative sustainability of Bounty® paper towels manufactured at two production facilities. We found that the longer running, more established line had a higher GNVA. The predominant components contributing to externality costs come from the stationary sources in the supply chain: electricity generation (27–35%), refineries (20–21%), pulp and paper making (15–23%). Health-related externalities from Particulate Matter (PM2.5) and Carbon Dioxide equivalent (CO2e) emissions are to a great extent driven by electricity usage and emissions by the facilities, followed by pulp processing and transport. Supply chains for other facility purchases, product distribution, and end-of-life management contribute the least to the environmental health-related costs.

The forest sector is vital in Europe, providing economic and social benefits to communities. However, this sector is also responsible for some environmental impacts, and it is crucial to ensure that these impacts do not outweigh the benefits described. For this reason, this paper proposes an environmental and economic assessment of three forest wood products – uncoated woodfree paper, natural cork stoppers, and particle boards. The life cycles of these products were modeled using foreground data and a life cycle assessment was conducted to determine the environmental impacts associated with these three life cycles. For the economic assessment, the net present value method was adopted. From the results, it is possible to conclude that the utilization of 1 ha of forest land for 100 years to plant Eucalyptus globulus used in the production of uncoated woodfree paper generates the least environmental impact per euro. A sensitivity analysis was conducted to determine the reliability of the results achieved given the uncertainty associated with the data used to model the three life cycles. The same critical impact categories and the same critical life cycle stage (raw materials’ extraction) were identified for the three systems under study. Given these similarities, an effort must be made by the forest sector to reduce the impacts of these categories and this life cycle stage. To assist on this task, a set of generic and industry-specific recommendations is provided for companies operating in the forest sector.

Developing monitoring system for paper industrial wastewater treatment system is an important route for wastewater reuse and recycling from wastewater, which are regarded as effective way for cleaner production. A novel hybrid deep leaning CLSTMA model, which based on sequential fusion convolutional neural network (CNN), long short term memory (LSTM) and attention mechanism (AM), was developed to monitor the water quality in a full-scale paper industrial wastewater treatment system for energy conservation and emissions reduction. The hybrid CLSTMA model for predicting water quality of paper industrial wastewater treatment system was divided into three steps: spatial information fusion by using CNN module, temporal information fusion by using LSTM module and variable weighted calculation by using AM module. Compare with other models (CNN, LSTM and CLSTM models), RMSE of CLSTMA model for the effluent chemical oxygen demand (CODeff) reduced by 23.3–31.55%, MAE of CLSTMA model reduced by 38.89–74.50%, R of CLSTMA model increased by 8.29–11.86%. For the effluent suspended solids (SSeff), compared with CNN and LSTM models, RMSE of CLSTMA model reduced by 10.26% and 9.92%, MAE of CLSTMA model reduced by 5.37% and 3.44%, R of CLSTMA model increased by 15.13% and 37.21%, respectively. While, R of CLSTMA was consistent with CLSTM model, but RMSE and MAE of CLSTMA model reduced by 16.07% and 7.49% than the CLSTM model. Simulation results demonstrate that the proposed CLSTMA model has a great potential in monitoring paper industrial wastewater treatment system for cleaner production.

Biobased and biodegradable polymers are a promising solution for agricultural plastics problems, especially for pollution and toxic residue from disposed non-degradable plastic mulch films. Application of biobased and biodegradable mulch films has been hindered by poor mechanical properties and higher cost than conventional plastic mulch film (polyethylene and poly (vinyl chloride)). This work explores the performance of multi-layer fertilizer-infused mulch papers fabricated via blade coating and melt compression molding with biodegradable poly (butylene succinate) (PBS), poly (hexamethylene succinate) (PHS), and their copolyesters. The water absorption, tear propagation properties, enzymatic degradation, and fertilizer release behavior of these multi-layer constructions are characterized. The influence of processing methodology on the coating performance is also discussed. It was found that a polymer concentration of 90 mg/ml in the blade coating process increased the coating thickness to about 30 μm, which slowed water absorption; however, the composition ratio of PBHS polymer coatings had little effect on water absorption. The coatings improved the tear propagation resistance up to 3 N (comparable with that of PE mulch film, 1.6 N) and biodegradation resistance of MP in soil. In this work, PHS coated MP provide an optimal strategy for the dual functions of mulching and fertilizer controlled release, as demonstrated by the barrier properties, degradation rate and mechanical properties. Plant growth trials demonstrated improved fertilizer utilization from slow-release coated papers, as shown by acceleration of the blossom and root growth.

The aim of this study is to enhance the use of agro-industrial byproducts and to address the environmental concerns by a novel method of co-production of thermoplastic composites with a solid residue constituting biorefinery. Accordingly, the reuse of 10–30 wt. % solid residues (SRH) from the enzymatic hydrolysis of recycled paper sludge (PS) in the production of thermoplastic composites with polypropylene (PP) was investigated. Thermal properties, water absorption, tensile strength and morphology of the prepared composites were evaluated. Higher thermal stability, rougher and wetter surface, and characteristics of a brittle material were observed in PP-SRH composites in comparison to the pristine PS-PP composites and the neat PP. The water absorption increased with increasing amount of SRH, but in lower proportion compared to other common raw materials used in the preparation of composites. Use of SRH resulted in similar or better properties compared to the composites made with the unhydrolyzed paper sludge, suggesting that SRH has potential for recycling and utilization as filler in the development of thermoplastic composites.

The papermaking industry has developed rapidly in recent years in China. Papermaking is a high-energy-consuming process. Consequently, large-scale paper mills usually have cogeneration systems that supply both electricity and steam for the papermaking process. In China, almost all these cogeneration systems in paper mills are powered by coal combustion, which consumes a large amount of energy and emits large amounts of greenhouse gas. The Integrated Gasification Combined Cycle (IGCC) technology is regarded as a clean and efficient method of coal utilization. In this work, an IGCC process for application in paper mills was designed and modeled. An IGCC coupled with a cascade refrigeration process (CRP) was further proposed in order to reuse the waste heat from the dryer section and improve the energy efficiency of the papermaking process. A paper with a conventional cogeneration system, one with an IGCC cogeneration system, and one with an IGCC coupled with a CRP cogeneration system were analyzed and compared in terms of energy efficiency, capital investment, operational cost, and dynamic payback period. The results showed that the integration of IGCC technology allows paper mills to be more competitive than those featuring conventional cogeneration systems in terms of energy efficiency and operational cost.

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.

Microbial fuel cell (MFC) is considered to be a sustainable technology for cellulosic waste treatment and energy recovery; however, studies on cellulose-degrading exoelectrogens are scarce. Giant panda gut microbiota may provide potential cellulose-degrading exoelectrogens due to consumption of high-fiber diet. In this study, strain LZ-P1 isolated from giant panda gut simultaneously showed cellulose-degrading and electricity-generating characteristics. 16S rRNA gene sequence revealed 99% homology with Cellulomonas iranensis. Results showed that the strain generated 1.08 U/mL endoglucanase and 180 mV electricity when cellulose was used as the sole carbon source. Genome sequence confirmed that strain LZ-P1 possessed complete cellulose degradation and extracellular electron transfer pathways. Proteomic analysis further confirmed that the enzymes involved in cellulose-degradation and extracellular electron transport were remarkably up-regulated, including endoglucanases, riboflavin biosynthesis protein, and cytochrome C oxidase. When strain LZ-P1 was applied to MFC-mediated paper recycling wastewater treatment, a maximum power density of 44.05 mW/m2 and 8.72% coulombic efficiency were recovered in 72 h. Therefore, strain LZ-P1 would be a potential candidate for cellulosic waste management and energy recovery.

Recycling and recovery of materials from used products is one of the major avenues to reduce material throughput. Ideally, all materials are anticipated for being reused by the economy an infinite number of times. In reality, recovery of secondary materials may be difficult because of high costs, or because of degraded quality compared with virgin materials. The search for potential reduction of throughput in material cycles should be based on a knowledge of the limits to repeated cycles. To gain understanding of recycling limits, we developed a method to estimate the actual reduction potential for each throughput in a material's multi-cycle life. First, we investigated the material flow system of paper in Taiwan, and developed a supply chain network of paper flows. Systematic elaboration of the flows revealed where paper can be recycled and where paper can be lost. Second, we estimated the reduction potential with a material input–output Markov chain model, which maps the distribution and loss of materials on the supply chain processes. The model estimated the quantities and the life pathways of recycled materials across continuous life-cycles. An indicator was used to quantify the total performance of the material across repeated life-cycles. This method offers an opportunity to examine practices that approach the limit of reduction. This case study shows that the use and separation of paper waste after discarding may need to be reformed to extend the life-cycles of the material.

Recycling wastewater of the pulping and paper-making industry are widely considered for clean production, which heavily rely on the timely and accurate monitoring in paper-making wastewater treatment processes. A novel predicting model based on genetic-deep belief network algorithm was proposed to improve the predictive accuracy and reliability for process monitoring. Considering the deep belief networks (DBN) as a deep learning model is aiming to describe the relationship among variables in a complex process modeling, genetic algorithm (GA) was employed to reduce the input variables dimensionality, simplify the network structure and overcome the dynamic characteristic difficulties of process data in monitoring. Compared with DBN and back propagation neural network (BPNN), the GA-DBN effectively achieved a better predictive accuracy than other tests models in complex wastewater treatment processes. The value of the coefficient of determination of GA-DBN model is increased by 1.71–1.86% and 5.21–9.32%, respectively. The GA-DBN model can be structured with fewer variables or samples to describe the complex paper-making wastewater treatment process, obtaining the better model performance and predictive accuracy.

Due to production technologies such as blasting, transportation, and loading, large quantities of dust are produced in surface mines. This dust not only pollutes the environment but also restricts the development of coal mining enterprises. This work aims to use waste paper as raw material for the efficient extraction of cellulose, in which waste materials can be converted to useable materials. This work can broaden the sources of raw materials and provide new methods for the efficient preparation of dust suppressants. As a matrix, sodium carboxymethyl cellulose is a novel crust-dust suppressant that is synthesized by graft copolymerization with polyvinylalcohol and N-vinylpyrrolidone in this study. The results of experiments revealed the high purity of sodium carboxymethylcellulose prepared in flotation for 20 min, the degree of substitution DS > 0.8, and the viscosity of 2% aqueous solution>300 mPa s, which can satisfy the requirements of the experiments. The microscopic reaction and structure of the product are analyzed by infrared spectrometry, scanning electron microscopy and thermogravimetry, and the microscopic mechanism of a crust-dust suppressant is investigated. The reaction process and structural characteristics of the product were analyzed by infrared spectroscopy and scanning electron microscopy, and the product reaction process and final structure were deduced. Thermogravimetric experiments showed that the product had strong thermal stability and ensured the performance of the product during use. This paper reveals the combination of dust suppressants and coal via molecular dynamics simulation. The product performance experiments show that the product has a high shell strength of 98 HA, satisfactory freeze-thaw resistance and high temperature resistance, permeability higher than 15 mm/min, and dust suppression rate of approximately 88% when the wind speed reaches 15 m*s−1 and it can degrade without pollution. In general, the product can effectively suppress coal dust and other forms of dust.

Remediation of contaminated soil can be performed by using various techniques, which must be adequately tailored for each specific case. The aim of this research is to critically evaluate the potential use of red mud and paper ash and a combination of the two as immobilization additives for the remediation of contaminated soil from one of the most polluted sites in Slovenia. The proposed procedure involves the preparation of geotechnical composites made from contaminated soil and mixed with 25 wt% of immobilization additives and an optimal quantity of water to achieve consistency, at which maximum compaction according to the Proctor Compaction Test procedure can be achieved. The results reveal a positive, time-dependent trend for the immobilization of potentially toxic elements in the composite with paper ash, because of the formation of the new hydration products with potentially toxic elements. In a composite containing only red mud, potentially toxic elements were immobilized by sorption mechanisms with no general time-dependent trends. The composite with a combination of additives demonstrates the remediation characteristics of both red mud and paper ash. Using this approach excavated contaminated soil, red mud and paper ash can be successfully recycled in the proposed composites, which can be beneficially used in situ for rehabilitation of contaminated sites. Nevertheless, mobilization of some potentially toxic elements at high pHs may represent a limiting factor and has to be taken into the consideration when a combination of red mud and paper ash is used as immobilization additive.

Indonesia’s internationally- and domestically-significant pulp and paper industries source their feedstock from tree plantations. A suite of regulatory (Indonesian Sustainable Production Forest Management Certification and Timber Legality Verification) and market instruments (forest certification) have been introduced to promote sustainability and legality of production from tree plantations, and some producers have also adopted other voluntary sustainability measures. This study investigates sustainability and legality compliance by actors in an Indonesian pulp and paper value chain as a case study of environmental innovation. Results are based on primary fieldwork along segments of the value chain, and analysis of audit reports and other publicly-available information. The value chain sources fibrewood from tree plantation concessions and pallet wood from a variety of suppliers. Audit reports suggest high levels of compliance with sustainability and legality requirements, but our research suggests that these reports might not reflect some area of poor performance and non-compliance. We identify weaknesses in the design of regulatory systems, and in auditing and monitoring processes, as the principal reasons for these deficiencies. Drawing on relevant theory and on practice elsewhere, we suggest that compliance and sustainability can be improved by addressing key areas of regulatory silence, by shifting auditing to be more performance-than paper-based, by strengthening independent monitoring from civil society, by increasing the frequency of witness auditing from the National Accreditation Board, and by fostering synergies between regulatory instruments and voluntary forest certification. These changes would improve the effectiveness of regulatory and voluntary instruments to promote cleaner production in Indonesian pulp and paper value chains.

Generation of fines and ultra-fines is a concept that mining and metallurgical sectors can never shy away since the beginning of coal exploration. These coal fines and ultra-fines are what coal mines regarded as waste material without economic value until the present moment. Poor technologies in the past led to stockpiling of large quantities of fines and ultra-fines. Increase in mechanization in the coal mining industry has also led to the generation of large quantities of coal fines and ultra-fines. Several techniques in the mineral processing sector have been explored to beneficiate the coal fines and ultra-fines. The explored beneficiating technologies include enhanced gravity separation, oil agglomeration, flotation, flocculation, spirals, water only cyclone and dense medium cyclone. These beneficiating technologies have their own limitations when treating fine and ultrafine coal. Major limitations were operation cost and separation efficiency. However, many researchers have improved these beneficiation technologies in terms of cost and separation efficiencies producing clean coal product that meet the end user product specifications. This paper reviews recent developments in beneficiation technologies of coal fines and coal ultra-fines.

In this study, we developed and demonstrated an integrated closed eco-system for pollution reduction and prevention in rice-paper producing and livestock farms in a small-scale craft village which is located in a dry region of Vietnam with a lack of available surface water sources. The system is developed on the basis of material and energy exchange potentials between the wastewater and exhaust gas flows, and the use of available firewood ash as material for absorption. Two operation modes were presented aiming at a complete treatment of wastewater and exhaust gases as required by the Vietnamese national standards, and the recovery of valuable components in the system (N, P) for obtaining value-added products (such as fertilizer, irrigation water, etc.). In addition, the maximization of potentials on existing natural conditions at the local family, the avoidance of chemicals used in the system etc. have also helped to lower the investment and operation costs of the treatment facilities. The application of this system also contributes to the “greening” of the rice production chain in the Mekong Delta, Vietnam and is an example for a local closed cycle economy. Several public activities have also been conducted at the demonstration site (at the local family) with the purpose of maintaining and multiplying the system's effectiveness among the local public community.

The pollution of water resource and shortage of clean water have become increasingly severe, developing an urgent demand of reliable, efficient yet low-cost material for everyday water purification. In the present work, a superhydrophobic paper tissue-based SiO2/PDMS composite has been prepared for both oil absorption and water-in-oil emulsion separation. The fabrication process is quite simple since it takes the full advantage of tissue that has naturally strong capillary force of which allows the material to absorb oil from water much more rapidly and completely (>99.9%) even under harsh conditions. The study has shown the novel material is exceptionally efficient in separating water-in-oil emulsion under gravity but no need of extraneous pressure. A variety of emulsions has been proven with high flux (>2,000 L m−2 h−1) and high separation efficiency (>99.4%). It is believed that this study has proposed a highly reliable and efficient, low cost strategy in both oil absorption and water purification, which shed light on water treatment of both civil use and industry.

The limited water supply of the Metropolitan Area of Mexico City has become a challenge for local companies. The region's aquifer is listed as closed due to pressure on the water supply as a result of growth in manufacturing as well as increased domestic water use. The environmental, economic and legal benefits of a cleaner production scenario studied were highly encouraging; implementation of cleaner technologies reduces water extraction by up to 16 times. While initial investment is high, the internal rate of return rate is approximately 35% per year, implying a three year return on initial investment. Under this scenario, the business complies with environmental regulations, avoiding great amounts of water extraction and future wastewater discharge, thus conserving this vital resource. This study proves what Silvo et al. (2009) states that In the longer run the combination of the Integrated Pollution and Prevention Control permit approach with other regulatory and voluntary policy instruments taking into account the results of system assessments such as Life Cycle Assessment could potentially produce eco-efficient solutions. Thus, for this industry, cleaner production pays off in the long run.

Life Cycle Assessment (LCA) is a well-established and informative method of understanding the environmental impacts of consumer products across the entire value chain. However, companies committed to sustainability are interested in more methods that examine their products and activities' impacts. Methods that build on LCA strengths and illuminate other connected but less understood facets, related to social and economic impacts, would provide greater value to decision-makers. This study is a LCA that calculates the potential impacts associated with Bounty® paper towels from two facilities with different production lines, an older one (Albany, Georgia) representing established technology and the other (Box Elder, Utah), a newer state-of-the-art platform. This is unique in that it includes use of Industrial Process Systems Assessment (IPSA), new electricity and pulp data, modeled in open source software, and is the basis for the development of new integrated sustainability metrics (published separately). The new metrics can guide supply chain and manufacturing enhancements, and product design related to environmental protection and resource sustainability. Results of the LCA indicate Box Elder had improvements on environmental impact scores related to air emission indicators, except for particulate matter. Albany had lower water use impacts. After normalization of the results, fossil fuel depletion is the most critical environmental indicator. Pulp production, electricity, and fuels for product production drive fossil fuel depletion. Climate change, land occupation, and particulate matter are also relevant. Greenhouse gas (GHG) emissions by pulp, electricity, papermaking, and landfill methane from the disposed product, drive climate change impacts. Pulp provides significant offsets to balance climate change impacts due to sequestration of atmospheric carbon dioxide. Ninety-nine percent of land occupation is for the growth of the trees for pulp production. Papermaking, electricity, and pulp production cause the most potential particular matter formation.

Due to rapid deforestation, the paper industry is facing problems like shortage of forest based raw materials, cost increment and negative effects on the environment including increasing air, water and soil pollution. In India, agro residues utilized in stubble burning could be used as a sustainable fiber resource for papermaking, but the paper made from these possesses poor strength properties. Considering the multiple advantages of using agro residues and weak strength properties of the paper made from these, this study was conducted. The effect of blending hardwood pulp and agro pulp with cationic starch or chitosan at wet-end of papermaking with and without subsequent surface sizing using oxidized starch was explored. As a wet-end additive, chitosan dose of 0.5 kg/t was more promising than cationic starch dose of 5 kg/t with all pulps. Paper was produced from 85% agro and 15% hardwood pulp and 0.5 kg/t of chitosan at wet-end after surface sizing with oxidized starch. It improved the tear index, Taber stiffness, double fold and air permeance by 2.7%, 6.5%, 170%, and 300%, respectively with 18.4% decrease in Cobb60 as compared to paper made with 100% hardwood pulp. FTIR analysis was further done to evaluate the effect on crystallinity ratio and energy changes in hydrogen bonds in the papers of differently blended pulps after surface sizing. The study signifies the enhancement in strength and surface properties of paper made using agro pulp after addition of biopolymers at wet-end with and without surface sizing.

Industrial productivity is often judged solely by the primary product's marketability, while opportunities for secondary products derived from process by-products are often overlooked. In paper mills, large volumes of moisture-rich paper mill residuals (cellulose sludge) are produced, for which commercial use is currently difficult. Port Hawkesbury Paper LP, Port Hawkesbury, Nova Scotia, produces over 7 t/hr of waste sludge with a seasonally-dependent dryness ranging from 25 to 38% (w/w). Various chemical or mechanical dewatering options exist; however, knowledge of the unique sludge composition and properties is essential to predicting how the product will react under each method. Sonication, Fournier rotary press technology, freeze/thaw cycling, and gravity drying were among the dewatering opportunities briefly explored outside of the chosen method, acidification. Notably, many industries utilizing dewatering technologies may not be producing value-added by-products, while geographic and climatic placement may limit processes which are possible for others. In the present study examining enhanced end-use value, further dewatering occurred through a comparative in situ experiment contrasting sulfuric acid and ferric sulfate acidification (direct acid injection into sludge). While both proton donors acidified the sludge and decreased moisture content, sulfuric acid was the more cost-effective option, yielding an ∼4% increase in dryness, with commensurate economic and environmental benefits.

Waste generation from groundnut and sugarcane industries are at high alarming rate due to their disposal constraint. These wastes are currently used as a raw material for the production of compost, fuel, alcohol, and paper. Cellulose and its derivatives are being used in many industries like paper, pharmaceutical, and energy owing to its physicochemical properties. Application of cellulose in the leather industry uses cellulose derivatives as finishing chemicals such as nitrocellulose, ethyl cellulose. In the current study, an attempt has been made to find the application of cellulose from groundnut husk and sugarcane bagasse as an auxiliary chemical in leather finishing. Cellulose is extracted from wastes by modified acid hydrolysis method to enhance the yield. Extracted cellulose has been characterized and compared with commercial cellulose sample. From the characterization studies, it confirms that extracted cellulose matched with commercial samples. Extracted cellulose used in leather finishing as an ingredient to upgrade the low-quality leathers, which primarily have grain damages. Cellulose with different concentration of plasticizer has been used in the base coat along with binders and pigments. Finished leathers have been characterized to understand the physical characteristics. From the various analysis, it ascertains that the cellulose has imparted fullness to the finished leather without impacting the aesthetic property. The study provides a better utilization of sugarcane bagasse and groundnut husk wastes in leather industry leading to effective waste management prototype.

[EN] Current wastewater treatment plants (WWTPs) paradigm is moving towards the so-called water resource recovery facilities in which sewage is considered a source of valuable resources. In particular, urban WWTPs are crucial systems to enhance phosphorus (P) recycling. This paper evaluates the implementation of a P-recovery system in Calahorra WWTP combining the operation of a new sludge line configuration coupled to a struvite crystallisation reactor at demonstration-scale. This new configuration consisted in the elutriation in the gravity thickener of the mixed sludge contained in the mixing chamber in order to reduce the phosphate load to the anaerobic digestion. The results indicated that the P available in the primary sludge overflow was nearly five times more than the obtained for the conventional configuration (1.88 vs. 0.39 gP/kg sludge treated), and the uncontrolled P precipitation inside the anaerobic digester was reduced by 43%. Regarding the total P entering the WWTP, 19% of the total P could be recovered with the new configuration proposed in comparison with 9% in the previous conventional configuration. The average recovery efficiency in the crystallisation plant was 86.9 0.4%, yielding a struvite recovery of 8.0 +/- 0.6 kg/d (0.67 +/- 0.04 kg/m(3) fed to the crystalliser). The potential struvite production with the new configuration would be around 41 kg/d (15 t/y) crystallising the thickener supernatant which could be increased up to around 103 kg/d (38 t/y) treating all the P enriched streams (thickener supernatant and centrate streams). The paper demonstrates that WWTPs can contribute to reduce P scarcity, resulting in environmental and economic benefits. (C) 2019 Elsevier Ltd. All rights reserved., This work was co-financed by the European Financial Instrument for the Environment (LIFE +) as part of the PHORWater Project (LIFE12 ENV/ES/000441). The authors also like to acknowledge the support received from Consorcio de Aguas y Residuos de La Rioja and from EDAR del Cidacos (Calahorra).

This paper reviews various aspects of the enzymatic transesterification method to convert used cooking oil to biodiesel. The goal of this paper is to provide a thorough overview from general biodiesel production processes, reaction conditions, challenges, and solutions for higher biodiesel production yield through introducing various microorganisms that are capable of producing the enzymes required to convert used cooking oil into biodiesel. The characteristics, composition, and advantages of the used cooking oil, as feedstock for biodiesel, is also discussed. In addition, the existing transesterification methods including homogeneous alkali-catalyzed, homogeneous acid-catalyzed, non-catalytic reaction under super-critical conditions, and enzyme-catalyzed reactions are explained. Furthermore, the advantages of the enzymatic method over other methods, and the enzymes, which are the key elements of such reactions, are discussed. Lipases are the most promising enzymes currently known for biodiesel conversion. The physiological and physical properties of microbial lipases, the catalytic mechanisms of the enzymes, various methods of enzyme immobilization such as adsorption, covalent and affinity binding, entrapment, and the whole-cell immobilization are also reviewed. At the end, three case studies demonstrating unique and efficient enzymatic transesterification approaches are presented.

The research on the preparation of activated carbon co-activated by hydrothermal carbonization and pyrolysis was uncommon and less experiments used ultrasonic assisted impregnation. The synergistic effect of two catalysts had certain research value. There are still just a few studies on the performance prediction of activated carbon. In this paper, wheat straw, corn straw and sorghum straw were used as the raw materials. ZnCl2 and H3PO4 were used as the catalysts for the synergetic catalysis. Hydrothermal carbonization combined with pyrolysis was used to co-activate with the ultrasonic auxiliary impregnation method in order to prepare straw activated carbon. The straw activated carbon was characterized by different means and the principle of the method was analyzed. Then the performance prediction models of straw pyrolytic activated carbon using methylene blue number and iodine number as the main evaluation index based on Linear Regression, Support Vector Regression, Random Forest Regression were proposed and compared. The results indicated the three kinds of straw showed similar characteristics in the preparation of straw pyrolytic activated carbon whose specific surface area reached 1258.3927 m2/g, 1101.8430 m2/g and 1060.9723 m2/g respectively. The Random Forest Regression model was the most suitable. The n_estimators was set to 10. The evaluation indexes of the model were all good. It demonstrated the three kinds of straw were highly efficient precursor for the preparation of activated carbon used to remove dyes from wastewater. The preparation method in this paper combines the advantages of physical and chemical activation. The prediction model will accelerate the utilization of straw resources, realize the controllable and clean preparation of straw activated carbon and reduce environmental pollution.

This study uses municipal sewage sludge (MSS) as a fertilizer for cultivating Pennisetum hybridum (hybrid Giant Napier grass). The effects of the MSS treatment on the chemical composition of Pennisetum hybridum and on the properties of paper made from its pulp were investigated. The study found that the holocellulose content of Pennisetum hybridum exceeded 72% and the fiber length reached 0.83 mm for one-year-old MSS treated plants. The tensile index of paper made from Napier grass fiber increased by 194% after beating. SEM observation revealed that the Pennisetum hybridum fiber bonded more tightly after beating. The content of carboxylic acid groups was similar in the fibers of 3-month-old and 1-year-old hybrid Giant Napier plants, and higher than that for 1.5-year-old plants. The present research demonstrates that Pennisetum hybridum fiber is suitable for pulping and paper-making after fertilizing treatment of the plants with MSS, which provides new ways for MSS utilization.

This paper investigates the feasibility of dyeing cotton fibers with solution extracted from date pits which are abundant vegetal material. The extraction step and its optimization were conducted in the first part of this paper. This second part studies the influence of the main dyeing conditions on the color yield K/S and the CIELab coordinates. The studied parameters are pH of the dye bath, temperature and duration of dyeing. Experiments were carried out using Box-Behnken experimental design to be able to analyze the main effects of each parameter, to detect interactions between these parameters and to deduce optimum conditions for dyeing process. The fastness properties of dyed samples were also evaluated. Obtained results indicate interesting sweat, washing and rubbing fastness in the range of 4–5. Three metallic mordants (Alun, ZnSO4 and CuSO4) and three biological mordants (gall nuts, chlorophyll (a) and green almond shell) were used to improve the degree of absorption as well as the color fastness of cotton fabrics dyed with aqueous extract from date pits. The obtained results showed high improvement of fastness (sweat, friction, washing and light fastness) for biological mordants than the metallic ones.

This paper aims to evaluate the feasibility of hydrothermal liquefaction (HTL) of Radiata pine with black liquor from an existing Kraft pulp mill. The biomass into the HTL process was assumed at 2000 t/day and converted into bio-crude through the HTL process and upgraded to produce a gasoline and diesel blend. The HTL process was scaled-up based on an existing published patent. Mass and heat balance of the process was obtained through the process simulator, Aspen Plus. Process Integration was carried out to minimise the hot and cold utility of the process. The production rate of the process is 78.7 kt/y of fuel. The minimum fuel selling price (MFSP) was estimated at 0.95 USD/LGE (litre gasoline equivalent). A sensitivity analysis was carried out to determine the MFSP in 2017 and to study the changes of MFSP due to the uncertainty in the capital cost estimation.

Biodiesel is considered as an alternative for petroleum fuels. Hence, identifying efficient biomass for biodiesel production is necessary to meet the demand. This study reports the optimum conditions of Sterculia foetida oil for biodiesel production and its engine performance, emission and combustion analysis. Gas Chromatography-Mass Spectrometry revealed the dominance of fatty acids in the order of sterculic acid (32%) > palmitic acid (15.88%) > oleic (10%) > linolenic (9.95%) > malvalic acid (9%) respectively. Oil extracted from the seeds of Sterculia foetida were purified by the degumming process to remove the unwanted impurities present in the oil. Box-Benhken design was used for optimizing transesterification process. A Maximum biodiesel yield of 90.2% was obtained at a temperature of 55 °C, catalyst concentration 1.5%, Oil to methanol ratio 1:12, agitation speed 900 rpm. ANN model was also utilized for the prediction of biodiesel yield using feed-forward backpropagation exhibited significant correlation (R2 - 0.9) with experimental results. Biodiesel blends and their properties were also analysed. Carbon monoxide and hydrocarbon emission were found to be low with the observation of increased nitrogen oxide emission. D90STB10 and D80STB20 was showing better performance and also lesser emission ompared to the conventional fuel.Combustion analysis of Sterculia foetida biodiesel (STB) and biodiesel blends (D90STB10, D80STB20, D70STB30, D60STB40 and STB100) for the various load at constant speed were analysed. Cylinder gas pressure, cumulative heat release rate, heat release rate, mass fraction burnt and mean gas temperature were discussed in the current paper.

Few studies have investigated the performance of anaerobic digestion (AD) to convert animal and agro-industrial wastes to organic fertilizers over a long-term field conditions. This paper studied three large-scale mesophilic digesters (D1–D3) over two years for their effects on feedstocks, which were dairy manure for D1 and D2 and co-digestion mixed manure and agro-industrial wastes for D3. Hydraulic retention times (HRT) were 9 d for D1, 12 d for D2, and 34 d for D3. Digester influent and effluent samples were taken every two months from the digesters and analyzed for pH, and concentrations of total solids (TS), ammonium nitrogen (NH4-N), total Kjeldahl nitrogen (TKN), total phosphorus (TP), and eight metals. The study revealed high variability in converting feedstock in the three digesters. Compared with their respective influent, the mean digester effluent pH decreased from 7.9 by 0.6 in D1 (p < 0.01) and by 0.3 in D2 (p < 0.01), but it increased from 6.1 by 1.8 in D3 (p < 0.01). The mean digester effluent TS increased from 3.4% by 0.1% (p > 0.05) in D1, but it decreased from 4.9% by 1.3% in D2 (p < 0.05) and from 12.3% by 4.8% in D3 (p < 0.01). All three digesters significantly increased NH4-N concentrations by 21.4–81.8% (p < 0.05), but insignificantly changed TKN and TP concentrations (p > 0.05). Effects of AD on all metal concentrations were mixed and were insignificant (p > 0.05) because of large concentration variations. However, study of a ratio quotient (qMg) using magnesium (Mg) as the reference discovered accumulation of NH4-N, copper, potassium, and sodium, but loss of TKN, TP, iron, manganese, zinc, and calcium during AD for D2 and D3. The impact of AD conversion was closely related with types of feedstock (on pH) and HRT (on TS and NH4-N). The results of this study can assist in developing strategies for cleaner production using AD in an environmentally sustainable manner.

Thermomechanical pulp (TMP) has great potential in packaging paper production. However, the lack of raw materials and relatively low physical performance of TMP due to the high lignin content limit its large-scale application. In this study, we use thermomechanical pulping of plant residues combined with ozone treatment to cut costs and improve the physical performance of TMP. During TMP pulping, the effects of the ozone on the structure and physical properties of fibers were investigated. Changing the ozone dosage showed a distinct effect on the surface lignin content and morphology of fibers. In the oxidation process, the structure of lignin was damaged and the physical properties were improved significantly. Moreover, it also proved the feasibility of the mass production of this approach. The fibers of this type have a great future as complementary raw material to recycled fibers to produce packaging paper in applications of paper products of higher quality.

This work presents the results in the field of materials engineering, and they are related to recycling of paper production waste sludge particles at amounts of 10 wt% and 20 wt% in tall oil polyol-based rigid polyurethane foam with and without tris (1-chloro 2-propyl) phosphate flame retardant. The impact of both systems on physical and mechanical properties, thermal stability, fire resistance and ignitability is studied. Paper production waste sludge particles filled rigid polyurethane foams display better fire performance thus resulting into reduction of the emission of CO2 and CO as well as reduction in average heat release rate. Scanning electron microscopy has shown that paper waste sludge particles and tris (1-chloro 2-propyl) phosphate together act systematically, and synergism between two materials may be observed. It is as well determined that paper production waste sludge particles reduce thermal conductivity by approx. 15% for polyurethane foam with paper production waste sludge particles and by approx. 13% for polyurethane foam with paper production waste sludge particles and conventional flame retardant. Moreover, the substitution of tris (1-chloro 2-propyl) phosphate, petroleum based polyol and hydroflurocarbons with 10 wt% and 20 wt% of PPWS particles, tall oil polyol and water reduces carbon dioxide emission by 60.8% and 39.6%, respectively, contributing to cleaner production of rigid polyurethane foam.

Electricity consumption and material wastage of manufacturing industries have directly or indirectly influenced the environment. Many manufacturing enterprises are committed to improving energy and material efficiencies. To achieve this goal, one of the high-efficiency ways is to optimize the scheduling. In this study, a multi-object optimization model is constructed for a particular kind of batch processing scheduling problem existed in flexible flow shops, where the objects include makespan, electricity consumption and material wastage. First, the models for electricity consumption and material wastage are built, based on which a mathematic model for scheduling problem is built afterwards. Finally, a hybrid non-dominated sorting genetic algorithm II (NSGA-II) method is employed to solve the multi-object optimization scheduling model. A case study based on a real-world paper mill industry is presented to demonstrate the effectiveness of the method and its application in practice. Moreover, a real-life scheduling problem is investigated, and the result shows that the proposed method is more efficient than manual scheduling in energy and material saving. In fact, many tissue paper mills or other manufacturing industries schedule by manual labor in China, indicating that the proposed method has a significant potential in improving energy and material efficiencies in the studied flexible flow shop, and in energy and material saving in similar industries.

Although the environmental performance of the paper industry has drastically improved since the nineties, Western manufacturers still refuse to reuse agricultural waste. Moreover, papermakers make extensive use of poorly biodegradable polyelectrolytes which are toxic to fish. With this in mind, we suggest pulping lignocellulosic residues by sulfur-free processes, decrystallizing cellulose, and introducing positively charged functional groups with the goal of partially replacing conventional cationic polymers. Functionalization of pulps from orange tree trimmings, rapeseed stalks and wheat straw was carried out with different concentrations of (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CHPTAC). When the mole ratio of CHPTAC to anhydroglucose units was 4, cationic fibers reached charge density values over 0.2 meq/g after 40 or 60 min of reaction. Then, we tested the performance of these fibers in papermaking, using titanium dioxide, whose zeta potential is negative, as filler. Opacity of lightweight paper was raised to 90%, surpassing a conventional cationic polyacrylamide (CPAM), while the increase in brightness (from 37.8% to 41.9%) was not as good as that achieved with CPAM. Even if residues cannot replace wood, chemical modifications of them can result in valuable cationic fibers, making synthetic polyelectrolytes less necessary.

Recycling is becoming one of the main activities of the papermaking industry to palliate the consumption of natural resources. However, with the recycling process, the fibers experience structural damages due to the hornification phenomena and the mechanical refining. The present work aims to compare the effect of mechanical refining during recycling cycles, to recover the original mechanical properties of paper with the incorporation of lignocellulosic micro/nanofibers (LCMNF) from banana leaf residue. For that, industrial fluting paper was submitted to a recycling cycle and the effect of the increasing intensity of PFI-refining was compared versus the incorporation of LCMNF additions ranging from 1.5 to 4.5 wt%. In addition, with the objective of demonstrating that the proposed process could be plausible at a large scale, process water with high conductivity and charge density was used for comparison with tap water, usually used at laboratory scale. Results showed that the incorporation of 1.5 wt% of LCMNF was enough to recover the original properties of fluting paper (a breaking length value greater than 3443 m) with a low impact in pulp drainability (54 oSR). At the same time, no structural damages were caused to the fibrous compounds, implying that the life span of paper products can be successfully increased. Higher dosages lead to papers with significantly improved mechanical properties, opening the opportunity to adopt environmental friendly strategies such as decreasing basis weight or, on the other hand, to reach new market niches by maintaining the basis weight.

Cascading use of biomass is a recognized strategy contributing to an efficient development of the bioeconomy and for mitigating climate change. This study aims at assessing the potential of cascading use of woody biomass for reducing GHG (greenhouse gas) emissions and increasing the overall wood flow efficiency in the European Union's forest and bioeconomy sectors. A scenario and life cycle approach was followed to quantify the potential benefits of cascading use of woody biomass. We started from a reference scenario in which (post-consumer) waste wood and paper are re-utilized for energy only (S0). Then we compared the reference scenario with two alternative scenarios, the current waste wood and paper recycling practices (S1) and the maximum technical potential to increase recycling of waste wood and paper flows (S2). Following a supply chain perspective, different stages of production were analysed, including forgone fossil-fuels substitution, optimization at manufacturing level and forest regrowth. Through cascading use, the wood use efficiency ratio (cascade factor) in the European wood sector would be increased by 23% (S0 vs S1) and 31% (S0 vs S2) and GHG emissions (cradle-to-gate energy use) would be reduced by 42% (28 MtCO2-eq/year) and 52% (35 MtCO2-eq/year) in scenarios S1 and S2. However, increased wood product cascading is counter effected in the short term by reduced savings in the energy sector by 49% and 48% (−43 and −42 MtCO2-eq/year) in scenarios S1 and S2 due to delayed availability of waste wood and waste paper fibers. This explorative study highlights the potential of cascading use of woody biomass in the wood production chains to contribute to a reduction of environmental impacts related to wood resource and energy use, but it also reveals trade-offs in terms of GHG emissions reduction, relevant especially in meeting short-term (2020–2030) renewable energy targets.

Environmental issues, legal requirements, and economic benefits of recycling activities lead to the development of reverse logistics operations and waste management. The current research considers a closed-loop supply chain for a cardboard recycling network including multiple suppliers and production stages. A mixed integer linear programming model is proposed to optimize the paper and cardboard recycling network, and a robust optimization approach is utilized to deal with demand uncertainty in this network. The model maximizes the total profit. It considers the operation, transportation, purchasing and holding inventory costs as well. Moreover, to illustrate the application of the proposed model, a real-world cardboard closed-loop supply chain design is investigated. The proposed model considers the option to open a new recycling center in the current network. The proposed model determines the optimal quantities of the waste paper, paper, sheet and cardboard that flow in this network. Finally, the computational analysis indicated that the proposed model provides efficient solutions for the studied cardboard closed-loop network.

This study presents a novel decentralized sanitary separation system as a zero-discharge solution for blackwater (BW) (faeces, urine and toilet paper) treatment for remote tourist facilities located in sensitive areas. The system operates with low water and energy consumption, enables safe operation and requires low maintenance. The BW was collected from two vacuum toilets (VTs) (0.8 L flush water) and separated in peat filters (PFs) to obtain a liquid fraction (LF) and a solid fraction (SF) of the BW. The LF from the PFs was thereafter treated in a biofilter (BF) and finally evaporated in the evaporation module (EM) powered by solar vacuum collectors (SVC). In the PFs, particles larger than 1 mm were reduced from the BW by 96.5%. Furthermore, the total suspended solids (TSS) mass removal efficiency of the PFs averaged 51.5%. Reduction of ammonia through nitrification was noticeably enhanced after 100 days of the system operation (max. 55.8%). 21.2% or 0.54 kg of total phosphorus (TP) was retained in the PFs, to be further composted and reused for agricultural purposes. An additional 5% or 0.10 kg of TP was retained in the BF. The final step of the LF treatment was in the EM at a sanitizing temperature of >60 °C to prevent the release of human pathogens into environment. With a total electricity consumption of 9.1 kWh/day and a heat consumption of approximately 5.1 kWh/day gained by the SVC, the system successfully integrated different approaches to treating the BW, recycling nutrients, and removing pathogens.

Globally, the processing of milk and dairy products leads to huge volumes of dairy processing wastewater treated sludge. Currently, there are knowledge gaps relating to the volumes generated and the nutrient and metal contents of these sludges. This lack of knowledge prevents the dairy processing industry from making informed pre and post waste generation decisions. Using Ireland as a case study volumes generated are estimated (2012–2017) and a two year seasonal database (2016–2018) across four sludge types (bio-chemically treated activated sludge; lime treated dissolved air flotation processing sludge; a combined treatment sludge and anaerobically digested sludge) utilising samples from nine dairy processing plants was created. Results show that dairy processing sludge increased by 39% in the period up to 126,718 tonnes (wet weight). Database results showed that nutrient contents did not vary seasonally but varied significantly across sludge type and processing plants. The median values (g kg−1 dry weight) for N:P:K for the four sludge types were N: 57.2, 19.5, 46 and 70.4, P: 36.8, 65.9, 20 and 14.6, and K: 7.2, 3.9, 2.9 and 6.1, respectively. Heavy metal concentrations across all samples were significantly lower than those regulated by the European Union for controlling metals accumulation in agricultural land due to sludge recycling. The characterization profile presented in this paper serves as a national and international reference database for future investigations that focus on the valorisation of dairy processing sludge.

This paper investigates the production of hydrogen (H2) and methane (CH4) from palm oil mill effluent (POME) using an integrated approach of thermophilic continuous stirred tank reactor (CSTR) and mesophilic microbial electrolysis cell (MECs). CSTR reactor was operated at pH 5.5, 80 rpm, 2 days HRT, 60 g COD L-1 d-1 organic loading rate (OLR) and 55 °C temperature with the given hydrogen yield of 205 ml H2 gCOD-1 along with acetic, butyric, propionic, and lactic acid as by-products. Continuous, single-chambered MECs fed with dark fermentation effluents were operated at an applied voltage of 0.5 V at 37 °C to obtain methane yield and production rate (MPR) of 290 ml CH4 gCOD-1 and 2700 ml CH4 L-1 at 8 days of hydraulic retention times (HRT). The overall process led to total energy recovery of 92.72% with 91% COD removal efficiency. Microbial community analysis reveals Thermoanerobacterium sp dominated in CSTR whereas exoelectrogens of Methanobacterium formicicum and Methanobacterium beijingense were found to be the chief dominant microbial species on anodic electrode of MECs.

Tanneries boost the local economic development, but lead to severe environmental pollution; hence, improving the environmental assessment of this sector is essential. In this paper, the Life Cycle Assessment method was applied to estimate impacts on the environment and human health of retanning, fatliquoring and dyeing. The analysis was performed from a “gate to gate” perspective. Moreover, sulpho chlorinated paraffin and epoxidized vegetable oil have been evaluated as alternative fatliquoring agents. The production of electricity required for the rotation of drums gives the main contribute to most of the impact categories, followed by the azo-dye production. Emissions of sulfur dioxide, nitrogen oxides, manganese, vanadium and nickel associated to power plants are the main sources of terrestrial acidification and particulate matter formation, as well as of human and marine toxicity (4.48·10−1 and 1.09·10−2 kg of 1,4-DBeq kg−1 crust leather, respectively). Nitrate loads from wastewater treatment and oxidative treatments affect heavily marine eutrophication (6.9·10−1 g N eq kg−1 crust leather). The use of epoxidized vegetable oil would affect human toxicity, ecosystem, metal and water resources depletion more than the use of sulpho chlorinated paraffin, mainly due to pesticides distribution and other cultivation practices. Phosphate and nitrate releases due to fertilization determine the high impact on the categories freshwater and marine eutrophication. Progress in increasing the conversion efficiency is demanded, but overall focus must be made on the substitution of fossil fuels with cleaner alternatives. The transition towards a circular economy is encouraged; increasing rates of reduction, reuse, recycle and recover of solid waste and tannery effluents are recommended. Agricultural practices with a reduced consumption of phytosanitary products and mineral fertilizers, alternative to conventional farming, would strongly contribute to increase the sustainability of epoxidized vegetable oil as alternative fatliquoring agent.

Organic micropollutants like pharmaceuticals, personal care products, pesticides and industrial chemicals have received an ever growing attention due to their adverse ecological effects in natural water bodies. A promising technology to remove the micropollutants from the wastewater is biocatalytic treatment using oxidoreductase enzymes. In order to improve removal efficiency and feasibility, the focus has been on developing enzyme-mediator systems and immobilisation techniques. Nonetheless, since oxidoreductase enzymes often promote coupling reactions, enzymatic reactions do not necessarily result in simpler compounds. Thus transformation products, which might be in equally or even more hazardous pollutants, can be still present in the wastewater after treatment. Therefore, the toxicity and ecological effects of the reaction products have to be investigated rigorously to ensure that the treatment mitigates the environmental and health related impacts.The objective of this paper is to give an overview of research carried out with oxidoreductase enzymes to treat different organic micropollutants and their mixtures along with real wastewater and to collect available information on different techniques, transformation products and toxicity. Though in most cases the reviewed enzymatic treatment methods resulted in less toxic effluent, the application of mediators, while facilitating higher transformation rates, increased the level of toxicity. Hence, it was concluded that the suitability of biocatalytic methods should be assessed from the perspective of toxicity beside the removal efficiency in order to allow the upscaling of the technology to a feasible and sustainable wastewater treatment solution.

The paper devised a unified basis for energy recovery processes in municipal treatment plants based on sludge footprints. Emphasis was placed upon innovative energy recovery technologies to test whether energy neutrality could be sustained or even, net useful energy could be produced. In this context, it evaluated first the energy potential of municipal wastewater treatment plant based on sludge footprints: it adopted a unified perspective where energy recovery was considered as an integral part of energy conservation in sludge. Sludge footprints of different activated sludge configurations were first analyzed based on latest concepts of process stoichiometry and modeling. The performance indicators of process modifications were analyzed and interpreted for energy conservation for a wide range of sludge age between of 0.5–50 d. An influent COD level of 500 mg/L was adopted, also defining all significant COD fractions compatible with related characterization studies. The role of primary sedimentation was accounted for where applicable. Calculations showed that 1259 kcal/m3 (75%) to 379 kcal/m3 (23%) of COD energy could be preserved in sludge as the sludge age was increased between the range of 0.5–50 d. Conventional activated sludge (CAS) conserved around 35–40% energy, corresponding to 600–650 kcal/m3. Primary sedimentation boosted the overall energy conservation to 901–990 kcal/m3, corresponding to 54–59% of the available energy in sewage COD. As expected, energy recovery by means of anaerobic digestion (biogas), remained far below the energy consumption in the treatment plant. This study envisaged syngas production by means of high temperature pyrolysis as a novel alternative instead of sludge digestion. Pyrolysis revealed a potential to yield a net useful energy (positive net energy) of 0.08–0.49 kWh/m3 for systems operated at sludge ages of 2–10 d without primary sedimentation; much higher net useful energies of 0.33–0.59 kWh/m3 could be obtained in systems with primary sedimentation operated at sludge ages 2–14 d. The study provided conclusive evidence that the real problem in establishing energy neutrality in treatment systems was the low energy recovery of the conventional sludge digestion and not the level of energy conservation in the activated sludge process; therefore, the step forward should look for more effective energy recovery processes such as high temperature pyrolysis (syngas generation) or similar novel technologies.

The main problem and also challenge was to find a satisfactory effective tool for real-time control the torrefaction/pyrolysis process of biomass and to evaluate (also in real-time conditions) biochar quality. This paper presents results from investigation on a new method for both evaluating biochar quality and control biomass thermal processing at temperatures of 300, 350 and 400◦C. Thermal processing of biomass in this temperature range is torrefaction and pyrolysis. Investigation was focused on processing Virginia Mallow (Sida Hermaphrodita) energetic crops. Several strong correlations were observed as follows: carbon and hydrogen content in biochar (charcoal), oxygen content, ash and volatile matter from biochar, calorific value and temperature of the process and finally, acetic acid in condensate and carbon content in the biochar. The results show that the content of acetic acid, being one of the major compounds present in the condensate (black liquor, biooil), is in satisfactory linear correlation with the process temperature and furthermore, with carbon content in biochar. The mathematical description for this polynomial function was proposed as follows: Carbon (%) = 0.6e-3 x Acetic Acid (ppm)+49.5. The correlation between acetic acid in black liquor and carbon in biochar was used to introduce a new method which can be considered as a diagnostic tool for determining biochar quality in real-time conditions during biomass thermal processing. Hence, carbon content in biochar as well as its calorific value can be determined by measuring percentage of acetic acid in the condensate. This correlation was considered as the main novelty presented here. This method provides relatively fast evaluation of quality of biochar produced in industrial scale torrefaction systems, what makes it possible to optimize process parameters (temperature, retention time) in real time conditions and improve biochar production process in this way.

Toxic and hazardous sulfur dioxide (SO2) residue reduction is not only one of the core issues in the preservation process with SO2 solid antistaling agents in actual table grapes cold chain, but also one of the important ways to improve the cleaner production efficiency of the table grapes. The aim of this paper is to propose an improved preservation process for the table grapes in cold chain by combining the fumigation treatment with the slow-release SO2 solid antistaling agent. The process was performed to reduce the toxic and hazardous SO2 residue of the table grapes, improve the cleaner production efficiency of the cold chain, guarantee the quality and safety of the table grapes, and finally enhance the human health. The slow-release SO2 solid antistaling agent was developed with no pricking holes and relatively stable release rate of the SO2. According to the comprehensive analysis of the fumigation treatment condition determination, the slow-release SO2 solid antistaling agent performance, the table grapes quality performance, the SO2 residue performance and the evaluation on improved preservation process, the proposed improved preservation process with SO2 residue reduction could effectively reduce the bleaching injury, the decay rate, the threshing rate and the toxic and hazardous SO2 residue of the table grapes. There was no bleaching injury after the fumigation treatment at the optimal fumigation treatment conditions with 5000 ppm fumigation concentration and 20 min fumigation time. The maximization reduction range of the average decay rate and the average threshing rate of the table grapes was about 91.3% and 44.8%, while the maximization reduction range of the average SO2 residue in table grapes peels was about 44.7%. The proposed improved preservation process could be extended for other cold chain applications to reduce their SO2 residue and improve their cleaner production efficiency.

Remnant obtained from chemical retting of coconut fibre was found to have an exorbitant COD, BOD, TDS, sulphide content having blackish brown colour. Traditional (physico-chemical) treatment could not reduce its COD, TDS, colour substantially. Further, the traditional method was lengthy, consumed huge chemicals and time. Present paper reports a quicker, simpler, economic i.e., an industrially viable method to separate the chemicals and biomass by employing electrocoagulation (EC). The performance of EC was analyzed by keeping temperature, and pH of remnant constant, while varying current flow (100–2000 mA), time (15–90 min) and number of iron electrodes (2,4,6). Efficacy of EC was evaluated in terms of reduction in conductivity, pH, TDS, COD, TOC, colour and quantity of sludge generated from the wastewater. Six electrodes with 2000 mA current flow for 90 min were found to give noticeable reduction on COD (92.8%), TOC (56%), TDS (99%), and colour. To reduce pH, and TDS to an acceptable level, filtration with activated charcoal was attempted on recovered water from EC. Resultant water was also found to have acceptable LC50 value for safe disposal. Carbon content (53%) in the sludge was high, contained lignin and cellulose whiskers also, as revealed from the EDX and FTIR, SEM respectively. Cost of EC ($ 0.087 USD/L) was found to be much less as compared to traditional method ($ 0.384 USD/L).

Environmental concerns regarding the toxicity of trace elements (TEs) and the harmful effects of these elements on humans have attracted worldwide attention. To meet stricter environmental policies, some coal-fired power plants have installed ultra-low emission equipment. In this paper, the behavior and fate of the trace elements As, Se, and Cd originating in an ultra-low emission coal-fired power plant equipped with air pollution control devices (APCDs), including selective catalytic reduction (SCR) equipment, a low-temperature economizer (LTE), an electrostatic precipitator (ESP), a wet flue gas desulfurization (WFGD) system, and a wet electrostatic precipitator (WESP), were investigated. Onsite samples of the feed coal, bottom ash, fly ash, gypsum, desulfurization slurry, WFGD effluent, WFGD-treated water, and WESP effluent were systematically collected and analyzed. The SCR and LTE configurations achieved a partial removal of As, Se, and Cd. The ESP trapped virtually all the particles and had a synergistic effect on the removal of the TEs. A systematic study of the recycling of the desulfurization slurry revealed TE enrichment in the WFGD system; because it concentrated in the liquid fraction of the gypsum slurry, Se was particularly susceptible to this enrichment. The effluent water treatment system achieved TE removal with efficiencies exceeding 94%. WESP operation achieved extensive removal of TE-enriched particles with percentages greater than 90%. The overall efficiencies of As, Se, and Cd removal obtained by the APCD system as a whole were 95.94%, 98.22%, and 92.70%, respectively.

Chromotropic Acid Grafted Amphoteric Polyurethane (CAGAPU) was synthesized with Chromotropic Acid (CA) as a modifier for Polyurethane (PU). The structure of CAGAPU was confirmed by FT-IR, 1H-NMR. The retanning process and the experiments of CAGAPU with formaldehyde indicate the following: (1) The leather retanned by CAGAPU can be comparable or surpassed to the market PU-based retanning system in terms of shrinkage temperature and sensory performance. (2) The leather collagen fibers are smoother and orderly which provides a potential value for the appearance of the leather and fur industry. (3) The CAGAPU retanned system can bring down the free formaldehyde content in aldehyde tanned leather significantly. (4) The optimum dosage of CAGAPU is 20 g and the best retanning time is 6 h (5) The CAGAPU retanned system can reduce the free formaldehyde, Biochemical Oxygen Demand (BOD), Total Dissolved Solids (TDS) and Total Suspended Solid (TSS) from the source which retard pound on the economy and environment greatly compare to the traditional governance. Therefore, this paper provides the possibility for the sustainable development of leather. The work has changed the traditional way of “terminal treatment” and realized the “initial treatment” and may also offer a new idea of solving the problem of formaldehyde in the newly decorated houses or in the air.

Microbiomes in the built environment is an emerging topic of high-relevance, as biodeterioration and biodegradation of porous and polymer materials may be major public health risk factors. Epidemiological studies have confirmed indoor airborne microorganisms and their metabolites cause significant toxic immune reactions, with clinical effects associated with more than 60% of occupants’ chronic infections. The present study reports the potential inhibitory effect on microbial and fungal colonization of hydrothermal hot-compression for the manufacture of a series of novel cellulose-based panels engineered for insulating building applications. This method was examined as it is a green manufacturing technique which simultaneously self-bonds the cellulose fibres, as well as potentially having an anti-microbial effect. The technique renders the novel materials non-toxic, additive-free, biodegradation resistant, as well as increasing the recyclability potential of the materials at their end-of-life. Prototypes were formulated from three cellulosic materials sourced from complex post-consumer coffee industry heterogeneous waste stream ─jute textile, paper cups, and coffee grounds─ holding initially high-levels of microbiological contamination. The raw materials were characterized with Infrared Spectroscopy (FTIR) and Scanning Electronic Microscopy (SEM). Microbial species were identified using culture-dependent and culture-independent DNA quantitative methods for the raw materials, as well as the processed panels. The experimental results confirmed a high-level of bacterial and fungal contamination with ubiquitous environmental bacteria such as Bacillus, Burkholderia, and Stenotrophomonas species for the Jute textile and Paper cup fibres. However, the microbes were minimized or non-detectable for all three processed panel samples. This promising result demonstrates that complex cellulosic waste materials can be converted to low-microbial biomass potential industrial feedstock for the green manufacturing of building materials.

In the current paper, a suggested process of coupled ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) to produce isotonic solution (IS) and drinking water from coastal well water was investigated. Due to its high fouling potential, the feed water was pretreated using UF. Results showed that UF eliminates almost the totality of natural organic matter (NOM), and a relatively high portion of calcium (calcium rejection ∼75%) due to the complex Ca-NOM formed. To understand the fouling mechanism, previously developed mathematical models and equations were adopted. It was shown that the fouling mechanism for UF fits the blocking pores model. For NF, the extended model using cross-flow mode showed a slight difference compared to UF (No compression cake phase). It was concluded that, with some experimental precautions, fouling mechanism of the NF membrane used is internal pore blocking mechanism. Due to its attractive quality, the brine of NF was used to produce drinking water by RO treatment. The energy consumption of the UF-NF-RO system was investigated for different operating conditions. Finally, the permeate of the UF-NF process was compared to a commercialized IS. It was found that the two solutions revealed a remarkable similarity. However, a specific post-treatment should be added to the process to accomplish the pharmaceutical exigencies of IS.