ABSTRACT
Objective: This study aimed to assess the concentration of heavy metals in suspended sediments in the Coxim and Taquari Rivers, Mato Grosso do Sul, over a hydrological year. It observed variations in concentrations and their relationship with land use and cover in the watershed.
Theoretical Framework: The research is based on the significance of suspended sediments as carriers of nutrients and pollutants in fluvial systems, as well as on the criteria established by CONAMA Resolution 454/2012 regarding sediment quality. Previous studies highlight the importance of fine particles in transporting heavy metals, such as Iron (Fe) and Aluminum (Al), due to their greater specific surface area.
Method: Four sampling campaigns were conducted at points P1, P2, and P3, covering both flood and drought periods. Flow rates were measured using an acoustic Doppler meter (ADP M9) and sediments were collected using the Equal Width Increment (IIL) method. Acid digestion followed USEPA (1996) protocols, while granulometry was analyzed via laser diffraction (Mastersizer 2000).
Results and Discussion: Net flow rates varied from 220 m3/s (P1) to 226.5 m3/s (P2), with sediment transport ranging from 1,708.56 t/day to 12,473.05 t/day. At point P2, loads of 405,873.6 kg/day of Al and 267,214.5 kg/day of Fe were reached. The metals Zn and Ni exceeded the limits set by CONAMA 454/2012, while Cu, Cr, Cd, and Pb remained at lower levels. The sediments consisted mainly of fine sand (60%), with smaller particles (17%) playing a significant role in metal transport.
Research Implications: The results underscore the need for public policies focused on sustainable land management and siltation control, emphasizing the importance of sediment monitoring as an environmental indicator.
Originality/Value: This study contributes by integrating data on metal transport with the physical characteristics of sediments, proposing the inclusion of parameters such as Fe and Al in environmental regulations for sediments.
Keywords: Pantanal, Taquari River, Sediment Transport, Fluvial Sedimentology, Heavy Metals.
RESUMO
Objetivo: Este estudo teve como objetivo avaliar a concentração de metais pesados em sedimentos suspensos nos Rios Coxim e Taquari, Mato Grosso do Sul, ao longo de um ano hidrológico, observando variações nas concentrações e sua relacio com o uso e ocupação do solo na bacia hidrográfica.
Referencial Teórico: A pesquisa fundamenta-se na relevância dos sedimentos suspensos como vetores de nutrientes e poluentes em sistemas fluviais, bem como nos critérios estabelecidos pela Resolução CONAMA 454/2012 para a qualidade de sedimentos. Estudos prévios destacam a importáncia de partículas finas no transporte de metais pesados, como Ferro (Fe) e Alumínio (Al), devido á maior área superficial específica.
Método: Foram realizadas quatro campanhas de amostragem nos pontos P1, P2 e P3, abrangendo períodos de cheia e estiagem. As vazdes foram medidas com medidor acústico Doppler (ADP M9) e os sedimentos coletados pelo método de Igual Incremento de Largura (IIL). A digestão ácida seguiu protocolos da USEPA (1996), enquanto a granulometria foi analisada por difração a laser (Mastersizer 2000).
Resultados e Discussão: As vazões líquidas variaram de 220 m/s (P1) a 226,5 m/s (P2), com transporte de sedimentos de 1.708,56 t/dia a 12.473,05 t/dia. Alcançaram-se cargas de 405.873,6 kg/dia de Al e 267.214,5 kg/dia de Fe no ponto P2. Metais Zn e Ni ultrapassaram limites da CONAMA 454/2012, enquanto Cu, Cr, Cd e Pb mantiveram-se em níveis menores. Sedimentos consistiram majoritariamente de areia fina (60%), com partículas menores (17%) destacando-se no transporte de metais.
Implicações da Pesquisa: Os resultados apontam para a necessidade de políticas públicas voltadas ao manejo sustentável do solo e ao controle do assoreamento, ressaltando a importáncia do monitoramento de sedimentos como indicador ambiental.
Originalidade/Valor: Este estudo contribui ao integrar dados de transporte de metais e características físicas dos sedimentos, propondo a inclusão de parámetros como Fe e Al na regulamentação ambiental para sedimentos.
Palavras-Chave: Pantanal, Rio Taquari, Transporte de Sedimentos, Sedimentologia Fluvial, Metais Pesados.
RESUMEN
Objetivo: Este estudio tuvo como objetivo evaluar la concentración de metales pesados en sedimentos suspendidos en los ríos Coxim y Taquari, en Mato Grosso do Sul, a lo largo de un año hidrológico, observando las variaciones en las concentraciones y su relación con el uso y la ocupación del suelo en la cuenca hidrográfica.
Marco Teórico: La investigación se fundamenta en la relevancia de los sedimentos suspendidos como vectores de nutrientes y contaminantes en sistemas fluviales, así como en los criterios establecidos por la Resolución CONAMA 454/2012 para la calidad de los sedimentos. Estudios previos destacan la importancia de las partículas finas en el transporte de metales pesados, como Hierro (Fe) y Aluminio (AD), debido a su mayor área superficial específica.
Método: Se realizaron cuatro campañas de muestreo en los puntos P1, P2 y P3, abarcando períodos de crecida y sequía. Los caudales se midieron con un medidor acústico Doppler (ADP M9) y los sedimentos se recolectaron mediante el método de Incremento de Ancho Igual (IIL). La digestión ácida siguió los protocolos de la USEPA (1996), mientras que la granulometría se analizó por difracción láser (Mastersizer 2000).
Resultados y Discusión: Los caudales netos variaron de 220 m/s (P1) a 226,5 m/s (P2), con un transporte de sedimentos que osciló entre 1.708,56 t/día y 12.473,05 t/día. En el punto P2 se alcanzaron cargas de 405.873,6 kg/día de Al y 267.214,5 kg/día de Fe. Los metales Zn y Ni superaron los límites establecidos por la CONAMA 454/2012, mientras que Cu, Cr, Cd y Pb se mantuvieron en niveles menores. Los sedimentos estuvieron compuestos mayoritariamente por arena fina (60%), destacándose las partículas más pequeñas (17%) en el transporte de metales.
Implicaciones de la investigación: Los resultados señalan la necesidad de políticas públicas orientadas a la gestión sostenible del suelo y al control de la sedimentación, subrayando la importancia del monitoreo de los sedimentos como indicador ambiental.
Originalidad/Valor: Este estudio contribuye al integrar datos sobre el transporte de metales y las características físicas de los sedimentos, proponiendo la inclusión de parámetros como Fe y Al en la regulación ambiental de los sedimentos.
Palabras clave: Pantanal, Río Taquari, Transporte de Sedimentos, Sedimentología Fluvial, Metales Pesados
1 INTRODUCTION
transport is the main mechanism of particle transfer suspended and dissolved from the earth to the oceans . It is estimated that, globally , more than 18.3 billion tons of particles terrigenous be transferred annually (Yao et al., 2015). Among these particles , the sediments carry nutrients and contaminants , including metals heavy , which can affect significantly you ecosystems aquatic and health human .
You metals heavy metals such as Cd, Pb, Zn, Fe and Al can be transported in sediments and accumulated in ecosystems marine and riverine . Anthropogenic sources , such as agriculture , industry and urbanization , intensify your presence us bodies of water , increasing you contamination risks . Studies point out that particles minors , such as silt and clay , have bigger adsorbability metals heavy due to its bigger surface area and presence of oxides metallic and matter organic ( Pye, 2004). However , the particle size predominant and the factors places , such as soil characteristics and practices agricultural , too influence transportation of these contaminants .
In the Upper Paraguay Basin , the rivers Taquari and Cushion play a role important in sediment supply in suspension to the Pantanal, one of the largest systems wetlands of the world . Problems as siltation , loss of biodiversity and changes in the water quality they are directly related to the sediment and metal transport heavy . Despite of that , few studies focus on in the composition chemistry and transportation of these sediments in suspension .
This study he has as objective characterize the transport of metals heavy in sediments suspended in the Taquari and Coxim Rivers , relating your concentrations and granulometry with factors hydrological and land use . The research aims to contribute to the understanding of the impacts environmental and provide subsidies for management sustainable basin hydrographic .
2 METHODOLOGY
The Taquari River, a tributary of the Paraguay River, rises on one of the slopes of the Serra do Caiapó, near the city of Alto Taquari, in the state of Mato Grosso. Its basin is located between latitudes 17°S and 20°S with longitudes 53°W and 58°W, covering an area of approximately 65,023 km2 - It is one of the largest tributaries of the Upper Paraguay Basin (BAP) and has been the subject of controversy in recent years due to frequent flooding of land in the middle/lower stretches, making navigation difficult and reducing fishing potential. As it is a long and wide river, it was divided into 3 distinct stretches:
* Alto Taquari - from the springs to the city of Coxim, confluence with the Coxim River;
* Médio Taquari - from the city of Coxim, over a distance of 335 km, to Porto Rolon ;
* Baixo Taquari - from Porto Rolon , over a distance of 100 km, to its mouth on the Paraguay River, close to Porto da Manga .
The points monitored in this study were all within the stretch of the Médio Taquari in the urban perimeter of the city of Coxim in the State of Mato Grosso do Sul. Upstream from the city, there is accelerated land use and occupation, with a predominance of agriculture, livestock farming and tourism. The predominant climate in the region, according to the Kôppen climate classification , corresponds to the " Aw " type, that is, a tropical climate with a dry winter, recording annual temperature variations of around 15°C in winter and 35°C in summer, with a dry period with low rainfall lasting three to four months, with very distinct periods, a dry season lasting four to five months and rainy season with precipitation reaching 1550 mm. year 1
In this study, four surface water sampling campaigns were carried out in the Taquari and Coxim Rivers, during a hydrological year where the dry season typically occurs from June to September and the flood season from December to February. The samplings were used to evaluate the concentration of heavy metals that reach the city of Coxim/MS during a monitoring year divided into 4 campaigns C1, C2, C3 and C4.
Figure 1.0 shows the study area with the points sampled in each campaign where:
* Point 1 (P1) Taquari River upstream from the mouth of the Coxim River;
* Point 2 (P2) Coxim River before its mouth with the Taquari;
* Point 3 (P3) Taquari River downstream from the mouth of the Coxim River, in the section that comprises the urban perimeter of the city of Coxim/MS.
2.1 MEASUREMENT OF TOTAL LIQUID DISCHARGE
To measure the liquid discharge in this work, an acoustic Doppler meter (ADP M9) was used. Figure 4.4 manufactured by Sontek , designed with the objective of performing flow measurements in various types of application in rivers and open channels. It is a small, portable and easy-to-operate equipment, and at the same time robust enough to be used in extreme conditions, with accurate results in record measurement time. It allows scanning of the depth and velocity profile in a high number of verticals, allowing a greater volume of collected data, consequently greater accuracy of the measured values.
After the specific calibrations of the equipment recommended by Sontek , measurements were taken at points P1, P2 and P3. Since the equipment used in the campaigns did not have a real-time kinematic positioning device (RTK) attached, it was necessary to implement a method of correction of the measurements since the moving bottom velocities are high in this basin, underestimating the liquid discharge measurements. Figure 2 shows the equipment being used in the field.
As shown in Figure 2 b), the M9 consists of nine beams: eight velocity measurement transducers, four of which are 3.0 MHz and four of which are 1.0 MHz; and a 0.5 MHz vertical acoustic beam, which provides depth data. The equipment is 13 centimeters in diameter, has a velocity profile range of 0.2 to 30 meters in depth, and can reach up to 80 meters with the use of an integrated GPS.
The measurement consists of passing the M9 profiler from one bank of the river to the other in such a way that the crossing speed is never greater than the speed of the river. To guarantee accurate data, this procedure is repeated around three times, back and forth crossings, totaling a volume of six measurements.
2.2 SAMPLING OF SUSPENDED SEDIMENTS
For suspended sediment sampling, the Equal Width Increment - IIL method was adopted, which has a single analysis from a composite sample in determining suspended sediment transport. The US D49 sampler was used to perform sampling to determine solid discharge at points P1, P2 and P3, with 4 annual collections at each point. Figure 3 shows the sampler used and a representation of the sampled verticals.
Approximately 45 liters were required in each section to acquire suspended sediments. To characterize the suspended sediments, the sample was left to rest for 96 hours. After this period, it was reduced with the aid of a suction pump to reduce the sample, removing only the non-decanted part from the container, until a volume of approximately 500 mL of water plus sediments was obtained. After this procedure, the sample was dried in an oven at 60°C. Figure 4 shows the reduced volume of a sample of approximately 45 liters.
This procedure ensured the extraction of suspended solid mass. The samples were homogenized and divided for analysis of heavy metals, volatile solids and granulometry. In the analysis of heavy metals, approximately 2 g of suspended material were used and acid digestion was performed, following the methodology of the United States Environmental Protection Agency (USEPA, 1996). This technique performs acid digestion, solubilizing the elements in a homogeneous manner. In this method, 2 g of dry sediment is weighed and heated with the addition of nitric acid and hydrogen peroxide to eliminate organic matter. Finally, hydrochloric acid is added to complete the digestion.
To characterize the suspended sediments, granulometric analyses of the suspended material were performed using the laser diffraction technique, according to Pye (2004), this method is based on the phenomenon that particles scatter light in all directions with an intensity pattern that is dependent on the size of the particles.
THE The Mastersizer 2000 laser granulometer is used to determine only the fine fraction, allowing readings of fine particles in the range between 0.05 and 2000 um. Figure 4.10b shows the equipment used in the granulometric analyses.
The loss on ignition method D2974-00, standardized by the American Society for Testing and Materials (ASTM 200), was used to determine the organic matter. This method volatilizes all organic matter at a temperature of 440°C, consisting of placing approximately 1 gram of dry sediment in a weighed porcelain capsule for one hour and taking it to the muffle to burn the volatile material for 4 hours. The capsules are then cooled in a desiccator and the mass is measured to quantify the fixed and/or volatile matter.
3 RESULTS AND DISCUSSIONS
The net flows measured at points P1 (Taquari River), P2 (Coxim River) and P3 (Taquari River downstream) varied significantly throughout the hydrological period. The values recorded for the flood (December to February) and dry (June to September) periods are presented in Figure 6.
At points P1 and P2 of the Taquari River and Coxim River, there were significant changes during the hydrological period in the months of January and February, when rainfall frequency is constant in the basin. The Taquari River (P1) presented flows close to 220 m3/s. Ide (2003) was able to measure flows of 317.84 m3/s in the river section (P1) in January, showing the great variability in the volume drained compared to 2016.
In the Coxim River, Point 2, Barbedo (2003) measured flows with values of 288.82 m3/s. At this same point (P2), flows were measured with values below those found 13 years earlier for the same period corresponding to flooding in the basin, with the values found in the period being 226.5 m3/s, showing that the volume decreased when compared to the same period in 2003 and 2016.
3.1 METHODS FOR CALCULATING SUSPENDED PARTICLE TRANSPORT
To determine the suspended solids discharge, Carvalho (2008) suggests the simplified methodology of Colby (1957) that uses the variables, flow in m3/s, time (s) and the average concentration of suspended sediments. The product results in the input in tons per day of suspended sediments, obtained according to equation 1.0.
Qss = 0.0864 x Ol x Cs (t/day) (1)
Where:
* Ol = Net flow rate (m3/s)
* Cs = Concentration of suspended sediments ( ppm or mg L-1)
* OQss = Suspended solids discharge (t/day)
* 0.0864 = Unit Transformation Constant
The solid discharge values found in this research were lower when compared to other studies, the average concentrations for points P1, P2 and P3 were respectively 3,341.74 t/day, 4,418.63 t/day and 7,396.86 t/day. Table 1 presents the results obtained by analyzing the solid discharges at the sampled points.
In a study carried out by Barbedo (2003) at the same points P1 and P2 of this research, higher values were found for both points, the results found in 2003 were 15,289.133 t/day for point 1 and 21,046.471 t/day at point 2, showing a large difference in the transport of suspended sediments. According to Nearing (2007), differences in sediment production values for hydrographic basins are attributable to instrumentation, basin morphology, degree of channel incision, vegetation cover associated with agricultural practices.
3.2 CONCENTRATION OF METALS IN SUSPENDED SEDIMENT
Heavy metal concentrations in suspended sediments varied significantly between the monitored points and campaigns. Table 2 presents the average results obtained for the main metals analyzed.
The average values of heavy metals in suspended sediments were classified according to CONAMA Resolution 454/2012, which indicates that there is a possibility of adverse effects on biota. The metals Cu and Cr were below level 1 at all points, for Cd and Pb they were classified as level 1 and the metals Zn and Ni were classified above level 2, a concentration range in which there is a high probability of toxic effects on aquatic organisms.
According to Oberholster et al. (2010), high concentrations of Al and Fe can have harmful effects on the aquatic environment and on humans who may consume fish containing high levels of Al. At a neutral pH, as in the case of the Taquari and Coxim Rivers, Al and Fe can accumulate in significant quantities in some organisms of the primary chain, which can lead to aquatic imbalance such as a lack of fish (SOUCEK et al., 2001).
Conama 454/2012 does not take into account these two parameters (Fe, Al), found in high concentrations in the river basins of the Pantanal in the South of Mato Grosso. A new approach should be discussed regarding the inclusion of these parameters, since the National Environmental Council (CONAMA) determines the maximum concentrations of metals in river and lake water, so that they can be classified into classes. The maximum permitted concentrations of iron and aluminum dissolved in class 2 water according to CONAMA Resolution No. 357 are respectively 0.3 mg/L and 0.1 mg/L, a contradiction due to the high levels of iron and aluminum found in the sediment and the slightly acidic conditions of the Pantanal river water, which favors the release of these metals into the soluble phase.
3.3 TRANSPORTATION OF HEAVY METALS
The values of metal transport in suspended sediments varied significantly between the campaigns and the points monitored. Figures 7 to 9 show the masses of metals transported to points P1, P2 and P3 in the suspended sediments. It can be seen that the scale of suspended metal transport in Kg day · occurs in P3>P2>P1 in all campaigns carried out.
Studies carried out by Sampaio (2003) at the same points P1 and P2 of this study showed high levels of Fe in the water, reaching values of 21.567 mg L 'of Fe and around 0.2 mg L · of Mn for point 1 (upstream from the mouth of the Coxim River) for the month of January, which corroborates the data found.
It is also noted that for the metals Fe and Al in all sections, there is a transport of tons per day, adhered to the sediments. Values of 405,873.6 kg day for Al in P2 in campaign 3 and 267,214.5 kg day-1 for Fe show that in certain periods of the year the transport in the sections can be extremely high due to high precipitation.
According to Vanzela (2004), high levels of total iron found in surface waters are probably related to the poor conservation of soils in rural areas, where the contribution of erosion and silting processes in soils formed based on iron oxides, considerably increasing the amount of soil in contact with water, thus resulting in an increase in the concentration of iron, both soluble and suspended in water.
For the metals Zn, Pb , Ni and Mn, transport varies from kilograms to tons per day depending on the time of year. For the metals Cu, Cr and Cd, at some times of the year in some sections, transport along with the suspended sediment may be zero and may also be in the range of kg day-1.
Figure 10 shows the boxplots for the concentration of heavy metals at points P1, P2 and P3.
Figure 10 - Representation of metal concentrations in suspended sediments through Boxplot for: a) Cd , b) Pb; с) Zn; d) Cr; e) Cu; f) Ni ; g) Mn; h) Al; 1) Faith
Cd presents average concentration values of around 0.002 mg g-1 for the three monitored points. There is a tendency for this metal to increase for points P1, P2 and P3.
Pb also showed approximate average concentrations for the three monitored sections. It is observed that in P1 and P3 they present approximate variabilities and in P2 there is an increasing trend for this metal .
Ni metal , average concentrations are around 0.03 mg g-1 with an increasing tendency due to greater variability in the upper limit.
Cu showed a mean concentration of 0.20 mg g-1 and similar variability in P2 and P3. Point P1 showed less variability for this metal.
At point P2, an average concentration of 0.27 mg g-1 was observed, at point P1 0.21 mg g-1 and at P2 0.18 mg g-1, for Mn. There is a tendency for this metal to increase in the sections for all three points, with similar variability.
A higher concentration and variability of Al can be inferred for point P2. Points P1 and P3 showed approximate average concentrations. At point P3, a tendency for this metal to increase was observed, and at point P1, a tendency for it to decrease.
It can be seen that in P2, Fe also presents greater variability, with an average concentration of 14.1 mg g-1, a higher value compared to points P1 and P3. In P1, 7.9 mg g-1 was found and in P3, it was 10 mg g-1, with smaller and approximate variabilities.
For points P1 and P3, Zn showed an average concentration of 0.036 mg g-1, with a tendency for this metal to increase in the sections. Point P2 presented 0.047 mg g-1 with low variability.
In P2, Cr showed a concentration of 0.02 mg g-1, a higher value than in P1 and P3. In P1, this metal showed an increasing trend, due to the upper limit of variation observed.
3.4 GRANULOMETRY
The particle size curves of the suspended material obtained by the laser particle sizer are in Appendix B. The proposed pumping sampling collection method proved to be efficient and statistically significant; in general, the particle size at all points remained similar. Figure 5.11 shows the particle size classification of the suspended sediment at points P1, P2 and P3.
Figure 5.11 shows that approximately 60% of the suspended sediments at all points are classified as fine sand in the granulometric range of 0.25 mm to 0.125 mm and that only a small portion of fines, silt and clay are present in the fine sediments. According to studies by Pye (2004), smaller particles tend to absorb heavy metals better and probably these fines, which in this study represent about 17% of the sediments, can be responsible for a large part of the aggregate transport of heavy metals at the points studied. However, the portion of metals aggregated in larger particles cannot be ruled out, where in studies by Falco (2017), it shows that sand particles can accumulate up to 10% of the metals present in a sediment sample.
Regarding the granulometry of the suspended sediment, it is observed that at all points, there is a predominance of fine sand. In studies by Galdino et al. (2016), the main types of soil in the upper and middle Taquari region are discussed, formed by sand naturally enriched with quartz, known as quartzose sand or neosol. quartzarenic , whose formation is fragile and with little interaction between particles, favoring transport to water bodies.
3.5 ORGANIC MATTER IN SUSPENDED SEDIMENTS
In general, the percentages of organic matter found in this research were low at all points, and according to research conducted by Embrapa (2007), when the levels of organic matter are less than ten percent, the material can be considered inorganic or mineral, with a predominance of silicate materials, clay and metals such as Ca, Fe, Mn and others (Esteves, 1988). Figure 12 shows the percentage of organic matter found at each monitored point.
The organic matter values were in the range between 5% and 8% at all points, indicating that the suspended sediments are of mineral origin, as they contain less than 10% organic matter (Belo et al., 2010).
4 CONCLUSIONS
The work characterized the quality of water and suspended sediments in a section of the Taquari River, which includes the mouth of the Coxim River, seeking to evaluate the contribution of heavy metals from the Coxim River basin to the Taquari River.
The concentrations of metals in suspended sediments for Cd and Pb were at level 1 according to CONAMA Resolution 454/2012, and at level 2 for Zn and Ni , which may have toxic effects on aquatic organisms.
The transport of suspended sediments in P3 is greater than the sum of the contributions from the confluences of the Taquari River (P1) and Coxim River (P2), probably due to the existence of sandbanks forming islands that contribute significantly to the transport of sediments to this section (P3). These transports of suspended solids in the monitored period are in the range of 4,100 to 12,500 t/day.
It is observed that about 60% of the suspended sediments transported in P1 (Taquari River upstream of the mouth of the Coxim River), P2 (mouth of the Coxim River) and P3 (Taquari River downstream of the mouth of the Coxim River) are fine sands, for the metal Al, about 405,873.6 kg.day-1 were transported in P2 in campaign 3 and 267,214.5 kg.day-1 for Fe, showing that in certain periods of the year the transport in the sections can be extremely high due to the flood period in the basin.
of metals Zn, Pb , Ni and Mn varies from kilos to tons per day, depending on the season. For the metals Cu, Cr and Cd, at some times of the year in some sections, transport along with the suspended sediment may be zero and may also be in the range of Kg day-1.
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Abstract
Objective: This study aimed to assess the concentration of heavy metals in suspended sediments in the Coxim and Taquari Rivers, Mato Grosso do Sul, over a hydrological year. It observed variations in concentrations and their relationship with land use and cover in the watershed. Theoretical Framework: The research is based on the significance of suspended sediments as carriers of nutrients and pollutants in fluvial systems, as well as on the criteria established by CONAMA Resolution 454/2012 regarding sediment quality. Previous studies highlight the importance of fine particles in transporting heavy metals, such as Iron (Fe) and Aluminum (Al), due to their greater specific surface area. Method: Four sampling campaigns were conducted at points P1, P2, and P3, covering both flood and drought periods. Flow rates were measured using an acoustic Doppler meter (ADP M9) and sediments were collected using the Equal Width Increment (IIL) method. Acid digestion followed USEPA (1996) protocols, while granulometry was analyzed via laser diffraction (Mastersizer 2000). Results and Discussion: Net flow rates varied from 220 m3/s (P1) to 226.5 m3/s (P2), with sediment transport ranging from 1,708.56 t/day to 12,473.05 t/day. At point P2, loads of 405,873.6 kg/day of Al and 267,214.5 kg/day of Fe were reached. The metals Zn and Ni exceeded the limits set by CONAMA 454/2012, while Cu, Cr, Cd, and Pb remained at lower levels. The sediments consisted mainly of fine sand (60%), with smaller particles (17%) playing a significant role in metal transport. Research Implications: The results underscore the need for public policies focused on sustainable land management and siltation control, emphasizing the importance of sediment monitoring as an environmental indicator. Originality/Value: This study contributes by integrating data on metal transport with the physical characteristics of sediments, proposing the inclusion of parameters such as Fe and Al in environmental regulations for sediments.