TABLE OF CONTENTS

Title Page    –         –         –         –         –         –         –         –         –         i

Certification           –         –         –         –         –         –         –         –         ii

Dedication   –         –         –         –         –         –         –         –         –         iii

Acknowledgments –         –         –         –         –         –         –         –         iv-v

Table of Contents  –         –         –         –         –         –         –         –         vi-vii

CHAPTER ONE: INTRODUCTION          –         –         –         –         1-5

CHAPTER TWO: LITERATURE REVIEW        –         –         –         6

2.1     Morphology of Shelled Benthos (Periwinkle)          –         –         6-7

2.1.2 Life cycle      –         –         –         –         –         –         –         –         7-8

2.1.3 Feeding Habit         –         –         –         –         –         –         –         8

2.1.4 Distribution   –         –         –         –         –         –         –         –         9

2.2     Factors Affecting its Existence –         –         –         –         –         9

2.1 Temperature     –         –         –         –         –         –         –         –         9-10

2.2.2  Salinity       –         –         –         –         –         –         –         –         10

2.2.3  Predation     –         –         –         –         –         –         –         –         10-11

2.2.4  Exposure     –         –         –         –         –         –         –         –         11-12

2.2.5  Food of Periwinkles         –         –         –         –         –         –         12-14

2.2.6  Remedies     –         –         –         –         –         –         –         –          1416

CHAPTER THREE: ECOLOGICAL IMPORTANCE OF THE SHELL

3.1.1 Horticulture  –         –         –         –         –         –         –         –         17

3.1.2 Tools  –         –         –         –         –         –         –         –         –         17-18

3.1.3 Currency       –         –         –         –         –         –         –         –         18

3.1.4 Art      –         –         –         –         –         –         –         –         –         18-19

3.1.5 Poultry Feed –         –         –         –         –         –         –         –         19

3.1.6 Building Materials and Construction    –         –         –         –         20

3.1.7 Bio-Medical Application   –         –         –         –         –         –         20-21

CHAPTER FOUR: SUMMARY AND CONCLUSION

4.1     Summary     –         –         –         –         –         –         –         –         22-23

4.2     Conclusion  –         –         –         –         –         –         –         –         23

             REFERENCES

CHAPTER ONE: INTRODUCTION

The reuse and recycling of wastes have proven to be an efficient method of addressing the waste disposal problem in recent times (Ahmed et al., 2010). Waste generation increases with climate change, population growth, and economic development (Gichamo et al., 2019). Waste reuse help in reducing waste generation, lowers the rate of depletion of natural resources, and maintains ecological balance. Most of these wastes, primarily because of industrialization, become an environmental menace resulting in pollution if not properly disposed. Pollution prevention and control involve preventing or removing harmful materials from streams or effluents before disposal to the environment (USEPA, 2012). Pollution prevention amounts to reducing the quantity of waste required to be controlled, treated, or disposed. It is a process that helps protect the environment by conserving and protecting natural resources, which ultimately translates to a reduction in both financial costs associated with waste management and environmental cost related to public health and the environment.

The booming seafood industry has seen an increase in the number of waste shells generated globally annually. For instance, there are about ten million tonnes of waste shells generated in China (Mokh et al., 2018), nearly two million tonnes in Japan (Sawai, 2011), and two hundred and five thousand tonnes in France (Nguyen et al., 2017). Converting these wastes into valuable products can help reduce the number of shell wastes disposed into the environment.

Also, the public health risk associated with the indiscriminate disposal of the shells will be reduced considerably. The usability of these shells lies in their availability, low cost, and high amounts of calcium carbonate (Barros et al., 2009) and chitin (Maruthiah et al., 2017), which can be extracted and used to produce various products.

The reuse capacity of these shells can be expanded by utilizing them for the development of value-added products. In that sense, the utilization of shell waste is a valuable strategy for sustainable resource management, reduced waste storage (Jovic et al., 2019), reduced material costs, and wealth creation.

Several authors have reported the various applications of waste shells (egg, oysters, snail, cockle, mussel, clam, and scallop shells). These shells have been suitable in engineering, medicine, pollution control, agriculture, and other applications of human endeavors. In building and It construction, studies have revealed that the similarities in the composition (especially calcium oxide-CaO) of the waste shells and limestone is one of the significant reasons they could be used as substitutes for limestone (Safi et al., 2015). The overdependence on naturally occurring limestone, granite, and other naturally occurring raw materials for building and construction activities, has led to an increase in the cost of these materials. In the coastal regions of the Niger Delta, for instance, a 50kg bag of cement and a tonne of granite chippings costs about N 4,000 ($ 9.76) and N10, 500 ($ 25.61), respectively. The exploitation of these natural resources has often led to the degradation of the environment caused mainly by mining activities. Groundwater, air, and land pollution (which are health risks to humans) are some of the consequences of mining activities (Sottanzadeh et al., 2018). Recent studies have shown that using crushed waste shells as aggregates in concretes does not improve its performance significantly. The concrete’s durability, compactness, and compressive strength have often declined with time (Nguyen, 2017; Wang, 2019).

Onoda and Nakanishi, (2012) deployed calcium phosphate made from oyster shells to remove lanthanum metals from wastewater efficiently. In a similar study, Naik et al., (2016) investigated the removal of heavy metals (Mercury, Cadmium, Arsenic, Lead, Nickel) using mainly bivalve, crab, and oyster shells powder. They concluded that a heavy several other works utilizing waste shells like Mollusca shells (Weerasooriyagedra and Kumar, 2018) and Mussel shells (Jone et al., 2011) in removing heavy metals from wastewater have been reported. Waste shells have also been successfully used as bio-filters in water quality improvement. Zukri et al., (2018) used calcinated mussel shells to solve eutrophication in lake water in their work. They established an uptake efficiency of 31.28% and 21.74% of ammonium and phosphorous oxide ions, respectively, when a 7.5g of mussel shell was used. Oyster shells have been used as aerated biological filters for municipal wastewater treatment. The oyster shells effectively treated the wastewater with a chemical oxygen demand removal of 85.1%, ammonia nitrogen removal of 98.1%, and total phosphorous removal of up to 90.6%. A similar study has been conducted using oyster shells as a bio-filter for nitrogen uptake in domestic water purification (Shih and Chang, 2015).