Mussel Shells Research Articles

Performance Pheretima sp. and The Quality of Vermicompost on Media Using Clam and Snail Shell Flour

The abundance of green mussel shells, clam shells, and snail shells that have not been maximally utilized has caused environmental disturbances. These shells can be used as a substitute for worm food because of their good nutritional content. This research aimed to analyze the productivity of Pheretima sp. with the combination of shell powder (green mussel, clam, and snail) and cow dung to their living media (feed) and the quality of vermicompost. The data were analyzed using SAS Studio application with completely randomized design (CRD), 10 treatment levels, with 3 replications each. The observed variables included earthworm productivity, vermicompost quality, and vermicompost performance. The results of the studyshow a significant (P<0.05) on the use of green mussel shell 10% in all earthworm productivity variables, and show a significant (P<0.05) on the use of green mussel shell 30% in vermicompost quality and vermicompost performance. The combination of 10% green mussel shell powder in cow dung media can increase the productivity of Pheretima sp. The best vermicompost testing result on water spinach plants was found in the treatment with the addition of 30% green mussel shell powder in cow dung media.

Can mussel shell waste optimize cement and air lime mortars hygrothermal performance?

Mussel shells used as aggregates for mortars have flaky and irregular particles, which significantly increases the pore volume. This leads to the identification the microstructure of mussel shell mortars as a light and porous composite, which could have good hygrothermal properties. In the present study, the density and thermal properties are assessed on cement and air lime mortars, each with three replacement percentages of replacement of conventional sand by mussel shell sand (25 %, 50 % and 75 %), are evaluated and compared with their respective baselines (0 % replacement). Thermal conductivity measurements are also carried out on different loose fractions of the mussel shell aggregate to understand the behaviour of this material without binder matrix. Finally, adsorption and desorption cycles at 80 % and 50 % relative humidity are carried out on loose aggregate fractions and on the eight mortars. The results are very positive for the mussel shell mortars, as it can be concluded that the use of mussel shell aggregates improves the thermal performance and the potential moisture buffering capacity of both cement and air-lime coating mortars.

Exploring the acid-insoluble shell organic matrix of freshwater mussels (Unionoida) as a proxy for palaeodietary and paleoenvironmental studies

ABSTRACT The shells of freshwater mussels, commonly found at archaeological sites associated with the Kodjadermen-Gumelnița-Karanovo VI human groups (5th millennium BCE, Romania and Bulgaria), were a significant dietary component for this population. The organic matrix of these ancient shells is often well-preserved and can be analysed using stable isotopes. This study establishes the empirical relationship between the isotopic composition of the acid-insoluble shell organic matrix (AIM) and the soft tissues of modern Unio tumidus. A quality criterion for AIM (C:N ratio 3.6 (3.3–<3.8)) was defined, and isotopic offsets (Δ15NAIM-defatted body = +0.95‰, Δ13CAIM-defatted body = +0.93‰ for soft tissues; Δ15NAIM-muscle = +1.7‰, Δ13CAIM-muscle = +0.3‰ for the adductor muscle) were determined. Our data suggest that the Gumelnița mussels were omnivorous, with a similar trophic level to carp and pond turtles, sourced from diverse water bodies (rivers, lakes …) based on δ13C values.

Freshwater Mussel (Unio pictorum) Shells Reveal Hydrological and Environmental Change From 1300 BC to the Present Day.

Preserved biological communities can provide baseline data about the historical ecosystems and environmental conditions that preceded recent anthropogenic alteration. Freshwater mussel shells show particularly good preservation, and the shell assemblages commonly found during archaeological excavations can offer insights into past ecosystems. We studied assemblages of Unio pictorum mussel shells from palaeochannel silts associated with the Late Bronze Age site of Must Farm in eastern England (c. 850 BC), on an ancient tributary of the modern-day River Nene. We compared archaeological shells from two sediment horizons (broadly 1300-700 BC) to live individuals collected from two analogous sites on the present-day Nene. Size and growth rate, interannual growth variability and stable isotope (δ18O and δ13C) composition were compared between the populations. Size and the von Bertalanffy growth parameter L∞ differed among all four populations. Mean lengths and L∞ were higher in the two modern populations (mean lengths 77.3 ± SE 0.8 and 73.8 ± SE 1.1 mm, L∞ 91.8 ± 5.4 and 79.0 ± 8.1 mm) than the ancient populations (mean lengths 58.1 ± SE 1.6 mm and 68.4 ± SE 0.9 mm; L∞ 71.5 ± 16.9 and 76.8 ± 6.2 mm). Modern individuals also showed greater variation in age-corrected year-to-year growth. δ13C was lower in modern shells (-11.8‰ for modern shells, -9.03‰ and -9.02‰ for ancient shell populations), potentially reflecting altered hydrological and nutrient regimes. δ18O and δ13C were positively correlated for all but one sampled ancient shell, but not modern shells. These results reflect changes in local environmental conditions, particularly the transition from a shallow, slow-flowing tributary to a deeper, canalised river with faster flow, as well as effects of anthropogenic nutrient enrichment. The findings demonstrate the importance of long-term data in studying anthropogenic ecosystem alteration and avoiding shifting baseline syndrome in conservation planning.

Suitability of using mussel shells as partial replacement of aggregates in self-compacting concrete

Abstract The handling of mussel shell wastes in coastal regions presents an issue that may be addressed by using mussel shells as a construction material. Shells from waste mussels replace aggregate in concrete, whole or in part. The shells of the mussels are well suited to be incorporated as aggregate into a concrete mix since they are primarily composed of limestone, a substance similar to the other ingredients in concrete. The current study focuses on the suitability of using mussel shells to replace aggregates in self-compacting concrete (SCC). The aggregates were substituted with mussel shells in 5, 10, 15, and 20 percentages. The mixes were initially tested for workability, including slump cone test, L-box test, flow test, and V-funnel test, followed by determining the mechanical behavior, such as flexural strength (FS), compressive strength (CS), and split tensile strength (STS). Also, the microstructural analysis of the mixes was done using scanning electron microscopy (SEM) and energy dispersive x-ray (EDX). The results showed that the concrete’s fresh, hardened, and microstructural properties could be improved by substituting aggregates with mussel shells up to 15%. Some prime results of the SCC mix exhibited a slump flow value range of 600–700 mm, a V-funnel flow time of 10–13 sec, an L-box test ratio greater than 0.8, CS of 41.97–52.93 MPa, STS of 3.69–4.18 MPa, and FS of 3.75–4.28 MPa. The study concludes that better-performed SCC can be produced at an optimum dosage of 15% mussel shells to partially replace aggregates.

Addition of mussel shells enhance marine benthic biodiversity in two degraded coastal soft sediment ecosystems

The decline in coastal shellfish populations, attributed to anthropogenic stressors such as harvesting via dredging, can deplete the seabed of vital biogenic habitat. This removal of shellfish significantly reduces habitat complexity, biodiversity, and the hard substrate required for the natural recovery of some key species. A common method for oyster restoration involves deploying oyster shell material to provide habitat and substrate for settling larval oysters. In contrast, hard substrate is not required for the mussel lifecycle and as a result the deployment of mussel shell for seabed restoration has received minimal attention, with the effects of reintroducing this material poorly understood. Deploying mussel shell material has the potential to aid in ecosystem recovery, including reviving seabed biodiversity, especially in areas that have been depleted of shellfish via damaging methods such as dredging. This study aimed to investigate the ecosystem effects of returning mussel shells onto two locations with differing soft sediment (sand and mud) in areas historically subjected to excessive dredging of mussel populations and sedimentation. Within 2 years 4 months the infaunal taxa richness was higher in the shell areas compared to the reference areas in both locations, while abundance of infauna was higher in only the sand location and infaunal diversity did not differ at either location. Epifaunal diversity was also higher in the shell area compared to the reference areas at both locations, while the abundance and richness did not differ. Few significant differences were seen in benthic biogeochemical variables between the reference and shell areas and those observed were likely the result of the addition of the shell material changing the sediment composition. These findings demonstrate that mussel shells are a restoration tool that can enhance epifaunal biodiversity and infaunal taxa richness in soft sediment ecosystems historically impacted by shellfish overharvesting and sedimentation.

Finding food: how generalist predators use contact-chemosensory information to guide prey preferences.

Understanding the processes that guide carnivores in finding and selecting prey is a fundamental, unresolved challenge in sensory biology. To our knowledge, no published work has yet revealed the complete structural identities of compounds that cue preferences by generalist predators for different prey species. With this research imperative in mind, we determined the chemistry driving consumer preferences for live intact prey using two generalist predatory species (sea stars, Pisaster ochraceus; whelks, Acanthinucella spirata), along with two foundation prey species (mussels, Mytilus californianus; barnacles, Balanus glandula), inhabiting rocky, wave-swept shores. Each prey species is known to secrete either a 29.6 kDa (named 'KEYSTONEin') or a 199.6 kDa (named 'MULTIFUNCin') glycoprotein as a contact-chemical cue. Here, experimental manipulations utilized faux prey consisting of cleaned barnacle or mussel shells infused with KEYSTONEin, MULTIFUNCin or seawater (control) gels. Whelks exhibited a strong penchant for MULTIFUNCin over KEYSTONEin, irrespective of shell type. In contrast, sea stars generally preferred KEYSTONEin over MULTIFUNCin, but this preference shifted depending on the experimental context in which they encountered physical (shell) and chemical (glycoprotein) stimuli. This study ultimately demonstrates clear and contrasting chemical preferences between sea stars and whelks. It highlights the importance of experimental setting in determining chemical preferences. Finally, it shows that prey preferences by these predators hinge only on one or two contact-protein cues, without the need for quality coding via fluid-borne compounds, low-molecular-weight substances or mixture blends.

Stabilization of Arsenic and Heavy Metal Contaminated Soil Using Fishery By-Products and Evaluation of Heavy Metal Uptake in Crops

Objectives : Heavy metals eluted from mine waste pollute surrounding soil and water systems, which can spread to crops and have a harmful effect on the human body. The purpose of this study was to evaluate the feasibility of recycling discarded mussel shells(MS) and manila clam shells (MC) as stabilizers for the immobilization of arsenic(As) and heavy metals(Pb, Zn) in soil.Methods : MS and MC were processed with -#10 mesh natural material, -#20 mesh natural material, and -#10 mesh calcined material and treated at 0-10 wt%. After 1 week or 4 weeks of wet curing, it was eluted with 0.1 N HCl and the concentrations of As, Pb, and Zn in the soil were analyzed through inductively coupled plasma optical emission spectroscopy(ICP-OES) analysis. In addition, red lettuce was cultivated in the stabilized soil and the concentration of heavy metals that were transferred to crops was evaluated. The stabilization mechanism was investigated by scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDX) analysis.Results and Discussion : The stabilization efficiency for arsenic and heavy metals was in the order of natural -#10 mesh &lt; natural -#20 mesh &lt; calcined -#10 mesh. The calcined stabilizer showed a high stabilization efficiency of 98% at a 2 wt% treatment level. Pb was not detected in the red lettuce grown in the stabiliz ed soil, and the standard for leafy vegetables (Pb-0.3 mg/kg or less) was satisfied according to the Ministry of Food and Drug Safety. The SEM-EDX analysis revealed that As was stabilized through Ca-As precipitation and heavy metals(Pb, Zn) were stabilized through pozzolanic reactions.Conclusion : Stabilizers developed from MS and MC can be effectively applied to the stabilization of As and heavy metal-contaminated soil, and are expected to be used as economical and environmentally friendly stabilizers.

Bioinspired surface modification of mussel shells and their application as a biogenic filler in polypropylene composites

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.

From Waste to New Ways: Feasibility of Microwave-Assisted Extraction of Chitin from Green Mussels (Perna Viridis) for Development of TEA-Functionalized CO2 Capture Adsorbent

As the world progresses, environmental problems emerge, such as the rise in global greenhouse gas emissions, specifically carbon dioxide (CO2) and improper waste management. To address these issues, this study aims to extract a natural polymer, chitin, from waste green mussel shells using a novel microwave-assisted extraction method. The extracted chitin was used as a support material for the functionalization of the adsorbent for potential CO2 capture. The process involves demineralization and deproteinization for mussel shells under the influence of a microwave unit. Results show that microwave power level 2 has produced the highest chitin yield (6.40%) among all the power levels. To enhance its CO₂ adsorption capacity, the extracted chitin underwent a sol-gel pre-treatment followed by functionalization with triethanolamine (TEA). Scanning electron microscopy (SEM) revealed a "brick wall-like" or flaky crystal structure with an increased surface roughness, suggesting successful TEA incorporation. Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirmed the presence of amine groups and enhanced thermal stability of the functionalized chitin. These characteristics are essential for CO₂ capture applications. This research demonstrates that waste green mussel shells coupled with microwave-assisted extraction can be a promising route in extracting chitin and its potential application to CO2 capture. Future work will focus on improving the pre-treatment process to produce a more suitable chitin support and optimizing the adsorbent's CO₂ capture capacity.

Utilization of Green Mussel (Perna viridis) as A Lead Metal Pollutant Adorbent in Batik Dye Waste

Lead (Pb) from batik dyeing waste that is thrown into the environment can pollute the environment so it needs processing before being thrown into the environment. The aim of this research is to determine the effect of green mussel shells as an adsorbent with different concentrations on reducing Pb heavy metal contamination in batik dyeing waste and to determine the optimal concentration of green mussel shells to reduce Pb heavy metal contamination in batik dyeing waste. The research method used was experimental with 4 treatments with different concentrations of green mussel shell ash as an adsorbent (0, 10, 20, and 30%). The results of the research showed that a green mussel shell ash concentration of 30% was the best concentration because it was able to reduce Pb levels in batik dyeing waste by 68.52%. Characterization of green mussel shell ash includes average pore radius (10.674 nm), total pore volume (0.005 cc/g), and surface area (0.969 m2/g).

In-Depth Study on Synergic Interactions and Thermo-Kinetic Analysis of (Wheat Straw and Woody Sawdust) Biomass Co-Pyrolysis over Mussel Shell-Derived CaO Catalyst Using Coats–Redfern Method

The behavior of wheat straw biomass (WS), woody sawdust biomass (WB), and their blends during catalytic co-pyrolysis are analyzed in the presence of CaO catalyst, which is obtained from the calcination of mussel shells. Synergy analysis of blends and pure materials is measured by studying the difference between theoretical and experimental values of wt.%/min, (RL%), and (WL%), which correspond to maximum weight loss rate, residue left, and weight loss, respectively. The Coats–Redfern method is utilized for evaluating the thermo-kinetic properties. The chemical reaction order model F1 is the best model that describes the Ea of 60.05 kJ/mol and ∆H, ∆G, and ∆S values of 55.03 kJ/mol, 162.26 kJ/mol, and −0.18 kJ/mol.K, respectively, for the optimum blend 80WS−20WB, reducing the thermo-kinetic properties. Model D3 showed better results for the Ea, ∆H, ∆G, and ∆S for the 5% CaO blend, which certified the viability of co-pyrolysis of WS and WB, while DTG indicated that exothermic and endothermic reactions occur together.

Eumelanin-Enhanced Photothermal Disinfection of Contact Lenses Using a Sustainable Marine Nanoplatform Engineered with Electrospun Nanofibers.

Bacterial keratitis (BK) is a severe eye infection commonly associated with Staphylococcus aureus (S. aureus), posing a significant risk to vision, especially among contact lens wearers. This research introduces a novel smart nanoplatform (deMS@cNF), developed from demineralized mussel shells (deMS) and reinforced with chitin (CT) nanofibrils, specifically designed for portable photothermal disinfection of contact lenses. The nanoplatform leverages the photothermal properties of eumelanin in mussel shells (MS), which, when activated by a simple bike flashlight, rapidly heats to temperatures up to 95°C, effectively destroying bacterial contamination. In vitro tests demonstrate that the nanoplatform is biocompatible and non-toxic, making it suitable for medical applications. This study highlights an innovative approach to converting marine biowaste into a safe, effective, and low-cost portable method for disinfecting contact lenses, showcasing the potential of the deMS@cNF platform for broader antimicrobial applications.

Parasites disrupt a keystone mutualism that underpins the structure, functioning, and resilience of a coastal ecosystem

AbstractParasites can alter the traits or densities of mutualistic partners, potentially destabilizing mutualistic associations that underpin the structure, functioning, and stability of entire ecosystems. Despite the potentially wide‐ranging consequences of such disruptions, no studies have directly manipulated parasite prevalence and/or intensity in a mutualistic partner, nor quantified the resulting community‐level effects. Here, we investigated the effects of a common trematode parasite (Cercaria opaca) on the strength of a keystone facultative mutualism in western Atlantic salt marshes between the foundational marsh cordgrass, Spartina alterniflora, and the ribbed mussel, Geukensia demissa. Cordgrass increases mussel survivorship and growth through shading, while mussels enhance cordgrass growth by producing nutrient‐rich biodeposits. This mutualistic association also creates conditions that enhance biodiversity and ecosystem functioning, and mediates the ability of foundational plants to resist and recover from extreme drought. We used lab and field assays to show how increasing infection with trematode metacercariae negatively influenced mussel biodeposit production, as well as the strength of mussel shells and byssal attachments. By conducting a field manipulation using experimentally infected mussels, we demonstrated that the mutualistic benefits of mussels to cordgrass growth decreased with increasing trematode infection intensity—a pattern likely generated by reduced mussel biodeposition and enhanced mortality. Additionally, increasing parasite loads in mussels led to predictable decreases in the abundances of benthic invertebrates, as well as in key ecosystem characteristics and process rates (i.e., redox potential and sediment accretion). Finally, a survey of five North Carolina salt marshes demonstrated that infection with C. opaca was most common in mussels in areas experiencing cordgrass die‐off due to drought, and that infection intensity decreased with distance from die‐off areas. Because the mussel–cordgrass mutualism underpins marsh ecosystem resilience to drought‐associated die‐off, our results suggest that parasitism may depress recovery from these disturbances. Although this is the first experimental demonstration of parasites indirectly altering community structure and functioning by undermining an ecologically influential mutualism, this type of relationship could be common in nature, given that parasites frequently infect influential mutualists.

Bivalve shell growth from molecular to sclerochronological scale: Environment and intrinsic factors control increment deposition

Biomineralisation of bivalve shells raises questions at the level of genes to the final calcified product. For the first time, gene expression has been studied in association with growth increment deposition in the mussel Mytilus galloprovincialis. A short-term experiment highlighted that biomineralisation genes exhibit a rhythm of expression consistent with the observed tidal increment formation. Long-term mark-recapture experiments were conducted in three Mediterranean environments and revealed that the mussel shells harbour complex incrementation regimes, consisting of daily, tidal and a mixed periodicity of ∼1.7 growth increment.d−1 formed. The latter is likely related to the local tidal regime, although the mussels were continuously submerged and exposed to a small tidal range. The pattern of growth increments shifted from mixed to daily in Mediterranean lagoon, and to tidal at sea, probably linked to biological clocks. Based on our results and the literature, a hypothetical model for mussel shell increment formation in various habitats is proposed.

Synthesis, Characterization, and Antibacterial Activity of Chitosan Derived from Charru Mussel (Mytella charruana) Shells in Baroy, Lanao del Norte, the Philippines

Charru mussel, an invasive species found along the coastal areas of Baroy, Lanao del Norte, the Philippines, is commonly processed into the local delicacy known as “amahong,” with the shells often discarded as waste from this practice. This study aims to extract chitosan through demineralization of charru mussel shells using 1.25 N HCl, deproteinization using 3% NaOH yielding chitin, and deacetylation of chitin using 45% NaOH. The result shows a chitin yield of 21.27 ± 0.98% and a chitosan yield of 11.07% ± 0.66%. ATR-FTIR analysis confirmed the characteristic bands and functional groups associated with chitosan. SEM imaging revealed an amorphous and uneven particle shape, and TGA results exhibited thermal degradation at 550 °C, at which point chitosan breaks down. The synthesized chitosan displayed antibacterial activity at all concentrations (100, 200, and 300 μg/mL) against S. aureus while ineffective against E. coli. This study underscores the untapped potential of charru mussel shells as a source of chitosan, offering valuable insight for waste management.

Epibiont communities on mussels in relation to parasitism and location in the rocky intertidal zone.

The factors shaping host-parasite interactions and epibiont communities in the variable rocky intertidal zone are poorly understood. California mussels, Mytilus californianus, are colonized by endolithic cyanobacterial parasites that erode the host shell. These cyanobacteria become mutualistic under certain abiotic conditions because shell erosion can protect mussels from thermal stress. How parasitic shell erosion affects or is affected by epibiotic microbial communities on mussel shells and the context dependency of these interactions is unknown. We used transplant experiments to characterize assemblages of epibiotic bacteria and endolithic parasites on mussel shells across intertidal elevation gradients. We hypothesized that living mussels, and associated epibacterial communities, could limit colonization and erosion by endolithic cyanobacteria compared with empty mussel shells. We hypothesized that shell erosion would be associated with compositional shifts in the epibacterial community and tidal elevation. We found that living mussels experienced less shell erosion than empty shells, demonstrating potential biotic regulation of endolithic parasites. Increased shell erosion was not associated with a distinct epibacterial community and was decoupled from the relative abundance of putatively endolithic taxa. Our findings suggest that epibacterial community structure is not directly impacted by the dynamic symbiosis between endolithic cyanobacteria and mussels throughout the rocky intertidal zone.

Paving the Way for Sustainability: A Study on Porous Asphalt Mixtures Reinforced with LDPE Plastic Waste and Freshwater Mussel (Pilsbryoconcha Exilis) Shell Filler

This study aimed to explore the impact of different fillers, namely conventional (stone ash) and alternative (mussel shell powder), along with varying percentages of Low-Density Polyethylene (LDPE) additives, on the performance of porous asphalt mixtures. Asphalt mixtures' Marshall Stability and Flow were examined with LDPE percentages of 0%, 2%, 4%, and 6%. Results highlighted that the choice of filler and LDPE content significantly influences the mixture's stability and flow. A shift from 100% stone ash to 50% mussel shell powder resulted in a slight decrease in stability for 0% and 2% LDPE. In contrast, the stability was notably higher for 4% and 6% LDPE, including the alternative filler. Mixtures with 100% stone ash exhibited increased flow values with rising LDPE concentrations, while mixtures with 100% mussel shell powder showed an opposite trend. Furthermore, mixtures containing mussel powder generally had higher flow values than those with stone ash at similar LDPE percentages. The study underscores the intricate relationship between filler types and LDPE additives in influencing the properties of asphalt mixtures. These findings pave the way for the potential use of alternative fillers in asphalt mixtures, emphasizing the importance of understanding material interactions for optimal pavement design.

Vital effects and the fractionation of rare earth elements and yttrium during uptake by and transfer within freshwater bivalves and their shells

Mussels are commonly used as bioarchives in environmental monitoring, yet the impact of vital effects on the trace element or isotope ratios used as biogeochemical proxies is often only ill constrained. A prime example of such trace elements are the Rare Earth elements and Yttrium (REY) which have become (micro)contaminants in freshwater systems worldwide. We here report on the distribution of REY in different soft tissues and in the shells of freshwater bivalve A. anatina, commonly known as “duck mussel”, from the Danube River in Hungary and the Vistula River in Poland. Both rivers are contaminated with anthropogenic Gd from contrast agents used in magnetic resonance imaging (MRI). Regardless of the mussels' origin, all of their compartments show very similar shale-normalised REY patterns. None of the samples show any anthropogenic Gd anomaly, implying that in freshwater anthropogenic Gd from MRI contrast agents is either not bioavailable or that REY from ambient river water are insignificant for the REY budget of freshwater mussels. Compared to ambient water, the bivalves bioaccumulate the REY with preferential uptake of Ce and of light REY over heavy REY. However, REY concentrations in mussels are similar to or lower than those in their potential food source, with minor fractionation along the REY series besides slight preferential uptake of La and Y. Comparison of shells and tissues reveals the systematic oxidative decoupling of Ce from its REY neighbours, probably due to the presence of Ce(IV) solution-complexes in the mussels' extrapallial fluid. Despite possible REY fractionation during their initial uptake, vital effects do not impose any major control on REY fractionation during REY transfer within the mussels or during formation of their shells. Mussel shells may, therefore, conveniently be used for environmental monitoring of REY without major disturbance from vital effects.

Microwave-assisted hydrothermal synthesis of carbonated apatite with calcium and phosphate resources derived from green mussel shell and bovine bone wastes

Resources recovery of calcium and phosphates from respective green mussel shells and bovine bones by calcination and chemically extracting are viable precursors for carbonate-rich apatite biomedical material applications. Because of their high osteoconductivity, carbonate-rich apatite bioceramics are being studied intensively for synthetic bone transplants. In the study, powder processing routes of calcination and following chemical dissolution in MgCl2 and H2SO4 were each for recovering calcium of mussel shells and phosphate of bovine bones yielding a crystal-forming solution feedstock for use in microwave-irradiated synthesis. FTIR spectra and XRD patterns validated the crystallinity and phase identification for as-synthesized powders. As a result, the presence of CO3, PO43-, and OH- bands in carbonate-calcium phosphate complexes were present in FTIR spectra. According to the XRD Rietveld method, the as-synthesized powder product contained brushite, carbonated hydroxyapatite (CHA), calcite, and gypsum. The recoverable CHA crystallites' size was 40 nm. This present study demonstrated that microwave irradiation synthesis of CHA powder with calcium and phosphates derived from mussel shells and bovine bones is the potential to yield a large amount of CHA for bioceramics and would aid in the design of a powder processing step for preparing the CHA powder precursor in biomedical applications.