Eggshell

An eggshell is the outer covering of a hard-shelled egg and of some forms of eggs with soft outer cots.

An eggshell is the outer covering of a hard-shelled egg and of some forms of eggs with soft outer cots. ===Environmental issues=== The US food industry generates 150,000 tons of shell waste per year. The disposal methods for waste eggshells are 26.6% as fertilizer, 21.1% as animal feed ingredients, 26.3% discarded in municipal dumps, and 15.8% used in other ways. Some landfills do not take the waste because the shells and the attached membrane attract vermin. When unseparated, the calcium carbonate eggshell and protein-rich membrane are useless. Recent inventions have allowed for the egg cracking industry to separate the eggshell from the eggshell membrane. The eggshell is mostly made up of calcium carbonate and the membrane is valuable protein. When separated both products have an array of uses. ==Uses== ===Chemicals=== Because of their calcium carbonate content, waste eggshells have the potential to be used as raw material in the production of lime. ===Pharmaceuticals=== The rich calcium carbonate shell has been used in the application for calcium deficiency therapies in humans and animals. A single eggshell has a mass of six grams which yields around 2200 mg of calcium (6000 mg × 0.95 × 0.4= 2280 mg). Eggshell particles are used in toothpaste as an anti-tartar agent. Powdered eggshells have been used for bone mineralization and growth. ===Food=== Recent applications of eggshells include producing calcium lactate as a firming agent, a flavor enhancer, a leavening agent, a nutrient supplement, a stabilizer, and thickener. Eggshells are also used as a calcium supplement in orange juice. ===Other=== Eggshells have been incorporated into fertilizers as a soil conditioner. They have also been used as a supplement to animal feed. More recently the egg calcium carbonate particles have been used as coating pigments for ink-jet printing. Powdered eggshells are also used in making paper pulp. Recently eggshell waste has been used as a low cost catalyst for biodiesel production. Chicken eggshells have been additionally incorporated as a calcium precursor into the synthesis of calcium-based metal-organic frameworks (MOFs). Recently, researchers have utilized chicken eggshells as a biofiller with a conducting polymer to enhance its sensing properties. Typically, eggshells were used as biofiller in polyaniline matrix to detect ammonia gas. The optimum ratio between eggshells and polyaniline could enhance this sensor measurement. Ostrich eggshells have been used by Sub Saharan hunter-gathers. For instance the Juǀʼhoansi have used them to carry water and create beads from them. ==Further reading==

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