A bibliometric review of river sediment pollution assessment for 2004-2023 using PRISMA guidelines

Abstract

The rapid expansion of industry and the intensified use of fertilizers and pesticides have led to a substantial increase in pollutants entering rivers, causing elevated nutrient runoff that triggers eutrophication and harms aquatic life. In major natural aquatic systems around the world, such as those in downstream or agricultural regions, pollution primarily enters rivers through various nonpoint sources. Meanwhile, human-made impervious surfaces and heavily engineered waterways contribute point source pollution to the sediment systems within river basins. These systems are under increasing chemical stress from various contaminants, resulting in pollution levels that negatively affect both human health and ecosystems. Before evaluating different remediation technologies in detail and comparing the efficiency of different analytical methods, it is essential, to first prioritize a comprehensive assessment of the current state of emerging pollutants, focusing on their presence and impact on river sediments. This thorough evaluation is crucial for understanding the environmental impact, to identify pollutants that harm aquatic life, disrupting ecosystems, reducing biodiversity and providing valuable insights to enhance sediment management strategies. In the present study, a systematic approach has been applied for the literature review, starting with selecting relevant keywords and finding the most important articles through a screening process for 20 years spanning from 2004 to 2023 on River Sediment Pollution Assessments (RSPA), with the help of the search engine SCOPUS. This review mainly synthesizes research on various emerging sources of pollution that face river catchment mostly nowadays in river sediments. The 10 important river sediment contaminating parameter has been selected for this study namely, Polychlorinated Biphenyls (PCBs), Freely Dissolved Polychlorinated Biphenyls (FDPCBs), Total Suspended Solids (TSS), Particulate Organic Matter (POM), Total Organic Carbon (TOC), Total Organic Nitrogen (TON), Total Organic Phosphorus (TOP), Heavy Metal Concentration (HevMetC), Pesticide Concentration (PestC) and Ecotoxicity Test (EcoT). Out of 509 journal papers screened from SCOPUS, after thorough evaluation, 169 are found very relevant for inclusion in this study. This study provides a comprehensive assessment of sediment sources, pathways, and storage within river systems, with a focus on sediment management and the effects of local and global environmental changes. Contaminated sediments are a primary concern, as they often transport pollutants, complicating management strategies. The study involves a comprehensive evaluation through a three-stage sequential process: bibliometric examination, scientometric investigation, and qualitative valuation of such target contaminants as keywords, following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyse) guidelines. This study systematically evaluates the current research landscape related to (RSPA) using the VOSviewer tool. This is followed by a quantitative analysis of the selected literatures, focusing on the most productive journals, commonly used keywords, influential authors, highly cited articles, and the countries most involved in the field. Key insights from the sample led to a qualitative evaluation, where past and current research trends are identified and discussed. The methods for the detection of pollutants have also been analysed along with the yearwise analysis of the published papers giving the in-depth current trend of the research regarding the RSPA. Finally, gaps in the past researches are highlighted, leading to recommendations for future studies with analytical directions. This bibliometric review aims to guide both new and experienced researchers working in this emergent field of RSPА.