Metals In River Systems Research Articles

Lead levels and abundance of microplastics in surface water and sediment along a rural–urban river gradient

Microplastics are commonly found in aquatic ecosystems and can pose environmental threats to aquatic organisms. While the threats of microplastic ubiquity are recognized, few studies have concomitantly quantified microplastic abundance and heavy metals along a rural–urban river continuum. In the current study, we studied changes in microplastics and heavy metals (using lead as a proxy) by collecting sediment and water samples along a rural–urban river over two seasons (temperate spring and summer) and across five sites in a North American River. Our results revealed that microplastics decreased in a downstream direction in surface water but did not change predictably in sediment samples collected along the river continuum. Regarding the relationship between microplastic abundance and lead concentrations, we found a positive relationship between microplastics in sediment samples and lead concentrations. Contrariwise, we found no discernible correlation between microplastics in surface water and lead concentrations along the river continuum. Given the presence of microplastics at every site and moderate lead pollution documented in the Wolf River, our results provide baseline data that can aid in the concurrent assessment of microplastics and heavy metals in river systems. These findings can inform environmental managers in planning pollution management strategies for waterways flowing through rural–urban areas.

Human health risk assessment of heavy metal and pathogenic contamination in surface water of the Punnakayal estuary, South India

Variation in levels of toxic heavy metals in river system during the COVID-19 pandemic lockdown might potentially assist in development of a public health risk mitigation system associated with the water consumption. The water quality of Punnakayal estuary in the Thamirabarani River system from the south India, a vital source of water for drinking and domestic purposes, industrial usage, and irrigation was assessed here. A comparitive assessment of physico-chemical variables (pH, EC, TDS, DO, BOD, turbidity and NO3), microbiological parameters (total coliform bacteria, fecal coliform bacteria, fecal streptococci and escherichia coli) and toxic metals (As, Cr, Fe, Cu, Zn, Cd, and Pb) suggested a decrease of 20% in the contaminant ratio during the lockdown period in comparison to the pre-lockdown period. The Health risk assessment models (HQ, HI, and TCR) highlighted carcinogenic and non-carcinogenic hazards for both children and adults through the ingestion and dermal adsorption exposures. The HI values for both As and Cr exceeded the acceptable limit (>1) during the lockdown period, but the potential risk for children and adults remained low in compaisio with the pre-lockdown period. Our results suggested that the Thamirabarani River system remained hostile to human health even during the lockdown period, and it requires regular monitoring through a volunteer water quality committee with private and government participations.

A New Multibranch Model for Metals in River Systems: Impacts and Control of Tannery Wastes in Bangladesh

A new multibranch Integrated Catchment (INCA) model INCA-Metals has been developed to simulate the impact of tannery discharges on river systems. The model accounts for the key chemical reaction kinetic processes operating as well as sedimentation, resuspension, dilution, mixing and redistribution of pollutants in rivers downstream of tannery discharge points and for mine discharges or acid rock drainage sites. The model is dynamic and simulates the daily behaviour of hydrology and eight metals, including cadmium, mercury, copper, zinc, lead, arsenic, manganese and chromium, as well as cyanide and ammonia. The model is semi-distributed and can simulate catchments, tributaries and instream river behaviour. The model can also account for diffuse pollution from rural runoff as well as point sources from effluent and trade discharges. The model has been applied to the new Savar tannery complex on the Dhaleshwari River system in Bangladesh to assess the impacts on pollution levels in the river system and to evaluate a set of treatment scenarios for pollution control, particularly in the dry season. It is shown that the new effluent treatment plant at Savar needs to significantly improve its operation and treatment capability in order to alleviate metal pollution in the downstream Dhaleshwari River System and also protect the Meghna River System that falls in the Bay of Bengal.

The impact of anthropogenic organic and inorganic pollutants on the Hasdeo River Water Quality in Korba Region, Chhattisgarh, India.

In the name of development, industries discharge their wastewater, which contains different Metallic species and massive organic load into the next-door river system. In this study, we assess the impact of organic and inorganic contaminations on Hasdeo River at Korba region, which is fifth critically polluted city in India. Hear, a new approach for water quality indexing like Water quality index (WQI), Heavy metal pollution index (HPI) and metal index (MI) has been proposed to represent pollution due to heavy metals in river system. The sample's pollution parameters and heavy metals contamination is exceed from BIS or WHO standards of drinking water (all p<0.05). WQI shows that the entire water samples are not suitable for drinking and aquatic life but they are safe only for irrigation. HPI and MI calculation revels that more than 95% sampling sites are critically polluted with heavy metals. Thus, a high level of industrialization deterioration of river water quality is recorded for adequate action.

Probabilistic health risk assessment of heavy metals at wastewater discharge points within the Vaal River Basin, South Africa.

Recently in South Africa, wastewater treatment plants (WWTP) have come under scrutiny because of increased reports of their ineffectiveness to treat wastewater adequately. This study focused on assessing potential health risks for humans exposed to concentrations of heavy metals in river systems that receive effluents from wastewater treatment plants in the Maluti-a-Phofung municipality. Untreated influents and treated effluents from two plants, one in the town of Phuthaditjhaba, the other in the town of Harrismith, were analysed for heavy metals. Water samples were also collected from the Elands and the Wilge Rivers, which receive effluents from the treatment plants in Phuthaditjhaba and Harrismith, respectively. All samples were analysed for heavy metals; Iron (Fe), Magnesium (Mg), Manganese (Mn), Zinc (Zn), Copper (Cu), Chromium (Cr), Nickel (Ni), Lead (Pb), Cobalt (Co), Arsenic (As), Cadmium (Cd) using Inductively Coupled Plasma Mass Spectrometry. The probabilistic human health risk was estimated using the Total Hazard quotient and Monte Carlo techniques. The results showed that there was no significant difference between treated and untreated wastewater (P>0.05) in the concentration of heavy metals for both wastewater treatment plants using the student T-test. This indicated the inability of both treatment plants to remove metal contaminants adequately. Projections of non-cancer risk for metals in river water samples indicated a high potential for non-cancer risk for humans upon exposure via ingestion, with Arsenic being a significant contributor to overall risk. The results of this study underscore the need for improved wastewater treatment facilities in this region in order to ensure ecosystem integrity and public health safety.

Model simulation of heavy metals in river systems: Case study the Negro river basin

This work describes a water quality model for heavy metals simulation in river systems. The proposed strategy comprises an 1D modeling approach with an ADZ-QUASAR extension to represent the behavior of heavy metals. This methodology seeks to strengthen their predictive capability based on the integration of variables which play an important role in the adsorption and desorption of these particles. The methodology was implemented in a reach of the Negro river (eastern side of Antioquia, Colombia), using Chromium, Copper and Nickel as heavy metals, because these are the heavy metals representative of the currents in the study area. Results are showing, with some degree of uncertainty, the capacity of the methodology to predict the behavior of environmental interesting substances, which makes it an important management tool.

The natural and human structuring of rivers and other geomorphological systems: A tribute to William L. Graf

This special issue honors the contributions of William L. Graf to geomorphology and river science. A hallmark of Will's work over the course of his career has been a focus on the natural and human structuring of river systems. More broadly, Will has been an innovator and leader who has shaped the way in which geomorphologists conduct research. Through his work, he has made fundamental contributions to basic fluvial theory, to the understanding of human impacts on river systems, and to policy-relevant science. He has demonstrated by example how to pursue policy-relevant science and to participate in science-based policy formulation. His contributions to river science can be classified into several themes: (1) the hydrology and geomorphology of suburban drainage systems, (2) riparian vegetation and river systems, (3) the spatial structure and dynamics of incised channels, (4) the dynamics of dryland river systems, (5) heavy metals in river systems, (6) dams and dam removal, and (7) water and public policy. The papers in this special issue reflect many aspects of these themes and address topics related to (1) the understanding of rivers and other geomorphic systems in the midst of dynamic physical change, (2) human influences on geomorphic processes, (3) the intersection of geomorphology and public policy, and (4) the fusion of geomorphic analysis and GIScience.

The role of fluvial geomorphic processes in the dispersal of heavy metals from mine sites

It is not uncommon for more than 90% of the total metal load in rivers to be transported in the solid phase, either sorbed onto particle surfaces and coatings, or incorporated into mineral grains. Fluvial geomorphic processes are therefore of fundamental importance in the transport and fate of heavy metals derived from mine sites. In this paper, the role of physical processes in the dispersal of heavy metals in river systems are reviewed for channels that have (1) remained relatively unchanged in terms of process and form following the introduction of mine wastes, and (2) exhibited a significant metamorphosis in channel form in response to the influx of mining and milling debris. In general, all processes responsible for the variations in metal concentrations within sediments moving through stable channels also operate in channels undergoing metamorphosis. However, downstream, lateral, and vertical patterns in metal values tend to be more complex where channel transformations have occurred. This complexity results, in part, because temporal and spatial changes in the types, rates, and magnitudes of erosional and depositional processes lead to highly variable stratigraphic sequences of post-mining age, and because greater quantities of contaminated debris is stored along the channel margins where it can be eroded and sporadically redistributed during times of flood.