River Sediments Research Articles

Sewage and Organic Pollution Compounds in Nairobi River Urban Sediments Characterized by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS).

Nairobi River sediments from locations adjacent to the Kawangware and Kiambio slums were analyzed via Fourier transform ion cyclotron resonance mass spectrometry with atmospheric pressure photoionization (APPI-FT-ICR-MS). The data from these ultrahigh resolution, untargeted measurements provided new insights into the impacts of local anthropogenic activity, which included likely benzo- and dibenzothiophene pollution with a suspected petrogenic origin, and prominent surfactant-like compositions. Other features in the data included highly abundant tetra-oxygenated compounds, and oxygenated nitrogen compounds with sphingolipid interpretations. Most notably, several hydrocarbon and oxygenated compound classes in the sediment data featured intensity patterns consistent with steroid molecular formulas, including those associated with sewage contamination investigatory work. In support of this interpretation, standards of cholesterol, β-sitosterol, stigmasterol, coprostanol, cholestanol, and 5α-sitostanol were analyzed via APPI, to explore steroid ionization behavior. Generally, these analytes produced radical molecular ions ([M]•+), and water-loss pseudo molecular ion species ([M-H2O]•+ and [M+H-H2O]+), among various other less intense contributions. The absence of pseudo molecular protonated species ([M+H]+) was notable for these compounds, because these are often assumed to form with APPI. The standard measurements demonstrated how steroids can create the observed intensity patterns in FT-ICR-MS data, and hence these patterns have the potential to indicate sewage contamination in the analysis of other complex environmental samples. The steroid interpretation for the Kawangware and Kiambio data was further verified by subjecting the steroid standard radical molecular ions to collision-induced dissociation and comparing the detected fragments to those for the corresponding isolated ions from a Kawangware sediment sample.

From flood to turbidity current: combined models to simulate continent to ocean sediment transport in the Var system, France

Turbidity currents are a form of gravity-driven flow that occurs in subaqueous environments. These currents contain a low volumetric percentage of particles but are very important in transporting them from coastal to deep-marine environments. In the Var sediment routing system, southeastern France, there is a sedimentary record of turbidity currents formed by submarine landslides and flooding of the Var River. In 2006, there was continuous monitoring of the marine section that recorded four turbidity currents. To explore the connectivity between the terrestrial source and marine basin we linked two reduced complexity models of sediment transport and landscape change. The aim of the paper is to combine two models, one dedicated to the prediction of river water and sediment run-off, and the second dedicated to the transport, erosion, and sedimentation by a turbidity current. The landscape evolution model CAESAR-Lisflood was used to model discharge and sediment yield. The behaviour of turbidity currents was modelled with the cellular automata model CATS. From calibration of the two models against observations of discharge and suspended sediment in the Var River system, we find that in 2006, two rainfall events would have led to hyperpycnal turbidity currents. These two events match well with two of the four-recorded events. Focusing on the largest event we find that the source pulse of sediment from the terrestrial environment is short-lived, less than half a day, but contains a significant quantity of fine particles. The event transferred on the order of 105 m3 of suspended sediment from source to sink. This study demonstrates that hyperpycnal turbidity currents can be generated with concentrations as low as 2-6 kg/m3 at the Var River mouth far below the theoretical 40 kg/m3 threshold, suggesting active convective sedimentation in the surface plume and sea-water dilution at the flooding river mouth. A substantial amount of sediment (35% of the input volume) is directly transferred towards the deepest part of the system during a short-living hyperpycnal turbidity current. However, a considerable (65%) part remains in the surface as a hypopycnal plume feeding the hemipelagic sedimentation.

Investigating the Characteristics of Engineering Properties of Concrete Made from Hormak River Sediments and Sistan Reed Fibers

The purpose of this research is to investigate the characteristics of engineering properties of concrete made from Hormak river sediments and Sistan reed fibers.in order to investigate the effect of reed fibers on the engineering properties of concrete, the ratio of water to cement in all designs is constant and equal to 195 to 410 and experiments have been performed on 5 samples containing fibers and without fibers, before determining the optimal amount of each From the mentioned fibers to strengthen the concrete, the results of the necessary tests on fresh and hardened concrete were examined. In this study, in addition to mixing reed fibers with concrete, laboratory methods such as Compressive and tensile strength were used to confirm the accuracy of the results and the importance of selecting suitable materials at low cost in a short time before the concrete mixing project. The results show that the addition of reed fibers to concrete has increased the compressive strength in concrete samples Comparing the results of this test in ordinary concrete and fiber reinforced concrete, showed that this increase in strength at the ages of 7 to 28 days has increased only in samples S2 and S3 and is Similar to the typical concrete example isS1, While in S4 and S5 samples, which were samples of three-row fibers, there is a large decrease in compressive strength. Adding reed fibers initially increases the compressive and tensile strengths, but over time reduces these resistances. DOI: https://doi.org/10.52783/pst.789

Engineering Characteristics of Concrete Made from Daz Shrub Fibers and Iranshahr Daman River Sediments in the Southeast of Iran in Strengthening Structures Against Earthquakes

The purpose of the present research is the engineering characteristics of concrete made from Daz shrub fibers and Iranshahr Daman river sediments in the southeast of Iran in strengthening structures against earthquakes. Therefore, in order to determine the textural characteristics and composition of sediments of the Daman River, 15 samples of the sediments of this river were collected in separate bags, and then to study, the composition, texture and constituents of these sediments were made into thin sections. The laboratory was transferred. Statistical graphs and parameters of sediments were drawn to determine the average size, frequency and cumulative graphs. Examining the process of texture changes along the river, after drawing the relevant graphs of texture changes and the composition of sediment samples taken from Daman River, shows textural changes. Also, a comparison between single-stranded, two-stranded and three-stranded leaves of Daz shrub was used to increase the strength of concrete, and the results showed that the effect of concrete strength is by changing the number of leaves from one strand. It varied in three fields. The resistance of two strands of Daz leaves was 10.1 MPa, a single strand was 9.5 MPa, and a sample of cylindrical concrete consisting of three strands of Daz leaves was the least resistant, i.e. 5.1 MPa. Therefore, the highest resistance is related to the concrete made of two strands of leaves. DOI: https://doi.org/10.52783/pst.788

Migration and transformation mechanisms of iron and manganese during river infiltration affected by the changes in riverbed sediment thickness

Riverbed scouring and siltation, affected by variations in river flow and sediment concentration, can cause changes in the sediment thickness, leading to the complex feedback between riverbed permeability and nutrient–reactive transport processes. Currently, the migration and transformation of iron and manganese under changed riverbed sediment thickness have not been taken into account. Based on indoor one-dimensional soil column simulation experiments, along with in-situ monitoring, Rhizon pore water sampling, and 16 s rRNA high-throughput sequencing technologies, this study revealed the migration and transformation patterns of iron and manganese in the river infiltration zone and their contribution rates under different sediment thickness conditions. The results demonstrated that as the riverbed sediment thickness increased, the river infiltration rate and sediment permeability coefficient demonstrated a significant decrease over time. For instance, a 5 cm sediment thickness can decrease the sediment permeability coefficient by 30 % within 32 d of infiltration, expand the disconnection zone to 25 cm, narrow the oxidation–reduction zone, and cause the iron and manganese reduction zone to evolve from a single peak to a double peak pattern. Additionally, as the sediment thickness increased, the contribution of organic matter bound iron-manganese oxidation and iron-manganese oxide reduction to Mn2+ and Fe2+ concentrations in sediment pore water decreased, while the contribution of adsorption and complexation-precipitation increased. This study holds great significance for ensuring the safety of drinking water supply and promoting the sustainable utilization of groundwater resources.

The Influence of Geographical Conditions on Flood Disasters in Tunggul Irang Ilir Village

Natural disasters such as floods can be caused by both natural and non-natural factors, such as human activities. The convergence of human activities, static environmental conditions, and dynamic natural phenomena can result in flooding. Static natural elements (topography, rivers, and geographical conditions) and dynamic natural factors (rainfall, tidal currents, land subsidence, and river sedimentation) are the causes of flooding disasters. Tunggul Irang Ilir Village is a village located in the Martapura District of Banjar Regency that experiences flooding every year. It is known that the floods in Tunggul Irang Ilir Village involve several factors, primarily due to the village's geographic conditions, making the area prone to flooding disasters. Therefore, research is conducted on the geographical conditions' impact on flooding in Tunggul Irang Ilir Village to understand the village's geographical conditions and their influence on the floods that occur annually. Using a qualitative descriptive research method, data is collected through documentation, interviews, and observation. Data analysis involves stages such as data reduction, data presentation, conclusion drawing, and verification. This research employs data triangulation, technique triangulation, and time triangulation to test validity. The results of the research indicate that geographic conditions, including the village's location, climate, weather, low land topography, and Martapura River overflow, are factors causing floods in Tunggul Irang Ilir Village.

The Impact of Induced Industrial and Urban Toxic Elements on Sediment Quality

Abstract: The increasing population has subjected rivers and streams to high levels of both industrial and domestic pollution. Significant environmental challenges have been brought about by their effects, particularly with regard to biota, ecosystem processes, soil quality, and groundwater pollution. This study examined the effects of human activity by applying pollution index models to evaluate the input of toxic elements in river sediments. Prior to sediment quality analysis, the total amount of arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg), thorium (Th), and uranium (U) was determined in the concentration range of 1.09–10.0 mg/kg, 8.53–475 mg/kg, 0.12–0.16 mg/kg, 4.85–77.5 mg/kg, 3.14–5.9 mg/kg and 0.93–2.86 mg/kg, respectively. The enrichment factor, contamination factor, pollution load index, and geo-accumulation index revealed alarmingly high levels of Pb and Hg contamination at some sampling points, which are related to possible human input, ranging from severe enrichment to considerable contamination. The low ranges of pollution indices of some toxic elements suggest enrichment through the natural weathering process and atmospheric deposition. The Pearson correlation coefficient revealed a significant correlation between Pb-Fe and As-Fe, suggesting the possibility of acid mine contamination. Continual monitoring of river sediment is essential to minimize the impact of toxic elements to sustain sediment health and quality.

Downstream change of luminescence sensitivity in sedimentary quartz and the rearrangement of optically stimulated luminescence (OSL) components along two large rivers

Recently, it has been proposed that the luminescence sensitivity of quartz grains, i.e. their luminescence response to unit dose, might be used for sediment fingerprinting. Sensitivity is determined both by the origin of quartz grains and the sedimentary processes they underwent. However, a more detailed understanding of the factors influencing sensitivity is essential in order to expand and specify the applicability of the parameter in sediment sourcing and geomorphological studies alike. In the present research, we examined the spatial changes of sensitivity parameters of coarse grain quartz in modern sediments of the largest rivers of the Carpathian Basin, Central Europe, to determine the role of source areas and transportation distance.Based on the luminescence analysis of 39 samples, quartz extracts with a Carpathian origin (catchment of the Tisza River have a significantly higher sensitivity, except the LM-OSL medium component, than those originating from the Alpine domain (catchment of the Danube River). No clear relationship could be identified between natural sensitisation and transportation distance. In terms of the Tisza the observed downstream increase of quartz sensitivity is due to high sensitivity quartz grains supplied by its tributaries. In the meantime, a recurring change was observed along the Danube, which can be attributed mostly to local erosional processes. Consequently, tributaries and erosion can overprint the potential downstream sensitisation of quartz grains in large rivers.Meanwhile, in terms of the Danube on sections where a significant downstream increase was detected in LM-OSL fast component sensitivity, LM-OSL medium component sensitivity systematically decreased. Additionally, during laboratory sensitization, the CW-OSL sensitivity of Danube samples increased considerably, whereas changes were more moderate in the case of Tisza samples. Moreover, in the case of Tisza-related quartz extracts, the 110°C TL sensitivity and the LM-OSL fast and medium components showed a strong correlation, indicating the stability of luminescence processes (trapping and recombination). Whereas, in the case of the Danube both LM-OSL components show a weak correlation with the 110°C TL intensity. All these indicate that Alpine-origin quartz grains are more susceptible to the rearrangement of electron traps and/or recombination centres, which can also be an indicator of sediment sources in Quaternary studies in the region.

Contamination of toxic elements in the sediments, water, and igneous rocks of the Sefid-rud River in Northern Iran using contamination indicators, with a specific focus on Ti-rich coastal sediments

The Sefid-rud River is a significant river on the southern coast of the Caspian Sea in Iran. In this study, we collected 28 samples of surface sediments and water to assess the level of metal contamination. Chemical analysis revealed that the average concentrations of heavy metals in both sediments and water increase from upstream to downstream. There is no clear significant relationship observed between changes in the values of investigated elements in sediments and water. The levels of these elements in the sediments, exceed toxic response thresholds. In the water samples, As, Ni and V concentrations exceed the WHO standard values. According to the Igeo, EF and PLI indices, the sediments at most stations are not contaminated by any of the elements. The CF and Dc indices suggest low contamination levels at all stations. The NIPI and ecological risk indices (Er and RI) indicate non-polluted conditions at all stations except SF22, SF20, SF11, and SF6. The MI and HEI indices indicate pollution in all water samples of the Sefid-rud, but critical values are only observed at SF5 and SF15. The other stations show no contamination. The Cf index indicates high pollution levels for all elements except Cu, Zn, and Pb. The upstream area poses a relatively high and considerable ecological risk according to the PERI index. In conclusion, the sediments of the Sefid-rud River have a higher potential for the exchange of toxic substances compared to the aquatic environment.

Heavy metals and metalloid contamination and risk evaluation in the surface sediment of the Bakkhali River estuary in Bangladesh

Current state of contamination and subsequent risk of contaminated sediment of a tidal river of Bangladesh was evaluated in the present study. Sediment samples were collected from five locations in the tributary of Bakkhali River estuary during summer (April) and winter (December) season, 2020. Collected samples were processed using standard protocol and the content of heavy metals (Cd, Cr, Cu, Pb and Zn) and metalloid (As), were analyzed by the Flame Atomic Absorption Spectrometer. Sediment contamination was evaluated by pollution load index (PLI), contamination factor (CF), degree of contamination (Cd), potential ecological risk index (PERI), non-carcinogenic and carcinogenic risk (CR) due to the dermal contact of the sediment. Multivariate statistical analysis such as principal component analysis (PCA) and cluster analysis (CA) were also applied to find out the possible sources of the contaminant in the sediment. Results showed the average concentration of As, Cd, Cr, Pb, Cu and Zn was 9.74 ± 3.57, 2.00 ± 0.85, 48.75 ± 8.92, 29.78 ± 8.39, 5.44 ± 2.03 and 56.94 ± 8.57 mg/kg, respectively. Concentration of Cu, Pb and Zn were within the recommended level whereas the concentration of As, Cd and Cr were suppressed the recommended level of WHO and FAO/WHO standards. PLI, CF and Cd revealed considerably low degree of contamination of the sediment. Geo-accumulation index indicated uncontaminated to moderately contaminated condition of the sediment. Although the values of enrichment factor revealed no potential enrichment for most of the metals, Cd showed a minor enrichment during the winter season. Based on the ecological risk assessment, the sediment from all of the sample locations was found to be of moderate to low risk. PCA and CA analysis revealed the origin of contaminants mainly from anthropogenic sources. Although different metals showed non-carcinogenic risk to the inhabitants, cancer risk values for dermal contact (CRderm) were much lower than 10−6 indicating no cancer risk for adult and child. However, the findings also revealed that children were more susceptible to CRderm compared to adults. The present study concluded that long term dermal contact of the sediment of Bakkhali River estuary will be contagious to the people. Therefore, regular monitoring of the estuarine environment is necessary so that contamination does not get worse.

Study on mechanical properties of unsaturated silt in the Yellow River flood area

The alluvial deposits of the Yellow River led to the formation of less clay content, loose soil particles, and low compactness of the unsaturated silt, which makes it complicated to determine the mechanical properties of the Yellow River flood area soil. To investigate the mechanical characteristics of unsaturated silt, the relationship between unsaturated silt saturation and matric suction is analyzed through the soil-water characteristic test, and the soil-water characteristic curve is fitted by the Van-Genuchten model. A series of consolidated undrained shear tests were conducted on silt in Kaifeng using the GDS triaxial apparatus, the influence of moisture content, matric suction (u a-u w), and net confining pressure (σ 3-u a) on the strength characteristics of unsaturated silt was discussed. The results indicated that the net confining pressure, moisture content, and matric suction significantly influenced the shear characteristics of unsaturated silt. The shear strength of unsaturated silt increased with increasing net confining pressure at the same moisture content. The strain-hardening state of silt at high confining pressure was more obvious, while the silt at low confining pressure showed a weak strain-hardening state. Under a constant net confining pressure, the deviatoric stress versus deviatoric strain curves of silt with low moisture content exhibited a strain-softening state, while other moisture content showed a weak strain-hardening state. At the same matric suction, the shear strength increased with increasing normal stress. The cohesion increased and then decreased while the internal friction angle decreased and then increased with the increasing moisture content and matric suction.

Effect of Land Use Land Cover on the Hydrology of Rwizi River Catchment located in Southwestern Uganda

Changes in land use and land cover usually affect the hydrological processes of river flows, sediment transport, and water quality on a global scale. Hence, the objective of this paper was to investigate the effect of Land Use Land Cover (LULCC) on the Hydrology of Rwizi River Catchment located in South-western Uganda using appropriate standard techniques and procedures including Soil and Water Assessment Tool (SWAT). Model calibration and validation demonstrated good agreement (R² = 0.76-0.86, NSE = 0.75-0.78). LULC analysis revealed significant increases in built-up areas and forestland, with declines in grazing land and wetlands. These changes were driven by socio-economic factors and hydro-climatic influences. The study found strong correlations between LULC types and sediment yield, highlighting the implications for water quality and erosion control. The results show that urban growth raises surface runoff and peak flows as a result of a rise in impervious surfaces, whereas agricultural intensification raises water demand and lowers base flow, especially during dry spells. Deforestation has led to increased sedimentation rates, degrading water quality. These findings underscore the significant anthropogenic and climatic impacts on LULCC dynamics and hydrological processes in the catchment. The study emphasizes the critical need for integrated watershed management strategies to mitigate these impacts and ensure sustainable water management practices. By advancing understanding in hydrological sciences, this research informs policy and management decisions for sustainable development in tropical river basins globally.

Examining ecological risks of metals in downstream river sediments: Researching agricultural carbon emission efficiency in environmental regulation perspective

This research investigates the ecological impacts of heavy metals in downstream river sediments with a focus on carbon emission efficiency in agriculture under the environmental regulation context. In this study, thirty sediment samples have been taken from the downstream region of the Shichuanhe River located in Xi'an, Shaanxi province, China, to analyze the availability of heavy metals. The results show that there are high ecological impacts in relation to the heavy metals and that impacts the carbon emission efficiency in agriculture directly. The analysis has also found the importance of significant environmental regulations in the management of such risks. This research has offered a unique angle on the relationship between heavy metal pollution and agricultural carbon release and has given important information on the improvement of environmental control measures. The implications highlight the need for the implementation of measures to enhance the policies that will help to prevent the ecological threats that are connected with heavy metals in the agricultural areas and, thus, improve the management of the environment.

Intercomparison of optical scattering turbidity sensors for a wide range of suspended sediment types and concentrations

To monitor the effects of rapid changes in climate and land use on sediment export from erodible environments, it is crucial to accurately quantify highly fluctuating suspended sediment concentrations (SSCs) in contrasted river systems that drain small to mesoscale catchments. To this end, we investigate the turbidity-based quantification of SSCs in the range of 0.05–100 g/L through laboratory experiments performed with 7 different types of turbidity sensors and sediments from 10 watersheds. We find that measurements of scattered light from multiple angles may allow for: (1) an extended monitoring range with SSCs up to 10–100 g/L, where enhanced uncertainty may occur near the transition in the effective operational ranges of the underlying signals (typically somewhere in the range of 1–10 g/L); and/or (2) a slightly reduced sensitivity to sediment properties. The specific turbidity of the investigated sensors is inversely related to particle diameter (D10) for SSCs up to 1–5 g/L. Backscatter and combined-signal sensors also show a dependency on sediment colour (CIE a∗), which becomes particularly prominent at SSCs above 10 g/L. We relate this increase in colour dependency with SSC to the expected effect of cumulative near-infrared light absorption associated with multiple scattering. We discuss covarying physical properties of naturally occurring river sediment that can dampen or enhance measurement sensitivity and result in turbidity-based SSC rating curves that may strongly differ in magnitude and form from curves derived for industrially prepared material that is often used for sensor calibration. Although the differences in SSC per sensor among sediment types are generally less than one order of magnitude, the systematic errors and uncertainties associated with high SSCs are typically greater than one order of magnitude and may disproportionally affect the quantification of sediment loads during large-magnitude flow events.

Evaluation of baffle-plate bioreactor coupling with adsorption column for the remediation of aquaculture wastewater

In this study, a baffle-plate bioreactor was designed and coupled with an adsorption column for the remediation of aquaculture wastewater. Specifically, baffle-plate was installed in the bioreactor to improve the removal of carbon (C) and nitrogen (N), while the ceramsite prepared from steel slag and river sediment was filled into the column for the adsorptive removal of phosphorus (P). To evaluate the performance of the bioreactor, the operation conditions (e.g., hydraulic retention time (HRT) and C/N ratio) were tentatively optimized. Under the optimal operation conditions, the effects of sulfamethoxazole (SMX) on the performance of the bioreactor and the microbial community were comprehensively investigated. Satisfactorily, the removal rates of NH4+-N, NO3−-N and permanganate index (IMn) were all above 88 % before adding SMX. Moreover, neither IMn nor NH4+-N was influenced by the SMX shock, whereas the NO3−-N removal was significantly deteriorated owing to the inhibitory effect of SMX on denitrifying bacteria. As revealed by the analysis of microbial communities, the microbial abundance obviously increased in the aerobic (e.g., Azohydromonas and Chitinophagaceae) and anaerobic (e.g., Alkaliflexus) zone as compared to the initially inoculated sludge. Nevertheless, the abundance of most denitrifying genera decreased after adding SMX, leading to the inefficient denitrification. In addition, the ceramsite prepared under the optimum conditions had great void fraction (55.2 %) and water absorbency (29.5 %). The average removal rate of phosphorus by the adsorption column was 71.6 %. Overall, these findings may shed new lights into the coupling of bioreactor and adsorption column for the remediation of aquaculture wastewater.

Statistical studies of the characteristics and key influencing factors of sediment changes in the upper Yangtze River over the past 60 years

Sediments in the upper Yangtze River have significantly changed over the past 60 years. The characteristics and causes of these sediment changes must be determined in the upcoming phases of the comprehensive management of the Yangtze River Basin. Based on sediment observation data from 1960 to 2020, this study examined the trends and sudden changes in the sediments in the mainstream and its significant tributaries in the upper Yangtze River. The relative contributions of precipitation change and various human activities to sediment load changes are quantified. The relationships between sediment variations and the construction and large dam projects, soil and water conservation measures, and earthquake disasters are established. The results indicate that there was a significant decline in sediment load with main changes occurring around the 1985s and 2010s. Multiple double mass curves are used to quantify the relative contributions of precipitation change and human activities to sediment load changes. The relative contribution of dams to the decrease in sediment load ranges from 53 % to 74 %. Precipitation change serves a significant role in the observed changes, accounting for a range of 10 % to 27 %. Soil conservation measures take some time to show their impact on sediment reduction. These measures work by stabilizing the soil and improving hydrological conditions. On average, they contribute between 7 % and 20 % towards reducing sediment. In recent times, there has been a noticeable rise in sediment load in rivers like the Jialing and Min Rivers. This unexpected increase could potentially be linked to a combination of factors including earthquakes, heavy precipitation, and localized sediment scouring. The results of this study offer valuable insights into the variations in river sediment load, aiding in the improved management of water resources and sediment in large dams. These findings provide helpful insights for dam management.

Petroleum spills and assessment of heavy metals in water, sediment, soil from Afiesere River, Ughelli, Delta State, Nigeria

The study which was to determine the concentrations of heavy metals in water, sediment and soil of Afiesere river because of the anthropogenic activities of petroleum exploration and attendant spills in the area. Surface water, sediment, surface soil and sub-surface soil samples were collected from Afiesere River, Ughelli, Delta State. Some physiochemical parameters of water were analysed using standard methods and Hanna water quality checker. The concentrations of five heavy metals, namely; lead (Pb), cadmium (Cd), zinc (Zn), copper (Cu) and nickel (Ni) were determined in water, sediment, surface soil, and sub-surface soil using Flame Atomic Absorption Spectrophotometer (Flame-AAS). The results obtained show the mean values of pH, temperature, total dissolved solid, conductivity, dissolved oxygen, biological oxygen demand, phosphate, nitrate, and sulphate as follows: 6.87 ± 0.18, 27.40 ± 0.28oC, 4.00 ± 0.00 mg/L, 8.67 ± 0.25 µs/cm, 4.23 ± 0.08 mg/L, 0.65 ± 0.17 mg/L, 0.01 ± 0.00 mg/L, 0.01 ± 0.03 mg/L, and 2.17 ± 0.18 mg/L respectively. The heavy metals; Pb, Cd, Zn, Cu and Ni mean concentrations are as follows: in water, 0.06 ± 0.02, 0.02 ± 0.01, 0.46 ± 0.01, 0.03 ± 0.01 and 3.56 ± 0.07 mg/L; in sediment, 0.52 ± 0.03, 0.02 ± 0.00, 0.21 ± 0.02, 0.07 ± 0.01 and 0.26 ± 0.01 mg/kg; in surface soil, 0.50 ± 0.03, 0.02 ± 0.00, 0.07 ± 0.01, 0.03 ± 0.00 and 2.91 ± 0.03 mg/kg; in sub-surface soil, 0.55 ± 0.02, 0.02 ± 0.01, 0.26 ± 0.02, 0.06 ± 0.01 and 0.36 ± 0.08 mg/kg respectively. The results showed a significant difference at P<0.05. The results obtained in this study were within and above the set standard for water, sediment and soil by World Health Organization (WHO). The metals are toxic, can bio-accumulate and are potential carcinogens; therefore treatment of water is very important. Periodic medical examination of the inhabitants of the area must be a top priority.

Comparative study using spectroscopic and mineralogical fingerprinting for suspended sediment source apportionment in a river–reservoir system

AbstractThe need to control soil erosion has received increasing attention, but quantitative data on the sources of suspended sediment in many river–reservoir systems is still lacking. The goal of this research was to compare the application of spectroscopic [mid‐infrared (MIR)] and mineralogical [X‐ray diffraction (XRD)] fingerprints for assessing relative sediment source contributions from different land use groups (agricultural lands, forests and human settlements) in the Konar–Damodar river–reservoir system in India. Source apportionment was estimated using partial least square (PLS) regression for spectroscopic tracers (MIR) and the Bayesian MixSIAR model for mineralogical tracers. Both methods identified differences between the pre‐ and post‐monsoon sediment contributions of forests (overall contribution bounds of ~35–43%). During monsoon seasons, both fingerprinting methods indicated agricultural land use as the primary source of suspended sediment. Although there were some temporal variations in the predicted contributions of the land use sources, the MIR‐PLS and mineralogical–MixSIAR methods produced comparable ranges. The respective variations in contributions, using MIR‐PLS and mineralogical–MixSIAR, were ~31 to 66% compared with ~36 to 61% for agricultural lands, ~21 to 43% compared with ~15 to 39% for forests and ~16 to 37% compared with ~19 to 32% for human settlements.

Effect of Treated Wastewater on the Distribution of Antyibiotic-Resistant Microorganisms in the Aquatic Environment

The effect of waste treatment plants in Pushchino, Russia on abundance of antibiotic-resistant microorganisms and determinants of multiple drug resistance in the Oka River water and sediments was investigated. Treated wastewater was found to contribute to contamination of the Oka surface water layer with aminoglycoside-resistant strains. The role of Pushchino waste treatment plants in the dissemination of multidrug-resistant strains and plasmids of the А/С incompatibility groups (IncA/C) was demonstrated. Waste treatment plants were shown to affect both the total abundance of eubacteria in sediments and to assect their composition, increasing the relative abundance of pseudomonads.

Distribution, source apportionment and ecological risk assessment of heavy metals in Limbe River sediments, Atlantic Coast, Cameroon Volcanic Line

The objective of this research was to assess sediments contamination, provenance and metal pollution using single and complex pollution indicators. Limbe River sediment samples were analysed using Inductively Coupled Plasma—Mass Spectrometry. The Limbe River sediments exhibit high content in Fe2O3 sourced from haematization of basaltic rocks. The concentration of Cd, Co, Cr, Mn, Ni, Pb, Sn, Sr, V and Zn exceed upper continental crust and local baseline values for heavy metals. Correlation matrix analysis indicates the presence of common input sources and similar geochemical characteristics of heavy metals. Contamination factor (CF: 0.01–10.34), contamination degree (Cdeg: 14.91–36.57), pollution load index (PLI: 0.84–1.77), and nemerow integrated pollution index (NIPI: 0.2–1.7) indicates significant to high levels of contamination. The enrichment factor (EF: 0–5.67) and geo-accumulation index (Igeo: -7.55–2.59), suggests moderate to significant metal pollution of the Limbe River ecosystem, suggesting potential ecological effects. Modified hazard quotient (mHQ: 0.082–6.35) and toxic risk index (TRI: 10.49–27.43), indicates low to extreme pollution severity and high toxicity risks of heavy metals to the aquatic ecosystem fauna and flora. Primarily anthropogenic activities and secondary lithogenic provenance is attributed to sediments contamination and metals pollution. This study suggests that a greater emphasis should be placed on monitoring various provenances of metals entering the aquatic ecosystem from anthropogenic practices. The study emphasizes the significance of continual protection of aquatic ecosystem and biological resources and adaptive management. The development of reasonable goals for monitoring and remedial programmes can be aided by this data.