Polluted Water Research Articles

Analysis of the dynamics of the ecological state of watercourses in the sub-basin of the Syan River

Based on the generalization of the results of regime observations by environmental monitoring services, an analysis of the dynamics of the ecological state of watercourses in the sub-basin of the Syan River (at six observation points) has been carried out. The dynamics of water use in the Syan River sub-basin for 2021–2022 were analyzed, according to which the total discharge in the Syan sub-basin in 2022 decreased by a quarter. The discharge of polluted wastewater in 2022 was a third higher, accordingly, the discharged volume of treated sewage was also lower than in 2021. An analysis of potentially possible sources of pollution of water bodies in the Syan River sub-basin has been carried out. The most significant impact on the water quality change here is caused by the wastewater discharges of municipal enterprises: the municipal enterprises “Novoyavorivskvodokanal” and “Yavorivvodokanal”. A significant cause of surface water pollution is the discharge of wastewater by the private sector. The Yavoriv quarry “Sіrka” causes the ingress of sulfates into the Shklo River, a significant trend towards their reduction has been observed from 2020 to 2022 by 71.9 %. In Lviv region, agriculture accounts for about 11%, which also negatively affects the state of water bodies. According to the results of monitoring of surface waters within the Ukrainian part of the Vistula River basin, presented by the Basin Water Resources Management of the Western Bug and Syan Rivers for 2021–2022, a high total content of pesticides was observed in 2022, in particular, at the observation point of the Vishnya River in Mostyska – about 5.5 µg/dm3. Also, a high content of manganese, zinc and iron was recorded here. The analysis of monitoring observations of the state of water bodies in the Syan River sub-basin and the calculated water pollution coefficients based on them show that the cleanest water in this area is the water of the Vyar River (the highest Pollution Index in 2021 – 1.463) and the water of the Zavadivka River (the highest Pollution Index in 2021 – 1.218). The most polluted water was the water of the Vishnya River at the observation point in Mostyska, especially due to the high content of iron (7.6 MPC) and manganese (30 MPC), where the pollution coefficient in 2020 was 4.761, and in 2022, it decreased by half. Also, the water of the Shklo River in urban-type settlement Krakivets was quite polluted, where the pollution coefficient in 2022 was 2.057. The BOD5 value was highest in 2021 in the Shklo River – 3.5 MPC and in the Vishnya River in Chernove village – 2.9 MPC, however, in 2022, it decreased to 1.8 MPC across the study area. The COD value in 2021 in all investigated observation points was above the norm, the highest in the Vishnya River, in Chernove village – 2.3 MPC, in 2022, it significantly decreased across the study area, the highest was in the Shklo River in urban-type settlement Krakivets – 1.6 MPC. A high content of ammonium salts and nitrites was recorded in 2022, respectively: in the Shklo River – 3.8 MPC and 2.7 MPC; in the Vishnya River in Chernove village – 2.5 MPC and 3.2 MPC. The phosphate content was highest in 2022 in the Vishnya River in Chernove village (2.6 MPC), however, in 2021 and 2022, it was below the permissible level across the study water area. In all observation points of the Syan River sub-basin, a significant zinc content was observed in the water, the highest was in 2020 in the Vyаr River in Pidmostychi village (5.2 MPC) and in 2022 in the Shklo River in urban-type settlement Krakivets – 4.7 MPC. A high content of sulfates was observed in the Shklo river, especially in 2020 (4.4 MPC), which may be the cause of the influence of the Yavorivsky “Sirka” quarry. Regarding the assessment of water quality in the Syan River sub-basin by pollution levels, in all observation points during the analyzed period, the water is mainly characterized as “slightly polluted”, only at the observation point of the Vishnya River in Mostyska in 2020 and 2021 – “moderately polluted”, in the Zavadivka River, Grushiv village in 2020 the water was “slightly polluted; bordering on clean”.

Advanced Filtration Techniques in Environmental Engineering

Granular filters and membrane filters, two essential filtration methods in environmental engineering, are thoroughly examined in this study. These techniques greatly aid air pollution control problems and water and wastewater treatment. The first section of the study outlines the basic ideas that underpin each filtration technique. The mechanical particle trapping mechanisms of granular filters, their wide range of applications in water treatment, and design factors, including media kinds and layers, are all examined. On the other hand, membrane filters are closely scrutinised because of their size exclusion principles, variety of types (from microfiltration to ultrafiltration), and vital function in industrial waste treatment and desalination processes. The study goes into additional detail about the maintenance, clogging, and financial ramifications that different filtering techniques must deal with. A comparison analysis provides insights into each method's applicability for various environmental engineering applications by illuminating its efficacy, affordability, and application specificity. The study's conclusion considers the potential for growth and current and upcoming technical developments in the filtration industry. This study lays the groundwork for forthcoming advancements and uses in the field of environmental engineering while also highlighting the significance of these filtering methods in modern ecological engineering.

Use of water quality parameters to assess the ecological health of Atlantic coastal areas in the northwestern Morocco

Coastal waters are confronted with multiple stressors, including chemical contamination/pollution and climate change. Water quality along the Atlantic coast of Morocco was assessed, in this study, at six stations over four seasons, including three heavily industrialized stations (S2, S4, and S6) and three clean stations (S1, S3, and S5), spreading over a distance of ∼300 km from Azemmour to Essaouira cities. The physicochemical characteristics (temperature, salinity, pH, dissolved oxygen, suspended matter, and sulfate), and chlorophyll-a, as well as nutrients (nitrite, nitrate, ammonium, total phosphorus, orthophosphate, and silicate) were analyzed to investigate their spatial and seasonal trends in the study areas. The results revealed significant spatiotemporal variations in the distribution of the hydrological characteristics across the sampling sites. In addition, the observed sulfate and nutrient concentrations showed significant spatial and seasonal differences. The disturbed stations showed the highest concentrations of nutrients, while the clean stations exhibited the highest concentrations of chlorophyll-a, particularly in the spring season. As expected, the compressive pollution index (CPI) and water pollution index (WPi) results supported the pollution status of stations. Accordingly, the surface seawater quality was better in the clean stations compared to the polluted stations. According to the CPI and WPi values, the sampling stations were classified in the following descending order of pollution, from strongly and moderately polluted stations to slightly or unpolluted stations (S4 > S2 > S6 > S1> S3 > S5). The total phosphorus, orthophosphate, sulfate, and chlorophyll-a concentrations were substantially higher than the surface water quality standards of Morocco, especially at the most industrialized stations in the winter.The physicochemical, biological, and nutrient data obtained in this study provide a valuable reference for assessing the ecological quality status of the Atlantic coastal environments in the study areas.

Human activities and densities shape insecticide resistance distribution and dynamics in the virus-vector Culex pipiens mosquitoes from Morocco

BackgroundMosquitoes of the Culex pipiens complex are widely distributed vectors for several arboviruses affecting humans. Consequently, their populations have long been controlled using insecticides, in response to which different resistance mechanisms have been selected. Moreover, their ecological preferences and broad adaptability allow C. pipiens mosquitoes to breed in highly polluted water bodies where they are exposed to many residuals from anthropogenic activities. It has been observed for several mosquito species that anthropization (in particular urbanization and agricultural lands) can lead to increased exposure to insecticides and thus to increased resistance. The main objective of the present study was to investigate whether and how urbanization and/or agricultural lands had a similar impact on C. pipiens resistance to insecticides in Morocco.MethodsBreeding sites were sampled along several transects in four regions around major Moroccan cities, following gradients of decreasing anthropization. The imprint of anthropogenic activities was evaluated around each site as the percentage of areas classified in three categories: urban, agricultural and natural. We then assessed the frequencies of four known resistance alleles in these samples and followed their dynamics in five urban breeding sites over 4 years.ResultsThe distribution of resistance alleles revealed a strong impact of anthropization, in both agricultural and urbanized lands, although different between resistance mutations and between Moroccan regions; we did not find any clear trend in the dynamics of these resistance alleles during the survey.ConclusionsOur study provides further evidence for the role of anthropic activities in the selection and maintenance of mutations selected for resistance to insecticides in mosquitoes. The consequences are worrying as this could decrease vector control capacities and thus result in epizootic and epidemic outbreaks. Consequently, concerted and integrated disease control strategies must be designed that include better management regarding the consequences of our activities.Graphical

Mycosorption: a sustainable approach for removing heavy metals from simulated polluted water in non-competitive and competitive systems

Mycosorption: a sustainable approach for removing heavy metals from simulated polluted water in non-competitive and competitive systems

Integration of satellite surveillance and metagenomics for the monitoring and protection of water basins from oil spills

The planetary crisis regarding water resources means that new methods are needed to monitor large areas of water basins that are threatened by chemical and natural pollutants, together with climate change. With the aim to detect oil spill, we applied an algorithm, which could consistently and reliably confirm the presence of oil in four polluted lake waters analyzed. Combined algorithm application and metagenomic analysis from the spill areas that had been detected by the satellite identified drivers of the microbial response to oil pollution. Based on ortholog abundances, metabolic pathway reconstruction carried out in PICRUSt2 highlighted the degradative capacity of these microorganism. These microorganisms could be suitable candidates for treatment of crude oil, aromatic hydrocarbons and the desulfurization of persistent petroleum substances like dibenzothiophene.Environmental changes have been analysed with the combination of satellite monitoring and metagenomic in other studies. Red snow phenomenon, in Franz Josef Land's Arctic observed by satellite, is the result of a microbial succession dominated by Chlamydomonas nivalis, a unicellular, red-colored photosynthetic green algae. Similarly, satellite monitoring and metagenomic monitoring were used to assess the impact on coral reefs of a huge quantity of mud spill from iron ore mining on the Abrolhos Bank reef in Brazil.In our study, the combination of satellite sensing and metagenomics analyses offer useful tools for the real-time monitoring of water bodies threatened by oil spills, as well as for the design of recovery strategies based on the use of valuable hydrocarbonoclastic microorganisms.

Synthesis of ferrihydrite/polyaniline composite using waste Fe(III)/EPS-cultures with polyaniline and its application for tetracycline photo-Fenton degradation

Antibiotics pollutants are arousing seriously environmental issues, so the highly efficient photo-Fenton catalysts have been developed in their treatments. In this work, according to the results of XRD, Raman, FTIR, and XPS, ferrihydrite/polyaniline (Fh/PANI) catalyst could be successfully prepared in waste iron-bacterial cultures (shorted as Fe(III)/EPS-solutions) with PANI conductor ((C6H7N)n, 200–300 nm). The Fh/PANI was an optimal photo-Fenton catalyst with good physical properties for tetracycline hydrochloride (TCH, C22H25ClN2O8) degradation. In photo-Fenton systems with 30 mmol/L H2O2, 40 mg/L TCH, 0.2 g/L catalyst, and pH 4.0 under the visible light irradiation, degradation efficiency was 94% for Fh/PANI (82% for Fh). Kinetics data of TCH degradation well followed to pseudo-first-order model (R2=0.974 for Fh/PANI, and R2=0.929 for Fh). The Fh/PANI catalyst had a good stability for TCH degradation, and the efficiencies ranged in 94%−77% within its five runs. The TCH could be efficiently mineralized into H2O and CO2 inorganic molecules, and the producing ∙O2− was the key action group. These results indicate Fh/PANI photo-Fenton catalyst will have a potential application in treating antibiotic polluted waters. It also can provide a good approach of preparing Fe-(oxyhydr)oxide/conductor composites in waste iron-bacterial cultures.

Insights into uranium sequestration by coal fly-ash-derived zeolites: Understanding via wet chemistry, and advanced spectroscopies

The operation of nuclear power plants requires a supply of nuclear fuel where uranium plays a substantial role as a primary fissile material. Its extraction from U-bearing minerals and handling may cause a leakage of heavily toxic radioactive pollution, which ends up in water bodies and soil. Therefore, tackling U-contaminated water is crucial to preserve water integrity and quality. Zeolites are known as profound ion exchangers with great affinity towards cationic species present in polluted waters. Various zeolite synthesis routes have made this group of aluminosilicates even more promising to be applied as water purification materials. Here, the synthetic gismondite, faujasite, and Linde type-A zeolites from coal fly-ash were synthesized via tailored, coupled fusion-hydrothermal method and applied to remove aqueous uranium (primarily as 238U) under varying pH, time (sorption kinetics), and initial U concentrations (sorption isotherms). The maximum U uptake was observed for Na–P1 (GIS) zeolite, which equals 48.72 mg U/g, the highest reported value on maximum U adsorption capacity for zeolitic materials. The U adsorption kinetics showed that equilibrium is reached after approximately 3 h of adsorption and that the removal process follows a Freundlich isothermal model for all zeolites, thus preferential adsorption onto heterogeneous surfaces. Advanced spectroscopic studies, including laboratory-scale X-ray Photoelectron Spectroscopy with synchrotron light X-ray Absorption Near Edge Structure in High Energy Resolution Fluorescence Detection mode, revealed that at acidic pH, predominantly an ion exchange between Na+ ions with hexavalent uranyl species takes place. In contrast, in the neutral pH region, the U is immobilized via precipitation in the form of μm-scale mineral aggregates of Na-schoepite: Na[(UO2)4O2(OH)5](H2O)5↓. The outcomes of the research study has demonstrated that synthetic zeolites, obtained from industrial by-products such as coal fly-ash, can be successfully valorized to efficient U adsorbents while unveiling the insights to understand the zeolites/U interactions at the nanoscale level.

Polluted surface water is a repository of antibiotic-resistant Escherichia coli harbouring Plasmid-Mediated Quinolone Resistance (PMQR) determinants

ABSTRACT We investigated the carriage of PMQR determinants by E. coli from surface water and their antibiotypes. Water samples were collected and analysed from two surface water: Agbowo (AG) and Arulogun (AR) in South-west Nigeria for E. coli, which were identified using PCR detection of uidA. Susceptibility to antibiotics was done using the disc-diffusion method. Detection of PMQR genes in isolates showing complete resistance or intermediate susceptibility to the fluoroquinolone antibiotics was done using primer-specific PCR. Thirty-six E. coli isolates were obtained [AG (20) and AR (16)]. The isolates showed different levels of resistance to the tested antibiotics, with 100% resistance to amoxicillin-clavulanate. None of the isolates was positive for extended spectrum β-lactamase (ESBL) production, but 25 showed complete resistance or intermediate susceptibility to the fluoroquinolone antibiotics. Two isolates each from AG and AR carried qnrA, one isolate carried qnrS, with one each from AG and AR carrying aac(6′)-lb-cr. Four isolates carried oqxAB, but, qnrB and qepA were not detected in any isolate. This study revealed that polluted surface water is a ‘hub’ of antibiotic-resistant E. coli harbouring PMQR genes.

Unlocking solutions for cleaner waters: The Industrial Wastewater Quality Index in Egypt and beyond

AbstractThis research study conducted in Egypt focuses on addressing the issue of industrial water pollution and promoting sustainable water and environmental management practices. The study introduces a novel tool called the Industrial Wastewater Quality Index (IWQI) and utilizes two assessment methods to evaluate the extent of water pollution caused by industrial effluents. The IWQI takes into consideration both the environmental limits specified by Egyptian legislation and industry‐specific parameters, effectively condensing extensive water quality data into simplified categories. The IWQI model proves to be a dependable instrument for assessing the overall quality of groundwater intended for industrial use. It incorporates multiple water quality indices and employs multivariate statistical analysis techniques to determine the contribution of each parameter to industrial water quality. This comprehensive analysis enhances the reliability of the model, making it a valuable point of reference for similar locations worldwide, particularly those sharing similar climatic conditions. The outcomes of this study provide valuable insights for policymakers and stakeholders involved in regulating and mitigating industrial water pollution in Egypt. The findings also have relevance to other countries facing similar challenges, highlighting the importance of developing effective techniques for investigating pollution sources, monitoring water quality, and forecasting future trends. The study underscores the necessity of implementing proactive measures to address industrial water pollution and protect water resources and ecosystems. By emphasizing these aspects, the study emphasizes the importance of promoting sustainable water and environmental management practices. Overall, the IWQI and the study's findings contribute to the development of strategies to manage and control industrial water pollution and can guide policymakers and stakeholders in Egypt and other countries facing similar challenges.

Numerical Simulation of the Marine Environmental Capacity of Jinpu Bay

Based on the study of the marine environmental capacity, a water quality model and a response field-based linear programming method are adopted here. Water quality control objectives are taken as the constraint conditions, according to the requirements of Jinpu Bay’s functional zoning. The pollutant response coefficient and water quality background value are combined with the values of the water concentration quality control points set in each functional area and the target value of the functional area wherein they are located. The maximum allowable emission intensity of inorganic nitrogen, phosphate and chemical oxygen demand (COD) can be calculated using the linear programming method of the maximum allowable emission of pollutants at estuaries or sewage outfall points on Jinpu Bay. The research results reveal the diffusion of marine pollutants and the marine environmental capacity of Jinpu Bay. Some rivers need to reduce the discharge intensity and some other outlets still have a certain residual capacity. Based on this, the environmental capacity of Jinpu Bay was evaluated, and a technical reference is provided for the economic development of the region and the formulation of pollutant emission control policies.

Methamphetamine Removal from Aquatic Environments by Magnetic Microrobots with Cyclodextrin Chiral Recognition Elements.

The growing consumption of drugs of abuse together with the inefficiency of the current wastewater treatment plants toward their presence has resulted in an emergent class of pollutants. Thus, the development of alternative approaches to remediate this environmental threat is urgently needed. Microrobots, combining autonomous motion with great tunability for the development of specific tasks, have turned into promising candidates to take on the challenge. Here, hybrid urchin-like hematite (α-Fe2O3) microparticles carrying magnetite (Fe3O4) nanoparticles and surface functionalization with organic β-cyclodextrin (CD) molecules are prepared with the aim of on-the-fly encapsulation of illicit drugs into the linked CD cavities of moving microrobots. The resulting mag-CD microrobots are tested against methamphetamine (MA), proving their ability for the removal of this psychoactive substance. A dramatically enhanced capture of MA from water with active magnetically powered microrobots when compared with static passive CD-modified particles is demonstrated. This work shows the advantages of enhanced mass transfer provided by the externally controlled magnetic navigation in microrobots that together with the versatility of their design is an efficient strategy to clean polluted waters.

Monitoring grey water footprint and associated environmental controls in agricultural watershed.

The grey water footprint (GWF) is an advanced index linking pollution load and water resources. However, the existing agriculture-related GWF was developed based on hydrological processes, which limits its role in watershed water pollution level (WPL) measurements. The main scope of this study is to calculate GWF and WPL based on runoff, total nitrogen (TN), and total phosphorus (TP) observations in the Hujiashan Watershed of China's Yangtze River Basin. Partial least squares structural equation modeling (PLS-SEM) was utilized to explore the impact pathways of environmental features on GWF and WPL. On this basis, propose measures for the management of this agricultural watershed. The results showed that the TN concentration had a V-shaped trend in 2008-2015, while the TP gradually decreased. The GWF calculations for the TN and TP were compatible with the temporal trends for the concentrations, which were higher in the wet season (0.45 m3/m2 for TN, 0.10 m3/m2 for TP) than in the dry season (0.11 m3/m2 for TN, 0.02 m3/m2 for TP) and increased from upstream to downstream. The WPLs of TN exceeded 2.0 in the midstream and downstream areas, whereas those for TP were inconspicuous. According to PLS-SEM, the GWF is primarily influenced by topographical variables and hydrological features, whereas the WPL is mainly controlled by hydrological features and landscape composition. Fertilizer reduction and efficiency measures should be implemented on farmland and appropriately reducing farming activities on slopes to relieve the GWF and WPL in the watershed.

Regulable surface hydroxyl group content in disperse ultrafine amorphous SiO2 nanoparticles

AbstractAmorphous silica (SiO2) nanoparticles (NPs) can be applied in environmental pollutant remediation, element removal, and water purification. The content of surface silanol groups in amorphous SiO2 NPs affects the characteristics of SiO2 NPs. However, the regulation of surface silanol group content in amorphous SiO2 NPs below 10 nm remains a challenge. Herein, tunable surface silanol group content was achieved in disperse ultrafine amorphous SiO2 NPs by controlling calcination and rehydroxylation. The surface silanol group content in amorphous SiO2 NPs is low (10 nm) and can be tuned from 0% to 2.5%. The amount of naphthalene adsorbed by the SiO2 NPs increases with increasing surface silanol group content. The surface silanol group content in SiO2 NPs can be an effective means to tune their adsorption performance and applications.

Assessment of the Impact of War on Concentrations of Pollutants and Heavy Metals and Their Seasonal Variations in Water and Sediments of the Tigris River in Mosul/Iraq

The war-related contamination of water and sediment of the Tigris River within the urban area of Mosul leads to seasonally independent exceedances of the WHO limit values for Cd, Pb, Cr, and Ni in water and sediments. Furthermore, exceedances consistently occur for conductivity, PO43−, and SO42−, as well as sporadically for salinity and COD in water samples, and consistently for salinity in sediment samples, highlighting the direct impact of war (ammunition, ignition of sulfur fields), as well as indirect effects (destroyed wastewater infrastructure). Conflict-related emissions from the former conflict zone (S5–S7) are highlighted by the sudden increases in load from S4 to S5, although partially masked by the discharge of highly polluted water from the Khosr River (between S3 and S4). Due to the sorption of sediments and the presumed wind-borne discharge of highly polluted particles into the Tigris River, sediments at S10 on the southern edge of Mosul showed the highest pollutant loads. Significant statistical differences were observed through T-test analyses for E.C., TDS, salinity, COD, PO43−, NO3−, SO42−, Cd, Pb, Zn, Cr, and Ni for water samples, as well as salinity, Cd, Pb, Zn, and Cr for the sediment samples for seasonal comparison. Since the percentage difference of water samples at S4–S7 is smaller than upstream and downstream, contaminant input is not limited to rainwater but also occurs via the year-round infiltration of highly polluted wastewater from the surrounding valleys or suburban areas, as well as presumably polluted groundwater or windblown particulate input.

Assessment of water quality and associated human health risk of a tropical freshwater body in Edo State, Nigeria

The quality of freshwater sources is a key factor in sustainable development. This study investigated the water quality suitability of Ossiomo River for human consumption and the implications for public health. Water samples were collected and analysed from October 2021 to March 2022. Results indicated that the water physico-chemical parameters from sampled locations were within their respective National Environmental Standards and Regulation Enforcement Agency (NESRA) permissible limits except for pH (< 6.5), dissolved oxygen (< 6.0mg L−1), cadmium (> 0.005m /L−1), manganese (> 0.05mg L−1) and total hydrocarbon content (>10mg L−1). Comprehensive pollution index (0.4–1.0) and water quality index (251.57–765.37) values indicate that the water body was slightly polluted and unsuitable for human consumption (WQI > 50). Health risk assessment showed that children and adults were predisposed to non-carcinogenic risk (HIoral > 1) and carcinogenic risk (ICR: 1.21E-02 and 2.84E-03) from heavy metals through oral exposure. Natural run-off and anthropogenic activities were identified sources of heavy metals and hydrocarbons within the catchment. The study has provided data for water resource quality monitoring and raised concerns as to the need for immediate action to safeguard the public health of communities surrounding the Ossiomo River, through the provision of alternative sources of potable water.

Impacts of hinterland surface water on the coastline of Al Hoceima Bay (Central Rif, Morocco)

The present work aims to assess the chemical and bacteriological quality of the two Ghiss-Nekôr tributaries of Al-Hoceima Bay. A set of field data collected, either from direct analysis or from satellite data, was used to conduct this study. We relied on GIS tools for data processing and analysis. The nutrient analysis indicates normal surface water quality, with nitrogen and phosphorus concentrations typical of less polluted waters. These nutrients originate from continental inputs due to runoff. Nitrates are the most common mineral nitrogen species, resulting from the leaching of nitrate-based fertilizers from agricultural and domestic sources. Bacterial analysis reveals water contamination by total coliforms (TC), Escherichia coli (EC), and intestinal enterococci (IE). Hinterland inputs from the two rivers are the primary source of liquid and solid pollutants in Al-Hoceima Bay. They are influenced by climatic and anthropogenic factors such as hydraulic development, agriculture and urbanization.

Alterações químicas e isotópicas em águas superficiais e subterrâneas em uma Bacia Hidrográfica na Amazônia Central

ABSTRACT Environmental monitoring of water is essential for efficient management of water source conservation in river basins. However, there is a lack of studies with this synergy applying unconventional techniques. We evaluated chemical characteristics of surface and underground waters (2021-2022), including for the first time the analysis of the isotopic composition of waters collected from water sources throughout Educandos`s Basin, in the city of Manaus-AM/Brazil, to evaluate chemical-isotopic changes in the view of anthropogenic impacts. Statistical analyzes were used to compare means, graphical analyzes and Principal Component Analysis to identify the main patterns of the data sets. Our results demonstrated a significant increase in pH, electrical conductivity and an increased in nitrates in polluted groundwater and reduced DO in contaminated surface waters. Furthermore, the isotopic signature did not indicate pollution through changes in the isotopic composition of natural and polluted waters, however, it showed more depleted signatures in one of the underground monitoring wells, indicating an impact site vulnerable to the interaction of aquifer waters with Rio Negro and Igarapé. When analyzing chemical parameters with isotopic composition, it can be allowed a better understanding of the mechanisms of circulation and mineralization of underground and surface waters in the Urban Hydrographic Basin.

Pea grain shells as a raw material for sorptive treatment of polluted waters

In the complex processing of pea grain, as well as in the production of groats and flour, a number of wastes are generated, a significant part of which is utilized. The conversion of waste processing to secondary raw materials not only allows for the resolution of environmental problems but also expands the opportunities for raw materials in economic sectors. Pea grain shells, which contain biopolymers, vitamins and minerals, can be considered as one of the sources of raw materials for obtaining sorption materials. The object of the research in this work was the shells isolated from the grain of the Amior and Temp pea varieties of Russian selection. The aim of the study was to investigate the structure, physical properties, and component composition of the pea grain shells, as well as to evaluate the prospects of their use as raw materials for the production of sorbents for the treatment of polluted surface water and wastewater. To determine the quality indicators of pea grain shells, the generally accepted methods were used. The share of shells in pea grain was found to be 7.1-10.6%. The main components in the composition of pea grain shells are polysaccharides, with a predominance of fiber, largely determining the structure and properties of this raw material. Pea grain shells are characterized by low density, good hygroscopicity and moisture retention capacity. The proteins and pectins present in the composition of the pea shells have sorption properties. It is possible to increase the degree of purification of surface and waste water from harmful impurities by using extracts from pea shells containing biopolymers that form insoluble complexes with pollutants.

Synthesis and performance evaluation of zinc oxide tubes/alginate microfibre composites for photodegradation of methylene blue: a novel reporting approach.

This research investigates the efficacy of zinc oxide (ZnO) tubes in decontaminating polluted water using a substrate-free hydrothermal synthesis process for ZnO tubes. The synthesized tubes are impregnated into calcium alginate microfibres, strategically chosen for their high surface area to enhance photocatalytic degradation performance and for practical handling during decontamination and subsequent collection, thereby preventing secondary contamination. Structural and morphological analyses, conducted using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD), thoroughly characterize the properties of the ZnO tubes and the composite material. The efficacy of this composite is demonstrated through the photocatalytic degradation of methylene blue (MB), as a representative organic pollutant, resulting in an 88% degradation of MB after 5 hours of irradiation by a sun simulator. Cyclic tests exhibit consistent degradation levels in the first four cycles (81-89%), followed by a subsequent decrease to 72% in the fifth cycle, coinciding with the breakdown of the microfibres into shorter fragments. Innovatively, this study introduces an approach to reporting photocatalytic degradation results, utilizing normalized pollutant concentration plotted against irradiated energy instead of time, as energy encompasses irradiated power, time, and surface area. This reveals that the 88% degradation of MB is achieved by irradiating the sample with an approximately 18 kJ. Additionally, a new metric, Specific Energy Efficiency (SEE), is introduced. It expresses the ratio of degraded pollutant mass to the mass of photocatalytic active material per unit of irradiated energy, with the maximum and cumulative SEE in this study being 1.044 μg g-1 J-1 and 326 ng g-1 J-1, respectively. This research not only contributes to the understanding of ZnO tubes' efficiency in polluted water decontamination but also introduces valuable insights for standardized reporting in photocatalytic degradation studies.