Resource Utilization Approach Research Articles

Characterization, pollution, and beneficial utilization assessment of dredged sediments from coastal ports in China

China, the world's largest dredging nation with over 2 billion cubic meters dredged annually, urgently needs tailored strategies for reusing those dredged sediments based on their physicochemical traits and pollution levels. The properties (grain size, pH, density, and conductivity), nutrient contents (organic matter, N, P, K), and heavy metal risks (Cu, Pb, Zn, Cr, Cd, Ni, Hg, As) of dredged sediments were investigated across 14 ports in China. Notably, 80 % of dredged sediments in China coastal ports are composed of silt. Significant variations in organic matter, nutrient, and heavy metals concentrations were observed. Environmental indices (m-ERM-Q < 0.5, Igeo < 1 and PERI <150) indicate sediment-associated nutrients & heavy metals pose low environmental risks, except for Cd and Hg, which are potential pollution concerns. This research offers insights into tailored strategies for managing dredged sediments and proposes resource utilization approaches, including wetland restoration, for practical application in China.

Incorporating Indium Oxide into Microplasma Reactor for CO2 Conversion to Methanol.

The clean conversion of CO2 is a strategic issue for addressing global climate change and advancing energy transformation. While the current clean CO2 conversion is limited to the H2 pyrolysis process, using H2O as a proton source is more promising and sustainable. A microplasma discharge method is developed, driven by electricity, and utilized for CO2 conversion with H2O. The microplasma integrates the advantages of high energy density in discharge plasma and microchannel reaction spaces, achieving a rapid resource conversion process of CO2 and water and a high selectivity for methanol production. By further combining In2O3 with microplasma and optimizing the structure of In2O3, is improved the selectivity of methanol production to 86.66%. The methanol production rate reached 72.64mmol g-1 h-¹, which is higher than other clean energy-driven conversion technologies. This work provides a green route for uphill reactions in clean CO2 conversion, offering a new approach for CO2 emission reduction and resource utilization.

Study on the remediation of groundwater nitrate pollution by pretreated wheat straw and woodchips

Groundwater nitrate contamination poses a threat to both the ecological environment and human health. This study investigated the potential of using saturated Ca(OH)2 to pretreat wheat straw and woodchips, aiming to enhance their efficacy as carbon sources for denitrification. The optimization of pretreatment conditions, and the elucidation of underlying mechanisms were explored. The pretreatment process involved the dissolution of lignin and hemicellulose, exposure of the cellulose structure, reduction of hydrogen bonds within cellulose, hydrolysis of polymerized cellulose, and the formation of cracks and hierarchical structures on the surface of the carbon source. These alterations improved the attachment and utilization of microorganisms. The maximum enzymatic reducing sugar yields for wheat straw and woodchips were achieved at solid-liquid ratios of 1:40 and soaking times of 5 and 2 days, respectively. The response surface predicted the optimal pretreatment conditions for wheat straw to be a solid-liquid ratio of 1:88.1 and a soaking time of 8.2 h. Alkaline treatment increased the denitrification rate of woodchips by fivefold and prevented the initial organic matter leaching rate of wheat straw, thereby reducing the risk of secondary pollution. The predominant microbial communities in all samples exhibited functions related to lignocellulose degradation and denitrification. The community composition of solid-phase carbon sources was found to be richer than that of liquid-phase carbon sources, and the pretreatment increased the abundance of lignocellulose degradation and denitrification functional microorganisms. The pretreatment liquid of wheat straw achieved the highest denitrification rate constant (0.43 h−1). Our result validated the feasibility of using the pretreatment liquid as a denitrification carbon source and presenting a novel approach for waste resource utilization.

Dual Metallosalen-Based Covalent Organic Frameworks for Artificial Photosynthetic Diluted CO2 Reduction.

Directly converting CO2 in flue gas using artificial photosynthetic technology represents a promising green approach for CO2 resource utilization. However, it remains a great challenge to achieve efficient reduction of CO2 from flue gas due to the decreased activity of photocatalysts in diluted CO2 atmosphere. Herein, we designed and synthesized a series of dual metallosalen-based covalent organic frameworks (MM-Salen-COFs, M: Zn, Ni, Cu) for artificial photosynthetic diluted CO2 reduction and confirmed their advantage in comparison to that of single metal M-Salen-COFs. As a results, the ZnZn-Salen-COF with dual Zn sites exhibits a prominent visible-light-driven CO2-to-CO conversion rate of 150.9 μmol g-1 h-1 under pure CO2 atmosphere, which is ~6 times higher than that of single metal Zn-Salen-COF. Notably, the dual metal ZnZn-Salen-COF still displays efficient CO2 conversion activity of 102.1 μmol g-1 h-1 under diluted CO2 atmosphere from simulated flue gas conditions (15 % CO2), which is a record high activity among COFs- and MOFs-based photocatalysts under the same reaction conditions. Further investigations and theoretical calculations suggest that the synergistic effect between the neighboring dual metal sites in the ZnZn-Salen-COF facilitates low concentration CO2 adsorption and activation, thereby lowering the energy barrier of the rate-determining step.

Dual Metallosalen‐based Covalent Organic Frameworks for Artificial Photosynthetic Diluted CO2 Reduction

Directly converting CO2 in flue gas using artificial photosynthetic technology represents a promising green approach for CO2 resource utilization. However, it remains a great challenge to achieve efficient reduction of CO2 from flue gas due to the decreased activity of photocatalysts in diluted CO2 atmosphere. Herein, we designed and synthesized a series of dual metallosalen‐based covalent organic frameworks (MM‐Salen‐COFs, M: Zn, Ni, Cu) for artificial photosynthetic diluted CO2 reduction and confirmed their advantage in comparison to that of single metal M‐Salen‐COFs. As a results, the ZnZn‐Salen‐COF with dual Zn sites exhibits a prominent visible‐light‐driven CO2‐to‐CO conversion rate of 150.9 μmol g−1 h−1 under pure CO2 atmosphere, which is ~6 times higher than that of single metal Zn‐Salen‐COF. Notably, the dual metal ZnZn‐Salen‐COF still displays efficient CO2 conversion activity of 102.1 μmol g−1 h−1 under diluted CO2 atmosphere from simulated flue gas conditions (15% CO2), which is a record high activity among COFs‐ and MOFs‐based photocatalysts under the same reaction conditions. Further investigations and theoretical calculations suggest that the synergistic effect between the neighboring dual metal sites in the ZnZn‐Salen‐COF facilitates low concentration CO2 adsorption and activation, thereby lowering the energy barrier of the rate‐determining step.

Breaking the Conversion-Selectivity Trade-Off in Methanol Synthesis from CO2 Using Dual Intimate Oxide/Metal Interfaces.

The selective hydrogenation of carbon dioxide (CO2) to value-added chemicals, e.g., methanol, using green hydrogen retrieved from renewable resources is a promising approach for CO2 emission reduction and carbon resource utilization. However, this process suffers from the competing side reaction of reverse water-gas shift (RWGS) and methanol decomposition, which often leads to a strong conversion-selectivity trade-off and thus a poor methanol yield. Here, we report that InOx coating of PdCu bimetallic nanoparticles (NPs) to construct intimate InOx/Cu and InOx/PdIn dual interfaces enables the break of conversion-selectivity trade-off by achieving ∼80% methanol selectivity at ∼20% CO2 conversion close to the thermodynamic limit, far superior to that of conventional metal catalysts with a single active metal/oxide interface. Comprehensive microscopic and spectroscopic characterization revealed that the InOx/PdIn interface favors the activation of CO2 to formate, while the adjacent InOx/Cu interface readily converts formate intermediates to methoxy species in tandem, which thus cooperatively boosts methanol production. These findings of dual-interface synergies via oxide coating of bimetallic NPs open a new avenue to the design of active and selective catalysts for advanced catalysis.

MXene laminar membrane functionalized with Pd-Cu for efficient and selective nitrate reduction to ammonia

Conversion of nitrates (NO3−) to ammonia (NH3) by electrocatalysis is a sustainable approach for resource utilization from wastewater. Nonetheless, this conversion is often constrained by sluggish mass transfer. In this study, we developed a laminar membrane using Pd-Cu bimetal functionalized 2D MXene (Ti3C2Tx) to accelerate the mass transfer during NO3− reduction. The resulting membrane exhibited outstanding NO3−-N removal efficiency (99.0 ± 0.5 %) and NH4+-N selectivity (74.1 ± 0.6 %), and maintained excellent NO3−-N removal efficiency with various influent NO3− concentrations. Its nitrate reduction performance was relatively stable even in low-conductivity influents similar to surface water, presence of dissolved oxygen (DO) or after membrane fouling. The NO3−-N removal rate in the electrocatalytic filtration system was 11 times that without filtration, attributed to a ten-fold improvement in the mass transfer constant (km) with filtration and the increased active sites for NO3− reduction by 2D MXene. The filtration process ensured a higher NH4+-N selectivity by preventing the re-oxidation of NH4+-N on anode. The mechanism of nitrate reduction on the laminar membrane was predominantly direct reduction, and the spatial distribution analysis of atomic hydrogen (H*) demonstrated that it was difficult for H* to participate in nitrate reduction reaction due to the strong adsorption of H* on the membrane. Theoretical calculations suggested that Pd-Cu bimetal could greatly diminish the energy barriers for NO3− to NH4+ and enhance the conversion efficiency. This finding offers valuable insights for developing efficient and robust nano-laminar membranes aimed at nitrate removal and ammonium production in water.

Rapid Whole Genome Characterization of High-Risk Pathogens Using Long-Read Sequencing to Identify Potential Healthcare Transmission.

Routine use of whole genome sequencing (WGS) has been shown to help identify transmission of pathogens causing healthcare-associated infections (HAIs). However, the current gold standard of short-read, Illumina-based WGS is labor and time-intensive. In light of recent improvements in long-read Oxford Nanopore Technologies (ONT) sequencing, we sought to establish a low resource utilization approach capable of providing accurate WGS-based comparisons of HAI pathogens within a time frame allowing for infection prevention and control (IPC) interventions. WGS was prospectively performed on antimicrobial-resistant pathogens at increased risk of potential healthcare transmission using the ONT MinION sequencer with R10.4.1 flow cells and Dorado basecalling algorithm. Potential transmission was assessed via Ridom SeqSphere+ for core genome multilocus sequence typing and MINTyper for reference-based core genome single nucleotide polymorphisms using previously published cut-off values. The accuracy of our ONT pipeline was determined relative to Illumina-based WGS data generated from the same genomic DNA sample. Over a six-month period, 242 bacterial isolates from 216 patients were sequenced by a single operator. Compared to the Illumina gold-standard data, our ONT pipeline achieved a Q score of 60 for assembled genomes, even with a coverage rate of as low as 40X. The mean time from initiating DNA extraction to complete genetic analysis was 2 days (IQR 2-3.25 days). We identified five potential transmission clusters comprising 21 isolates (8.7% of all sequenced strains). Combining ONT WGS data with epidemiological data, >70% (15/21) of the isolates originated from patients with potential healthcare transmission links. Via a stand-alone ONT pipeline, we detected potentially transmitted HAI pathogens rapidly and accurately, aligning closely with epidemiological data. Our low-resource method has the potential to assist in the efficient detection and deployment of preventative measures against HAI transmission.

Wet Extraction of By-Product Samples and Fractionation of Valuable Compounds using Supercritical CO2 Extraction: An Innovative Approach for Sustainable Resource Utilization

This research explores an innovative method for extracting and fractionating valuable compounds from by-product samples through the utilization of supercritical carbon dioxide (SC-CO2) extraction. By-products generated from various industrial processes often contain untapped reservoirs of valuable compounds, necessitating environmentally sustainable and economically viable extraction techniques. SC-CO2 extraction, known for its unique properties such as low toxicity, non-flammability, and tunable solubility, presents a promising avenue for efficient and selective extraction of target compounds.The study focuses on wet extraction, emphasizing the extraction of valuable compounds from by-products in their natural, moisture-laden state. This approach not only enhances the sustainability of the extraction process by minimizing pre-treatment steps but also broadens the scope of potential target compounds. The study further explores the critical parameters of SC-CO2 extraction, including pressure, temperature, and flow rate, to optimize the extraction efficiency and selectivity for different classes of compounds.

Passivation of heavy metals during co-composting of Camellia oleifera by-products and river sediment with the additives of MnO2-loaded biochar

Composting is not only a green and sustainable way to treat and reuse agricultural waste but also an effective method for passivating heavy metals. However, there is no research on the co-composting of the by-products of Camellia oleifera and sediment to simultaneously achieve the remediation of heavy metal and resource utilization of Camellia oleifera by-products. Moreover, MnO2 and biochar have been widely used to promote humification in the composting process. However, few studies have investigated the efficiency of MnO2-loaded biochar in promoting the passivation of heavy metals in the co-composting system of Camellia oleifera by-products and sediment, and its effects on composting biological characteristics are often ignored. Therefore, this study investigated the changes in the heavy metal bioavailability and the microbial communities in sediment and Camellia oleifera by-products co-composting with the additives of MnO2-loaded biochar. The results showed that the MnO2-loaded biochar effectively passivated heavy metals and improved microbial diversity and structure, which increased the Copper and Lead residual fractions (RES-Cu and RES-Pb) by 14.01 % and 17.57 %, respectively, while the Cadmium exchangeable fraction (EXC-Cd) and the Zinc bioavailability fraction (BF-Zn) decreased by 24.72 % and 10.99 %, respectively. pH, temperature, and bacterial community were the critical regulators for heavy metals passivation by MnO2-loaded biochar. This study not only provides a promising resource utilization approach for Camellia oleifera by-products but also provides a new perspective and theoretical reference for the remediation of heavy metals contaminated sediment by composting.

Endogenous iron-enriched biochar derived from steel mill wastewater sludge for tetracycline removal: Heavy metals stabilization, adsorption performance and mechanism

Steel mill wastewater sludge, as an iron-enriched solid waste, was expected to be converted into iron-enriched biochar with acceptable environmental risk by pyrolysis. The purpose of our study was to evaluate the chemical speciation transformation of heavy metals in biochar under various pyrolysis temperatures and its reutilization for tetracycline (TC) removal. The experimental data indicated that pyrolysis temperature was a key factor affecting the heavy metals speciation and bioavailability in biochar, and biochar with pyrolysis temperature at 450 °C was the most feasible for reutilization without potential risk. The endogenous iron-enriched biochar (FSB450) showed highly efficient adsorption towards TC, and its maximum adsorption capacity could reach 240.38 mg g−1, which should be attributed to its excellent mesoporous structure, abundant functional groups and endogenous iron cycling. The endogenous iron was converted to a stable iron oxide crystalline phase (Fe3O4 and MgFe2O4) by pyrolysis, which underwent a valence transition to form a coordination complex with TC by electron shuttling in the FSB450 matrix. The study provides a win-win approach for resource utilization of steel wastewater sludge and treatment of antibiotic contamination in wastewater.

Coupling of struvite crystallization and aqueous phase recirculation for hydrochar upgrading and nitrogen recovery during hydrothermal carbonization of sewage sludge

Recycling of aqueous phase (AP) as a by-product after hydrothermal carbonization (HTC) of sewage sludge (SS) has been of interest. The combination of magnesium ammonium phosphate (MAP) or the so-called struvite crystallization and aqueous phase (AP) recirculation has great potential for resource recovery and hydrochar enhancement. In this study, both the aqueous phase of HTC after MAP recovery of NH4+-N (AP-MAP) and the untreated aqueous phase of HTC (AP-HTC) were reused for HTC of fresh SS, and both aqueous phases were recycled four times. The effects of the two AP cycles on the properties of AP and hydrochar at 200, 230, and 260 °C were studied, and the effect of temperature on the two AP cycles was similar. The hydrochar produced by the AP-MAP cycle had lower nitrogen content than that of the AP-HTC cycle due to the low ammonia nitrogen (NH4+-N) content, and the combustion performance was improved. MAP recovery reduces the accumulation of NH4+-N in the AP cycle and MAP is also a high-quality fertilizer. Therefore, the combination of MAP recovery and AP recycling provides a feasible technical approach for resource utilization, eutrophic AP treatment, and production of high-quality hydrochar in the HTC process of SS.

Harmony in detoxification: Microalgae unleashing the potential of lignocellulosic pretreatment wastewater for resource utilization

Lignocellulosic biomass is a pivotal renewable resource in biorefinery process, requiring pretreatment, primarily chemical pretreatment, for effective depolymerization and subsequent transformation. This process yields solid residue for saccharification and lignocellulosic pretreatment wastewater (LPW), which comprises sugars and inhibitors such as phenols and furans. This study explored the microalgal capacity to treat LPW, focusing on two key hydrolysate inhibitors: furfural and vanillin, which impact the growth of six green microalgae. Chlorella sorokiniana exhibited higher tolerance to furfural and vanillin. However, both inhibitors hindered the growth of C. sorokiniana and disrupted algal photosynthetic system, with vanillin displaying superior inhibition. A synergistic inhibitory effect (Q < 0.85) was observed with furfural and vanillin on algal growth. Furfural transformation to low-toxic furfuryl alcohol was rapid, yet the addition of vanillin hindered this process. Vanillin stimulated carbohydrate accumulation, with 50.48 % observed in the 0.1 g/L furfural + 0.1 g/L vanillin group. Additionally, vanillin enhanced the accumulation of C16: 0 and C18: 2, reaching 21.71 % and 40.36 %, respectively, with 0.1 g/L vanillin. This study proposed a microalgae-based detoxification and resource utilization approach for LPW, enhancing the comprehensive utilization of lignocellulosic components. The observed biomass modifications also suggested potential applications for biofuel production, contributing to the evolving landscape of sustainable biorefinery processes.

Resource utilization of field acid mine drainage: Formation of layered double hydroxides, its removal capacity and mechanism for antimony

Although acid mine drainage (AMD) has been recognized as a major environmental pollutant, it is also a potential source of valuable metals and sulfate. In this study, a resource utilization approach of field AMD for the formation of iron-based layered double hydroxides (LDHs) with sulfate intercalation was proposed and its capacity for removing antimonate [Sb(V)] was examined. Layered double hydroxides derived from field AMD possesses a more rapid equilibration time (<120 min) and a larger removal capacity (78 mg g−1) for Sb(V) compared with other LDHs from chemical reagents. Following the treatment of field AMD containing 10.7 mg L−1 Sb, a residual Sb concentration of 4.0 μg L−1 was achieved using a dose of 1 g L−1 LDHs, which meets the drinking water standard of 5 μg L−1 recommended by China's Ministry of Health. Leaching tests showed negligible metal(loid)s dissolution in Sb-loaded LDHs over a short period. The interactions between Sb(V) and LDHs include anion exchange and formation of brandholzite, which were further investigated at the electronic scale using density functional theory (DFT) calculations. It is envisaged that this approach for preparing LDHs will provide theoretical support for the remediation and resource recovery of AMD.

Optimizing makespan and resource utilization in cloud computing environment via evolutionary scheduling approach.

As a new computing resources distribution platform, cloud technology greatly influenced society with the conception of on-demand resource usage through virtualization technology. Virtualization technology allows physical resource usage in a way that will enable multiple end-users to have similar hardware infrastructure. In the cloud, many challenges exist on the provider side due to the expectations of clients. Resource scheduling (RS) is the most significant nondeterministic polynomial time (NP) hard problem in the cloud, owing to its crucial impact on cloud performance. Previous research found that metaheuristics can dramatically increase CC performance if deployed as scheduling algorithms. Therefore, this study develops an evolutionary algorithm-based scheduling approach for makespan optimization and resource utilization (EASA-MORU) technique in the cloud environment. The EASA-MORU technique aims to maximize the makespan and effectively use the resources in the cloud infrastructure. In the EASA-MORU technique, the dung beetle optimization (DBO) technique is used for scheduling purposes. Moreover, the EASA-MORU technique balances the load properly and distributes the resources based on the demands of the cloud infrastructure. The performance evaluation of the EASA-MORU method is tested using a series of performance measures. A wide range of comprehensive comparison studies emphasized that the EASA-MORU technique performs better than other methods in different evaluation measures.

Revealing the mechanism of quartz sand seeding in accelerating phosphorus recovery from anaerobic fermentation supernatant through vivianite crystallization

The recovery of phosphorus (P) through vivianite crystallization offers a promising approach for resource utilization in wastewater treatment plants. However, this process encounters challenges in terms of small product size and low purity. The study aimed to assess the feasibility of using quartz sand as a seed material to enhance P recovery and vivianite crystal characteristics from anaerobic fermentation supernatant. Various factors, including seed dosage, seed size, Fe/P ratio, and pH, were systematically tested in batch experiments to assess their influence. Results demonstrated that the effect of seed enhancement on vivianite crystallization was more pronounced under higher seed dosages, smaller seed sizes, and lower pH or Fe/P ratio. The addition of seeds increased P recovery by 4.43% in the actual anaerobic fermentation supernatant and also augmented the average particle size of the recovered product from 19.57 to 39.28 μm. Moreover, introducing quartz sand as a seed material effectively reduced co-precipitation, leading to a notable 12.5% increase in the purity of the recovered vivianite compared to the non-seeded process. The formation of an ion adsorption layer on the surface of quartz sand facilitated crystal attachment and growth, significantly accelerating the vivianite crystallization rate and enhancing P recovery. The economic analysis focused on chemical costs further affirmed the economic viability of using quartz sand as a seed material for P recovery through vivianite crystallization, which provides valuable insights for future research and engineering applications.

Constructing triple-protected Si/SiOx@ZnO@C anode derived from volatile silicon waste for enhanced lithium storage capacity

Silicon anode is deemed to be one of the most promising anode materials and has attracted wide attention from all walks of life. However, its commercial application is severely limited owing to the high cost, serious volume expansion, and poor electrical conductivity. Herein, Si/SiOx nanoparticles were successfully prepared by sand milling the low-cost volatile deposited silicon waste from electron beam refining polycrystalline silicon. Furthermore, the atomic layer deposited (ALD) zine oxide on Si/SiOx nanoparticles enhances the integrity of the electrode structure and provides a steady solid electrolyte layer (SEI). The outer layer is wrapped by a uniform carbon shell to restrict the volume expansion and boost the conductivity of the electrode during lithiation/delithiation. Impressively, lithium-ion batteries (LIBs) employing the Si/SiOx@ZnO@C anodes display excellent rate performance (up to 844.48 mAh g−1 at 2 A g−1) and cycle stability (912.7 mAh g−1 at 1A g−1 over 50 cycles). Moreover, the Si/SiOx@ZnO@C electrode exhibits high initial coulombic efficiency (76.8 %) and the reversible specific capacity maintains at 846 mAh g−1 over 200 cycles with a current density at 0.5 A g−1. The improvement is ascribed to the synergistic effect of triple-protected layer that effectively enhances the stability of SEI and the conductivity of the electrode. This work not only opens a novel and economic strategy for the manufacture of high-performance silicon-based anode but also furnishes an original approach for recycling and resource utilization of silicon waste.

Research on Recycling of Phosphorus Tailings Powder in Open-Graded Friction Course Asphalt Concrete

The reuse in high-value materials is one of the important resource utilization approaches of phosphorus tailings. At present, a mature technical system has been formed on the reuse of phosphorus slag in building materials, and silicon fertilizers in the extraction of yellow phosphorus. But there is a lack of research on the high-value reuse of phosphorus tailings. In order to make safe and effective utilization of phosphorus tailing resources, this research concentrated on how to solve easy agglomeration and difficult dispersion of phosphorus tailing micro-powder, when it was recycled in road asphalt. In the experimental procedure, phosphorus tailing micro-powder is treated in two methods. One method is to directly add it with different contents in asphalt to form a mortar. Dynamic shear tests were used to explore the effect of phosphorus tailing micro-powder on the high-temperature rheological properties of asphalt influence mechanism of material service behavior. The other method is to replace the mineral powder in asphalt mixture. The effect of phosphate tailing micro-powder on the water damage resistance in open-graded friction course (OGFC) asphalt mixtures was illustrated, based on the Marshall stability test and the freeze-thaw split test. The research results show that the performance indicators of the modified phosphorus tailing micro-powder meet the requirements for mineral powder in road engineering. Compared with standard OGFC asphalt mixtures, the residual stability of immersion and freeze-thaw splitting strength were improved when replace the mineral powder. The residual stability of immersion increased from 84.70% to 88.31%, and freeze-thaw splitting strength increased from 79.07% to 82.61%. The results indicate that phosphate tailing micro-powder has a certain positive effect on the water damage resistance. These performance improvements can be attributed to the larger specific surface area for phosphate tailing micro-powder than ordinary mineral powder, which can effectively adsorb asphalt and form structural asphalt. The research results are expected to support the large-scale reuse of phosphorus tailing powder in road engineering.

Novel resource utilization approach of spent catalyst from flue gas denitrification: Preparing high quality titanium-bearing pellets

Spent titanium-based catalyst is a waste generated by the selective catalytic reduction (SCR) denitrification process, whose generation is dramatically increasing in the iron and steel industry year by year. A novel approach was proposed in this work to prepare titanium-bearing pellets by using spent catalyst. The influences of spent catalyst addition on the comprehensive properties of pellets were studied. The corresponding relationship between the change of phase structure and the spent catalyst pellets' strength was investigated. The results demonstrated that the spent catalyst could be adsorbed on the surface of ore particles physically and chemically, improving the adhesion of particles inside the pellet and the hydrophilicity, thus obtaining good comprehensive performance of the green pellets. When adding 5.0 wt% spent catalyst, the bentonite dosage could be reduced by 50%, and the strength of roasted pellets could meet the requirement of large blast furnaces. The consolidation mechanism of the spent catalyst pellets indicated that TiO2 reacted with FeO first to generate FeTiO3 in the preheating process and further oxidized to form Fe2TiO5 in the roasting process. The unreacted TiO2 would appear in the roasted pellets and inhibit recrystallization and polycrystalline growth of Fe2O3 grains, resulting in the reduction of compressive strength. Overall, high-quality titanium-bearing pellets could be obtained when the amount of spent catalyst was less than 5.0 wt%. This study thus provided an alternative route to resource utilization of spent catalysts in iron and steel enterprises.

An IoT-based resource utilization framework using data fusion for smart environments

Nowadays, many communities are emerging towards smart environments, requiring the communication and collaboration of diverse Internet-of-Things (IoT) devices. A smart environment exploits the use of IoT technology to share and process data among such devices for a better living. However, this comes with additional costs, such as the exponential growth of IoT devices, the heterogeneity of IoT use cases, and the new complex features encountered by IoT data, which complicate their processing and analysis using the traditional techniques. This causes a dramatic performance degradation of the used processing resources, which directly affects the overall efficiency and performance of IoT-based systems. Although different studies have presented resource utilization approaches for IoT systems, but they were not evaluated from different resource utilization perspectives. Besides, no efforts have been directed to investigate their effectiveness to process the unprecedented IoT data features that inevitably impact the accuracy and efficiency of resource utilization. In this paper, the Triple Phases Resource Utilized Data Fusion (TPRUDF) framework is proposed as the first IoT-based cost-aware resource utilization using data fusion. It exclusively considers different IoT data features by employing three phases of data fusion: (1) data in – data out, (2) data in – feature out, and (3) feature in – decision out. TPRUDF fuses the raw IoT data by maintaining the complex IoT data features, independent of the IoT domain or the computing model, using the spatiotemporal data fusion (STDF) IoT-based data fusion approach. TPRUDF then fuses the uncorrelated data features via the Principal Component Analysis. Finally, it employs two different resource utilization techniques: (1) Genetic Algorithms and (2) Particle Swarm Optimization, fusing their results using the voting logic fusion technique. A public edge-computing simulator is used to evaluate TPRUDF via three real-world smart cities datasets. The experimental results of the proposed TPRUDF framework indicate that it: (1) achieves an average accuracy level of resource utilization equal to 91%, (2) increases the resource utilization throughput by an average of 40% and eventually minimizes the processing delay, (3) boosts the resource utilization availability by 60%, and (4) decreases the energy consumption by 35%.