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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.

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.

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.

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.

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.

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.

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.

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.

There is a high content of calcium carbonate in mussel and oyster shells, which can be used in the formulation of medicine, in construction or as filler in polymer materials. This work has as its main objective to obtain calcium carbonate from mussel and oyster shells and used as filler in polypropylene compared their properties with polypropylene and commercial calcium carbonate composites. The shellfish was milling and heated at 500 ºC for 2 hours. The powder obtained from shellfish were characterized by scanning electron microscopy (SEM), X-ray fluorescence, particle size distribution and abrasiveness and compared with commercial CaCO3 and mixed with polypropylene. The thermal and mechanical properties of polypropylene with CaCO3 obtained from oyster and mussel shells and with commercial CaCO3 were analysed. The results showed that CaCO3­ can be obtained from oyster and mussel shell and is technically possible to replace the commercial CaCO3 for that obtained from the shells of shellfish in polypropylene composites.

Samples of shells of oysters and mussels from sea farm around the Santa Catarina Island in south Brazil were collected and analyzed by DRX, FRX, SEM, CHN-S, FTIR, TG, AAS/Flame and AAS /GF. The results showed that the crystalline structure of mussel's shells is mainly formed by aragonite and the oyster's shells by calcite. The calcium percentage in both shells species was in the range of 33 to 35% and also 850 and 1200 mg/kg of strontium was detected in the shells of oysters and mussels, respectively. The content of organic matter was larger in the mussel's shells and the thermal degradation of both shells species occurred by three events at different temperatures from 250 to 830 ºC.