Pollution Of Bottom Sediments Research Articles

Environmental and Geochemical Assessment of Bottom Sediment Pollution (Approaches, Monitoring, Utilization)

The results of ecological and geochemical assessment of the state of bottom sediments of small rivers in the city of Berezniki (Perm region) are presented, and the issues of environmental monitoring of small rivers of Verkhnekamie are identified. A comprehensive assessment of bottom sediment contamination is carried out. Their unsatisfactory condition in terms of the heavy metals content (Ni, Cu, Zn, Pb, Cd, Hg) and As was noted. Possible environmental actions for the disposal of such sediments are analyzed. It is concluded that it is advisable to carry out on-site remediation or dispose of sediments at specialized landfills followed by recycling.

The impact of destruction of the Kakhovka dam on the environmental status of the Odesa area of the Black Sea

The paper provides a chronological description of the aftermath and the effect of blowing up the Kakhovka hydroelectric power plant dam by Russian occupation forces of 6 June 2023 on the seawater quality in the coastal zone of Odesa agglomeration, according to the results of operational environmental monitoring in the early weeks upon the man-made disaster. Such a description is indispensable for assessing the scope of pollution of marine water areas and calculation of the damage inflicted on the marine ecosystem and its natural resources, adjustment and verification of mathematical models which will further be used to prognosticate the consequences of the dam destruction for the marine ecosystem. According to the data published in open sources, development of the environmental, sanitary and microbiological situation in the coastal zone of the city of Odesa over June 2023 is described, the dynamics of some indices of the sea water quality are shown, and the pollutants the concentration of which exceeded the maximum permissible concentrations set for them, as well as sanitary and microbiological indices, according to which the population is forbidden from swimming in the sea, are indicated. In addition, as a consequence of the abnormal desalination of sea waters and the inflow of a large amount of nutrients and organic matter into the sea, the phenomenon of algal bloom is described, and a qualitative forecast of its consequences is provided. It is concluded that owing to the accumulated reserves of organic matter in the bottom sediment probability of hypoxic conditions and suffocation of hydrobionts in the summer periods will increase in the years to follow. It is in view of the accumulation of pollutants in bottom sediments and the expected secondary pollution of sea water that the biological diversity of the marine ecosystem within the Odesa region will degrade and the quality of its biological resources will deteriorate.

ORGANOCHLORINE PESTICIDES POLLUTION OF THE BOTTOM SEDIMENTS OF NAKHODKA BAY AND PARTIZANSKAYA RIVER

Link for citation: Mazlova E.A., Blinovskaya Ya.Yu., Sokolova L.I., Tursunova G.Sh. Organochlorine pesticides pollution of the bottom sediments of Nakhodka bay and Partizanskaya river. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 25-35. In Rus. Relevance. The new data on the organochlorine pesticides pollution of the bottom sediments of Nakhodka bay and Partizanskaya river were obtained in 2020–2021. The objective of the article is to report the organochlorine pesticides pollution level of the bottom sediments and to define the possible sources of organochlorine pesticides in the marine environment. Techniques: sample collection of bottom sediments, Gas Chromatography Mass Spectrometry analysis of samples, Gas-liquid Chromatography method with electronic capture detector, statistical processing, assessment of the organochlorine pesticides contamination of sediments. Results. The new data were obtained on the organochlorine pesticides concentrations in Nakhodka bay in 2020–2021. The previous data on the studied area are described. The concentration of HCH pesticides (α- , β- and γ-HCH), DDT and its metabolites was analyzed. It was found that the concentration of α- , β- HCCH and DDT in bottom sediments increased in 2021.To determine the quality of bottom sediments, the average annual values of organochlorine pesticides concentrations in the bottom sediments gathered during the field works were compared with the quality guidelines. There are no approved quality guidelines for maximum permissible concentrations of pollutants in bottom sediments in the Russian Federation. For this reason, we used the quality guidelines applied in foreign countries («Dutch sheets» (Neue Niederlandische Liste. NNL) and Canadian quality standards for marine and estuarine bottom sediments (Canadian Sediment Quality Guidelines, CSQGs). Possible sources of organochlorine pesticides in the marine environment were analyzed. The results of this work showed that despite the ban on the use of these substances, these pesticides are included in the multiple compounds used in different industries and continue to enter and accumulate in the marine environment.

ОЦЕНКА ЗАГРЯЗНЕННОСТИ МОРСКИХ ВОД

Assessment of the seawater quality is based on the calculation of the integrated index water pollution (IWP). The average concentration of the most significant pollutants in a local area of the sea during a certain period expressed in units of the maximum allowable concentration (MAC) is at the core of the index. The long-term practice of using the IWP has allowed for significant additions and corrections in the calculation methodology and in scientific interpretation of results, which improves the accuracy of assessing the state of marine environment based on standard hydrochemical studies. To assess the seawater quality by one parameter, a six-rank scheme is proposed, the scale of which was developed on the basis of the MAC for an analyzed substance. Additional criteria of seawater pollution related to eutrophication, amount of marine litter, pollution of bottom sediments and suspended solids and tissues of marine biota are proposed.

ASSESSMENT OF BOTTOM SEDIMENT POLLUTION IN SMALL RIVERS, VLADIMIR REGION

The results of assessing pollution of bottom sediments in four small rivers of the Vladimir region with heavy metals (HM) and phosphates are presented. According to HM concentration coefficients characterizing the concentration (anomaly) of elements in bottom sediments in respect to their background content in the region, the zones of technogenic multi-element geochemical anomalies in the channels of all studied watercourses and their structure were identified. It has been established that Fe, Pb, Co, Cu, Zn, Cr, and Mn are the priority metals of technogenic geochemical anomalies in bottom sediments. The highest pollution of bottom sediments with these metals is typical for the zones influenced by the runoff from the territories of collective orchards, livestock complexes, large industrial cities and rural settlements. According to the total pollution indicator (Zc), which reflects the additive excess of the background content of a group of heavy metals that are part of technogenic geochemical anomalies, the studied watercourses are located in the following order: Sodyshka Kamenka Rpen Ilevna, and according to the phosphate content: Sodyshka Rpen Kamenka Ilevna. Correlations between the components of bottom sediments have been studied. The average load of heavy metals and phosphates on watercourses was assessed.

Pollution and Potential Ecological Risk Evaluation of Heavy Metals in the Bottom Sediments: A Case Study of Eutrophic Bukwałd Lake Located in an Agricultural Catchment.

Metals are natural components of the earth's crust and are essential elements in the metabolism of fauna and flora. However, some metals at high concentrations may pose an ecological risk. Ecological risk analysis is one of the best methods for detecting potential metal pollution problems and its impact on ecosystems. This study analyzed the potential ecological risk and contamination from heavy metals (Cd, Cu, Pb, Ni, Cr, and Zn) in bottom sediments. It analyzed the spatial variability of heavy metal concentrations in the bottom sediments of Lake Bukwałd. The potential ecological risk index (RI) was used to assess the impact of pollutants accumulated in bottom sediments on the environment. In addition to RI, the geochemical index (Igeo) and contamination factor (CF) were also calculated. The pollutant loading index (PLI) was used to compare the average content of metals in the bottom sediments of lakes. The obtained results indicate that agricultural activity determined the quality of the bottom sediments of the reservoir and the spatial content of trace metals in them. Higher concentrations of elements were found in sediments collected from the agricultural catchment, whereas the lowest concentrations were observed near the outflow from the lake. The calculated RI value was 153.3, representing a moderate ecological threat risk. The concentration of cadmium had the greatest influence on the value of the indicator. The analysis of the scale of pollution of bottom sediments using the geochemical index showed that the bottom sediments in terms of the content of most of the trace metals tested are class II. In Cu and Zn, the Igeo index classified these deposits as class 0 and class I. The highest CF values were determined for Cr, Ni, and Pb and classified as significant contamination. The remaining elements were classified as moderately contaminated. The designated PLI was 2.49, suggesting immediate action to reduce pollution and prevent the degradation of the lake.

Determination of pollution status of Nilüfer river by water and bottom sediment analysis

Abstract This study aims to evaluate the Nilüfer river in terms of water quality standards. Bottom sediment and water samples were taken from six different locations. The analysis of the physicochemical parameters of water compared with FAO for irrigation water quality standards. In addition, the SAR (sodium adsorption ratio), % Na, MAR (magnesium adsorption ratio), RSC (residual sodium carbonate), KR (Kelley's ratio) and % PI (permeability index) parameters were evaluated in water samples. The bottom sediment pollution situation was evaluated in terms of pollution index such as TEC (threshold effect concentration) and PEC (probable effect concentration). According to the results of the study, the irrigation water classes of the samples were determined as C2S1 and C3S1. Especially, sample sites S4, S5 and S6 were not suitable for irrigation in terms of RSC, KR. The bottom sediment exceeded the TEC and PEC limit values in terms of Zn, Cu, Cr and Ni contents. This may cause adverse effects on the majority of sediment-dwelling organisms.The use of alternative water sources should be preferred. The river can be used for irrigation with precaution but extensive treatment is required before use for irrigation purposes to prevent adverse public health effects.

ПОЛИАРОМАТИЧЕСКИЕ УГЛЕВОДОРОДЫ В ДОННЫХ ОТЛОЖЕНИЯХ КАСПИЙСКОГО МОРЯ

In this study, variations in the levels of oil hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), which are persistent organic pollutants generated by human activities, were assessed in the bottom sediments of the Caspian Sea (Russia) sampled from 2012 to 2021. The samples were analyzed for their chemical composition. The concentrations of the identified compounds responsible for hydrocarbon pollution were established. The quantitative results of the industrial environmental monitoring in the Russian sector of the Caspian Sea for subsoil use were also reviewed and processed by standard statistical methods. It was revealed that ΣPAH concentrations in the Northern and Middle Caspian Sea regions vary from analytical zero to 186.7 μg/kg and from zero to 467.8 μg/kg, respectively. The scale of oil pollution in these two regions was found to be determined by the following PAHs: phenanthrene, acenaphthene, and naphthalene. The origin of the listed PAHs provides vital information on the main sources of pollution of the Caspian Sea bottom sediments with hazardous organic substances. Based on the obtained data, the areas with background PAH pollution of the bottom sediments and those with the characteristic PAH of mainly natural and pyrogenic origin were located.

Monitoring of Benzo(a)pyrene Pollution of Bottom Sediments of the Lake Baikal in the Sites of Increased Anthropogenic Load over the Period from 2011 to 2021

Monitoring of Benzo(a)pyrene Pollution of Bottom Sediments of the Lake Baikal in the Sites of Increased Anthropogenic Load over the Period from 2011 to 2021

Elevated Urbanization-Driven Plant Accumulation of Metal(loid)s Including Arsenic Species and Assessment of the Kłodnica River Sediment Contamination

The impact of water and bottom sediment pollution of a river subjected to a strong industrial anthropogenic pressure of metal(loid) (including arsenic and its species) accumulation in riverbank plants such as Solidago virgaurea L., Phragmites L. and Urtica dioica L. was investigated. The high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) technique was used to study organic and inorganic arsenic species in selected plants and their response to heavy metal and arsenic contamination. The modified BCR extraction results showed that arsenic was mainly bound to the mobile reducible and organic-sulfide fractions in the Kłodnica River bottom sediments. Research has shown that the bottom sediments of the Kłodnica River are contaminated with metals, including Pb, Zn, Ni, As, and among arsenic species, the As(V) form dominated quantitatively, with its highest concentration being 49.3 mg kg−1 and the organic species occurred extremely rarely. The highest concentration of arsenic, among the tested plants, occurred in Phragmites communis L. The evaluation of the bottom sediment pollution was performed using Sb/As factor, geoaccumulation index (Igeo), enrichment factor (EF) and pollution load index (PLI). The ability of the plant to assimilate metals from the substrate was studied by calculation of the bioaccumulation factor (BAF). Values of the Igeo change in a wide range from class 1 (uncontaminated to moderately polluted for Cu and Zn) at the first sampling point, to 5 (highly to extremely polluted for Ba and Fe) at the K4 sampling point. The Igeo results show an increase in the contamination with elements toward the runoff of the Kłodnica River.

Оценка влияния выращивания товарной рыбы в садках на экологическое состояние водоема

Growing a large mass of hydrobionts in a limited area (cage fish farming) entails a local increase in the load on the ecosystem from additional organic matter. In connection with the high growth rates of development of cage farms in various open natural water bodies, it is necessary to improve the system for monitoring their impact on aquatic biocenoses. The quality of surface waters and bottom sediments of the Ermakovskiy Bay of the Ust-Kamenogorsk Reservoir has been assessed in the of operation area of the cage farm Shygys, LLP. According to the zooplankton indices, the Pantle-Bukk saprobity index in the modification of Sladechek was used, the oligochaete index was used for macrozoobenthos. The studies were carried out at three stations: 200 m upper the bay (conditionally background station); at the cage line (reflects the local impact of the fish farm on the reservoir); 200 m lower the bay (reflects the overall impact of the enterprise on the reservoir associated with the removal of pollutants). As a result of the research, it was found that before the start 
 of cage fish farm operation the quality of water and bottom sediments at all points of the study corresponded to the “clean” category. A year after the launch of the enterprise a decrease in the taxonomic richness of zooplankton was noted, which indicates a slight deterioration in the quality of surface waters. In the fourth year of cage farm operation the saprobity indices near the cage line grew up to 1.8, and lower the bay - to 1.6, which indicates a local deterioration of the surface waters quality (class III, moderately polluted water). A similar situation is also characteristic of benthic communities of invertebrates. In 2017, at all three research stations, and in subsequent years only at a conditionally background station bottom sediments were characterized as clean. In 2019-2021 the pollution of bottom sediments was on the rise in the cage zone and below the Yermakovskiy Bay. The values of the oligochaete index increased from 14-20 to 58-75%. In 2019, bottom sediments were rated as class IV (contaminated), and in 2021 - as class V (dirty). On the results of the studies there were developed the corrective measures for reducing the anthropogenic load on the open natural reservoir. In the future monitoring the changes in qualitative and quantitative indicators of hydrobionts in the operation area of fish cage farms will allow local monitoring of water quality and timely adjustment of reclamation and fish breeding activities.

Features Accumulation of Heavy Metals in the Bottom Sediments of Small Rivers

The article considers one of the aspects of anthropogenic impact on river ecosystems – the accumulation of pollutants in bottom sediments. The authors analyze the state of small rivers, the study of which is not given enough attention, while their importance for maintaining the ecological well-being of local territories and the formation of their biological diversity can hardly be overestimated. The bottom sediments of two rivers (according to V.L. Rokhmistrov’s classification - the smallest and small) are being investigated for the content of heavy metal ions; the granulometric composition of sediments and the content of organic matter in them are also determined. The results of the study indicate the presence of some regularities in the distribution of certain metals in bottom sediments of the river core, heavy pollution of sediments with mobile forms of heavy metals and their possible impact on the ecological state of its own drainage basin and the state of the large river fed by them.

Potentially toxic elements contents and the associated potential ecological risk in the bottom sedimentsof Hrazdanriver under the impact of Yerevan city(Armenia).

This research aims to assess the ecological status of the Hrazdan river (Armenia) section that flows through Yerevan. The distribution of potentially toxic elements (PTE) (Cr, V, As, Zn, Cu, Ni, Co, Mn, Pb, Ti, Mo, Fe, and Ba), the bottom sediments pollution level, and the ecological risk were assessed employing the single pollution index (SPI), the enrichment factor (EF), the geo-accumulation index (Igeo), and the potential ecological risk index (RI). On sampling sites, water quality parameters (turbidity, DO, electrical conductivity (EC), salinity, TDS, pH, temperature°C) were measured as well. The correlation analysis revealed a significant correlation between Zn-Cu, Pb; Cu-Pb, Mo; Co-Fe, Ti pointing out similar sources and origination of these elements. The results indicated that the content of the studied elements in the Hrazdan bottom sediments exceeded the background content in urban soils, which was due to a set of geological and anthropogenic factors. High contents of elements were determined on the sampling sites spatially confined to the residential and industrial areas. According to EF and Igeo data, the priority bottom sediment contaminants are As, Pb, Mo, Zn, V, and Cu. The RI value varies from 196 to 316 with the mean of 246 which corresponds to the moderate-level ecological risk. On the whole, a moderate (77.8%) and a considerable (22.2%) ecological risk was revealed. The major source of Pb, Cu, Zn, and Mo contents was identified as the surface runoffs in the urban environment. This was verified by the cluster analysis results.

Comparative Assessment of Organochlorine Pollution of Bottom Sediments in Different Types of Water Bodies in the Sevastopol Region (Crimea)

Comparative Assessment of Organochlorine Pollution of Bottom Sediments in Different Types of Water Bodies in the Sevastopol Region (Crimea)

Comparative Assessment of Organochlorine Pollution of Bottom Sediments in Different Types of Water Bodies in the Sevastopol Region (Crimea)

Comparative Assessment of Organochlorine Pollution of Bottom Sediments in Different Types of Water Bodies in the Sevastopol Region (Crimea)

Heavy Metals in the Bottom Sediments of the Black Sea Northwestern Shelf in Recent Years

Purpose. The study is aimed at investigating metal accumulation in the 0–2 cm layer of the bottom sediments of the Black Sea northwestern shelf over 2000–2020, and at identifying the sea bottom areas subjected to the increased anthropogenic load through comprehensive assessment of the degree of their pollution taking into account their granulometric composition. Methods and Results. The bottom sediments were sampled annually from the 0–2 cm depth at the same stations. The detected metal concentrations were compared with their content in the Earth crust and the background values. The dynamics and trends of the individual metals’ content in the shelf bottom sediments were assessed for the whole period of observations. The notion of the average characteristic concentration of an element is introduced; the procedure for its calculation is represented. The pollution of bottom sediments was analyzed with the regard for the element average characteristic concentration in the bottom sediments of various granulometric types. Increase in the average content of lead, zinc and chromium was revealed from the beginning of the observation period to 2020. The seasonal dynamics of these elements was found in the whole water area under study (as well as the iron content at some areas). Conclusions. Multiple cases of the lead, manganese and chrome concentrations exceeding their content in the Earth crust were recorded; as for zinc and copper, such cases were few and sporadic. The tendencies in variation of the bottom sediments content were determined: the average long-term values of the lead concentration increased by 1.2 times, those of zinc – by 1.6 times, and those of chrome – by 2 times; the concentrations of iron, manganese and copper remained essentially the same. Seasonal dynamics of the zinc, chromium, lead and iron content was shown. For a number of metals, the cases when their absolute content exceeded their average characteristic concentration in the corresponding type of the bottom sediments had been found. The regions subjected to a multi-faceted anthropogenic load were identified; the areas of possible local inflow of the monitored elements were revealed. The bottom sediments sampled in 2019 were the most polluted.

Tyazhelyye metally v donnykh osadkakh shel'fa severo-vostochnoy chasti Chernogo morya v sovremennyy period

Purpose. The study is aimed at investigating metal accumulation in the 0–2 cm layer of the bottom sediments of the Black Sea northwestern shelf over 2000–2020, and at identifying the sea bottom areas subjected to the increased anthropogenic load through comprehensive assessment of the degree of their pollution taking into account their granulometric composition. Methods and Results. The bottom sediments were sampled annually from the 0–2 cm depth at the same stations. The detected metal concentrations were compared with their content in the Earth crust and the background values. The dynamics and trends of the individual metals’ content in the shelf bottom sediments were assessed for the whole period of observations. The notion of the average characteristic concentration of an element is introduced; the procedure for its calculation is represented. The pollution of bottom sediments was analyzed with the regard for the element average characteristic concentration in the bottom sediments of various granulometric types. Increase in the average content of lead, zinc and chromium was revealed from the beginning of the observation period to 2020. The seasonal dynamics of these elements was found in the whole water area under study (as well as the iron content at some areas). Conclusions. Multiple cases of the lead, manganese and chrome concentrations exceeding their content in the Earth crust were recorded; as for zinc and copper, such cases were few and sporadic. The tendencies in variation of the bottom sediments content were determined: the average long-term values of the lead concentration increased by 1.2 times, those of zinc – by 1.6 times, and those of chrome – by 2 times; the concentrations of iron, manganese and copper remained essentially the same. Seasonal dynamics of the zinc, chromium, lead and iron content was shown. For a number of metals, the cases when their absolute content exceeded their average characteristic concentration in the corresponding type of the bottom sediments had been found. The regions subjected to a multifaceted anthropogenic load were identified; the areas of possible local inflow of the monitored elements were revealed. The bottom sediments sampled in 2019 were the most polluted.

Organicheskoye veshchestvo donnykh otlozheniy krymskogo i kavkazskogo poberezhiy (Azovskoye i Chernoye morya)

As part of the 113th cruise of the R/V “Professor Vodyanitsky”, research was conducted on organic pollution of bottom sediments in the coastal areas of Crimea and the Caucasus, as well as the water area in front of the Kerch Strait. Concentration of chloroformextractable substances was determined by the weight method and that of petroleum hydrocarbons was determined using infrared spectrometry. Both in 2020 and 2016 (the 83d cruise of the R/V “Professor Vodyanitsky”), properties of the bottom sediments of the Crimean and Caucasian coasts were typical of the marine soils of this region. This indicates that the studied water areas are generally in good condition. In accordance with the regional classification of bottom sediment pollution, the maximum concentrations of chloroform-extractable substances obtained for both the Black Sea and the Sea of Azov coast indicate pollution level III (23% of analysed samples). These values were found in bottom sediments in the Sevastopol water area (225 mg·100 g-1), in the coastal area of Cape Tarkhankut (120 mg·100 g-1) and Karadag (120 mg·100 g-1), the southern part of the Sea of Azov (125 mg·100 g-1) and Tuapse (110 mg·100 g-1). The content of chloroform-extractable substances in bottom sediments off the Black Sea coast of the Caucasus and the Sea of Azov coast is slightly lower than that off the Crimean coast. Pollution level II is assigned to bottom sediments in 46 % of the samples, with an average concentration of 72 mg·100 g-1 of air-dry solids. The rest (31 %) of the studied area was classified as conditionally clean (pollution level I, i. e. less than 50 mg·100 g-1). There has been a slight increase in the concentration of petroleum hydrocarbons in the bottom sediments of both the Black Sea and the Sea of Azov and their share in the total amount of chloroformextractable substances. In general, the level of pollution of bottom sediments by organic matter remained unchanged if compared with previous years, in particular with the data from 2016

EVALUATING THE ANTHROPOGENIC IMPACT ON THE PRUT RIVER NEAR YAREMCHE-TOWN ON THE POLLUTION LEVEL INDICES OF BOTTOM SEDIMENTS

Introduction. One of the most objective and reliable indicators of the state of pollution of the aquatic environment and the overall level of technological load on it is the content of pollutants in bottom sediments (BS). There are no large industrial enterprises in and around Yaremche-town (Ivano-Frankivsk region), so there are no significant discharges of toxic substances into the sewage system, especially directly into the river. However, every year in this picturesque cornerof Prykarpattia the number of sanatoriums, recreation centres, cottage towns and just residential buildings grows. Accord-ingly, the Prut River, which is the pearl of this region, quite often gets untreated runoff, which pollutes not only water but also settles on bottom sediments.The purpose of this study was to assess the anthropogenic load on the Prut River based on a comprehensive environmental analysis of the state of pollution of the bottom sediments of this river upstream and downstream from Yaremche.Methods. Water extracts from bottom sediments were prepared by the recommendations of the relevant regula-tions in the ratio "bottom sediments - water" as 1: 5 in terms of the dry mass of bottom sediments. Laboratory study of hydrochemical parameters of selected samples was performed by gravimetric, titrimetric, photometric and other methods of analysis.Research results. The accumulation of ammonium salts, nitrites and nitrates, which are easily soluble, in the far above the discharge site of wastewater, is obviously due to the significant sorption properties of river sludge, which prevents these ions from being washed away by the flow. At the point of discharge of wastewater from the city, the content of these ions increases and reaches a maximum at point 3 - at a distance of approx. 100 m below the discharge site. Further downstream, their number systematically decreases. A similar distribution of concentrations is observed in the case of phosphates. Their source of getting into the river also, for the most part, belongs to the housing and communal services. A significant contribution to the increased phosphate content in the sample below the discharge is made by urban wastewater, in which even after treatment the concentration of phosphate ions remains quite high. The fact of the presence of oil products in the bottom sediments at the investigated area was revealed. The constant increase in the number of road transport on the banks of this resort river inevitably leads to the ingress of products of incomplete combustion of fuel, uncontrolled spills.Conclusions. Upstream from the place of discharge into the Prut River of treated wastewater in the city of Yaremche, the concentrations of salts-pollutants of the biogenic group are formed due to uncontrolled sources of domestic sew-age. In this area, the pollution of bottom sediments is insignificant, slightly higher at the discharge site, and they are of the greatest importance below the discharge. This fact indicates the growing anthropogenic impact of coastal cities on the state of the river and in general, and pollution of bottom sediments, in particular. For the first time oil products were found in bottom sediments in the studied area. The reason for this phenomenon is the constant increase in the number of vehicles on the banks of this river.

The Effects of Land Use on Concentrations of Nutrients and Selected Metals in Bottom Sediments and the Risk Assessment for Rivers of the Warta River Catchment, Poland

Changes in the environment, aiming at agricultural intensification, progressive urbanisation and other forms of anthropopression, may cause an increase in soil erosion and a resulting increase in the pollution inflow to surface water. At the same time, this results in increased nutrient pollution of bottom sediments. In this study, the concentrations of total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), calcium (Ca), iron (Fe) and potassium (K) were analysed using bottom sediment samples collected at 39 sites located along the entire length of the Warta River and its tributaries. Agricultural use of land adjacent to rivers was found to significantly degrade sediment quality, while anthropogenic land use (as defined by Corine Land Cover classification—CLC), unlike previous studies, reduces the pollution loads in the bottom sediments. Forest use also contributes to the reduction of the pollution load in sediments. It was found that the significance of the relationship between pollutant concentrations and land use depends on the length of the river–land interface. According to the analyses, the level of correlation between the analysed constituents depends on the use of land adjacent to rivers. The impact of agricultural land use has the strongest effect in the 1 km zone and 5 km in the case of anthropogenic land use. The results showed that the variability of total phosphorus TP concentrations is strongly correlated with the variability of iron concentrations. SPI values indicate that the risk to sediment quality is low due to TOC and Fe concentrations. In contrast, the risk of sediment pollution by TN and TP shows greater differentiation. Although the risk is negligible for 40% of the samples, at the same time, for 33% of the samples, a very high risk of pollution with both TN and TP was found.