Aluminum Residue Research Articles

Design of Experiment Applied in the Chemical Separation Process of Plastic and Aluminum Present in Aseptic Carton Packages

Objective: This study aimed to investigate the separation of polyethylene and aluminum residue layers from Tetra Pak post-consumer packaging. This was achieved by facilitating a spontaneous reaction between aluminum and water, with the assistance of NaOH as a catalyst. Theoretical Framework: Aseptic carton packaging is widely recognized as safe and high-quality in the food and beverage industry. This type of packaging offers several properties, acting as a barrier against gases, light, loss of flavor, and water vapor while providing shape and flexibility. These characteristics are achieved by combining plastic, paper, and aluminum. Despite the significant advantages of multilayer films, recycling this material presents challenges. Methodology: During the initial planning phase, a 26-2 fractional factorial experiment was conducted to evaluate 6 different process variables: agitation (rpm), pre-treatment, NaCl concentration (g/L), time (minutes), temperature (°C), and NaOH concentration (mol/L). Subsequently, a second experimental design called the Design Central Composite (DCC) was implemented. The results indicated that only temperature and time remained statistically significant. Results and Discussion: Based on the experimental results, were able to identify the most effective conditions for separating polyethylene and aluminum waste from Tetra Pak post-consumer packaging using response surfaces an optimal region can be defined with a minimum temperature of 50°C, a minimum time of 30 minutes, and a minimum NaOH concentration of 3 mol/L. Originality/Value: This study adds to the existing literature by examining the application of experimental planning techniques in the chemical separation process of plastic and aluminum in Tetra Pak® packaging through two consecutive experimental plans.

Feasibility of using ground Al-Al2O3 composite powders in laser powder bed fusion

The reincorporation of residues in the productive cycle helps reduce CO2 emissions and non-renewable resources extraction. Therefore, the present work studies the feasibility of reincorporating an aluminum residue in the productive cycle by means of an additive manufacturing technique. In this context, other issues considered are the importance of aluminum alloys, the improvement of their properties by adding alumina making composites materials, and issues that must be overcome when printing parts by laser powder bed fusion using a mix of Al and alumina powders. This work evaluates the suitability of Al alloy - alumina composite powders obtained by grinding Al alloy chips from sawing. Laser power and scanning speed were varied until the designed samples were obtained. The findings show that is possible to use powder obtained by grinding Al chips in the laser powder bed fusion technique to obtain Al-Al2O3 composites which exhibits hardness of 226 HV ± 34.3.

Efficient aluminum removal and microorganism inhibition in ready-to-eat jellyfish by slightly acidic electrolyzed water

Ready-to-eat jellyfish production is restricted by the high aluminum residue and unable use of thermal sterilization. In this study, the combined dealumination and sterilization by slightly acidic electrolyzed water (SAEW) were used to produce ready-to-eat jellyfish. The optimal aluminum removal amount reaching 120.17 mg/kg was obtained after response surface analysis. Structure observation through optical microscope after Masson staining and scanning electron microscope showed that the microstructure of jellyfish was not destroyed after SAEW treatment. The increase of total plate count (TPC) and pH value during storage was significantly inhibited by SAEW, while the other properties did not changed significantly. Staphylococcus, especially Staphylococcus epidermidis was dominant in the ready-to-eat jellyfish and many spoilage bacteria were inhibited by SAEW. The correlation network maps showed that Pseudomonas and Shewanella contributed most to the increase of TPC and pH value in the control group, while the correlated microbial genera mainly changed to Acinetobacter, Cutibacterium, and Pseudomonas after SAEW treatment, resulting in the decrease of hardness and chewiness of ready-to-eat jellyfish during storage. The inhibited Pseudomonas contributed most to the decrease of TPC and pH value after SAEW treatment. This study provides a novel technology of dealumination and sterilization for ready-to-eat jellyfish.

Joint process of laser shock polishing and imprinting for metallic nanostructure fabrication

Most fabrication methods of metallic nanostructures are time-consuming with multi-steps, which are difficult to achieve low-cost batch processing. In this study, joint laser process of laser shock polishing & imprinting (LSPI) is proposed to efficiently fabricate large-area nanostructures on the surface of cheap industrial aluminum foil without any pre-processing step. LSPI tailors the laser parameters of single laser manufacturing equipment to apply laser shock polishing (LSP) to polish the aluminum foil, and then laser shock imprinting (LSI) to obtain nanostructures with high accuracy, integrity and uniformity. This unique characteristic of proposed LSPI is enabled by pre-taking LSP process to improve the yield of following LSI process through significantly decreasing the surface roughness of aluminum foil. LSPI also reduces the aluminum residue inside the silicon mold, which improves the integrity of resultant nanostructure and facilitates the reuse of the mold. The working mechanism of LSPI are also investigated to reveal its fundamental fabrication principle, which may inspire other low-cost and efficient batch fabrication method for metallic nanostructures manufacturing in the future.

Facile and template-free fabrication of hollow spherical AlOOH and Al2O3 from the waste aluminum residue: Growth mechanism and fast removal of Congo red

Organic dye pollution has attracted considerable concern, and the adsorption technology using inorganic nanostructures has become prevalent. In this work, hollow spherical AlOOH (HSHA) was successfully fabricated via an one-pot and template-free hydrothermal method. After calcination at 550 ​°C for 1 ​h, hollow spherical Al2O3 (HSAO) with the same morphology was obtained. The hollow spherical structures comprised of plenty of uniform nanoflakes possessed the high specific surface areas and total pore volumes. HSHA and HSAO exhibit excellent adsorption performance for Congo red (CR) with the maximal adsorption capacities of 277.00 and 478.47 ​mg ​g−1, respectively. The adsorption almost reached the equilibrium within 10 ​min. The pseudo-second-order model fitted the adsorption process well. The adsorption was spontaneous. Both the Langmuir and Freundlich models fitted the adsorption well, but the Freundlich model was slightly better. HSHA and HSAO are the potential and qualified candidates for the dye removal.

A facile synthesis of MgAl/layered double hydroxides from aluminum wastes

This work aimed to study the synthesis of Mg/Al layered double hydroxides (LDH) from aluminum residues. LDH was produced by co-precipitation and hydrothermal methods using Al(OH)3 synthesized from aluminum residue. It was possible to confirm the formation of LDH, with an increase in crystallinity for the hydrothermal synthesis. The FTIR indicates no influence regarding the Al(OH)3 origin (synthesized or commercial). N2 adsorption/desorption isotherms indicate a mesoporous structure with non-rigid aggregates of plate-shaped particles creating slit pores of varying shapes and sizes. The synthesized materials presented surface area ranging from 27.66 to 96.08 m2/g and pore diameter between 20 and 500 Å. Finally, it can be affirmed that LDHs were satisfactorily synthesized using aluminum residue as a source of aluminum hydroxide.

Efficient adsorption of dyes by γ-alumina synthesized from aluminum wastes: Kinetics, isotherms, thermodynamics and toxicity assessment

This study aimed at synthesizing γ-alumina from aluminum residue obtained from a frame fabrication factory, through precipitation followed by calcination, and apply it as an adsorbent to remove dyes from aqueous solution. The produced adsorbent was designated as non-rigid of aggregates of irregularly shaped particles, with a plate format, a mesoporous structure and with high surface area (304.31 m2·g−1). The kinetic studies indicated the adsorption of methylene blue (MB) follows the pseudo-first order model, while the pseudo-second order best fitted in case of the adsorption of crystal violet (CV) and basic fuchsin (BF). The equilibrium studies indicated the adsorption process is exothermic and the Langmuir model best fitted the equilibrium data with qmax equal to 57.81, 32.92 and 31.92 mg·g−1 for MB, BF and CV, respectively. The adsorption capacity of synthesized alumina from waste was compared with commercial ones and proved to be superior in surface area and adsorption capacity, where this was 40–60% higher for the analyzed dyes. The thermal regeneration was effectively reported towards the attainment of 3 complete cycles of dyes adsorption/desorption. The toxicity assays using Artemia salina and Lactuca sativa as biomarkers reinforce adsorption results demonstrating the treatment of dye solutions by γ-alumina can decrease the mortality of the microcrustaces and the phytotoxicity of solutions. The obtained results indicated some minimum feasibility of the proposed material to be applied in real contamination scenarios.

Production of low-price carbon for removal of aluminium ions in potable water

Drinking-water plants often use aluminium (Al) salts as coagulant agents in the water-treatment process, which cause increasing aluminum residue levels in water. Aluminum accumulation in the human body has been related to neurological disorders such as Alzheimer’s disease, senile dementia and breast cancer. This work utilises the available industrial waste as a cheap source of carbon (C) that can be used in aluminium ion elimination from water supplies. The employed sugarcane bagasse activated carbon (SCB-AC) was derived from the waste of a Qus sugar factory in Qena City, Egypt. The activity of SCB-AC was compared with that of commercial activated carbon (Com-AC), and their physico-chemical properties were characterised by various techniques (energy-dispersive X-ray spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy). The findings demonstrate that SCB-AC has high performance for aluminium (III) (Al3+) removal like Com-AC, which reached 80% at a high initial concentration (10 mg/l). The thermodynamic constants revealed that the adsorption process has an exothermic nature. Briefly, SCB-AC is an inexpensive eco-friendly carbon with an excellent adsorptive ability like that of Com-AC for elimination of aluminium (III) in drinking water. The cost of manufacturing SBC-AC would be about US$40/t.

Removal of reactive yellow 160 from aqueous solution by alumina nanoparticles derived from aluminium waste residue

In the current study, alumina nanoparticles were prepared from waste aluminum residue by an extraction and gel formation method. The prepared alumina nanoparticles were used to remove reactive yellow 160 (RY160) from an aqueous solution. The kinetics and adsorption equilibrium were discussed as well. The results show that, the heat-treated samples were consistings only of Al and O elements only and their crystalline phase was pure alumina in the nano scale. The alumina nanoparticles were effective adsorbents for the removal of RY160 from aqueous solution with percentage removal 100 % for samples heat-treated at 110°C and 600°C. The adsorption data was well fitted to Langmuir isotherm model for all prepared samples indicating a monolayer adsorption. The adsorption process was found to be endothermic and the adsorption takes place physically on the surface of alumina nanoparticles. The prepared alumina nanoparticles samples can be used as an efficient adsorbent in water treatment.

Preparation of Zeolite X by the Aluminum Residue From Coal Fly Ash for the Adsorption of Volatile Organic Compounds.

In China, coal fly ash is a large-scale solid waste generated by power plants. The high value utilization of coal fly ash has always been a hot research issue in China for these years. In this paper, the synthesis of zeolite X using aluminum residue from coal fly ash can not only realize the resource utilization of waste, but also achieve the effect of energy saving and emission reduction. Zeolite X prepared by hydrothermal synthesis method have been found to have higher purity and better crystallinity by chemical composition analysis. By comparing and analyzing the adsorption performance of zeolite X and activated carbon on volatile organic compounds, it is found that the adsorption capacity of zeolite X is higher than that of activated carbon, and it has stronger stability. This indicates that the zeolite X synthesized by this environmentally friendly and economical method has a good application prospect in adsorbing volatile organic compounds.

A longitudinal assessment of aluminum contents in foodstuffs and aluminum intake of residents in Tianjin metropolis.

AimIn this report, we retrieved and analyzed the data of aluminum contents in foodstuffs over a 6‐year span between 2010 and 2015 and assessed the risk of dietary aluminum exposure in residents of Tianjin metropolis.MethodsA multistage random clustering method was used to survey Tianjin residents between 2010 and 2015. Samples were mainly purchased from breakfast vendors, farmers’ markets, and supermarkets in Tianjin between 2009 and 2015. A total of 1,814 persons aged at least 2 years from 1,262 households from randomly chosen communities were asked to complete the questionnaire on food consumption. Aluminum contents in the food samples were determined.ResultsTotally 21.14% of food samples exceeded the recommended aluminum residue limit over the study period. The mean aluminum levels in the food samples over the 6‐year span were 111.9 7 ± 265.26 mg/kg, and the mean P95 was 597.00 mg/kg. Totally 21.14% of the food samples exceeded the recommended aluminum residue limit (100 mg/kg). The lowest mean aluminum levels in food were detected in 2010, and the highest levels were found in 2015. The highest mean aluminum levels were found in jellyfish. The highest total mean aluminum intake in food was 83.61 mg/day in those aged at least 50 years and younger than 66 years. Meanwhile, children aged at least 2 years and less than 8 years had the highest mean weekly aluminum intake (18.19 mg/kg body weight/week); they also had the highest MOS (18.19).ConclusionThe findings indicate that despite the implementation since 2014 of the new policy on the use of aluminum food additives in China, residents in Tianjin still face high levels of aluminum exposure in foodstuffs with young children particularly vulnerable. Public awareness of the new policy should be enhanced, and more vigorous supervision of the use of aluminum food additives should be undertaken.

Aluminum residue waste for possible utilisation as a material: a review

Recycling and reutilization of industrial waste and by-products are subjects of great importance today in any sector and more so in cement and concrete technology. Aluminium is the most widely used non-ferrous metal in the world. During the production of aluminum, a huge amount of waste is produced, known as dross, which is used for recycling and re-extraction of remaining aluminum. The dross is found to be toxic and hazardous waste for the environment and hence recycling or locking up of this waste is very crucial. The dross is mainly composed of oxides and aluminum and in the recycling, salt process is employed to recycle aluminum from the dross. This paper examines various forms of production of aluminum scrap, treatment methods, and typical application of aluminum residue. Brief description on waste management aspects is provided in this paper. The important observations made from the review studies are summarized.

Residual aluminum control for source water with high risk of overproof coagulant residue: A novel application of principal component analysis

This study first applied the principle component analysis (PCA) and multivariate linear regression analysis (MLRA) to estimate the level of aluminum residue in two full-scale clarifiers, i.e. Densadeg and mechanical clarifier, potentially providing a predictive approach for aluminum residue and operation cost control. For Densadeg, effective relationships were established between aluminum residue and factors including FeCl3 dose, water temperature and turbidity (R2=0.802 and 0.774 for total and soluble Al, respectively). These three factors facilitated the control of aluminum residue, and FeCl3 dose was the most important. More factors were needed to effectively evaluate the residual total aluminum in mechanical clarifier, including the dose of FeCl3 and polyaluminum chloride (PACl), turbidity and tryptophan-like protein similarly contributing to the presumption result (R2=0.817). And water temperature also showed important impact on soluble aluminum besides the four factors aforementioned (R2=0.793). FeCl3 dosage and turbidity enhanced aluminum removal for both clarifiers, while water temperature showed distinct effects: negative for Densadeg but positive for mechanical clarifier. Tryptophan-like protein was associated with an undesirable increase in aluminum residue, as showed by the evaluation of aluminum residue in mechanical clarifier. Aluminum residue in Densadeg was less vulnerable to the fluctuation of PACl dose and organic matters.

Optimization of the pretreatment of wastewater from a slaughterhouse and packing plant through electrocoagulation in a batch reactor

ABSTRACTThe purpose of this study is to evaluate the removal of chemical oxygen demand (COD), turbidity and color of wastewater from a pig slaughterhouse and packing plant through the electrochemical technique and to optimize the ΔV (electric potential difference) and HRT (hydraulic retention time) variables in an electrocoagulation batch reactor using aluminum electrodes. The experimental design used was rotatable central composite design. For turbidity, the values for removal efficiency obtained varied from 92.85% to 99.28%; for color, they varied from 81.34% to 98.93% and for COD, they varied from 58.61% to 81.01%. The best optimized conditions of treatment were at 25 min for the HRT and 25 V for the ΔV, which correspond to electrical current of 1.08 A and a current density of 21.6 mA cm−2. The aluminum residue varied from 15.254 to 54.291 mg L−1 and the cost of the treatment was US$4.288 m−3. The novelty of the work was the simultaneous optimization of three response variables using the desirability function applied to the treatment of wastewater from slaughterhouses.

Impacts of Binder-Zeolite Interactions on the Structure and Surface Properties of NaY–SiO2 Extrudates

NaY–SiO2 extrudate was prepared by blending NaY powder with silica gel, followed with kneading, extruding, and calcination. The impact of silica binder on the structure and surface properties of NaY–SiO2 extrudate was investigated. The nitrogen adsorption/desorption isotherm suggests the formation of cylindrical mesopores for NaY–SiO2. X-ray powder diffraction, transmission electron microscopy, and Fourier transform infrared suggest that in kneading, dealumination and cleavage of the intracrystalline Si–O–Al bond via acid hydrolysis occur. This acid hydrolysis causes shrinkage of the zeolite lattice along the zeolite channel due to dislodgement of Al3+ cations. The dealumination increases the silica/alumina ratio of NaY concomitantly with the removal of Na+, leading to an increase in the hydrophobicity of NaY, while reaction of the silica binder with NaY debris and/or aluminum residue forms new Brønsted acid sites. Moreover, backfilling the vacancies created in the dealumination by mobile Si(OH)4 makes the zeolite more thermally stable, which lends the extrudate itself to industrial applications.

Use of Aluminum Residue and Recycled Asphalt Pavement Materials to Stabilize Silty Clay Soil

AbstractThe effectiveness of mixing aluminum residue and recycled asphalt pavement materials (RAPs) with silty clay soil on the soil’s physical properties was discussed. The mixing material that is used enhances the silty clay soil’s volume changes and bearing capacity and reduces settlement. Different percentages of aluminum and asphalts by weight, ranging from 2 to 10% in increments of 2%, were used to determine the enhancement in soil properties gained using these materials. Physical and mechanical testing was carried out according to applicable ASTM and AASHTO testing methods. Soil mixtures of various ratios were studied in the laboratory to note the enhancements in the swelling behavior, shear strength parameters, Atterberg’s limits, optimum moisture content, and corresponding maximum dry density. Moreover, this investigation also included evaluation of the bearing capacity of subgrade material. The results of this investigation showed that the addition of aluminum residue and recycled asphalt materi...

Recovery of Aluminum Residue from Incineration of Cans in Municipal Solid Waste

Recovery of Aluminum Residue from Incineration of Cans in Municipal Solid Waste

New selective two-step anodization of porous anodic alumina for thin-film encapsulation

In this paper, we propose a new selective two-step method of anodization of porous anodic alumina (PAA) for thin-film encapsulation. It is based on the formation of a selectively anodized porous alumina membrane using only photoresist (PR) which offers lots of vertical nanopores as release holes for sacrificial layer etching. This method allows finer patterning in the selective PAA process and reduces the whole process time and cost. Furthermore, it does not leave isolated aluminum (Al) residue during the anodization process, and the deposited Al film is not conformal over the 3-dimensional structure. The key for this new selective anodization method is the technique to form the locally anodized PAA membrane with the masking material PR by two-step anodization. The nanopores in the PAA membrane allow the penetration of plasma gas or etchant into the cavity to release the sacrificial layer underneath. To seal the packaging, a thin-film is deposited over the selectively anodized PAA membrane in a vacuum ambient atmosphere with no detectable internal deposition of the sealing material. Hermetically sealed thin-film vacuum encapsulation using the proposed selective anodization method is demonstrated, and its hermeticity is also monitored through the measurement of the center deflection of the sealing layer.

Effects of humic acid on residual Al control in drinking water treatment plants with orthophosphate addition

This study aimed to investigate the effects of humic acid (HA) on residual Al control in drinking water facilities that used orthophosphate addition. The results showed that adding orthophosphate was an effective method for residual Al control for the raw water without HA. When orthophosphate was added at 1.0 min before the addition of poly aluminum chloride (PACl), the concentrations of soluble aluminum (Sol-Al) and total aluminum (Tot-Al) residue were 0.08 and 0.086 mg·L−1, respectively; both were reduced by 46% compared with the control experiment. The presence of HA would notably increase the residual Al concentration. For the raw water with 5 mg·L−1 of HA, the concentrations of Sol-Al and Tot-Al increased from 0.136 and 0.174 mg·L−1 to 0.172 and 0.272 mg·L−1, respectively. For water with a HA concentration above 5 mg·L−1, orthophosphate was ineffective in the control of residual Al, though there were still parts of orthophosphate were removed in coagulation. The amounts of Al removal were positively correlated with the solids freshly formed in coagulation. Similar to the raw water without HA, the best Al control was obtained with orthophosphate salt added at 1.0 min before PACl. HA concentrations in the raw water, solution pH, and the orthophosphate dosage suitable for residual Al control by orthophosphate precipitation were also investigated.

EFFECT OF SUGAR ON ABSORPTION OF ALUMINUM RESIDUE IN FISH

The effect of sugar on absorption of aluminum (Al) residue in Tilapia was studied. This work was carried out on 28 random tilapia fish samples. Samples were divided into four groups (seven for each group) where the 1st group fish were grilled without additives and without wrapped with aluminum foil while the 2nd group, fish were grilled without additives but wrapped with aluminum foil. The 3rd group, fish were grilled with adding salts, onion, tomato, garlic and lemon, then wrapped with aluminum foil, while the 4th group, fish were grilled with adding salts, onion, tomato, garlic and lemon, then 5% sugar from weight of fish were spread on the whole fish surface and wrapped with aluminum foil. Samples were grilled in oven at 180oC for 20min. Each sample was divided into 2 parts; skin and muscle. The results showed that the highest level of aluminum residue in fish grilled with addition of salts, onion, tomato, garlic and lemon, while addition of sugar reduced migration of aluminum into the skin and muscle of fish.