Real-World Application of Nanochitosan in Refinery-Produced Water Treatment: A Case Study

The aquatic sector plays a vital role in providing the nutrition and socio-economic development of all countries. The fish processing industries generate huge quantities of solid waste in the form of crustacean shells, squid scales, prawns, and shrimp, which are thrown out after each processing stage. Dumping of shellfish waste is a major environmental issue in seafood industries due to the lack of an efficient, economical, and eco-friendly disposal methods for stainable solid waste management. Crustacean shells contain a considerable amount of biopolymers, which are natural polymers and abundantly available from their natural resources. Chitin and chitosan are the two important natural biopolymers found in crab shells, and these polymers are widely employed in several applications due to their excellent bio-compatibility and non-toxicity, and structural properties make them suitable for water treatment, biopharmaceutical, and drug delivery applications. This chapter focuses on the synthesis of nanochitosan from crab shells and its characterization using various techniques and also assesses their effectiveness in wastewater treatment. Particular emphasis is given to the working principle of various characterization tools like X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR) spectroscopic analyses, the microstructural characteristics, surface morphology, and elemental composition of the synthesized nanochitosan are examined through scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS). Thermal properties are identified with the support of Thermo Gravimetric Analysis (TGA) and X-Ray Fluorescence (XRF). The application of chitosan in the treatment of oil refinery wastewater by varying the processing conditions and the optimization of best processing conditions were explained in this chapter. This research project is aligned with the national priorities of Oman, OmanVision 2040, and United Nations Sustainable Development Goals (UNSDG -2030, Goal 14 – Life Under Water).