Valorization of Eggshell Biowaste for Sustainable Environmental Remediation

Abstract

The management of large amounts of eggshell waste annually produced in the world is problematic as generally this material is only disposed at landfills with odor production and microbial growth. On the contrary, significant environmental and economic advantages could be obtained transforming this biowaste into new value-added products. Eggshell biowaste was the starting material for the synthesis of hydroxyapatite by a simple and sustainable procedure and applied for the removal of Co2+ from aqueous solutions. The effects of contact time and initial metal concentration were investigated in batch experiments. Eggshell-based hydroxyapatite (ESHAP) before and after Co2+ removal was characterized by X-ray diffraction and scanning electron microscopy. The process was rapid and reached equilibrium within 80 min. The removal efficiency was in the range 70–80% which is generally higher than other waste-derived adsorbents. Adsorption of Co2+ on the surface of ESHAP particles and ion exchange with Ca2+ resulting in the formation of a Co-phosphate are the main mechanisms of the metal removal. The conversion of eggshell waste to a low-cost adsorbent for the treatment of metal contaminated waters could contribute to a more sustainable and effective management of this biowaste.

Improving the mechanical behavior of reduced graphene oxide/hydroxyapatite nanocomposites using gas injection into powders synthesis autoclave

“…The chemical formula of this ceramic is Ca 10 (PO 4 ) 6 (OH) 2 , in which the ratio of calcium to phosphate is 1.67, and the crystalline structure of HA is similar to the inorganic part of the human skeletal system. HA has a variety of uses other than orthopedic applications [2][3][4][5] . In recent years, additional researches have been done on calcium phosphates, which indicate the specific value of these ceramic structures [6][7][8][9] .…”

Biobutanol production from pruned vine shoots

“…However, the cost could be reduced up to 56% or 66% when using MFM as fermentation broth supplemented with CaCO3 or eggshell, respectively (Supplementary Table 20). Therefore, this approach could be considered in future scalable assays in order to evaluate its potential in reducing industrial operational costs associated with the components of the fermentation broth, but also in environmental terms, using eggshells as a valuable material in ABE fermentation processes, thus fulfilling the European environmental requirements for this waste [51].…”

Mechanism and Isotherm Modeling of Effective Adsorption of Malachite Green as Endocrine Disruptive Dye using Acid Functionalized Maize Cob (AFMC)

“…Estimation of the quantity adsorbed and percentage removal efficiency was done using Eq. 4 and 5 [37][38][39] : (4)…”