Green/sustainable strategy for the enhanced thermal destruction of abandoned, lost, discarded fishing gears (ALDFGs)

Abstract

One of the most prevalent wastes in the ocean is abandoned, lost, and discarded fishing gears (ALDFGs), which poses a potential mortality risk to all marine creatures. Considering the complex compositional nature and non-biodegradability, the thermal destruction of ALDFGs could offer a strategic measure to abate all hazardous potentials triggered by ALDFGs. More specifically, it is of paramount significance to completely break down ALDFGs into the smallest molecules such as syngas (H2 and CO). Also, the conversion of ALDFGs into the smallest molecular units offer an innovative means for neutralizing toxic chemicals (that are inevitably generated from thermochemical process) given that toxicity is proportional to the degree of aromaticity/substitution of heteroatoms (S, N, Cl, etc.). To enhance the overall thermal destruction efficiency, carbon dioxide (CO2) was used as a raw material. CO2 was employed as the renewable resource for carbon and oxygen to enhance syngas formation. In detail, this study experimentally proved the mechanistic contribution of CO2 to shifting carbon in wax-like/liquid hydrocarbons (HCs) into CO. The formation of CO from catalytic thermal destruction under CO2 condition was 64 times more than from thermal destruction without catalyst under CO2. Before the thermal destruction, the plastic types of ALDFGs (fishing rope (PP/PE), line (nylon 6), and net (PE)) were determined. Also, FT-IR analysis revealed that all plastics components in ALDFGs were partially oxidized.