Introduction

The eggshell is usually the part of the egg that is unused and is thrown out. Of course, this is justified as eggs are usually taken to be consumed or as a part of a greater recipe. The eggshell itself is usually thrown out due to its inconsumable nature. But actually, this pored layer of calcium carbonate may in fact hold some fascinating secrets and potential.

Proteins extracted from nature are usually impure and contaminated with natural contaminants, and thus must be cleaned and treated before it is able to be utilized. This usually requires dialysis using a semi-permeable membrane to spontaneously purify the item.

This investigation will look further into the chemical anatomy of the chicken eggshell and its potential usage as a readily available dialysis membrane for various uses.

Egg shell waste statistic

Eggshell waste is typically produced in places such as egg processing plants, chicken hatcheries, and other egg-producing locations. Global egg production in 2018 was approximately 78 million metric tons and residual eggshell waste was approximately 8.58 million metric tons, many of which are thrown away into landfills. This may lead to environmental concerns in the future.

Dialysis Membrane Types out there and Cost

1.  49mm (MD77) Dialysis Membrane. Cost: $572.00 per roll.

2. Cellulose membrane dialysis tubing avg flat width 76mm. Cost: $347.63.

Dialysis membranes, or dialysis tubings, are semi-permeable membranes (could be a film or a tubing). This is very useful in the process of dialysis: defined as the separation of particles in an aqueous environment, based on the ability to pass through a semipermeable membrane; for example: protein purification.

Egg Shell Processing

Extracting the eggshell from the egg itself requires the creation of a small opening on the top of the egg to allow for the innards to be extracted, leaving an empty shell, which can then be washed to be cleaned. The chicken eggshell processing used in the experiment involves the double-displacement reaction between the dominant calcium carbonate eggshell and a 15% aqueous Sodium Hydroxide (NaOH) solution. This basic solution also helps with the melting of the protein membrane leftover inside the eggshell as it is undesirable for this purpose. This reaction is done for a set amount of time under 100  °C (set with a hot plate) to maximize reaction rate. The sodium hydroxide solution aids in the dispersed & constant modification to the eggshell pores.

Conclusion and Future Outlook

As shown by the ink demonstration, the eggshell is indeed something with potential dialysis capabilities with the proper chemical modifications. It’s permeability is indeed something which could be proven to be useful to understand and may potentially have further applications. The next step would be to analyze the eggshell effectiveness in an actual dialysis process. More specifically, its effectiveness in the purification of silk fibroins in place of industrial dialysis bags. If this is shown to be successful, then it may revolutionize protein purification and show how expensive dialysis bags might be unnecessary for the process. Further investigations will also be made on how to reverse engineer the biological production of the egg shell structure from the calcium carbonate powders into other, more practical, shapes which may enhance its effectiveness in the dialysis process.