Development of biotechnologies for cleaning of water bodies on the Absheron Peninsula from organic and inorganic pollutants

Purpose. Assessment of the dynamics of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region. Methodology. The study on heavy metal contents in water, bottom sediments, and hydrobionts (fish) was conducted at various water bodies (Dnipro-Donbas hydraulic canal), fish ponds (ponds of PrJSC “AgroSoyuz”, PrJSC “Petrykivsky Rybhosp” and PE «Agrofirma «Nakhodka»), and multipurpose reservoirs (Dnipro reservoir, Sholokhivske reservoir) in Dnipropetrovsk region from 2015 to 2024. The determination of heavy metal concentrations (Pb, Cd, Mn, Cu, Fe, Ni, Zn) was carried out at the laboratory of the Research Center for Biosafety and Environmental Monitoring of Agricultural Resources of Dnipro State Agricultural and Economic University. The metal content was analyzed using atomic absorption spectrophotometry. The heavy metal contents were measured in four fish species (European perch, roach, Prussian carp, common carp). Sampling, data processing, and statistical analysis were conducted according to standard hydrochemical, hydrobiological, and ichthyological methods. The heavy metal contents were determined in fish muscles. Water quality was assessed according to general requirements and standards for fishery water bodies. Findings. The heavy metal contents in ecosystems of water bodies of different purposes was determined. In the sediment of ponds of PrJSC “AgroSoyuz” and PrJSC “Petrykivsky Rybhosp”, the heavy metal contents were significantly higher than in water or fish body: manganese within 41.24–68.43 mg/kg, cadmium – 0.32 mg/kg, lead 1.50–4.90 mg/kg (for ponds of PrJSC “AgroSoyuz”); manganese – 29.73 mg/kg, cadmium – 0.54 mg/kg, lead 5.72 mg/kg (for recreational pond of PrJSC “Petrykivsky Rybhosp”). For the water of these ponds, which is used for aquaculture, an excess of the content of some heavy metals – Mn, Zn, Cd - was recorded, and for the pond of PrJSC “AgroSoyuz” also Cu. Exceeding the normative heavy metal content for pond water of PE “Agrofirma “Nakhodka” was not noted. The content of some heavy metals in the water of the upper part of the Dnipro reservoir (Cu, Fe) did not meet the fishery norms. At the same time, the heavy metal contents in water and fish of these water bodies does not exceed the fishery standards for water used for fishery purposes. The heavy metal contents in the water of the upper part of the Dniprovske Reservoir (except for the Samara Bay) corresponded to fishery standards. The water in the Dnipro-Donbas hydrotechnical canal was characterized by high levels of heavy metals. Of the 6 investigated heavy metals, the maximum allowable concentrations were not exceeded only for lead (0.40 mg/dm3) The heavy metal contents in C. carpio muscles (juveniles and table fish) in different ponds of PrJSC “Petrykivskyi Rybhosp” (nursery and fattening) corresponded to fishery standards during the three years of the study (2011, 2015, 2016). In the Sholokhivske reservoir, the zinc content in C. gibelio muscles was 46.50 mg/kg, slightly exceeding the maximum allowable concentrations. Exceedances of copper and lead content were not noted. For fish from the Dnipro reservoir, the content of most heavy metals was elevated. In the meat of pelagic roach (R. rutilus), only copper content was within the normal limits (1.56 mg/kg), while all other 6 heavy metals exceeded the maximum allowable concentrations. In the meat of benthophagous Prussian carp (C. gibelio), elevated levels of accumulation of heavy metals were observed for manganese, iron, lead, and nickel, while zinc, copper, and cadmium content were within the standards. In the meat of European perch (P. fluviatilis), the highest content of heavy metals was observed for iron (80.54 mg/kg), with elevated levels observed for manganese, zinc, lead, and nickel. The obtained results indicate that the hydroecosystem of the Dniprovske reservoir, unlike other water bodies in the region, is significantly polluted with heavy metals. This is adequately reflected in the levels of heavy metal accumulation in the organisms of fish from different ecological groups - pelagic herbivores, benthophagous bottom-feeders, and predators. Originality. For the first time, the content of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region has been carried out over several years (2015–2024). Practical Value. The obtained results have theoretical and practical importance for the preparation of scientific-biological justifications for the fishery use of water bodies of various purposes in the region. Continuous monitoring of the heavy metal contents in hydrobionts is necessary to ensure food safety and the quality of raw materials and food fish products. Keywords: Dnipropetrovsk region, heavy metals, Dnipro Reservoir, Dnipro-Donbas Canal, ponds, Sholokhivske Reservoir, water, sediment, fish, accumulation of pollutants.

Heavy metal concentrations in surface waters of Hurghada and environs, Red Sea Coast, Egypt, and their correlation with sediment distribution

To investigate the changes in heavy metal content in the sub glacial water during the freezing and thawing process of seasonally frozen lakes, the Wuliangsuhai Lake in northern China was taken as the research object. The ice thickness, water depth, and heavy metal content at different depths of the lake were measured during the freezing and thawing periods. Based on a large amount of measured lake heavy metal data, MATLAB 2022b software is used to model data fitting and optimization identification, and wavelet analysis and 24 h sliding average method are used for verification analysis to describe the variation process of heavy metal concentration in ice water with depth and time. The results show that during the freezing and thawing periods of lakes, the water level is constantly changing, but the heavy metal content in the water below the ice follows the same distribution with water depth. During the freezing process, the heavy metal content in the water increases with the increase in ice thickness. A new numerical model describing the spatiotemporal distribution of heavy metals under the ice during the freezing period of the lake was obtained through calculation. The overall trend of the simulated contour lines is consistent with the measured values and has a small error. This study provides a reference for predicting the changes in heavy metal content under the ice cover during the freezing period in cold and arid regions. The model can be used to simulate the content values of heavy metals at different depths and times.

The new technologies used in the green transition towards carbon-free societies typically demand extensive use of metals. This leads to a heavily growing need for exploration and extraction of ore deposits. Exploration can be facilitated by measuring metal concentrations in ground and surface waters carrying trace concentrations of metals leached from nearby deposits. Currently, measuring metal concentrations in water is slow and expensive and it cannot be done on-site, which hinders the discovery of new ore deposits. To address this challenge, we have developed a method to collect and concentrate the dissolved metals in a solid filter and measure the metal concentrations directly from the filter with a portable X-ray fluorescence spectrometer. The permeable filter is made of mesoporous silicon modified with bisphosphonates. Two types of adsorbing materials for the filters were prepared based on scalable production methods: i) regenerative etching of metallurgical grade silicon powder, and ii) magnesiothermic reduction of silica from barley husks. Empirical calibrations were prepared in a concentration range of 10–200 μg/L for Mn, Co, Ni, Cu, Zn, and Pb using water samples prepared by spiking well water with standard metal solutions. Both filter types were tested for their ability to adsorb metals from the real water samples taken from drill holes. The developed system was able to detect metal concentrations down to 12 μg/L (ppb) showing its potential for on-site measurements of dissolved metals in water samples, which could be feasible in the discovery of new mineral deposits. This innovation enables smart sampling during exploration and provides real-time information on metal concentrations in water.

Total concentrations and sources of heavy metal pollution in global river and lake water bodies from 1972 to 2017

Lake Burullus is an important source of fish production in Egypt; it produces 20.5% of the Egyptian fisheries' production. There is intense controversy about the heavy metal pollution in Burullus water and its effects on fish health and safety for human consumption. Heavy metals represent a major concern for aquatic life and could negatively affect fish health. Agricultural and industrial water drainage represents a considerable part of the lake water supply. The present work was conducted to determine heavy metal concentrations in lake water and blue tilapia Oreochromis aureus musculature. Water samples were collected from six locations to determine cadmium, copper, lead, zinc and iron. Sixty O. aureus fish samples were also collected from the same sampling points to assess the prevalent parasites infesting fish and to determine the heavy metal (Cd, Cu, Pb, Zn and Fe) concentrations in fish musculature then study the relationship between heavy metals concentration and prevailing fish parasites. Results indicated that 53.34% of the examined fish were infested with encysted metacercaria. Centrocestus formosanus, Prohemistomum vivax, and Euclinostomum heterostomum were retrieved from gills, musculature, hepatopancreas and the posterior kidney. The parasitic intensity in fish tissues was between 1 and 9 cystg-1. Centrocestus formosanus was identified using the polymerase chain reaction in the gill tissues of 16 fish. The gill parasitic copepod Lamproglena monodi was identified in one fish. Degenerative changes such as thickening, corrugation, and destruction of gill filament are the most dominant pathological changes in infested fish gills. Heavy metal concentrations in water samples were at normal levels, except for copper and iron in the southern part of the lake. All heavy metals in fish musculature were below the permissible limits. The parasitic infestation was more dominant in the northern part of the lake than in the southern region; this could be due to elevated copper concentration in the southern part of the lake that could negatively affect the survival of the first intermediate host and parasite cercaria. In conclusion, captured fish from Lake Burullus were safe for human consumption, and heavy metal pollution in lake water does not represent a severe risk.

The coastal waters of Palu Bay are vulnerable to pollution from various activities of the surrounding population. This study aimed to determine the content of heavy metals Pb, Cd, and Cu in the water and sediment of the coastal waters of Palu Bay. The analysis of heavy metal content (Pb, Cd, and Cu) in water and sediment was conducted using an Atomic Absorption Spectrophotometer (AAS). Based on the research, the results showed that the heavy metal content in the water ranged from undetected to 0.04 mg/L for Pb, undetected for Cd and Cu. The heavy metals content in the sediment ranged from 2.17 to 13.8 mg/kg for Pb, undetected to 0.17 mg/kg for Cd, and 5.02 to 37.67 mg/kg for Cu. The Pb content in the water has significantly exceeded the quality standard as stipulated in the Minister of Environment Decree No. 51 of 2004. The Pb content in the sediment is still within safe limits according to Canadian quality standards. The Cd content in the sediment exceeded the quality standard at station 6, while for the other 9 stations, it was not detected. The Cu content in the sediment at 5 stations (2, 3, 4, 5, and 10) has exceeded the Canadian quality standard of 18.7 mg/kg.

The Esmoriz-Paramos is a lagoon of great ecological significance located on the Northwest coast of Portugal. The quality of water and sediment within this ecosystem has been gradually degraded due to the discharges of mostly untreated industrial waste and domestic sewage. Contaminants include heavy metals that can be taken up by fish from water, food, sediments, and suspended particulate material. Fish inhabiting polluted water bodies tend to accumulate many chemicals in high concentrations, even when the environmental contamination levels are low (Colombo et al. 1995). The leaping grey mullet (Liza saliens) is one of a few dominant species living in this environment. This species may contact xenobiotics in the water column or, when feeding, in the sediments. Previous studies have analyzed heavy metal concentrations in the water and sediments of this lagoon, and evaluated their bioaccumulation in L. saliens (Fernandes et al. 2007a, b). According to these studies, the seasonal range of metal concentrations in surface water was 0.003–0.031 mg Cu L, 0.006–0.811 mg Zn L and 0.01–0.026 mg Pb L, all mainly found in particulate matter. The main metals found in sediments were Cu, Zn and Pb, respectively 83, 241 and 87 mg kgd.w. The Cu and Zn concentrations in L. saliens liver were 262 and 89 mg kgd.w. and below the detection limit for Pb (0.073 ppm), whereas these concentrations in the gill were 9 mg Cu kg d.w.; 114 mg Zn kg d.w. and 0.6 mg Pb kg d.w. Also, significant age-related increase of metal concentrations in tissues, were noted, for Zn in gill and for Cu in liver and gill (Fernandes et al. 2007a). The gill is particularly sensitive to physical and chemical changes in the aquatic environment and it is the main target organ in fish for toxic waterborne heavy metals (McDonald and Wood 1993). Effects of metals on ionoregulatory gill functions have been well demonstrated, including regulation of plasma electrolytes (Mazon et al. 2002; Grosell et al. 2003; Martinez et al. 2004). The histological effects of metals on fish gill have also been studied in several fish species (Arellano et al. 1999; De Boeck et al. 2001). The mechanisms of acute Cu toxicity include the osmoregulatory disturbances involving Na, Cl and K uptake by the gill (Mazon et al. 2002; Grosell et al. 2003). Although the mechanisms of heavy metals toxicity are well known in acute exposure, the process may differ in chronic exposure (Handy 2003). The objectives of this study were to evaluate the plasma electrolyte concentrations of wild Liza saliens from the Esmoriz-Paramos lagoon and to assess the osmoregulatory responses and branchial histopathological changes related to chronic heavy metal exposure in this habitat.

안동호와 임하호의 수환경내 중금속의 오염정도와 서식 어종간의 중금속 축적 정도를 알아보기 위해 양호수의 수질, 저니 및 서식어종인 붕어를 이용하여 중금속 함량을 비교 분석하였다. 안동호와 임하호 수질과 저니내 중금속 함량은 안동호에서 높은 함량을 보이며, As는 함량의 차이가 큰 것으로 나타났다. 안동호와 임하호에 서식하는 붕어의 중금속 함량의 경우 안동호에 서식하는 붕어에서 높은 함량을 보이며, Cr, Cu, Cd 및 As는 함량의 차이가 큰 것으로 나타났다. 또한 비늘, 근육, 뼈 조직은 안동호와 임하호의 함량차이가 크며, 안동호에서 높은 함량을 나타냈다. 본 연구의 결과 안동호와 임하호의 수질과 저니 및 서식어종인 붕어의 중금속 함량은 안동호에서 임하호보다 중금속 함량이 높게 나타났으며, 안동호와 임하호의 함량차이도 큰 것으로 나타났다. 이는 안동호의 경우 안동호 상류 지점의 폐광산과 농경지로부터 하상퇴적물이 유입되어 하상퇴적물 속에 포함된 유기물을 붕어가 먹이로 섭취함으로써 중금속 함량에 영향을 미친 것으로 생각된다. Heavy metal contamination levels in Andong reservoir and Imha reservoir were measured with heavy metal contents in both water and sediment, and analyzed with heavy metal accumulation level in inhabitant fish, Carassius auratus, using an inductively coupled plasma spectrometer and an atomic absorption spectrometer. High levels of heavy metal contents in water, sediment and the tissues of C. auratus were detected. Likewise, relatively high levels of As were detected in water and sediment from Andong reservoir. In addition, higher levels of Cr, Cu, Cd and As content were detected in muscle and bone tissues of fish from Andong reservoir than those from Imha reservoir. As a result, the heavy metal content of water, sediment and inhabitant fish, C. auratus, in Andong reservoir was higher than Imha reservoir. We proposed that heavy metal contamination in water and inhabitant fish is attributed to various metals derived from abandoned mines and farmlands that are upstream of Andong reservoir.

Heavy metals are of serious concern for human health and food security. The risk to human health is directly related to soil and water pollution, which enter the food chain (vegetables and fruits). The current study was designed to investigate the heavy metals (Cr, Pb, Ni, Cd, and Zn) concentrations in five vegetables (Potato, Tomato, Turnip, Onion & Taro) and five fruits (Banana, Apple, Grapes, Pomegranate, and Guava) samples. We also estimated metal concentrations in water and soil samples. Torkham, a border region between Afghanistan and Pakistan, was selected for the purpose. The analysis was performed on Atomic Absorption Spectroscopy (AAS, Perkin- Elmer 700). In vegetables, the highest Pb and Ni were recorded in Potatoes (0.34 ± 0.066) and Onions (0.278 ± 0.021). While in tomatoes, the highest concentrations of Cd (0.90± 0.115), Zn (0.726 ± 0.008), and Cr (1.761 ± 0.028) were noted. While, in fruits the highest levels of Pb (0.32± 0.03), Cd (0.61 ± 0.0119), Zn (0.357 ± 0.0047) and Ni (0.111 ± 0.0128), while in apples we noted the highest Cr levels (0.789 ± 0.0452). We compared the metal concentrations with permissible limits set by World Health Organization/Food and Agricultural Organization (WHO/FAO). In the majority of the samples, the metal levels exceeded the permissible limits, while few were found within the safe limits. Based on heavy metals concentrations in soil, water, vegetables, and fruit samples. We calculated the health risk assessment, i.e., daily intake of metals (DIM) estimated daily intake (EDI), target hazard quotient (THQ), total target hazard quotient (TTHQ), carcinogenic risk (CR), health risk index (HRI) and contamination factor (CF). The EDI for Ni and Zn was in the safest region. While for Cd and Pb, the highest EDI was recorded in tomatoes (0.394) and guava (0.303), respectively. Similarly, Cr poses’ serious risk with the highest EDI in tomatoes (0.771), apples (0.563), turnip (0.393), guava (0.282), and banana (0.263). If HRI, THQ THQ, and TTHQ are less than one (< 1), it means the exposed populations are not at risk. In the present HRI, THQ and TTHQ were found to be less than one. The contamination factor for Ni and Zn was found to be considerable (CF<6), while Pb, Cd, and Cr presented the highest contamination degree (CF>6). This study suggested that some samples may impose a certain degree of potential health risk. It is required that proper action should be taken to avoid chronic exposure and consequent adverse health effects.

Variation in metal concentrations across a large contamination gradient is reflected in stream but not linked riparian food webs

Dombivli city is one of the most industrialized cities situated near Mumbai. The increase in industries, has led to increase in the discharge of industrial waste effluents from the industrial belt into the Ulhas River, due to improper environmental planning. This day by day increasing tremendous pollution load has prompted us to carry the systematic and detailed study on the heavy metal content in water of Ulhas River. The study was conducted over a period of two years i.e. in 2012 and 2013. The study was carried out along the banks of Ulhas River, near the discharge of effluents from Dombivli Industrial belt Phase I and Phase II. The sampling points were identified accordingly. The analysis for the majority of the toxic heavy metals like Mercury (Hg), Arsenic (As), Cadmium (Cd), Cobalt (Co), Lead (Pb), Nickel (Ni), Chromium (Cr), Copper (Cu), Zinc (Zn) and Iron (Fe) in water samples was done. The results of our study indicated that there is a need to conduct systematic and regular monitoring of pollution level along the Ulhas River with an intention to obtain the scientific data on heavy metal content in the river water. Such data will be useful to improve the industrial waste treatment technology adopted along the Dombivli industrial belt.

Ledulu Lake is one of the lakes in the Rote Ndao Region. Lake Ledulu was formed in the Quaternary period with Cenozoic constituents and Neogene deposits based on geological formations. The formations found in the Lake area are sediment, chemical, limestone. The purpose of this study was to measure the metal content in the lake water and its absorption by aquatic vegetation in the ecosystem of Ledulu lake, using Instrumental neutron activation analysis (INAA) technique. NAA is one of the modern methods that is able to measure the level of heavy metal uptake in aquatic biota (water animals and aquatic plants). The metal content in the water of the lake (mg/L) is: Bromine 405.06, Calcium 7,195.66, Cerium 9.10, Cobalt 2.43, Chromium 45.90, Lanthanum 12.07, Magnesium 1,189.93, Sodium 24,382.31. Aquatic plants that absorb heavy metals in lake Ledulu are Panicum sp, Ludwigia adscendens (L.) H.Hara, Ottelia alismoides (L) pers, Najas sp, Ipomea aquatica Forssk, Pontederia korsakowii (Regel & Maack) M.Pell. & C.N.Horn, Callitriche sp, Bacopa monnierii, and Nymphaea alba L. Sodium is not absorbed by Panicum sp, Ludwigia adsendence (L), and Nymphaea alba. Lanthanum is only absorbed by Panicum sp and Callitriche sp. All other elements can be absorbed by aquatic plants in the Ledulu lake ecosystem with different absorption concentrations.

Dombivli city is one of the most industrialized cities situated near Mumbai. The increase in industries, has led to increase in the discharge of industrial waste effluents from the industrial belt into the Ulhas River, due to improper environmental planning. This day by day increasing tremendous pollution load has prompted us to carry the systematic and detailed study on the heavy metal content in water of Ulhas River. The study was conducted over a period of two years i.e. in 2012 and 2013. The study was carried out along the banks of Ulhas River, near the discharge of effluents from Dombivli Industrial belt Phase I and Phase II. The sampling points were identified accordingly. The analysis for the majority of the toxic heavy metals like Mercury (Hg), Arsenic (As), Cadmium (Cd), Cobalt (Co), Lead (Pb), Nickel (Ni), Chromium (Cr), Copper (Cu), Zinc (Zn) and Iron (Fe) in water samples was done. The results of our study indicated that there is a need to conduct systematic and regular monitoring of pollution level along the Ulhas River with an intention to obtain the scientific data on heavy metal content in the river water. Such data will be useful to improve the industrial waste treatment technology adopted along the Dombivli industrial belt.

This study aimed to investigate nine heavy metal concentrations (As, Cd, Cr, Pb, Cu, Fe, Zn, Mn and Ni) in water, sediment and snakehead fish (Channa striata) and to identify abnormal chromosomes in C. striata from a reservoir near an industrial factory and a reference area. Heavy metal concentrations were measured by inductively coupled plasma optical emission spectrometry (ICP-OES). The metal concentrations in the water, sediment and C. striata samples did not exceed the standard limit of Thailand, except for Cr concentrations, which exceeded water quality standards. The concentrations of Cd, Fe, Mn and Ni in C. striata samples between the reservoir and the reference area were significantly different (p < 0.05). The diploid chromosome number of C. striata from both areas was (2n = 42). Eight types of abnormal chromosomes were identified and classified as a single-chromatid gap, a single-chromatid break, centric fragmentation, a centric gap (CG), fragmentation, deletion, single-chromatid decomposition and iso-arm fragmentation. The most frequent abnormal chromosome in the samples was CG. The percentages of abnormal chromosomes in the C. striata samples from the reservoir near the industrial factory and the reference area were significantly different (p < 0.05) at 8.44 and 1.20, respectively.