Green solutions to valorize marine dredged sediments as an anthropogenic geomaterial

Marine dredged sediments, MDS, generated in millions of tonnes, are usually dispersive, contaminated, and exhibit (engineering) characteristics that make them unfit as a resource for infrastructure development. To overcome these problems, researchers have resorted to dewatering MDS by employing flocculants and coagulants, vacuum preloading & filter press, and amendment with conventional cementitious materials, CCMs such as lime, cement, and industrial by-products (viz., steel slag, incinerated ashes, etc.). With this in view, the pros and cons of the utilization of CCMs to stabilize MDS (read as MDS-CCMs matrix) are discussed. In this context, the conceptualization of the mechanism(s) that hampers the development of strength in the MDS-CCMs matrix due to the presence of salinity and degradation of its inherent organic matter is highlighted. Subsequently, the hypothesis influencing their overall engineering performance and its comparison with the conventional concrete matrix due to the degradation is proposed. To overcome these issues, the amendment of MDS with organic matter rich waste materials (viz., landfill-mined soil-like fractions, an end product of landfill biomining activities) appears to be a promising way forward due to its ability of formation of organo-mineral metallic complexes and high buffering capacity. Though this strategy professes Green Solutions for Valorization of Dredged Sediments, GreSValDS, its feasibility and efficacy vis-à-vis the above-mentioned techniques must be established. It is believed that GreSValDS will overcome the issues associated with the MDS-CCMs matrix and also be a boon for integration of the industrial and municipal waste, leading to sustainable development and circular economy.