Industrial Residues Research Articles

Application of Bacillus cereus for synthesis of polyhydroxyalkanoates from industrial corn starch residue.

Starch hydrolysate from corn is typically employed as a carbon source for citric acid production by Aspergillus niger. Enzymatic or acid hydrolysis of corn starch generates a corn starch residue (CSR), which represents a potential bio-fermentation carbon source. In addition, polyhydroxyalkanoates (PHAs) can be used as an alternative to traditional petrochemical plastics. In this study, the potential applications of CSR in microbial PHA production were investigated. Two Bacillus cereus strains, MG1 and MQ1, were isolated based on their ability to grow with CSR as the sole carbon source and their capacity for PHA accumulation. After introducing key genes involved in the PHA synthesis pathway and optimizing fermentation conditions, the PHA content of MG2 reached 61.61 % of the cell dry weight (CDW), representing the highest PHA content (CDW%) in B. cereus. To the best of our knowledge, this is the first report of PHA synthesis from CSR in B. cereus and provides a novel approach for the rational utilization of CSR.

Solidified lake sediment with industrial waste and construction waste used as barrier cover material: mechanical strength, water resistance performance, and microscopic analysis

ABSTRACT This study introduces a novel landfill cover material, employing lake sediment as a substrate, stabilised with fly ash, slag, desulfurisation gypsum and construction waste. The mechanical properties, including shear strength parameters, unconfined compressive strength, hydraulic conductivity, volumetric shrinkage, and water content, of the solidified sludge were evaluated. The microscopic mechanism of the solidified sludge were investigated through XRD, FTIR, and SEM-EDS techniques. A novel three-layer composite capping cover system for landfills is proposed, comprising an upper capillary barrier layer, a middle drainage layer and a bottom impermeable layer . Indoor rainfall simulation tests were conducted to assess the water retention performance of this capping cover system under repeated moderate, heavy, and torrential rainfall events. The early strength of the solidified sludge exhibited rapid development, with cohesion and internal friction angle reaching 382.56 kPa and 57.67°, respectively, after 3 days. After 28d, the unconfined compressive strength ranged from 6.93 to 14.29 MPa, with hydraulic conductivity between 3.98–23.1 × 10−8cm/s. The hydration reactions of the industrial waste residues resulted in the formation of Ettringite, Gypsum, and hydrous calcium (aluminum) silicates. The Ettringite and Gypsum crystals formed an internal support framework, while the generation of gel-like substances such as C-S-H and C-A-S-H facilitated product aggregation. The RSM was employed to optimise the material ratio of the solidified sludge, while the Pearson coefficient facilitated correlation analysis. This study provides valuable data for designing landfill solidified sludge cover systems and offers a new approach for the co-disposal of sludge and industrial waste.

Advancements in the Use of Bayer Red Mud as a Sustainable Cementitious Material in Concrete: Challenges and Opportunities

Bayer red mud is an industrial waste residue formed in the alumina process produced by the Bayer process in the alumina plant. At present, the main disposal method of red mud is to send it to red mud dam for storage. Due to its high alkali content, it causes serious pollution to the surrounding environment and becomes an ecological problem to be solved urgently. In this paper, the application progress of Bayer red mud in concrete is summarized. This paper focuses on the possibility of red mud as a cementitious material and deeply discusses the influence of red mud on the working performance and mechanical properties of concrete. Finally, the shortcomings in the current research of red mud concrete are pointed out, to provide a reference for the research direction of Bayer red mud in concrete.

Closing the loop: sustainable approaches for managing and recovering food industry residues

Closing the loop: sustainable approaches for managing and recovering food industry residues

Alkali-Activated Mineral Residues in Construction: Case Studies on Bauxite Residue and Steel Slag Pavement Tiles.

This research aimed to investigate the potential of using alkali activation technology to valorize steel slag and bauxite residue for the production of high-performance pavement blocks. By utilizing these industrial by-products, the study seeks to reduce their environmental impact and support the development of sustainable construction materials. Lab-scale testing showed that bauxite pavers showed a decrease in mechanical strength with increasing replacement of ordinary Portland cement. Partial replacement up to 20% still exceeded 30 MPa in compressive strength. Steel slag-based pavers achieved the 30 MPa threshold required for the application with selected mix designs. Pilot-scale production-optimized formulations and standards testing, including freeze-thaw resistance, confirmed the technical viability of these products. Life cycle analysis indicated a 25-27% reduction in CO2 emissions for slag-based tiles compared to traditional concrete tiles. Moreover, using industrial residue reduced mineral resource depletion. This study examined the properties of the resulting alkali-activated binders, their ecological benefits, and their performance compared to conventional materials. Through a comprehensive analysis of these applications, our research promotes the circular economy and the advancement of sustainable construction products.

Laccase Characterization from Ganoderma lucidum Grown in Pineapple and Coffee Waste Substrates under Solid Fermentation.

<b>Background and Objective:</b> Laccase as a ligninolytic enzyme has been known for its green-catalysis mechanism, which has the potential to be applied to food industries. Lignocellulose found in agro-industrial waste is promising for laccase production as a substrate, that could be encountered in pineapple (<i>Ananas comosus</i>) and Arabica coffee (<i>Coffea arabica</i>) industrial residue. To boost enzyme activity, laccase characterization was performed using <i>Ganoderma lucidum</i> under solid-state fermentation. This study aims to determine the lignocellulosic waste substrate that can produce the highest laccase activity and evaluate the effect of lignocellulosic substrate types under solid-state fermentation. <b>Materials and Methods:</b> There were 3 variants of lignocellulosic substrates used, consisting of pineapple peel, pineapple leaf and coffee husk. Characterization was carried out during pre-production by determining lignocellulose composition by Van Soest method and qualitative assay of <i>G. lucidum</i> laccase, continued with post-production including dry cell weight, pH measurement during fermentation and laccase activity. Laccase activity was statistically analyzed using Analysis of Variance (ANOVA). <b>Results:</b> The characterization indicated that the type of substrate used had the potential to be used as a substrate in laccase production from <i>G. lucidum</i> under solid-state fermentation. The highest laccase activity was obtained on sample coffee husk S<sub>3</sub> on the 8th day of incubation with average values of laccase activity 2622.07±68.49 U/L. Based on ANOVA results, types of lignocellulosic waste substrates used have significant effects on laccase activity. <b>Conclusion:</b> <i>Ganoderma lucidum</i> has the potential to produce laccase enriched with pineapple waste and coffee husk substrates under solid fermentation.

Comprehensive evaluation of low-carbon cementitious materials prepared with industrial by-product calcium carbide residue (CCR) as alkali source

Comprehensive evaluation of low-carbon cementitious materials prepared with industrial by-product calcium carbide residue (CCR) as alkali source

Fly ash applications for mine workings backfilling – review of current practices and perspectives for oil shale industry residues

Fly ash applications for mine workings backfilling – review of current practices and perspectives for oil shale industry residues

Development of a Multianalyte Method for the Determination of Phenolic Compounds in Residues from Beverage Production Using a Cyclofructan-Based Column in HILIC-MS/MS

This study expands and shows the versatility of applications in hydrophilic interaction chromatography coupled with triple quadrupole mass spectrometry (HILIC-MS/MS) using a FRULIC-N column to determine 31 phenolic compounds in beverage industry residues (coffee, apple juice, beer, and wine). Optimization, via Doehlert design, determined the acetonitrile proportion (50-90%) and pH (3.0-7.0) in the mobile phase (MP). A 22 factorial design assessed the concentration of ammonium acetate (10-110 mmol L-1) in the MP and column temperature (20-60 °C). Injection volume (5-45 µL) was univariately optimized. Separations at 60 °C reduced chromatographic run time to less than 11 min. Gradient elution (500 µL min-1) employed an MP comprising acetonitrile and ammonium acetate (110 mmol L-1, pH 7). Validation demonstrated average coefficient of determination (R2 ) 0.9707, limit of detection 0.001-0.503 mg L-1 and quantification 0.004-1.524 mg L-1, precision < 12.2%, recovery 92.4-110.8%. The method was applied to five residues, indicating its viability for determining phenolics in beverage production residues.

Characterization of Al-Containing Industrial Residues in the ESEE Region Supporting Circular Economy and the EU Green Deal.

The increase in industrial waste generation presents a global problem that is a consequence of the needs of modern society. To achieve the goals of the EU Green Deal and to promote the concept of circular economy (CE), the valorization of industrial residues as secondary raw materials offers a pathway to economic, environmental, energetic, and social sustainability. In this respect, Al-containing industrial residues from alumina processing (red mud), thermal power plants (fly ash and bottom ash), and metallurgy (slag), as well as other industries, present a valuable mineral resource which can be considered as secondary raw materials (SRMs) with the potential to be used in construction, supporting the concept of circular economy. This paper focuses on the characterization of 19 secondary raw materials from the East South-East Europe (ESEE) region regarding their physical, chemical, mineralogical, and radiological characteristics. The goal is to provide a foundation for future innovations based on secondary raw materials, in alignment with the EU Green Deal and the principles of circular economy. The results showed that fly ash has the potential to be the best material among those analyzed to be used in the cement industry, mainly due to its favorable radiological and mineralogical properties. However, it is important to control the amount of free lime in the mixture, ensuring it remains below 10%. After evaluating secondary mineral raw materials for metal recovery, the results indicate that these materials are not viable sources for base metals or other technology-critical metals, such as REEs.

Exploring Potential of Organo-mineral Fertilizers in Augmenting Crop Yield and Quality – A Review

Inorganic fertilizers are essential for improving crop yield and quality through enhanced crop efficiency. However, their continuous use often causes nutrient imbalances, leading to poor yield and quality. Organic manures, while effective in improving soil fertility and crop productivity, face challenges such as limited availability, variable quality, transportation issues, heavy metal contamination and slow nutrient release. The exclusive dependence of either organic or inorganic fertilizers has not adequately fulfilled the increasing demands for enhanced agricultural output and quality. To address these challenges, organo-mineral fertilizers (OMFs) have emerged as an innovative solution. OMFs are derived from the combination of mineral and organic nutrient sources, integrating the benefits of both. This low input technology supplies nutrients in balanced quantities that are readily and steadily available throughout the growing season. OMFs improve soil physical properties, enhance fertility and support sustainable crop production. They also promote plant resistance to biotic and abiotic stress, offering a holistic approach to agricultural challenges. The development of OMFs aligns with the recycling of urban, industrial and agricultural residues, reducing dependency on raw materials for chemical fertilizers and contributing to environmental sustainability. Advances in OMF preparation, using various mineral and organic matrices, have demonstrated their ability to address nutrient deficiencies, particularly in tropical soils, where poor fertility often limits productivity. OMFs enhance soil physico-chemical and biological properties, addressing soil degradation while improving crop yield and quality. They ensure an optimal supply of nutrients, support long-term soil health and align with modern fertilizer management strategies aimed at sustainable agricultural productivity. In conclusion, OMFs are a promising solution for boosting crop quality and yield while maintaining soil fertility. By incorporating the advantages of organic and inorganic inputs, they provide a balanced, sustainable, and efficient strategy to address growing demands for food production.

Optimized Photocatalytic Degradation of Methylene Blue Using Titaniferous Sand/ZnO Composite: A Sustainable Approach to Wastewater Treatment

This study explores a novel approach to enhancing photocatalytic efficiency by utilizing an industrial residue, titaniferous sand, in combination with ZnO. The purifying efficiency of this semiconductor mixture was studied for the removal of methylene blue in a fixed-bed reactor. The main objective was to find out with what percentage the titaniferous sand could be incorporated into the ZnO for maximum photocatalytic performance. Box-Behnken Design (BBD) in the Response Surface Methodology (RSM) was used to optimize the operative parameters. The influence of titaniferous sand/ZnO ratio (A:1-2.8), pH (B:4-10) and irradiation time (C:120-480 minutes) on the degradation efficiency of the dye was studied. Initial concentrations of methyl blue and total semiconductor mixture were set at 25 mg/L and 10 g/L, respectively. The ANOVA analysis showed that the photocatalytic process was significantly affected by a positive individual effect of the titaniferous sand/ZnO ratio and the irradiation time. A quadratic polynomial of the second order accurately represented the experimental values with a correlation coefficient R2 of 0.9921. In addition, this model had a p-value of less than 0.0001 and an F-value of 84.09. Thus, the model used was quite appropriate. Optimal conditions were obtained for a ratio (titaniferous sand/ZnO) of 1.51057, i.e. a titaniferous sand percentage of 66%, a pH of 9.97487 and an irradiation time of 479.765 minutes. Under these conditions, a degradation of 99.4915% was obtained. In addition, the photocatalytic degradation kinetics of methylene blue on the titaniferous sand and ZnO mixture followed the Langmuir-Hinshelwood model and was of the first order with an apparent kinetic constant of 0.402 h-1.

Waste-based consumable for hardfacing by welding: a look from the Circular Economy

In the present work, the obtaining of a consumable for the restore parts by welding from the perspective of the circular economy is addressed, using industrial solid residuals (slag from steel production, graphite from fragments of electrodes of arc furnaces) and agroindustrial residuals (ash from the combustion of biomass (rice husk)) and conceiving the non-generation of new solid residuals in the hardfacing process. The conceptual scheme of obtaining a sustainable consumable for hardfacing by Submerged Arc Welding (SAW) is proposed, establishing the internal symbiosis between the obtaining and application processes, as well as the symbiosis of these with external processes and the possibility of introduction to industrial practice. The obtaining of a flux based on residuals and its application in the hardfacing of pieces are experimentally validated, confirming the possibility of recycling the resulting slag.

Hybrid model of multimodal based on data enhancement and lumped reaction kinetics: Applying to industrial ebullated-bed residue hydrogenation unit

Industrial ebullated-bed is an important device for promoting the cleaning and upgrading of oil products. The lumped kinetic model is a powerful tool for predicting the product yield of the ebullated-bed residue hydrogenation unit (EBRH), However, during the long-term operation of the device, there are phenomena such as low frequency of material property analysis leading to limited operating data and diverse operating modes at the same time scale, which poses a huge challenge to building an accurate product yield prediction model. To address these challenges, a data augmentation-based eleven lumped reaction kinetics mechanism model was constructed. This model combines generative adversarial networks, outlier elimination, and L2 norm data filtering to expand the dataset and utilizes Kernel Principal Component Analysis-Fuzzy C-Means for operating condition partitioning. Based on the hydrogenation reaction mechanism, a single and sub operating condition eleven lumped reaction kinetics model of an ebullated-bed residue hydrogenation unit, comprising 55 reaction paths and 110 parameters, was constructed before and after data augmentation. Compared to the single model before data enhancement, the average absolute error of the sub-models under data enhancement division was reduced by 23%. Thus, these findings can help guide the operation and optimization of the production process.

Compositional Design of New Environmentally Friendly Geopolymer Mortar Based on Kaolin and Granite Residues.

The use of industrial residues in civil construction is an exciting alternative to mitigate environmental impacts and promote the circular economy. This work developed new compositions of geopolymer mortars activated by NaOH from fine kaolin residue (RCF), coarse kaolin residue (RCG) and granite (RG). All residues were benefited and characterized by chemical analysis (X-ray fluorescence), mineralogical phases (X-ray diffraction) and granulometry (laser granulometry). Additionally, the RCF was calcined at 650 °C for 2 h (RCFC) to produce metakaolin, which is the starting point for the geopolymer reaction. A mixture of experimental designs was accomplished to evaluate the water/binder factor (Wexp (%)) necessary for new geopolymer mortar compositions to reach the consistency index (260 mm, ASTM C1437-15) and the effect of different curing conditions on the simple compressive strength (SCS). The geopolymeric compositions with RCFCs, pre-cured at room temperature, exhibited the highest Wexp% values (>40%) and significant SCS, with curing conditions A and B reaching 6 MPa and 7 MPa, respectively. Such behavior can be explained by the fact that the pre-curing step at room temperature keeps the system humidity relatively high, favoring the dissolution of Si4+ and Al3+ ions and, therefore, increasing the Si/Al ratio, which positively influences the geopolymerization kinetics reaction.

A promising technical route for converting lignocellulose to bio-jet fuels based on bioconversion of biomass and coupling of aqueous ethanol: A techno-economic assessment

A process for production of bio-jet fuel (sustainable aviation fuel, SAF) from lignocellulosic biomass by a novel technical route was designed. Techno-economic assessment of the process was further performed in the Chinese context. The route primarily included a first step of bioethanol production from bioconversion of biomass and a second step of hydrocarbon fuel production from aqueous ethanol by C–C coupling followed by hydrodeoxygenation (HDO). Two Cases were considered, in which wheat straw (WS, Case I) and industrial cellulosic residue (ICR, Case II) were employed as feedstock, respectively. As revealed by the assessment results, the consumption of biomass feedstock is 7.2 tonnes WS (5 % moisture content) or 16.0 tonnes ICR (45 % moisture content)/tonne bio-jet fuel for Case I and II processes, respectively. For a plant with an annual capacity of ∼20,000 tonnes bio-jet fuel, a total capital investment of 382 MM CNY is needed for Case I project, while 368 MM CNY needed for Case II project. The minimal selling prices (MSPs) of the bio-jet fuel to achieve zero net present value (NPV = 0) at a discount rate of 10 % are 12,258 CNY/tonne and 8952 CNY/tonne for Case I and II processes, respectively. The price of WS or ICR is the most sensitive factor affecting the MSP. For Case II project, the selling price of by-product steam also shows very significant impact on the MSP. Monte-Carlo simulation for risk analysis suggests that there is a high probability (96.66 %) for Case I plant to be profitable, while the probability of Case II plant is even as high as 99.99 % at the current price of bio-jet fuel (15,000 CNY/tonne). This work thus can provide important economic information for production of bio-jet fuel from lignocellulosic biomass by this novel route.

The physical and mechanical consequences of incorporating industrial residues into mortar and concrete mixtures for eco-friendly marine constructions

The physical and mechanical consequences of incorporating industrial residues into mortar and concrete mixtures for eco-friendly marine constructions

Antifungal Activity of Mexican Oregano (Lippia graveolens Kunth) Extracts from Industrial Waste Residues on Fusarium spp. in Bean Seeds (Phaseolus vulgaris L.)

Food security is essential to ensure everyone can access sufficient nutritious food. Cereals and legumes are fundamental foods worldwide. Phaseolus vulgaris L., the common bean, is an essential staple food in many nations worldwide. However, it is vulnerable to fusariosis, a disease caused by the fungus Fusarium spp. that can significantly decrease crop quality and yield. To combat plant diseases, industrial residues and plant residues are valuable due to their bioactive compounds with biotechnological applications. This study proposes using ethanolic extracts with phytochemical compounds, such as flavonoids, different from those reported in essential oils, to reduce the growth of Fusarium species both in vitro and in vivo. Industrial residues that are produced after extracting essential oils offer a promising alternative to develop organic biopesticides, promoting more sustainable and environmentally friendly agriculture.

Incorporation of spent bleaching earth and glass sediment as an alternative raw material for the manufacture of eco-products based on fired clay

This study explores the use of two industrial residues: spent bleaching earth (SBE) and glass sediment (GS), as alternative raw materials in the production of ceramic materials from fired clay. The mixtures incorporating 0%, 10%, 30%, and 50% by weight of these residues, were examined. The impact of quantity and type of waste on product properties (density, water absorption, compressive strength, and thermal conductivity) was assessed against NTC 4205 standards. Incorporating 50% SBE reduced thermal conductivity by 35%, but increased porosity affected compressive strength. Glass sediment incorporation increased thermal conductivity but surpassed pure clay in mechanical behavior. The triphasic mix (20% GS, 10% SBE with lime) demonstrated optimal mechanical performance, meeting fired clay masonry unit standards. An eco-product prototype based on this mix was successfully manufactured, affirming that industrial waste is a viable alternative raw material, yielding ceramic materials with properties meeting or surpassing Colombian construction industry standards.

Modeling Freeze‐Lining Formation: A Case Study in the Slag Fuming Process

Slag fuming (SF) is a metallurgical process designed to recycle Zn‐containing slags derived from various industrial residues. To protect the reactor from corrosive molten slag, a deliberate as‐solidified slag layer, known as a freeze lining (FL), is formed on the reactor walls using intense water‐cooled jackets. In this article, a computational‐fluid‐dynamics‐based model capable of simulating FL formation in a SF furnace is presented. To capture the complex multiphase flow dynamics, heat transfer, and FL formation during SF, a volume‐of‐fluid model is coupled with a mixture continuum solidification model. Three phases are considered: gas, liquid bulk slag, and solid slag (FL). Moreover, two types of FL are distinguished: one that solidifies on the reactor wall in the bulk slag region and another that solidifies on the reactor wall in the freeboard region owing to slag splashing. Comparisons between calculated FL thickness and heat fluxes and corresponding industrial data demonstrate satisfactory agreement. In this outcome, the robustness of the model is underscored and confidence in its accuracy is instilled. In the simulation results, valuable insights are provided into the evolution of the fuming process, particularly regarding the slag bath temperature, slag splashing dynamics, FL formation, local heat fluxes through the reactor wall, and global net energy balance.