Search

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the environmental pollution problems caused by vanadium-containing wastewater produced by mining, metallurgy, petroleum refining, and other industries, this study prepared mussel shells loaded nano-zero-valent iron composites(nZVI@CMS) by liquid-phase reduction method using pyrolyzed mussel shell powder(CMS) as the carrier. The morphology and structure of nZVI@CMS were characterized by SEM, TEM, XRD, BET, FT-IR and XPS. The adsorption performance of V(Ⅴ) on nZVI@CMS was investigated by batch adsorption experiments, and the adsorption mechanism of V(Ⅴ) on nZVI@CMS was analyzed using adsorption kinetics, adsorption isotherm, and adsorption thermodynamics. The results showed that nZVI@CMS was a loose and porous chain sphere-like structure containing a variety of oxygen-containing functional groups. The maximum adsorption of V(Ⅴ) by nZVI@CMS was 149.33 mg/g under the conditions of nZVI@CMS dosage of 0.05 g/L, initial pH=7, V(Ⅴ) concentration of 20 mg/L, solution volume of 100 mL, and temperature of 25 ℃. The adsorption of V(Ⅴ) by nZVI@CMS could be fitted by Langmuir adsorption isotherm equation and pseudo second-order reaction kinetic equation, and it was a spontaneous heat adsorption process. The main mechanisms of V(Ⅴ) removal by nZVI@CMS included adsorption, reduction, and co-precipitation. This study turned the mussel shells into treasure, and provided a new idea for the efficient treatment of V(Ⅴ) in wastewater.

Nitrogen and phosphorus in freshwaters are a global environmental challenge. Concurrently, the shellfish industry's calcareous waste shells (CWSs) amount to ~10 million tonnes annually. CWSs can effectively adsorb dissolved pollutants, including nutrients, from water, which has motivated a growing number of experimental studies on recycling CWSs in wastewater treatment. This comprehensive literature review summarises and critically assesses the effectiveness of using different CWSs for removing nutrients from water. The effects of CWS type, initial pollutant concentration, adsorbent dosage, particle size, and contact time (CT) are investigated. The results show that phosphorus removal has been examined more than nitrogen. Most studies have been conducted using synthetic wastewater under laboratory conditions only. There is a large variability in experimental conditions, such as CWS adsorbent dosages (0.1–100 g/L) and CT (0.083–360 h). The calcination of CWSs is frequently used to enhance adsorption capacity. The Langmuir isotherm model has been found to fit adsorption data best when raw oyster shells are used, while the Freundlich isotherm is best when the adsorbent is calcinated mussel shells. The pseudo-second-order (PSO) kinetics model tends to describe adsorption data better than the pseudo-first-order (PFO) model in all shell types. There is significant potential for using calcareous waste shells to remove nutrients from wastewater in line with circular economy aspirations. [ABSTRACT FROM AUTHOR]

This study explores the potential of mussel shells (MS) as biogenic fillers in polymer composites. The chemical composition and crystal structures of MS were characterised. To improve MS filler dispersion and adhesion within a polypropylene (PP) matrix, three surface modification methods were evaluated: polydopamine (PDA) coating, maleic anhydride-grafted polypropylene (MAPP) modification, and PDA/MAPP co-modification. The PDA coating, inspired by the adhesive properties of mussel foot proteins, successfully functionalized the MS surface, as confirmed by X-ray photoelectron spectroscopy (XPS). Thermodynamic analysis, based on contact angle measurements, revealed that MAPP and PDA/MAPP modifications reduced surface energies and potential energy differences. These changes enhanced filler dispersion and interfacial bonding by increasing hydrophobicity and reducing agglomeration in the PP matrix. Consequently, PP composites with 20% PDA/MAPP-modified MS fillers exhibited a 2.9% increase in tensile strength and a 7.5% increase in flexural strength compared to neat PP. Scanning electron microscopy (SEM) also showed reduced filler-matrix debonding and fewer voids. The proposed mechanism attributes these macroscopic property enhancements to the ability of the PDA coating to facilitate chemical and hydrogen bonding between MS fillers and MAPP.

BACKGROUND: In this study, biodiesel was prepared from chicken fat via a transesterification reaction using Mussel shells as a catalyst. Pretreatment of chicken fat was carried out using non‐catalytic esterification to reduce the free fatty acid content from 36.28 to 0.96 mg KOH/g oil using an ethanol/ fat mole ratio equal to 115:1. In the transesterification reaction, the studied variables were methanol: oil mole ratio in the range of (6:1 ‐ 30:1), catalyst loading in the range of (9‐15) wt%, reaction temperature (55‐75 °C), and reaction time (1‐7) h. The heterogeneous alkaline catalyst was greenly synthesized from waste mussel shells throughout a calcination process at different calcination times of (1‐5) h and temperatures of (700‐900) °C. The catalyst was characterized using BET, SEM, EDX, XRD, and FTIR. RESULTS: In the transesterification reaction, the best values of the studied parameters were: 21:1 methanol: oil molar ratio, 12 wt% catalyst loading, 5 h reaction time, and 63°C reaction temperature, which gave 96.2% methyl esters content. For catalyst synthesis, it was found that the optimum calcination conditions were 900 °C and 3 h, which resulted in a specific surface area of 10.5 m2/g and a large pore volume of 0.0033 cm3/g. CONCLUSION: A calcium oxide catalyst was successfully prepared from mussel shells. This catalyst was used to transesterify the chicken fat into biodiesel. The prepared catalyst exhibited a high active surface area and a pore volume, confirming that the CaO catalyst produced from waste mussel shells worked effectively, steadily, and affordably to produce renewable biodiesel. The best working conditions for the transesterification reaction were determined using the central Composite Design method (CCD). © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nitrogen and phosphorus in freshwaters are a global environmental challenge. Concurrently, the shellfish industry’s calcareous waste shells (CWSs) amount to ~10 million tonnes annually. CWSs can effectively adsorb dissolved pollutants, including nutrients, from water, which has motivated a growing number of experimental studies on recycling CWSs in wastewater treatment. This comprehensive literature review summarises and critically assesses the effectiveness of using different CWSs for removing nutrients from water. The effects of CWS type, initial pollutant concentration, adsorbent dosage, particle size, and contact time (CT) are investigated. The results show that phosphorus removal has been examined more than nitrogen. Most studies have been conducted using synthetic wastewater under laboratory conditions only. There is a large variability in experimental conditions, such as CWS adsorbent dosages (0.1–100 g/L) and CT (0.083–360 h). The calcination of CWSs is frequently used to enhance adsorption capacity. The Langmuir isotherm model has been found to fit adsorption data best when raw oyster shells are used, while the Freundlich isotherm is best when the adsorbent is calcinated mussel shells. The pseudo-second-order (PSO) kinetics model tends to describe adsorption data better than the pseudo-first-order (PFO) model in all shell types. There is significant potential for using calcareous waste shells to remove nutrients from wastewater in line with circular economy aspirations.

A series of Yttrium (Y)-doped Bi2MoO6 composites with calcined mussel shell powder (CMS) as supports were synthesized using a solvothermal method. The as-prepared samples were analyzed using multiple techniques to investigate their microscopic morphology, composition structure, and optical properties. The photocatalytic performance of the as-prepared samples was assessed via examining their capacity to degrade Rhodamine B (RhB) under visible-light irradiation. The photocatalytic data showed that the Y-doped Bi2MoO6/CMS composites exhibited better photocatalytic activity compared to pure Bi2MoO6 and undoped Bi2MoO6/CMS samples. Among the samples, the 0.5%Y-doped Bi2MoO6/CMS (0.5%Y-BC) showed the highest photocatalytic activity, achieving a maximum degradation rate of 99.7% within 60 min. This could be attributed to highly reactive sites due to Y doping, a narrower band gap, and a lower recombination rate of photoinduced electron–hole pairs. Additionally, the 0.5%Y-BC photocatalyst exhibited excellent stability and reusability properties even after four cycles, making it suitable for practical applications. The findings provided a feasible synthesis of nanocomposite photocatalysts with outstanding properties for organic pollutant removal from the solution system. [ABSTRACT FROM AUTHOR]

The processing of fishery products is not only for food consumption, but also the use of waste from these products has increased in recent years with the sustainability policy. Mussel meat, which is one of the aquatic products with high consumption in our country, is a delicious food product with high nutritional properties. While mussels contain low amount of fat and cholesterol; It also contains high levels of protein, carbohydrates, vitamins A, B1, B2, B6, B12, C and minerals such as calcium, iron, magnesium, phosphorus and selenium. It is seen that mussels are not only consumed as food, but also mussel shells are used as waste in the production of food packaging. In this study, mussels; mussel shell, mussel cultivation, purchasing and preservation, its importance in terms of human health and obtaining edible film from mussel Shell powder are included. [ABSTRACT FROM AUTHOR]

The high amount of hexavalent chromium in contaminated water must be removed because it can have serious implications on human health. Prolonged exposure to hexavalent chromium can lead to kidney damage and lung cancer in humans. The adsorption of hexavalent chromium from synthetic solution onto mussel shell (MS)-incorporated polyethersulfone (PES) flat sheet adsorptive membranes applied to a flat sheet adsorptive membrane crossflow (FSAMC) treatment system was studied in this work. The MS-PES flat sheet membranes were prepared by varying the mass ratio of MS-PES from 0 to 0.5, 1.0, and 1.5. The instrumental analysis was used to determine the physicochemical properties of the MS-PES membranes. The chemical composition of MS was analyzed using an energy-dispersive X-ray fluorescence spectrometer. The Brunauer-Emmett-Teller surface area of MS was determined by the multiple-point method using a surface analyzer. The surface and cross-sectional features of MS-PES membranes were observed under a scanning electron microscope. The analysis of water contact angle and porosity of MS-PES membranes was conducted using a contact angle goniometer and the gravitational method, respectively. The maximum adsorption capacity of 6.45 mg g–1 was obtained for the adsorption of hexavalent chromium onto MS-PES (1.0) membrane from synthetic solution. The analysis of experimental data was performed using the mass transfer factor models to determine the resistance of mass transfer (RMT) for the adsorption of hexavalent chromium from synthetic solution onto MS-PES membranes, which is dependent on either film mass transfer or porous diffusion. This work determined that the RMT for the adsorption of hexavalent chromium from synthetic solution onto MS-PES membranes applied to the FSAMC treatment system is dependent on film mass transfer. The knowledge of the RMT for transporting hexavalent chromium onto MS-PES membranes is considered expedient for designing an advanced water treatment system to release hexavalent chromium-free treated water. [ABSTRACT FROM AUTHOR]

The goal of this work was to evaluate the fire-protection attributes after treating wood with crude acidic carbonate solutions from a natural source. A broader aim of this project was to find ways to increase the period of usefulness of wooden objects, thus contributing to a sustainable society. In this context, samples of scotch pine (Pinus sylvestris L.) wood with insecticides, fungi, insects+fungi, samples were taken, and sea mussel (Chamelea gallina) powders were impregnated at different solution concentrations (1%, 3%, 5%) according to ASTM D 1413 76 principles. Thermogravimetric analyses (TGA) were carried out. Although there were no significant changes in the initial temperature, the turning point temperature, or the final temperature values compared to the control groups, the percent weight loss and percent residue amount increased in all the impregnated group periods. Although there was little change in some groups due to the heterogeneity and anatomical structure of the wood, the percentage of residue decreased as the percentage of weight loss increased. Compared to the control sample, the second highest adhesion was observed in 3% cork pine wood (0.81%), weight loss (65.7%), and the amount of residue was 22.0%. Based on the TGA results, mussel shell was found to delay the combustion.

A series of Yttrium (Y)-doped Bi2MoO6 composites with calcined mussel shell powder (CMS) as supports were synthesized using a solvothermal method. The as-prepared samples were analyzed using multiple techniques to investigate their microscopic morphology, composition structure, and optical properties. The photocatalytic performance of the as-prepared samples was assessed via examining their capacity to degrade Rhodamine B (RhB) under visible-light irradiation. The photocatalytic data showed that the Y-doped Bi2MoO6/CMS composites exhibited better photocatalytic activity compared to pure Bi2MoO6 and undoped Bi2MoO6/CMS samples. Among the samples, the 0.5%Y-doped Bi2MoO6/CMS (0.5%Y-BC) showed the highest photocatalytic activity, achieving a maximum degradation rate of 99.7% within 60 min. This could be attributed to highly reactive sites due to Y doping, a narrower band gap, and a lower recombination rate of photoinduced electron–hole pairs. Additionally, the 0.5%Y-BC photocatalyst exhibited excellent stability and reusability properties even after four cycles, making it suitable for practical applications. The findings provided a feasible synthesis of nanocomposite photocatalysts with outstanding properties for organic pollutant removal from the solution system.

Abstract Background Radial extracorporeal shock wave therapy (rESWT) is an attractive, non-invasive therapy option to manage fracture nonunions of superficial bones, with a reported success rate of approximately 75%. Using zebra mussels (Dreissena polymorpha), we recently demonstrated that induction of biomineralization after exposure to focused extracorporeal shock waves (fESWs) is not restricted to the region of direct energy transfer into calcified tissue. This study tested the hypothesis that radial extracorporeal shock waves (rESWs) also induce biomineralization in regions not directly exposed to the shock wave energy in zebra mussels. Methods Zebra mussels were exposed on the left valve to 1000 rESWs at different air pressure (between 0 and 4 bar), followed by incubation in calcein solution for 24 h. Biomineralization was evaluated by investigating the fluorescence signal intensity found on sections of the left and right valves prepared two weeks after exposure. Results General linear model analysis demonstrated statistically significant (p

We investigated the applicability of oyster (OS) and mussel shells (MS) as capping materials to inhibit the movement of nitrogen (N) and phosphorus (P) from river sediments. OS and MS are difficult to dispose of as waste, and have been used environmentally to clean up sediments contaminated with nitrogen and phosphorus. OS and MS increased the nutrient adsorption efficiency through simple heat treatment. The effectiveness of OS and MS capping with sand armor (SA) was evaluated in laboratory incubation experiments for 63 d. The sediments were capped with an active capping material (OS or MS) and then with either 1 cm or 3 cm SA. The pH and EC values were remarkably high under MS capping conditions because Ca2+ and Mg2+ were eluted from the MS material. The elution of Ca2+ and Mg2+ negatively affected the inhibition of NH4-N release by MS capping. OS capping demonstrated better performance for blocking the release of NH4-N and T-N than that of MS capping; the efficiency was enhanced by adding a 3 cm SA layer on top of the MS layer. In contrast, the PO4-P and T-P releases from the river sediments were effectively impeded by MS capping. OS capping with a 3 cm SA layer (OS/SA3) was recommended as the best capping strategy for inhibiting N and P releases from river sediments. The capping efficiencies of OS/SA3 for NH4-N, T-N, PO4-P, and T-P were 92.2%, 51.4%, 101.3%, and 93.3%, respectively. [ABSTRACT FROM AUTHOR]

In this work, a new type of micromesoporous substance was prepared with fatty alcohol-polyoxyethylene ether (AEO) surfactant freezing penetration and pyrolysis using shells as raw materials. The obtained material exhibited good adsorbability and could be added to oil-contaminated soil to adsorb the pollutant, which resulted in the regeneration of the initially polluted soil. It was determined that the main component of the developed substance was CaCO3. Importantly, the conducted experiments revealed that the obtained mussel micromesoporous material displayed certain adsorption effects toward petroleum hydrocarbons in a diesel solution. Moreover, it was found that chemical adsorption was more optimal than physical adsorption. The soil remediation effect was the best when the content of the mussel micromesoporous material in the soil was 400 g/kg. Under these conditions, the removal rate of petroleum hydrocarbon was established at 49.38%. This study indicated that micromesoporous material has great potential in the application of oil contaminated soil remediation. [ABSTRACT FROM AUTHOR]

In this study, a novel hybrid boron-doped titanium oxide–coated waste mussel shell (B-TiO2/shell) composite with good visible absorption was synthesized via hydrothermal method. The B-TiO2/shell exhibited a higher photocatalytic oxidation efficiency of X-3B than that of naked B-TiO2 under visible irradiation, due to the synergic effect from the well-dispersed B-dopant mixed phase crystalline structures (anatase and brookite crystals) and the adsorption from shell matrix. The photodegradation kinetics of X-3B can be described by the pseudo-first-order rate expression with chemisorption-controlled process, and regeneration experiments indicated its reusability. The present B-TiO2/shell would be applicable as economical and efficient photocatalyst for wastewater treatment. [ABSTRACT FROM AUTHOR]

High amounts of phosphate discharged in receiving water can lead to eutrophication. Once a water body is enriched with phosphate, it can prompt the growth of plants and cause algal blooms. The water body may also lose its important functions and cause adverse effects on the environment and human health. In this study, removal of phosphate from domestic wastewater treatment plant effluent was elucidated using iron-coated waste mussel shell. The phosphate adsorption by iron-coated waste mussel shell was examined with respect to initial phosphateconcentration (7 mg L–1), solution volume (0.2 L), adsorbent dosage (4–20 g), and contact time (1–5 day). The chemical composition of iron-coated waste mussel shell was analyzed using energy dispersive X-ray fluorescence spectrometer. The measurement of the specific surface area of iron-coated waste mussel shell was performed by multiple-point method according to the Brunauer, Emmett, and Teller theory. Several kinetic models (i.e., pseudo-first order and pseudo-second order) and isotherm models (i.e., Freundlich and Langmuir) were used to describe the adsorption behavior. The optimum removal efficiency of phosphate can reach at 95.7% after 120 h with the amount of iron-coated waste mussel shell used to run the experiment was 20 g and the treated effluent phosphate concentration of 0.3 mg L–1, was verified. Experimental data can be well described by pseudo-second order kinetic model (R2 > 0.99) and Freundlich isotherm model (R2 = 0.93), suggesting that chemisorption and multilayer adsorption occurred. Furthermore, a two-stage batch system was proposed to assess the optimum adsorbent dosage for phosphate removal. The two-stage system has contributed to reduce iron-coated waste mussel shell dosage by 56.94%, as compared to one-stage and thus reduced the operating cost of iron-coated waste mussel shell. [ABSTRACT FROM AUTHOR]

Background: Radial extracorporeal shock wave therapy (rESWT) is an attractive, non-invasive therapy option to manage fracture nonunions of superficial bones, with a reported success rate of approximately 75%. Using zebra mussels (Dreissena polymorpha), we recently demonstrated that induction of biomineralization after exposure to focused extracorporeal shock waves (fESWs) is not restricted to the region of direct energy transfer into calcified tissue. This study tested the hypothesis that radial extracorporeal shock waves (rESWs) also induce biomineralization in regions not directly exposed to the shock wave energy in zebra mussels. Methods: Zebra mussels were exposed on the left valve to 1000 rESWs at different air pressure (between 0 and 4 bar), followed by incubation in calcein solution for 24 h. Biomineralization was evaluated by investigating the fluorescence signal intensity found on sections of the left and right valves prepared two weeks after exposure. Results: General linear model analysis demonstrated statistically significant (p < 0.05) effects of the applied shock wave energy as well as of the side (left/exposed vs. right/unexposed) and the investigated region of the valve (at the position of exposure vs. positions at a distance to the exposure) on the mean fluorescence signal intensity values, as well as statistically significant combined energy × region and energy × side × region effects. The highest mean fluorescence signal intensity value was found next to the umbo, i.e., not at the position of direct exposure to rESWs. Conclusions: As in the application of fESWs, induction of biomineralization by exposure to rESWs may not be restricted to the region of direct energy transfer into calcified tissue. Furthermore, the results of this study may contribute to better understand why the application of higher energy flux densities beyond a certain threshold does not necessarily lead to higher success rates when treating fracture nonunions with extracorporeal shock wave therapy. [ABSTRACT FROM AUTHOR]

We investigated the applicability of oyster (OS) and mussel shells (MS) as capping materials to inhibit the movement of nitrogen (N) and phosphorus (P) from river sediments. OS and MS are difficult to dispose of as waste, and have been used environmentally to clean up sediments contaminated with nitrogen and phosphorus. OS and MS increased the nutrient adsorption efficiency through simple heat treatment. The effectiveness of OS and MS capping with sand armor (SA) was evaluated in laboratory incubation experiments for 63 d. The sediments were capped with an active capping material (OS or MS) and then with either 1 cm or 3 cm SA. The pH and EC values were remarkably high under MS capping conditions because Ca2+ and Mg2+ were eluted from the MS material. The elution of Ca2+ and Mg2+ negatively affected the inhibition of NH4-N release by MS capping. OS capping demonstrated better performance for blocking the release of NH4-N and T-N than that of MS capping; the efficiency was enhanced by adding a 3 cm SA layer on top of the MS layer. In contrast, the PO4-P and T-P releases from the river sediments were effectively impeded by MS capping. OS capping with a 3 cm SA layer (OS/SA3) was recommended as the best capping strategy for inhibiting N and P releases from river sediments. The capping efficiencies of OS/SA3 for NH4-N, T-N, PO4-P, and T-P were 92.2%, 51.4%, 101.3%, and 93.3%, respectively.

• Hydroxyapatite was prepared using mussel shells as calcium source by pH control. • Ag/hydroxyapatite behaved 100 % conversion of ethyl acetate at 260 °C. • Small Ag particles and Ag 2 O species were formed by more skeletal OH groups on HAP. • The lower ratio of Ag0/Ag+ was crucial for lower-temperature conversion of VOCs. Volatile organic compounds (VOCs) triggered serious air pollution and mussel shell caused the marine environmental issues. Herein, hydroxyapatite (HAP) using mussel shells as calcium source was prepared by hydrothermal method with different pH (pH = 6, 8, 10, 11) controls to support Ag catalyst for removal of VOCs. It was found that the amount of skeletal hydroxyl species and textual properties of HAP were controlled by pH effectively, and the increase of hydroxyl groups in the framework resulted in forming smaller-sized Ag 2 O particles. When pH was 8, the Ag/HAP-B pH=8 catalyst exhibited 100 % conversion of ethyl acetate and toluene at 260 °C and 300 °C, respectively. Silver species were more likely existed on the surface of HAP-B pH=8 to form large-size Ag particles (6.4 nm) and more Ag 2 O species. The lower ratio of Ag0/Ag+ were crucial for improving the VOCs oxidation activity at lower temperatures. This work applied waste mussel shells to prepare high value-added Ag/hydroxyapatite catalysts and to promote VOCs catalytic oxidation. [ABSTRACT FROM AUTHOR]

Cultivation of mussels stands as a significant economic activity in coastal regions Brazil. Often disregarded as waste, mussel shells (MS) possess properties that can be harnessed in the production of building materials. This study explores the utilization of large amounts of Perna perna MS as fine aggregates for the production of fluid mortars. Key parameters such as compressive strength, bulk density, water absorption and void ratio were evaluated. Specimens were prepared according to a full factorial design, with variations of MS content (%MS) (45 to 65 vol%) and water-to-cement (w/c) ratio (0.40 to 0.50). The resulting fluid mortars exhibited satisfactory strength, minimal segregation, and low void content with compactness at the aggregate-cement paste interface. The increase in %MS contributed to higher mortar bulk density but led to reduced void ratio, compressive strength, and workability. The incorporation of a superplasticizer (SP) significantly improved the matrix by enhancing the dispersion of cement particles, mitigating the adverse effects of reduced cementitious material, and enhancing strength. The influence of w/c on compressive strength was found to be 1.6 times greater than that for %MS, while its impact on void ratio was 0.5 times smaller. The full factorial model effectively predicted the mix design for MS-added mortars, yielding strengths ranging from 12 to 21 MPa and void ratios from 21 to 34%. [Display omitted] • Workable mortars with exclusive utilization of Perna perna mussel shells (MS) as fine aggregate. • Increasing %MS reduces compressive strength but increases bulk density. • w/c exerts 1.6 times greater effect on compressive strength reduction than %MS. • w/c has an antagonistic effect on void ratio, exerting − 0.5 times the influence compared to %MS. • Fresh mortar fluidity promotes microstructural compactness and improve properties. [ABSTRACT FROM AUTHOR]

Lightweight aggregates are extensively used in construction and other industrial applications due to their technological characteristics. The extraction of natural aggregates results in serious environmental effects. Thus, within the circular economy concept, the valorization of waste through the optimization of materials and product design is encouraged. In this work, glass lightweight aggregates were prepared from mixtures of white glass cullet and carbonate wastes from mining (wastes originating from the extraction, manufacture and marketing of magnesite and its derivatives) and the food industry (eggshell and mussel shell). The effects of different processing parameters, such as the particle size of the base glass, percentage of the blowing additive, shaping method, heating rate, temperature and processing time, were evaluated. The results indicate that the mineralogical composition of the blowing agent and the particle size of the base glass are the two processing parameters with the greatest impact on expansion efficiency. Thus, glass artificial aggregates were obtained with characteristics similar to those of commercial products (density values ranged between 0.3 and 0.8 g/cm3 and mechanical strength between 0.7 and 1.5 MPa) from thermal shock expansion treatments in the temperature range 800–900 °C and with dwell times no longer than 15 min.

It is well-established that multi-scale porous scaffolds can guide axonal growth and facilitate functional restoration after spinal cord injury (SCI). In this study, we developed a novel mussel shell-inspired conductive scaffold for SCI repair with ease of production, multi-scale porous structure, high flexibility, and excellent biocompatibility. By utilizing the reducing properties of polydopamine, non-conductive graphene oxide (GO) was converted into conductive reduced graphene oxide (rGO) and crosslinked in situ within the mussel shells. In vitro experiments confirmed that this multi-scale porous Shell@PDA-GO could serve as structural cues for enhancing cell adhesion, differentiation, and maturation, as well as promoting the electrophysiological development of hippocampal neurons. After transplantation at the injury sites, the Shell@PDA-GO provided a pro-regenerative microenvironment, promoting endogenous neurogenesis, triggering neovascularization, and relieving glial fibrosis formation. Interestingly, the Shell@PDA-GO could induce the release of endogenous growth factors (NGF and NT-3), resulting in the complete regeneration of nerve fibers at 12 weeks. This work provides a feasible strategy for the exploration of conductive multi-scale patterned scaffold to repair SCI., (© 2024 IOP Publishing Ltd.)

Hydroxyapatite (HA) nanoparticles derived from mussel shells were prepared using the wet precipitation method and were tested on human mesenchymal and epithelial cells. Shells and HA powder were characterized via X-ray diffraction analysis (XRD) and scanning electron microscopy along with energy dispersive X-ray spectroscopy (SEM/EDX), high resolution transmission electron microscopy (HR-TEM) and Fourier transform infrared spectroscopy (FTIR). The in vitro cytotoxic properties of HA and mussel shells were determined using sulphorhodamine B (SRB) assays for MCF-7 cells (HepG2) and colon (Caco-2) cells. Cell viability tests confirmed the nontoxic effects of synthesized HA and mussel shells on human mesenchymal stem cells (h-MSCs) and epithelial cells. Toxicity values were less than 50% of the cell's validity ratio based on analyses using different concentrations (from 0.01 to 1,000 μg). The results indicate that MSC and epithelial cell attachment and proliferation in the presence of both HA and shell occurred.The proliferation capability was established after 3 and 7 days. SEM images revealed that stem cells and epithelial cells attached to the scaffold indicated full and complete integration between the cells and the material. It seems that due to the ion exchange between bovine serum albumin solutions (BSA) and HA, the FTIR data confirmed an increase in the amide I and amide II bands, which indicates the compatibility of the BSA helix structure. This study sheds light on the importance of merging stem cells and nanomaterials that may lead to improvements in tissue engineering to develop novel treatments for various diseases.

Calcium oxide is one of the appropriate catalysts for biodiesel production. In this study, cheap and compatible with environment catalyst has been used. Mussel shell of Persian Gulf coast is one of the sources of calcium carbonate that is converted to calcium oxide at calcination temperature up to 950°C. Transesterification reaction was carried out at optimum condition of our previous study (calcination temperature of 1050°C, methanol to oil ratio of 24:1 and catalyst to oil ratio of to 12 wt.%) in a 250mL two-necked flask. In this study, the effects of stirrer speed (250 and 350rpm), the reaction temperature (328.15, 333.15, and 338.15K) and reaction time (1, 3, 5, 7 and 8h) on the methyl ester conversion were investigated. The methyl ester conversion, in stirrer speed of 250rpm, reaction temperatures of 328.15 and 333.15K and reaction times of less than 5h is too low. But at the reaction temperature of 338.15K (near to methanol boiling point), the mixing is increased slightly and the reaction occurs at a higher rate and the methyl ester conversion is increased. These results indicate that diffusion has a significant role in the methyl ester conversion rate in the heterogeneously catalyzed reaction. In stirrer speed of 350rpm, the diffusion problem has been solved somewhat and the reaction in the catalyst surface is the controller of the overall reaction rate. In this stirrer speed (350rpm) the methyl ester conversion versus time in all temperature shows pseudo-first-order kinetics. Firstly, the rate was determined at the various temperatures and then the activation energy for the transesterification reaction of soybean oil with methanol was obtained in the presence of mussel shell as the catalyst. Results demonstrate the high precision of the pseudo-first-order kinetics model regard to methyl esters concentration.

Nanosized calcium deficient carbonated apatite was synthesized from three different natural resources, namely chicken eggshells (calcite), cuttlefish bones (aragonite) and mussel shells (aragonite/calcite). The calcium precursors were ball-milled in (NH 4) 2 HPO 4 or H 3 PO 4 – containing aqueous medium for different times and then dried at temperatures ranging from 20 °C to 150 °C. The formation of hydroxyapatite (HA) is shown to be strongly affected by such treatment, the amount of synthesized HA increasing with temperature. Aragonite from cuttlebones and the aragonitic fraction of mussels is found to be transformed more easily with respect to the calcite from eggshells. The reaction is also favored by an acidic milling media with respect to basic one. The feasibility of the synthesis process at nearly room temperature described in the present work has interesting potentialities in the retention of the organic portions of the original biological resource in the produced nanometric inorganic compound. [ABSTRACT FROM AUTHOR]

This research covers investigation of mode-I fracture toughness of the recycled waste mussel shell particles reinforced epoxy composites. Vacuum assisted resin infusion molding (VARIM) method was applied to produce composites. The aim of the research is to use recycled waste shells to reduce production cost and to prevent environmental pollution. VARIM was applied to produce fiber reinforced composite. Therefore, as reinforcement particles mussel shell, and as particle reinforced composite production method VARIM are both two new points of the research. Mode-I fracture toughness experiments conducted according to ASTM D 5045 standards with single-edge-notch bending specimens for six repeats. According to mode-I tests, the fracture toughness of the mussel shell particle reinforced epoxy composites is 2.44 MPa∙m1/2. The failure region from one of the tested specimen was investigated by scanning electron microscope (SEM) in the next section of the paper. After the test results are given by diagrams, they are discussed according to other particle-reinforced composites to show the new material place in the literature by means of fracture toughness. [ABSTRACT FROM AUTHOR]

The aim of this research was to establish whether the shell of green-lipped mussels and Pacific oysters could be plasma sprayed to promote and accelerate the establishment of filter feeder colonies. While CaCO3 degrades before melting under equilibrium conditions, the hypothesis considered in this work was that the high-temperature, highly nonequilibrium conditions experienced by powders during plasma spraying may be sufficient to impart enough thermal energy into the powder, at a fast enough rate, that the CaCO3 phase would melt before undergoing total thermal degradation. Sprayable mussel and oyster shell powder was manufactured by crushing and milling. A range of plasma spray parameters incorporating a wide operating window of plasma power and gas velocity were trialed. Coatings were initially formed from both powders under all plasma spray conditions used. However, the samples degraded into powdery debris with time due to the reaction of CaO with water in the air to form Ca(OH)2. No evidence of CaCO3 melting was found, indicating that it was not possible to form a coating by thermal spraying. The mechanism of inflight particle phase degradation is presented for both powders, along with proposed mechanism of initial coating formation due to melting of CaO. [ABSTRACT FROM AUTHOR]

As phosphorus (P) exceeds 0.1 mg P L−1, the water is usually considered high enough to cause eutrophication. Thermally treated mussel shell (TMS), a calcium-rich (36.76%) biological material, was an environmentally friendly and low-cost adsorbent for P removal. To achieve very low concentrations of P, composite agents of PAC–TMS, Fe–TMS and La–TMS were prepared with the optimum weight ratio of 0.4, 0.2 and 0.2 (g g−1) [polyaluminium chloride (PAC), Fe(OH)3 or La2O3 to TMS] with the lower cost and high P adsorption efficiency, respectively, all of which had more than 80% of P removal rate after 12-h treatment of 5 mg L−1 P solution, much higher than that of TMS alone (50%). Isotherm experiment showed that these composite agents have maximum phosphate adsorption capacities of 91.74 mg P g−1 (PAC–TMS), 101.42 mg P g−1 (Fe–TMS) and 56.50 mg P g−1 (La–TMS), respectively. Additionally, the metal-modified TMS was almost independent of pH. Long-term efficient removal of P (< 0.1 mg L−1) was achieved during a 3-month removal trial of P-contaminated water while using these metal-modified TMS. Since metal-modified TMS both had calcium and other multivalent metal (Al, La or Fe), the modification pathway was mainly dependent on both enhance adsorption/precipitation by a simultaneous effect of the calcium and other multivalent metal. Article Highlights: PAC–TMS, Fe–TMS and La–TMS with optimum ratio of 0.4, 0.2 and 0.2 for P removal P adsorption capacities of 91.74(PAC–TMS), 101.42(Fe–TMS) and 56.50 mg g−1 (La–TMS) Long-term efficient removal of P (< 0.1 mg L−1) via these metal-modified TMS [ABSTRACT FROM AUTHOR]

An economical and environmentally friendly heterogeneous base catalyst has been developed from a waste freshwater mussel shell and employed successfully for the synthesis of 4H-pyrans in an aqueous medium at ambient temperature. 2-arylidenemalononitrile, an intermediate of 4H-pyran reaction, was also prepared using the same catalyst. The catalyst was characterized by FT-IR, XRD, XRF, EDS, and SEM. Analytical tools such as XRF and EDS explored the presence of calcium oxide as a main component in the mussel shell, while the XRD pattern showed crystalline nature and SEM image displayed porous surface with irregular cavities. The catalyst exhibited unprecedented performance in the one-pot three-component condensation reaction of C–H activated acidic compounds with aromatic aldehydes and malononitrile in the green reaction medium and offered pure products without chromatographic separation. [ABSTRACT FROM AUTHOR]

• Mussel shells are a by-product converted into fine aggregate after a low environmental impact process. • Shell aggregate disturbs microstructure and pore size distribution of cement coatings. • Particle shape and shell composition are the main characteristics affecting coating properties. • The use of 25% mussel shell leads to accurate surface and base layer coatings. The production of farmed mussels amounts to millions of tonnes across over 40 countries. Shell waste resulting from this production has a very significant environmental impact. In Galicia, mussel shell waste is transformed, using low impact heat treatment, into a by-product that can be used as an aggregate. This research investigates cement-coating mortars where conventional aggregate is partially replaced with mussel shell aggregate. Reference mortars and mortars with mussel shell sand replacing conventional sand at different rates: 25%, 50% and 75% have been tested. Results show the feasibility of mussel shell in cement coatings at an optimal replacement rate of 25% of the conventional aggregate. [ABSTRACT FROM AUTHOR]

Abstract The use of organic residues in agriculture can contribute to the management of plant diseases and improvements in soil fertility. However, their effects on banana Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), are poorly understood. In this study, the biotic and abiotic effects on soil suppressiveness of banana Fusarium wilt were evaluated after incorporation of composted sewage sludge, biochar, shrimp peels and mussel shells into the soil. Residues were incorporated at rates of 0, 1, 2, 3, 4, and 5%, v:v in soil previously infested with Foc. Plantlets of banana cv. Maçã (AAB) were transplanted seven days after residue incorporation. Notable with respect to the other residues and concentrations studied, sewage sludge at 4% and 5% reduced plant disease (disease severity index and external severity) and increased plant growth. All concentrations of biochar and sewage sludge at 2% and 3% had intermediate effects. Disease severity and plant growth in plants grown in soil containing shrimp peels and mussel shells were similar to those of the untreated control. Negative correlations were observed between disease parameters and soil basal respiration, bacterial population, electrical conductivity, pH, V% (base saturation), CEC, P, K, Ca, Mg, Na, Zn, Mn and B. Highlights • Sewage sludge at 4% and 5% reduced banana Fusarium wilt and increased plant growth. • Shrimp peels and mussel shells do not reduce banana Fusarium wilt. • Microbial respiration and bacterial population were predictors of FW suppression. • EC, pH, V%, CEC, P, K, Ca, Mg, Na, Zn, Mn and B were predictors of FW suppression. [ABSTRACT FROM AUTHOR]

Abstract Galician "Rías"·conditions (extension, water temperature ....) enable the production of excellent quality cultured mussels. This leads Spain to be the third producer country in the world. Cannery industry (35% of the total cultured mussel production) generates 25000 tons of mussel shell waste per year. Hence, it is necessary to find a sustainable use for this material. The purpose of this work is to verify the most significant changes in the properties of air lime coating mortar when replacing limestone sand with mussel shell sand. Two different air limes have been used: non-aged hydrated commercial lime powder and 10 month-old slaked lime putty. Reference mortars and mortars with mussel shell aggregate as a substitute for limestone aggregate at different rates - 25%, 50% and 75% - have been tested. The behaviour of mortars at the age of one year from kneading has been studied. Studies show that mussel shell increases the pore volume of air lime mortar mixtures, which means a reduction in the mortar's workability and density. The poor paste-aggregate cohesion of mussel shell particles in the air lime matrix worsen the mortar mechanical strength results, which is confirmed by ultrasound test results. Carbonation at this age and hygric behaviour are properties that improve with mussel shell content. Highlights • Air lime mortars with mussel shell as aggregate were designed. • ITZ of mussel shell aggregate was compared with ITZ of a limestone aggregate. • Chemical characteristics and shape of mussel shell affect the pore size distribution of air lime mortars. • Mussel shell aggregate reduces capillary uptake in air lime mortars. • Carbonation increases with mussel shell aggregate at one-year age. [ABSTRACT FROM AUTHOR]

Biogenic calcium carbonates naturally contain ions that can be beneficial for bone regeneration and therefore are attractive resources for the production of bioactive calcium phosphates. In the present work, cuttlefish bones, mussel shells, chicken eggshells and bioinspired amorphous calcium carbonate were used to synthesize hydroxyapatite nano-powders which were consolidated into cylindrical pellets by uniaxial pressing and sintering 800–1100 °C. Mineralogical, structural and chemical composition were studied by SEM, XRD, inductively coupled plasma/optical emission spectroscopy (ICP/OES). The results show that the phase composition of the sintered materials depends on the Ca/P molar ratio and on the specific CaCO3 source, very likely associated with the presence of some doping elements like Mg2+ in eggshell and Sr2+ in cuttlebone. Different CaCO3 sources also resulted in variable densification and sintering temperature. Preliminary in vitro tests were carried out (by the LDH assay) and they did not reveal any cytotoxic effects, while good cell adhesion and proliferation was observed at day 1, 3 and 5 after seeding through confocal microscopy. Among the different tested materials, those derived from eggshells and sintered at 900 °C promoted the best cell adhesion pattern, while those from cuttlebone and amorphous calcium carbonate showed round-shaped cells and poorer cell-to-cell interconnection.

In this work, a SiO2-doped natural photocatalyst derived from waste mussel shell (HAS) was prepared by acidification. The as-prepared sample was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma-optical emission spectroscopy (ICP-OES), field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV-visible diffuse-reflectance spectrum (UV-vis DRS), and Differential scanning and thermogravimetric analyses (DTA/TGA). The results exhibited that HAS was mesopores nanomaterial consisting of uneven arranged rod-like structure, the dominant component of HAS was SiO2 with a large number of hydroxyl groups, and a variety of transition metals uniformly distributed in HAS. Rhodamine B (RhB) and methylene blue (MB) removal efficiencies (equal to 92.59% and 99.14%, respectively) were observed under the HAS presence when exposed to the visible light. The degradation products were analyzed using liquid Chromatograph Mass Spectrometer (LC-MS) and Total Organic Carbon (TOC), among which, MB was degraded by demethylation and deamination, and RhB was degraded by N-deethylation and conjugate structure destruction. After four successive recycles, the removal efficiency of RhB and MB are still reach 86.103% and 75.844%. This study indicated that the mussel shells might be suggested as a novel natural photocatalyst in the application of dye wastewater treatment.

The exploration of cost-effective and highly efficient photocatalysts is still a great challenge. In this work, a cost-effective and highly active Bi2WO6/calcined mussel shell (CMS/BWO) composite photocatalyst was prepared by a facile solvothermal route, in which Bi2WO6 nanosheets were tightly, evenly, and vertically grown on waste calcined mussel shells (CMS). Multiple techniques are adopted to characterize the phases, morphology, and chemical properties of the as-fabricated catalysts. In contrast to the stacked Bi2WO6, CMS/BWO has numerous exposed edges and open transfer pathways, which can create more open space and reactive sites for photocatalytic reactions. Such favorable characteristics enable CMS/BWO to efficiently degrade organic pollutants (e.g., rhodamine B (RhB), methylene blue (MB), tetracycline hydrochloride (TC)) under visible light. Moreover, the generation of reactive species during the photocatalytic process is also examined by trapping experiments, disclosing the pivotal role of photo-generated holes (h+) and hydroxyl radicals (•OH) in the photo-degradation of pollutants. Above all, this study not only provides an efficient photocatalyst for environmental remediation, but it also opens up new possibilities for waste mussel shell reutilization.

Feather pecking is still a behavioral problem in laying hen flocks, resulting in impaired welfare and economic losses. Environment enrichment, e.g., providing access to litter, to increase foraging behavior in laying hens has been shown to decrease feather pecking. This study investigated the effect of spreading crushed mussel shells (particle size 10 to 20 mm) in the litter area as an environment enrichment and source of calcium for layers receiving a commercial feed and for layers given a feed with 40% less calcium. These treatments were compared with a control involving hens given the commercial feed, but no mussel shells in the litter. The study included 900 Dekalb White layers housed in a single-tier floor system during a production cycle (20 to 72 wk of age). The mussel shells were consumed to a lower extent than predicted, resulting in calcium deficiency in hens fed the low-calcium diet. This in turn was evident as increased degree of keel bone deviations and lower eggshell breaking strength. Daily addition of crushed mussel shells to the litter for laying hens on a balanced or calcium-deficient diets did not generate any positive effects on bird feather cover, eggshell quality, production performance, or fearfulness. Hence, with the particle size of mussel shells used in this study, there was no indication of improved welfare due to environment enrichment. [ABSTRACT FROM AUTHOR]