Industrial Waste Research Articles

The improvement of available phosphorous of reclaimed-mining soils with coal fly ash and empty fruit bunches of oil palm treatments

Abstract Reclaimed-mining soil (RMS) were categorized as having an acidic pH, low organic carbon (C), low available phosphorous (P), and high contents of aluminium (Al) and iron (Fe); therefore, soil ameliorants were essentially added to this soil for improving soil fertility. The purpose of the research was to measure the impact of combining empty fruit bunches of oil palm (EFBOP) and coal fly ash (CFA) on the available P of RMS. Three rates of CFA application: 0, 75, and 150 Mg ha−1 and three rates of EFBOP application: 0, 25, and 50 Mg ha−1 were organized using a completely randomized design. A 1000 g of soil was placed to an experimental pot, and then CFA and EFBOP according to the treatment were added to the pot. The mixture of soils, CFA, and EFBOP were homogenized, and then incubated at 70% water holding capacity for 45 days. Available P, total P, Al-P, Fe-P, soil pH, and exchangeable Al were quantifies following the completion of incubation period. The findings of this research indicated that available P rose from 3 mg kg−1 of control (soil without treatment) to 5-41 mg kg−1 of soils with different amounts of CFA and EFBOP addition. The application of CFA and EFBOP also resulted in increases in soil pH from 4.33 in the control to pH 4.48-6.23. Additionally, the levels of Al-P, Fe-P, and exchangeable aluminum decreased with the application of CFA and EFBOP. The findings of this study highlight the potency utilizing industrial and agricultural wastes as soil ameliorants for improving available P to support plant growth on the reclaimed-mining soils.

Cadmium (II) ion adsorption of an industrial liquid waste-derived ferric oxide loaded with chitosan: Parameters optimization, isotherms, kinetics and thermodynamics

In this work, ferric oxide prepared from an industrial liquid waste was loaded with chitosan, then the as-received ferric oxide loaded with chitosan (FOLWC) was utilized as a novel adsorbing material for the elimination of trace cadmium(II) ion from cadmium(II)-containing solution. First, the microstructure and phase composition of FOLWC was explored. Then, the effects of initial pH, contact time and adsorbent dosage on the cadmium(II) ion adsorption were investigated. An empirical quadratic polynomial equation which could predict the response value of cadmium(II) ion removal efficiency was obtained as follow: W=93.69+11.38A+2.90B+0.99C-1.36AB-1.51AC-0.15BC-7.70A2-2.35B2+1.76C2, where A, B and C represent the initial pH, adsorbent dosage and contact time, respectively. In addition, the optimization study of adsorption parameters was carried out using response surface methodology. The pH value of cadmium(II)-containing solution has a most significant effect on the cadmium(II) ion removal onto from FOLWC. The pH value, contact time and adsorbent dosage corresponding to the optimum conditions were obtained to be 6.77, 15.27 min and 1.71 g/L, respectively. The cadmium(II) ion removal efficiency was reached nearly 100 % on the optimum conditions. The adsorption kinetics result implies that a pseudo-second-order model can be consistent with the adsorption process. The cadmium (II) ion adsorption isotherm accords with Langmuir model. The studied maximum cadmium(II) ion adsorption capacity of 17.08 mg/g by FOLWC reached at 55 ℃. In addition, thermodynamic experimental data indicates that the whole removal process of cadmium(II) ion by FOLWC is not only endothermic but spontaneous as well. The principal adsorption mechanism is surface complexation, where the dominant surface groups including -OH, CO and N-H of FOLWC were replaced by the cadmium(II) ions. In summary, it shows that FOLWC can be taken as an efficient adsorbent for Cadmium ion removal from polluted water.

Microwave-assisted pyrolysis of industrial biomass waste: Insights into kinetic, characteristics and intrinsic mechanisms

Microwave-assisted pyrolysis is the preferred technology for enhancing the production of fuels and valuable chemicals. Therefore, pyrolysis experiments of furfural residue (FR) were performed using microwave equipment without microwave-absorbing additives. Further, to explore the interactions and intrinsic mechanisms of biomass components, thermogravimetric (TG), kinetic calculation, Py-GC/MS and TG-MS were also employed. Results showed that the temperatures and catalysts both affect the yields and compositions of products. Moreover, kinetic calculations showed a high-level consistency between FR pyrolysis and P3 mechanism. The product analysis also helps in the resolution of pyrolysis mechanism. For example, crystal substances in biochar were mainly SiO2, K2SO4, KAlSi3O8, and K2SO4 enhanced the reaction degree of biomass. While for bio-oil, the yield reached maximum (∼25 wt%) at ∼550 °C. The pH of bio-oil was acidic (2-4.3), and the main product in bio-oil was phenols, which was found the highest (84.63%) at 700oC. Interestingly, the interaction of cellulose and lignin promoted light hydrocarbon production. This research unveils innovative perspectives on the intrinsic mechanisms underlying microwave-assisted pyrolysis of biomass, which provides guidance for optimization of the microwave-assisted pyrolysis technology.

Sustainable and efficient removal of phosphorus from wastewater through red mud residue after deep dealkalization

The increase phosphorus content in industrial wastewater can seriously deteriorate the water quality and correspondingly cause the eutrophication of rivers, lakes and underground water. The calcium silicate powder (CSP) was prepared from the red mud residue after deep dealkalization for phosphorus removal from wastewater, and the corresponding removal performance and adsorption mechanism were investigated in this work. Under the optimal conditions, a phosphorus removal efficiency of 96.32 % and a maximum immobilization capacity of 24.08 mg∙g−1 were achieved. The kinetic and isotherm data are well-fitted by the pseudo-second-order and Langmuir models, while the phosphorus is mainly removed by chemisorption, accompanied by the formation of a monolayer film on the heterogeneous surface. A novel Source-Parameters-Strategy-Demand architecture was proposed to evaluate the application potential of calcium silicate powder and environmental risk. The findings confirmed the validity of calcium silicate prepared from red mud residue for the phosphorus removal from wastewater, which has the unique advantages in simultaneously solving the industrial solid waste pollution and excessive phosphorus discharge.

Sustainable resilient E-waste management in London: A circular economy perspective

The circular economy (CE) is reasoned to organize complex systems supporting sustainable resilience by distinguishing between waste materials and economic growth. This is crucial to the electronic waste (e-waste) industry of developed countries, and e-waste operation management has become their top priority because e-waste contains toxic materials and valuable sources of elements. In the UK, although London Metropolitan city boasts an ambitious sustainable resilience target underlying the context of CE, practical implementation has yet to be feasible, with few investigations detailing if and how the existing target implications enable industrial and social-ecological sectors to continue their performance functionalities in the face of undesired disruptions. In this paper, a dynamic Bayesian Network (dynamic BN) approach is developed to address a range of potential risks. The existing London e-waste operation management is considered as an application of study for sustainable resilience development. Through the utilization of dynamic BN, a comprehensive analysis yields a Resilience Index (RI) of 0.5424, coupled with a StdDev of 0.01350. These metrics offer a profound insight into the intricate workings of a sustainable system and its capacity to swiftly rebound from unexpected shocks and disturbances. This newfound understanding equips policymakers with the knowledge needed to navigate the complexities of sustainable e-waste management effectively. The implications drawn from these in-depth analyses furnish policymakers with invaluable information, enabling them to make judicious decisions that advance the cause of sustainable e-waste management. The findings underscore that the absorptive capacity of a sustainable and resilient e-waste operation management system stands as the foremost defense mechanism against unforeseen challenges. Furthermore, it becomes evident that two pivotal factors, namely “diversifying the supply chain” and “enhancing supply chain transparency,” play pivotal roles in augmenting the sustainability and resilience of e-waste operation management within the context of London's ambitious sustainability targets. These factors are instrumental in steering the trajectory of e-waste management towards a more sustainable and resilient future, aligning with London's aspirations for a greener and more eco-conscious future.

Study on Wastewater Treatment in the Textile Industry by Adsorption of Reactive Red 141 Dye Using a Phosphogypsum/Vanadium Composite Developed from Phosphate Industry Waste

Study on Wastewater Treatment in the Textile Industry by Adsorption of Reactive Red 141 Dye Using a Phosphogypsum/Vanadium Composite Developed from Phosphate Industry Waste

Design and modelling of mobile thermal energy storage (M−TES) using structured composite phase change material modules

This study concerns with a modelling led-design of a novel mobile thermal energy storage (M−TES) device aimed to address off-site industrial waste heat recovery and reuse in the UK. For the first time, salt-based composite phase change material (CPCM) modules were employed as the M−TES medium, utilizing air for charging and discharging. Two-dimensional (2D) and three-dimensional (3D) computational fluid dynamics (CFD) models were initially developed and validated against experimental data. The 2D model was used for parametric study to determine critical M−TES dimensions, followed by the 3D model for a comprehensive evaluation of thermal performance of the M−TES device. Key parameters examined included temperature uniformity within CPCM modules, evolution of air temperatures at the inlet and outlet, thermal storage capacities, charging/discharging rates, and specific efficiencies defined as heat transfer efficiencies and charging/discharging efficiencies throughout a complete cycle. The results under baseline conditions demonstrated that the M−TES device stored nearly 400 MJ of heat with a TES density of 560 kJ/kg after 10 h of charging, achieving an average CPCM temperature of 662 K. Approximately 97 % of the stored heat was released with the average outlet air temperature exceeding 468 K during the subsequent 10-hour discharging period. This work preliminarily verified the feasibility of the novel M−TES concept for integrating industrial thermal processing decarbonization with domestic heat supply.

Design and modelling of mobile thermal energy storage (M−TES) using structured composite phase change material modules

This study concerns with a modelling led-design of a novel mobile thermal energy storage (M−TES) device aimed to address off-site industrial waste heat recovery and reuse in the UK. For the first time, salt-based composite phase change material (CPCM) modules were employed as the M−TES medium, utilizing air for charging and discharging. Two-dimensional (2D) and three-dimensional (3D) computational fluid dynamics (CFD) models were initially developed and validated against experimental data. The 2D model was used for parametric study to determine critical M−TES dimensions, followed by the 3D model for a comprehensive evaluation of thermal performance of the M−TES device. Key parameters examined included temperature uniformity within CPCM modules, evolution of air temperatures at the inlet and outlet, thermal storage capacities, charging/discharging rates, and specific efficiencies defined as heat transfer efficiencies and charging/discharging efficiencies throughout a complete cycle. The results under baseline conditions demonstrated that the M−TES device stored nearly 400 MJ of heat with a TES density of 560 kJ/kg after 10 h of charging, achieving an average CPCM temperature of 662 K. Approximately 97 % of the stored heat was released with the average outlet air temperature exceeding 468 K during the subsequent 10-hour discharging period. This work preliminarily verified the feasibility of the novel M−TES concept for integrating industrial thermal processing decarbonization with domestic heat supply.

Green blend nanocomposites developed from waste sericin, polyvinyl alcohol and boehmite for flexible electronic devices

The present research article demonstrates the dispersion of boehmite (BHM) nanoparticles into sericin (SER) from silk industry waste with polyvinyl alcohol (PVA) to enhance the optical, mechanical, thermal and electrical characteristics of PVA/SER blend nanocomposites prepared by a simple green synthesis. Techniques such as Fourier-transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV visible spectroscopy, field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), differential scanning calorimetry (DSC) and thermogravimetry (TGA) were carried out for the characterization of the prepared composites. XRD revealed the increased crystallinity of the polymer blend by the reinforcement of BHM. The existence of intermolecular interactions in the blend composite was confirmed by FTIR and UV spectroscopy. The optical bandgap energy of the biopolymer blend decreases with the inclusion of BHM. The SEM and HR-TEM confirmed the homogeneous dispersion of BHM in the blend at 5 w% loading. The glass transition temperature and thermal stability of the blend nanocomposites were significantly improved by the inclusion of BHM was deduced from DSC and TGA. The dielectric constant and AC conductivity were remarkably increased with the reinforcement of nanoparticles. The activation energy obtained from AC conductivity decreased with the temperature. The mechanical properties of the blend nanocomposites (hardness, elongation, tensile strength and Young’s modulus) were greatly increased in presence of BHM. The 5 wt% sample has the highest tensile strength, Young’s modulus, dielectric constant, AC conductivity and optical properties, allowing it to be used to make optoelectronic devices with better charge-storing capacity and flexible-type electrochemical gadgets.

Enhancing Environmental Sustainability: Extreme Learning Machine Approach to Industrial Waste Management

Enhancing Environmental Sustainability: Extreme Learning Machine Approach to Industrial Waste Management

Alternative green application areas for olive pomace catalytic pyrolysis biochar obtained via marble sludge catalyst.

Evaluating industrial wastes in the system with minimum preprocessing and generation economically valuable products from them have critical importance. In this regard, especially cheap, wieldy, and readily available catalysts have been researched to increase variety of useful products in pyrolysis systems, to reduce process time, and to increase quality and diversity of products. Therefore, in this study, marble sludge (named K1) was evaluated as catalyst at different dosages (10%, 20%, 30%, 50%) and pyrolysis temperatures (300, 500, 700°C) in olive pomace (OP) pyrolysis and; the potential green applications of produced new biochars at new usage areas with different purposes based on characteristics were investigated. ANOVA test results showed that temperature and catalysts ratio had significant effect on pyrolysis product yields since significance value for K1 and temperature was lower than 0.05 for pyrolysis products. OP-K1 biochars had alkaline properties and high earth metal quantities. Moreover, increment in K1 ratio and temperature resulted in decrement of the biochar surface acidity. Therefore, it can be indicated that these biochars can have a potential usage for anaerobic digestion processes, lithium-ion batteries, and direct carbon solid oxide fuel cell (DC-SOFC) but further electrochemical property test should be performed. Moreover, produced biochars can be alternative fuels in some processes instead of coal since they have low S content and high heat values. Consequently, it is foreseen that produced biochars will have an important place in the development of potential usage areas with a new and environmentally friendly approach in different areas apart from the conventional uses of catalytic pyrolysis chars.

Anaerobic co‑digestion of bovine ruminal waste and brewery spent grain: Effects of inoculum to substrate ratio, mixing ratio, process stability, organic matter removal, and methane yield

The technological potential of co-digesting bovine rumen waste (BRW) with brewery spent grain (BSG) is significant, offering enhanced biogas production and effective waste management. This study's findings demonstrate that the anaerobic digestion process becomes significantly more efficient when difficult to degrade BRW is combined with easily degradable BSG. The highest methane yield obtained in the mono-digestion of BRW was 127.11 NmLCH4 gVS−1 with biodegradability of 33.89 % in inoculum to substrate ratio (ISR) 2, and for de BSG obtained was 304.18 NmLCH4 gVS−1 with biodegradability of 68.26 % in ISR 4. The overall average obtained in co-digestion for volatile solids (VS) removal was 26.28 %, and the concentration of methane present in the biogas was 57.18 %. The VS removal efficiency and the increase in biogas and methane yield were directly proportional to the rise in ISR and the proportion of BSG in the mixture. Specifically, the ideal mix of 25 % BRW with 75 % BSG at ISR 4 resulted in a notable methane yield of 255.30 NmLCH4 gVS−1. This process stabilizes digestion and significantly improves solids removal and methane concentration, making it a highly efficient solution for sustainable energy production and industrial waste management.

Bubble-induced self-assembly synthesis of defective hierarchical boehmite with ultra-high removal efficiency towards Congo red: Preparation and adsorption mechanism

To cope with the increasingly urgent environmental issue and provide promising alternative adsorbents, the synergistic preparation route of dissolution and bubble-induced self-assembly was firstly exploited to guide the reconstruction process of a defective hierarchical porous boehmite-microspheres (BMS) adsorbent in a favorable direction to improve the CR adsorption capacity using aluminium hydroxide industrial waste as raw materials. Multiple non-in-situ physicochemical characterization instruments demonstrate that BMS-4 adsorbent possesses abundant coordinatively unsaturated Al–species, large specific surface area, high porosity, oxygen vacancies and oxygen-containing groups, which promote the maximum adsorption capacities for CR up to 6805.08 ± 5.4 mg g−1. Moreover, the Pseudo-second order model and the Langmuir model are more suitable for describing the behavior of CR adsorption, which proves it is more inclined to be monolayer adsorption and there is no chemical reaction between CR and adsorbent. More importantly, it can be practiced in eight cycles of adsorption tests, achieving ultra-high stability for over 94.46 % of the original adsorption capacity. Combined with density-functional theory (DFT) calculations and experimental results, it is illustrated that the amino protonation is responsible for the additional enhancement of CR adsorption, in addition, oxygen vacancy capture and BMS-4/CR–SO3+–NH3 mechanism for enhanced adsorption of dyes is proposed, both of which show that bubble-induced self-assembly provides a promising route for the preparation of high-performance adsorbents.

Recovery and utilization of zinc dross for sacrificial anode cathodic protection of steel structures

Zinc dross is highly zinc-rich industrial waste produced during galvanization of steel. It is a byproduct of the reaction between molten zinc and loose iron particles in a molten zinc bath. Generally, 10–20% of galvanized zinc is converted into zinc dross. This work proposes a unique way of recycling of dross into a high value sustainable resource material leading to development of sacrificial anode used in cathodic protection of steel. The electrochemical behavior was studied in 3.5 wt% NaCl solution. The anode performance test was performed as per the standard DNV-RP-B401 in an artificial seawater solution. The performance parameters, (closed circuit potential (CCP), anode efficiency, and consumption rate) of the recovered zinc anode from dross, are close to the commercial zinc anodes. It satisfies the required anode criteria. Hence, the recovered zinc anode from dross could be used as a sacrificial anode for the cathodic protection of steel structures.

Fe/LiNO3/TiN co–modified MgO for enhanced thermochemical energy storage performance in MgO/Mg(OH)2 cycles

MgO/Mg(OH)2 thermochemical energy storage can convert solar energy and industrial waste heat into forms that are easier to store and transport by cyclic hydration/dehydration reactions. To achieve excellent energy storage performance, cyclic stability and optical absorption capability of MgO/Mg(OH)2, Fe/LiNO3/TiN co–modified MgO were synthesized for energy storage cycles by wet-mixing method. The energy storage performance, cyclic stability and dehydration kinetics of Fe/LiNO3/TiN co–modified MgO were studied in dual fixed–bed system and simultaneous thermal analyzer. The experimental results show that the Fe and LiNO3 in the composite not only increase the hydration conversion of MgO by 6.3 times at 30 min, but also reduce the dehydration temperature and dehydration activation energy of Mg(OH)2 by 99.4 °C and 64 %, respectively. TiN overcomes aggregation of MgO and sustains the excellent porous structure, which results in only a 9 % decrease in energy storage performance of Fe/LiNO3/TiN co–modified MgO after 15 energy storage cycles. Subsequently, TiN significantly strengthens the optical absorption performance of Mg(OH)2 and photothermal temperature under xenon-lamp simulated sunlight radiation. Furthermore, density functional theory calculation reveals that Fe and Li enhance the adsorption of H2O on MgO model and reduce energy barrier for hydration reactions by 62.76 %, while TiN effectively inhibits MgO clusters migration within the material and enhances the optical absorption coefficient. Hence, Fe/LiNO3/TiN co–modified MgO shows significant research value in MgO/Mg(OH)2 energy storage process.

Chemical bath assisted construction of CuO/BiVO4 p-n heterojunction photocatalyst for visible light driven rapid removal of MB and Cr(VI)

Nowadays, uncontrolled discharge of industrial wastes containing organic dyes, drugs, as well as heavy metals into the water bodies presents serious pollution of thereby posing threat to the environment. Hence, there is a need to adopt a targeted approach to tackle the matter of water pollution. A method photocatalytic elimination of pollutants using semiconducting materials is a captivating approach. In this study, we report simple chemical bath assisted synthesis of CuO/BiVO4 (CuBi) p-n heterojunction photocatalyst for effective photocatalytic degradation of pollutants. Physico-chemical characteristics of the CuBi composite and its individual counterparts were assessed by XRD, SEM, TEM, BET, XPS and UV–visible spectrophotometry. The CuO mico-planks, BiVO4 nanodots and CuBi composite were utilized for the photocatalytic breakdown of MB dye and Cr(VI) reduction. The CuBi p-n heterojunction demonstrated superior efficiency in degrading MB (99 % within 120 minutes) and reducing Cr (VI) (94 % within 45 minutes) when compared with its bare counterparts. Furthermore, repeating recycle studies for MB degradation and Cr(VI) reduction showed minimal loss in performance even after consecutive five cycles on the trot verified the strong photo-stability and reusability of our CuBi composite.

Synthesis of xonotlite using quartz glass powder waste as a silicon source

Quartz glass powder is a type of silicon-rich industrial waste. Accumulation of this waste has led to resource wastage and environmental pollution. In this paper, quartz glass powder is used as raw material for preparing xonotlite through hydrothermal synthesis. The effects of Ca/Si (C/S) molar ratio, liquid/solid ratio, reaction temperature, and reaction time on the conversion of quartz are studied. The phase and structural changes of glass powder are analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Based on this, the conversion mechanism of quartz in glass powder is explained. The dissolution rate of quartz in an alkaline solution is a critical factor that restricts hydrothermal reactions. The conversion rate of quartz can be effectively increased by raising reaction temperature and extending reaction time. When the reaction temperature is 240 °C and the reaction time reaches 14 h, the conversion of quartz can reach 94.5 wt%. This study reveals the conversion mechanism of quartz in hydrothermal reactions and provides a theoretical basis for the efficient utilization of glass powder.

Enhanced mechanical properties and tribological performance of anodic oxide coating by using thermal power plant waste material

Numerous researchers have dedicated their efforts to exploring the utilization of industrial waste, specifically fly ash (FA), as a reinforcement for developing economical composites and minimizing ecological pollution problems. FA consists of multiple phases, including quartz (SiO2) and mullite (3Al2O3·2SiO2), which can significantly enhance the mechanical properties of materials. In tribological applications, incorporating FA into surface coatings can offer a cost-effective alternative to enhance surface properties. Meanwhile, the usage of FA and its difference from other commercial ceramics (e.g., SiO2) is still unknown. Thus, the present study aims to clarify the role of FA and factors that contribute to improving mechanical properties and tribological performance with commercial SiO2 as a comparison using electrochemical anodization. The growth mechanism was investigated by varying the anodizing times while maintaining a constant (100 g/L FA) in the electrolyte for the first phase. Meanwhile, the mechanical and tribological properties of different reinforcement content (0, 10, 50, and 100 g/L) were determined for the second phase. Then, evaluations were conducted on the surface morphology, chemical composition, surface hardness, and tribological properties. The results revealed that growth of oxide coating was initiated within the first 5–10 min by forming the barrier layer. Pores began to appear visibly after 30 min of anodizing time, while the complete formation of porous anodic oxide coating was achieved at 60-min with pores dimension (width: 30.75 ± 14.45 μm and depth: 13.4 ± 6.43 μm). Interestingly, 100 g/L of FA-reinforced anodic oxide coating demonstrated lower surface roughness (4.08 ± 0.41 μm), higher surface hardness (444.4 ± 8.63 HV), lowest coefficient of friction (COF) (0.46), and low wear rate (reduction almost 31.8 %) compared to 100 g/L of commercial SiO2 reinforced anodic oxide coating. The electrophoretic deposition effect, combined with the quartz (SiO2) and mullite (3Al2O3·2SiO2) phase structure, enhances mechanical properties and tribological performance.

Compressive Strength of Geopolymer Mortar Reinforced with Rice Husk Fibers

Geopolymer concrete has been proposed to minimize carbon dioxide emissions related to the cement production industry. This environmentally friendly material consists of industry waste materials activated chemically by an activation solution. In this study, the geopolymer mortar has been designed with 70% fly ash and 30% metakaolin. Hydroxide sodium in 14 molar concentrations blended with sodium silicate in a 2.5:1 ratio was used as the activation solution. Rice husk fibers were added as reinforcement in (1%, 1.5%, and 2%), and waste paper (paper pulp and paper ash) was added in (1%, 2%, and 5%) by volume of cementitious material. The geopolymer mortar samples underwent a curing process through exposure to a temperature of 60°C in an oven for 24 hours. The findings indicate that the samples reinforced with 2% rice husk fibers exhibited the most significant improvement in compressive strength, with 59% and 55% increases after 7 and 28 days of curing, respectively. In general, using waste paper and rice husk fibers significantly enhanced the compressive strength of geopolymer mortar.

Preparation and characteristics of cold-bonded lightweight aggregates by recycling mine tailings and industrial waste residues based-binder

Preparation and characteristics of cold-bonded lightweight aggregates by recycling mine tailings and industrial waste residues based-binder