Experimental Investigation on the Effectiveness of Flocculant in Sediment Plumes

It is said that the economic growth of a country depends on its mineral wealth. With the global scenario of increasing demand for metals and minerals, countries are in search of alternate sources of metals for the future. Deep-sea mining has emerged as a potential source of rare earth elements, metals, and minerals, which are essential components for the modern technological industry. Even though deep-sea mining has gained global attention as a potential source of strategic metals, it also poses significant environmental concerns. The generation of sediment plumes during deep-sea mining is one of the most pressing environmental issues associated with this activity. These plumes elevate the turbidity of ocean water and have a longer settling time, which may vary from a few to several years leading to several ecological damages. Hence, more precise, direction-focused studies must be conducted before moving forward with deep-sea mining to mitigate or minimize the environmental damage. Flocculation could be a suitable option to reduce the impact of the turbidity flow of the sea-sediments generated by deep-sea mining. This study investigates the flocculation efficiency of polyacrylamide (PAM) on the turbidity reduction of bentonite suspensions in synthetic sea water. The addition of PAM in the suspension was found to accelerate the settling speed of suspended particles by the formation of flocs resulting in low turbidities, and this method can be adopted to reduce impacts of deep-sea mining in the marine ecosystem.