The Potential Use of Oyster Shell Waste in New Value-Added By-Product

Thamyres H Silva,Bruno Henriques,Filipe S Silva,Márcio C Fredel,Joana Mesquita-Guimarães

doi:10.3390/resources8010013

Abstract

Calcium carbonate is one of the most used raw materials in various industries, such as construction materials, food supplement, pharmaceutics, animal feed, plastic production, and others. Calcium carbonate can derive from marine wastes, like crustaceans and bivalve’s shells. The worldwide demand for new sources of food has increased exponentially, and following that tendency, the mariculture—especially the oyster culture—has been increasingly resorting to farming techniques. In 2016, 438 billion tons of oysters were produced. The majority of the shells were unduly discarded, presenting a public health problem. This article offers a solution based on the reuse and recycling of oyster shell residues in the production region of Florianópolis, SC, Brazil. The presented solution is an oyster shell by-product developed by a local company which produces artificial stone. The main component of the artificial stone is a composite material made of oyster shells incorporated in a polymeric resin. The mechanical properties, such as its flexural strength, hardness, Weibull modulus, and fracture analysis, were held in the artificial stone. The mechanical results of the new artificial stone were compared with other natural stones, such as granite and marble, and other commercial artificial stones. This material owns suitable mechanical properties for table tops and workbenches. Using this product as an artificial stone represents an innovation in the development of a new product and adds commercial value to local waste. This product is an excellent example of a circular economy for local producers who care about the environment, and it encourages the reduction of extraction of natural stone, such as granite and marble.

Highlights

With the exponential population growth in the 20th century and the demand for increased food production, the previous typical handcraft-based sectors began to focus their investment in the industrialisation of food production
After the oyster shells were cleaned and powdered by grinding, they were mixed with unsaturated polyester resin for the processing of the body part of the countertop, named as artificial stone
It was possible to analyse the quality of a product produced with oyster shell waste

Summary

Introduction

With the exponential population growth in the 20th century and the demand for increased food production, the previous typical handcraft-based sectors began to focus their investment in the industrialisation of food production. Aquaculture has experienced considerable growth on the global scale, and mariculture is one of the most significant industries [1,2,3]. Mariculture is related to the production of aquatic organisms in marine waters, which involves the cultivation (via farming techniques) of sea fish, crustaceans, and molluscs [4]. Seafood production sustains a part of the global economy, where the commercialisation of molluscs is in second place on a worldwide level, e.g.,. “with 16.1 million tons of molluscs (19 billion USD) produced annually”. According to the Food and Agriculture Organization of the United Nations (FAO), the value of the global production of this species for the year 2016 was 3.69 billion USD [5,6].

Objectives

Methods

Results

Conclusion