Oyster Shell Powder Research Articles

Performance of sustainable concrete made from waste oyster shell powder and blast furnace slag

Concrete is the most commonly used building material. While presenting excellent performance, it also has adverse effects on the Earth's climate and ecological environment. This study aims to investigate the viability of waste oyster shell powder (OSP) and industrial by-product blast furnace slag (BFS) as cement replacement alternatives in the preparation of sustainable concrete. The macroscopic performance parameters of the mortar, including the compressive strength, ultrasonic pulse velocity, and electrical resistivity, is tested experimentally, and the hydration and microscopic properties of the paste is investigated. The results reveal that the addition of OSP and BFS reduces the working performance, compressive strength, and cumulative heat of hydration of the mortar. However, the later stage pozzolanic reaction of the BFS significantly increases the compressive strength. Furthermore, the addition of BFS considerably increases the surface resistivity of the mortar. The heat of hydration experimental results show that the addition of OSP accelerates the hydration reaction. However, this acceleration effect is only significant in the first 24 h. Microscopic analysis of X-ray diffraction, attenuated total reflection Fourier transform infrared analysis, thermogravimetric analysis, and scanning electron microscopy reveal a synergistic effect between OSP and BFS, resulting in the formation of monocarboaluminate (Mc) and hemicarboaluminate (Hc). This also contributes to the increase in surface resistivity and compressive strength. Finally, the carbon emissions of the mortar are normalized based on the compressive strength. These findings indicate that OSP and BFS can significantly reduce carbon dioxide emissions per unit strength of mortars.

High retention supercapacitors using carbon nanomaterials/iron oxide/nickel-iron layered double hydroxides as electrodes

People's awareness regarding the environmental protection and energy crisis has greatly boost rapid development of advanced energy storage devices. In this regard, supercapacitors with long operation life and superior properties have considered as one of the powerful candidates for energy storage. Herein, electrodes with a 3D structure are fabricated by first mixing oyster shell powder with graphene oxide (GO) and iron sulfate solution and subsequently subjected to the hydrothermal reaction, in which GO is reduced to form reduced GO (rGO) and afterwards to fabricate rGO-FeOOH. Using dried rGO-FeOOH as the framework in the following chemical vapor deposition process, carbon nanotubes (CNTs) are successfully grew on the rGO surface. Then, NiFe layered double hydroxide (NiFeLDH) is deposited by electrochemical deposition to prepare the rGO-FeO-CNT-NiFeLDH electrodes. The rGO-FeO-CNT-700-NiFeLDH electrode performs an excellent capacitance of 411.9 F g−1 at a scan rate of 5 mV s−1. The rGO-FeO-CNT-700-NiFeLDH-60//AC-NiO asymmetric supercapacitor performs an energy density of 41.4 W h kg−1 with a power density of 5600 W kg−1. The capacitance increases up to 144.89% of its initial capacitance after operation for 3200 cycles and remains 102.2% capacitance retention after 5000 cycles demonstrating that the electrode with excellent property is applicable for energy storage devices.

Performance of Oyster Shell Powder Size on Methane Gas Generation in Two-Stage Anaerobic Digestion System

Performance of Oyster Shell Powder Size on Methane Gas Generation in Two-Stage Anaerobic Digestion System

Modification of oyster shell powder by humic acid for ammonium removal from aqueous solutions and nutrient retention in soil

Oyster shell (OS) can be used as absorbent, building material, catalysts and agricultural supplement due to the specific physicochemical properties. To add to the value of this wild raw material, a novel humic acid-modified oyster shell (HAOS) was prepared by introducing humic acid (HA) onto the OS surface through a solid phase grafting method. Thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) spectroscopy were performed to optimize the modification conditions. Batch adsorption experiments were designed to evaluate the effects of HA coating, pH, salinity, isotherm and kinetics on NH4+ adsorption. A soil column experiment was carried out to investigate the nitrogen release upon HAOS addition. The results showed that the adsorption capacity of HAOS for NH4+ increased by 43.5% compared with OS. The adsorption kinetics of NH4+ on HAOS could be explained by the pseudo-second-order kinetic model (R2 = 0.9864), and the maximum adsorption amount calculated from the Langmuir adsorption model (R2 = 0.9907) was approximately 56.1 mg g−1. Moreover, 5% HAOS addition could prolong the release time of NH4+ and decrease the amount of NO3- leaching from soil. The application of HAOS in the plant growth assay significantly increased the elongation and fresh weight of the test plants. Consequently, the novel HAOS had broad application prospects in ammonium treatment and soil fertility improvement.

Oyster Shell Waste (Crassostrea Gigas) as A Cheap Adsorbent for Adsorption Of Methylene Blue Dyes: Equilibrium and Kinetics Studies

In this study, Oyster (Crassostrea gigas) shell powder which contains calcium carbonate (CaCO3) was converted into calcium oxide (CaO). The Oyster shell powder that had been activated was utilized for the adsorption of the methylene blue (MB) dyeing material, which is one of waste water concerns. Oyster shells were crushed and sieved into 100 mesh sized powder and then calcinated at a temperature of 600℃ and 800℃ both for 4 hours period. To determine the adsorption equilibrium, methylene blue (MB) solution was used with varying concentration from 10 to 50 mg/L in which the adsorbent weighing 3 g was put into a conical flash and shaken until the adsorption equilibrium was reached. As for the adsorption kinetics, 250 mL MB solution was used with initial concentrations of 10, 20 and 30 mg/L, with an adsorbent weight of 3 g and a solution at pH 11 for each concentration. The evaluation of the experimental data from the adsorption process is well explained by the Freundlich equation, with the correlation coefficient value (R2) found to be 0.9999, where the value of the adsorption intensity (n) is close to unity; this shows that the adsorption is multilayer or in other words the adsorption energy is heterogeneous. The kinetics study also shows that pseudo second-order model is the most applicable to the adsorption process. From the pseudo-second-order model, with the correlation coefficient between 0.9984 - 0.9999 can explain that the methylene blue (MB) adsorption process is chemically based sorption or in other words termed as chemisorption.

A novel and efficient strategy mediated with calcium carbonate-rich sources to remove ammonium sulfate from rare earth wastewater by heterotrophic Chlorella species

This work was the first time to establish the desired approach with two heterotrophic Chlorella species for ammonium sulfate (AS)-rich rare earth elements (REEs) wastewater treatment by heterotrophic cultivation. The results showed that these two Chlorella species treated by 6 g/L CaCO3 performed the best ability to remove NH4+-N and SO42- of REEs wastewater. Moreover, the established process performed similar features in REEs wastewater treatment by replacing CaCO3 with eggshell powder (ESP) and oyster shell powder (OSP) enriched in CaCO3. Furthermore, microalgae treated by ESP/OSP in a 10-L fermenter showed 837.39 mg/(L·d) NH4+-N and 1,820 mg/(L·d) SO42- removal rates. The developed kinetic models could be well fitted to the experimental data obtained by the 10-L fermenter. Taken together, the established process mediated with two Chlorella species and ESP/OSP by heterotrophic cultivation was the great potential for AS-rich REEs wastewater treatment in a cost-effective manner.

A New Magnesium Phosphate Cement Based on Renewable Oyster Shell Powder: Flexural Properties at Different Curing Times.

Magnesium phosphate cement (MPC), a new type of inorganic cementitious material, is favored in engineering and construction because of its fast setting speed and high bonding strength, but is limited in practical application due to its high production cost and excessive release of hydration heat. Relevant research has investigated the application of discarded oyster shell powder (OSP) replacing cement mortar and has reported certain improvements to its performance. Consequently, focusing on discovering more effects of OSP on MPC performance, this study, by using a typical three-point bending test, used 45 cuboid specimens to investigate the influences of OSP mass content on flexural properties of MPC at different curing times. Results illustrated that MPC flexural strength was first increased and then decreased, and 3% is the critical value for OSP mass content. Similarly, the stiffness of all specimens presented a tendency to increase first and then decrease, with a maximum value of 36.18 kN/mm appearing at 3%, i.e., the critical OSP mass content. Finally, scanning electron microscope (SEM) and X-ray diffraction (XRD) were employed to analyze the microstructure and composition of specimens, confirming that the specimens generated not only the hydration product potassium phosphate magnesium (MgKPO4·6H2O, MKP), but also another new reactant (CaHPO4·2H2O).

Effects of Adding Oyster Shell Powder to Hanwoo Manure on its Quality and Microbial Composition

Effects of Adding Oyster Shell Powder to Hanwoo Manure on its Quality and Microbial Composition

Influence of Different Soil Conditioner on the Transfer and Transformation of Cadmium and Phthalate Esters in Soil

This study examines the existing common form of soil pollution, combined organic and inorganic pollution. Cadmium (Cd) is the most important inorganic element in soil pollution. Due to the widespread use of plastic film, phthalates have become the main organic pollutants in soil. Pot experiments were conducted with purple soil from southwest China, and Chinese cabbage was used as a biological indicator. Different concentration gradients of Cd and diethylhexyl phthalate (DEHP) was used as foreign pollutants. The soil was treated with one of the six common soil conditioners, namely potassium feldspar powder, oyster shell powder, biological carbon powder (biochar), calcium, potassium carbonate, and calcium phosphate, to examine the effect of conditioners on cadmium morphology, DEHP content in contaminated soil, and cadmium and DEHP absorption in Chinese cabbage. The results showed that biochar is the optimal soil conditioner for the remediation of cadmium-phthalate composite pollution in purple soil. Subsequently, the effects of soil biochar content on cadmium pollution and phthalate ester migration were studied. Uncontaminated control soil, Cd-contaminated soil, and DEHP-contaminated soil were examined by pot experiments, and biochar treatments with mass fraction of 0%, 0.5%, 1%, 3%, and 5% added to cadmium contaminated soil were used to determine its influence on Cd morphology and DEHP content of contaminated soil.

Fire-Resistant Properties of Modified Epoxy Based Intumescent Fire-Retardant Coating: Hybridizing of Oyster Shell Powder with Glass Frit

Fire retardant coatings play vital role in safety of construction nowadays, to delay the fire propagation and provide more time for evacuation. The current research work aimed to study the use of modified siloxane epoxy binder to develop intumescent coating. Polyamide amine was used as a hardener. Three different sets of formulations were developed by using three different fillers, namely the oyster shell powder (OSP), glass frit (GF) and combination of both oyster shell powder and glass frit (OG). All three set of formulation also includes the basic ingredients of intumescent coating. These samples were used to study the synergistic effects of fillers on thermal performance of the coating as well tested for char expansion, heat shielding, char morphology and composition. Fire resistant testing was conducted by using a Bunsen Burner and GF samples had found to have minimum substrate temperature of 175.3°C. The char morphology was analysed via Scanning Electron Microscope (SEM) which confirmed the adhesion between the matrix with fillers. Furnace test was carried out to investigate the char expansion of OSP/GF/OG with the modified siloxane epoxy composition and the maximum expansion was OSP 1% with intumescent factor of 7.78. XRD was conducted to evaluate the residual compounds in the char and FTIR was utilized to analyse the functional group where O-H, C-N, O=C=O and C=C bonds were found in the degradation compounds in the char residual of the coatings.

Reduced graphene oxide/oyster shell powers/iron oxide composite electrode for high performance supercapacitors

Recently, the awareness of energy crisis and environmental protection have remarkably increased. In this regard, supercapacitors have attracted significant attention due to their high-power performance and long cycle life. Herein, we propose the design and fabrication of a supercapacitor which possesses a hierarchical structure constructed by reduced graphene oxide (rGO) and oyster shell powder (OSP). The presence of OSP can prevent re-stacking of rGO during hydrothermal, as a result, build the basis of hierarchical structure for Fe2O3 deposition. Depending on the amount of OSP, the Fe2O3 nanoparticles with different morphologies of small particle, rod, needle, and large particle can be obtained via the hydrothermal process. Because of the synergistic effects contributed by rGO, OSPs, and Fe2O3, the as-synthesized rGO/Oyster/Fe2O3 composite electrode exhibits an excellent specific capacitances of 473.9 F g−1 and 214.1 F g−1 at the scanning rates of 5 and 100 mV s−1, respectively. Furthermore, an aqueous asymmetric supercapacitor, having the structure of rGO/Oyster/Fe2O3/Na2SO3//AC-MnO2/Na2SO4, shows a high operating voltage of 2.2 V, and performs a high energy density of 31.2 W h kg−1 at a power density of 2200 W kg−1.

Accelerated adsorption of tetracyclines and microbes with FeOn(OH)m modified oyster shell: Its application on biotransformation of oxytetracycline in anaerobic enrichment culture

Due to the persistence in residue and the emission to environment, antibiotics have become the emerging contaminants. Tetracyclines, as the largest amount of antibiotics in the breeding industry, were investigated in this study. For eliminating the tetracyclines, anaerobic culture was enriched from livestock waste after four generations and FeOn(OH)m modified oyster shell powders (OSPs) were amended into the enrichment culture as auxiliary method. Tetracycline and oxytetracycline were selected as the model compounds. The adsorption models (Langmuir and Freundlich isotherms) of tetracycline and microbes on OSPs were simulated respectively. With the addition of FeOn(OH)m modified OSPs, the transformation efficiency of oxytetracycline achieved 81.5% after 22 days’ incubation, approximately 1.85 times higher than the 4th generation (G-IV) enrichment culture without modified OSPs. Dehydration, demethylation, dehydroxylation and decarboxylation took place under anaerobic condition, inferred from the detected metabolites transformed from oxytetracycline. Genus Methanosarcina and two operational taxonomic units (OTUs) assigned to order Clostridiales, showed an increasing trend on abundance, indicating the contribution to transformation of oxytetracycline. Therefore, the FeOn(OH)m modified OSPs and enrichment culture can accelerate the transformation of oxytetracycline simultaneously, indicating a promising utilization not only for waste water system but also for antibiotic contaminated biomass treatment.

Effect of Biowaste on the High- and Low-Temperature Rheological Properties of Asphalt Binders

The growth of aquaculture has increased the production of oysters. However, the increased oyster shell volume has created serious environmental and recycling problems for the society. In order to study the sustainable utilization of waste oyster shells, asphalt binder of waste oyster shell powder was prepared by using modified asphalt material with waste oyster shells. The microstructure of oyster shell powder was analyzed by scanning electron microscopy experiments. The chemical composition of the asphalt binder was observed by Fourier transform infrared spectroscopy tests. The physical properties of the asphalt binder, including softness, high-temperature performance, and plastic deformation capacity, were initially evaluated through three indicators’ tests on asphalt. A preliminary performance evaluation of the asphalt binder was performed. The high-temperature stability of asphalt binders was evaluated using dynamic shear rheometry. The rutting resistance of the material was evaluated by temperature sweep tests, and the shear deformation resistance of the material was evaluated by frequency sweep tests. Multiple stress creep recovery tests determine the material’s ability to resist permanent deformation. The low-temperature rheological properties were evaluated by bending beam rheology tests. The study found that the waste oyster shell powder is a biomass with a porous irregular petal shape. No new characteristic absorption peaks are formed by mixing with asphalt. And, it can improve the viscosity, thermal stability, and temperature-sensitive properties of the material. It significantly improved the high-temperature rheological performance, rutting coefficient, and recovery elasticity of the material. However, it has little effect on low-temperature rheological performance. This study provides a solid foundation for the effective use of biowaste in engineering materials.

Textile Fabrics Containing Recycled Poly(ethylene terephthalate), Oyster Shells, and Silica Aerogels with Superior Heat Insulation, Water Resistance, and Antibacterial Properties

The textile fabric interface between the human body and the environment is currently being promoted by the clothing industry as a route to improve human health and comfort. Ternary blends of environmental waste materials, including recycled plastic bottles (poly(ethylene terephthalate), rPET), oyster shell powder (OSP), and silica aerogels (SAGs), were used to fabricate composite textiles. The structural, mechanical, and thermal properties of the resulting textiles were evaluated together with the water-contact angle and antibacterial effects. rPET textiles typically exhibit high hydrophilicity, poor thermal conductivity, and no antibacterial effects. Incorporating SAG and OSP as fillers in the processed filaments significantly enhanced the functional performance of rPET textiles. The addition of SAG enhanced hydrophobicity and decreased thermal conductivity. This allows better temperature regulation by rPET/SAG textiles. The addition of OSP resulted in a composite material with antibacterial properties (rPET/ASAG). The rPET/ASAG textiles boast excellent tensile strength, insulating effects, temperature regulation, water resistivity, laundering durability, and antibacterial properties. In addition, the developed rPET/SAG and rPET/ASAG fabrics are amenable to large-scale production and implementation in a variety of textile products.

Prevent the Nutrients Release from Polluted Marine Sediments Using Recycled Waste Oyster Shell Powder

To evaluate the remediation performance of recycled oyster shell powders to control nutrients release from polluted sediments. Different types of recycled oyster shell powder were applied on separated bottom sediments. The first type of oyster shell powder is Calcined Oyster Shell Powder (COSP) and another consist of ultrasonicated oyster shell powder (SOSP) which were composed of calcium peroxide. The recycled oyster shell powders were improving the water quality as slow oxygen releasing compound. The experimental results indicated that the Dissolved Oxygen (DO) in the treated columns were higher than the control column. pH was increased in the both experimental columns due to the hydrolysis of CaO2. Meanwhile, recycled oyster shell powders could prevent the nutrients (nitrogen and phosphorus) release from sediments into the overlying water. In addition, the total nitrogen and total phosphorus concentrations of the COSP applied column were decreased 27% and 20% compared to the control column respectively and the SOSP applied column were decreased 33% and 27% compared to control in the overlying water. It was proved that, COSP and SOSP can effectively adsorb phosphorus from sediments and prevent phosphorus release into overlying water from bottom sediments. In conclusion, COSP and SOSP applications was increased DO in the overlying water and nutrient released controlled effectively from the sediment.

Oyster Shell Powder, Zeolite and Red Mud as Binders for Immobilising Toxic Metals in Fine Granular Contaminated Soils (from Industrial Zones in South Korea).

Low-cost absorbent materials have elicited the attention of researchers as binders for the stabilisation/solidification technique. As, there is a no comprehensive study, the authors of this paper investigated the performance of Oyster shell powder (OS), zeolite (Z), and red mud (RM) in stabilising heavy metals in three types of heavy metal-contaminated soils by using toxicity characteristic leaching procedure (TCLP). Samples were collected from surroundings of an abandoned metal mine site and from military service zone. Furthermore, a Pb-contaminated soil was artificially prepared to evaluate each binder (100× regulatory level for Pb). OS bound approximately 82% of Pb and 78% of Cu in real cases scenario. While Z was highly effective in stabilizing Pb in highly polluted artificial soil (>50% of Pb) at lower dosages than OS and RM, it was not effective in stabilising those metals in the soils obtained from the contaminated sites. RM did not perform consistently stabilising toxic metals in soils from contaminated sites, but it demonstrated a remarkable Pb-immobilisation under dosages over than 5% in the artificial soil. Further, authors observed that OS removal efficiency reached up to 94% after 10 days. The results suggest that OS is the best low-cost adsorbent material to stabilize soils contaminated with toxic metals considered in the study.

Agricultural by-products and oyster shell as alternative nutrient sources for microbial sealing of early age cracks in mortar

Bio-concrete using bacterially produced calcium carbonate can repair microcracks but is still relatively expensive due to the addition of bacteria, nutrients, and calcium sources. Agricultural by-products and oyster shells were used to produce economical bio-concrete. Sesame meal was the optimal agricultural by-product for low-cost spore production of the alkaliphilic Bacillus miscanthi strain AK13. Transcriptomic dataset was utilized to compare the gene expressions of AK13 strain under neutral and alkaline conditions, which suggested that NaCl and riboflavin could be chosen as growth-promoting factors at alkaline pH. The optimal levels of sesame meal, NaCl, and riboflavin were induced with the central composite design to create an economical medium, in which AK13 strain formed more spores with less price than in commercial sporulation medium. Calcium nitrate obtained from nitric acid treatment of oyster shell powder increased the initial compressive strength of cement mortar. Non-ureolytic calcium carbonate precipitation by AK13 using oyster shell-derived calcium ions was verified by energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. Stereomicroscope and field emission scanning electron microscopy confirmed that oyster shell-derived calcium ions, along with soybean meal-solution, increased the bacterial survival and calcium carbonate precipitation inside mortar cracks. These data suggest the possibility of commercializing bacterial self-healing concrete with economical substitutes for culture medium, growth nutrient, and calcium sources.

Improvement in compressive strength of oyster shell powder−clay sintered material by acid treatment after curing

Improvement in compressive strength of oyster shell powder−clay sintered material by acid treatment after curing

Improvement in compressive strength of oyster shell powder - clay sintered material by resin coating

Improvement in compressive strength of oyster shell powder - clay sintered material by resin coating

Sustainable Mixtures Using Waste Oyster Shell Powder and Slag Instead of Cement: Performance and Multi-Objective Optimization Design

Sustainable Mixtures Using Waste Oyster Shell Powder and Slag Instead of Cement: Performance and Multi-Objective Optimization Design