Contamination Of Water Bodies Research Articles

The neglected role of ciliates as bioindicators

Abstract The impacts of anthropogenic synthetic contaminants are becoming a serious concern, primarily due to their harmful effects on human health and adverse effects on ecosystems, biodiversity, and human well-being. Of more than 100 million chemicals, ~0.36% are regularised, as recorded in the Chemical Abstracts Registry database. Such chemicals ultimately contaminate water bodies and reduce the amount of potable water. It is estimated that about 50% of the human population will suffer from water shortages by 2025 if the present trend continues. Gause’s classical work in population ecology stimulated interest in working with ciliates as model organisms in ecotoxicology. Ciliates are good indicators for assessing saprobic water quality due to their abundance, ubiquity, and sensitivity to anthropogenic impacts. However, although more than 50 ciliate species are now in use as bioindicators, researchers should attempt to utilize the excellent potential of ciliates as bioindicators in large-scale studies, considering their availability and cost-effectiveness. Any change in the community composition of ciliates in response to environmental shifts is a powerful tool for biomonitoring and bioassessment.

Pseudomonas putida Metallothionein: Structural Analysis and Implications of Sustainable Heavy Metal Detoxification in Madinah.

Heavy metals, specifically cadmium (Cd) and lead (Pb), contaminating water bodies of Madinah (Saudi Arabia), is a significant environmental concern that necessitates prompt action. Madinah is exposed to toxic metals from multiple sources, such as tobacco, fresh and canned foods, and industrial activities. This influx of toxic metals presents potential hazards to both human health and the surrounding environment. The aim of this study is to explore the viability of utilizing metallothionein from Pseudomonas putida (P. putida) as a method of bioremediation to mitigate the deleterious effects of pollution attributable to Pb and Cd. The use of various computational approaches, such as physicochemical assessments, structural modeling, molecular docking, and protein-protein interaction investigations, has enabled us to successfully identify the exceptional metal-binding properties that metallothionein displays in P. putida. The identification of specific amino acid residues, namely GLU30 and GLN21, is crucial in understanding their pivotal role in facilitating the coordination of lead and cadmium. In addition, post-translational modifications present opportunities for augmenting the capacity to bind metals, thereby creating possibilities for focused engineering. The intricate web of interactions among proteins serves to emphasize the protein's participation in essential cellular mechanisms, thereby emphasizing its potential contributions to detoxification pathways. The present study establishes a strong basis for forthcoming experimental inquiries, offering potential novel approaches in bioremediation to tackle the issue of heavy metal contamination. Metallothionein from P. putida presents a highly encouraging potential as a viable remedy for environmental remediation, as it is capable of proficiently alleviating the detrimental consequences related to heavy metal pollution.

Towards removal of PPCPs by advanced oxidation processes: A review

The continuous influx of emerging contaminants (ECs) into water bodies poses a significant threat to human health. Among these contaminants, pharmaceuticals and personal care products (PPCPs) are of particular concern due to their potential to exert adverse effects even at low concentrations. Therefore, it is imperative to explore methods for their effective removal or reduction to safeguard both human health and the ecological environment. Advanced oxidation processes (AOPs) have received substantial attention as promising treatment methods. AOPs are capable of efficiently treating water by generating reactive oxygen species (ROS) with potent oxidation properties, which can effectively eliminate various contaminants. This review delves into the diverse range of AOPs available, including ozonation, photocatalytic oxidation, the Fenton process, electrochemical oxidation, sulfate radicals-based advanced oxidation processes (SR-AOPs), and more. It also discusses the respective limitations and future prospects of these processes, aiming to provide insights into their potential for addressing the pressing issue of PPCP contamination in water bodies.

Amino acid functionalized metal oxide nanocomposite for the removal of fluoroquinolones

Antibiotic consumption has increased globally, and its discharge into water bodies at concentrations ranging from a few ng/L to mg/L has a detrimental effect on the ecosystems. Amino acid functionalized nickel ferrite nanoparticles were chosen to improve the stability of bare nanoparticles and prevent oxidation and leaching ions in nanoparticles thereby targeting the antibiotics in the contaminated water bodies. The removal of ciprofloxacin and lomefloxacin hydrochloride in the aqueous phase was investigated using a hydrothermally synthesized L-Leucine functionalized nickel ferrite nanocomposite (NFO@L). Various analytical techniques were used to analyze L-Leucine functionalized nickel ferrite, and the nanocomposite's average particle diameter was determined to be between 11 and 15 nm. The maximal measured zeta potential was −21.5 mV. Fourier transform infrared spectroscopy (FTIR), ninhydrin assay and X-ray diffraction (XRD) analysis confirmed the attachment of L-Leucine onto nickel ferrite. The nanocomposite's surface-to-volume ratio was calculated to be 92.916 m2/g. The S-shaped curve from the vibrating sample magnetometer analysis reflected the superparamagnetic behaviour of the nanocomposite with a saturation magnetization of 0.665 emu/g. Various parametric experiments were conducted, in which 93.549% ciprofloxacin was removed in 120 min at 303 K, pH 8 and NFO@L dosage of 100 mg in 100 mL whereas 75.192% lomefloxacin hydrochloride was removed in 140 min at 333 K, pH 9 and NFO@L dosage of 70 mg in 100 mL. The plot of experimental datum in kinetic and isotherm studies fitted well with the Pseudo second order kinetic model and Langmuir isotherm. There was no evidence of iron ions leaching from the final analyte. The recycle and regeneration studies showed good stability with a small reduction after four cycle runs. Based on these findings, the Leucine functionalized nickel ferrite nanocomposite could be a potent adsorbent for the removal of low-concentrated ciprofloxacin and lomefloxacin hydrochloride in the wastewater.

Preparation of graphene oxide-doped silica aerogel using supercritical method for efficient removal of emerging pollutants from wastewater

Emerging pollutants and a large volume of unused dyes from the textile industry have been contaminating water bodies. This work introduces a scalable approach to purifying water by the adsorption of Acid green 25 (AG), Crystal Violet (CV), and Sulfamethoxazole (SMA) from an aqueous solution by graphene oxide (GO) doped modified silica aerogel (GO-SA) with supercritical fluid deposition (SFD) method. Characterization of GO-SA using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), high-resolution scanning electron microscopy (HR-SEM), thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET) adsorption isotherms revealed the improvement in the adsorbent surface area, and its textural properties. The high removal percentages observed in most of the experimental runs provide evidence of the excellent performance of the adsorbent towards the anionic and cationic dyes along with the antibiotic. The adsorption isotherm and kinetics showed that the Langmuir isotherm and pseudo-second-order kinetic models could explain adsorption. The adsorbent holds a higher adsorption capacity for SMA (67.07 mg g−1) than for CV (41.46 mg g−1) and AG (20.56 mg g−1) due to the higher hydrophobicity that interacts with the hydrophobic adsorbent. The GO-SA successfully removed AG, CV, and SMA with removal percentages of 98.23%, 98.71%, and 94.46%, respectively. The parameters were optimized using Central Composite Design (RSM-CCD). The prepared aerogel showed excellent reusability with a removal efficiency of > 85% even after 5 cycles. This study shows the potential of GO-SA adsorbent in textile and other wastewater purification.

Углеводы в поверхностных водах Карелии и их связь с содержанием биогенных и органических веществ

The results of a long-term research of the content of carbohydrates in natural waters of Republic of Karelia (Russia) from 2011 to 2020 are summarized. In total, 34 water bodies (29 lakes and 5 rivers) were studied in different hydrological seasons. The presented sample of water bodies captures almost all types of surface waters in the humid zone in terms of trophicity and humus content. It was found that the carbohydrates concentration varies widely from 0.7 to 53.1 mg/L (average 3.3 mg/L) and its share of total organic matter averages 16%. It was revealed that the content and distribution of carbohydrates in surface waters depends both on natural (the level of trophicity and humus content in the reservoir) and anthropogenic factors (eutrophication, trout farms, industrial wastewater discharge, seepage waters of solid waste landfills, communal wastewater). In addition, all the studied water bodies were categorized into two groups according to the water pollution degree: contaminated and uncontaminated. It was revealed that the concentration of carbohydrates in contaminated water bodies of Karelia is on average 1.4 times higher than in uncontaminated ones. In addition, the content of carbohydrates increases together with such chemical parameters as 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD Cr), permanganate oxygen demand (COD Mn), chlorophyll a, mineral and total phosphorus (Pmin and Р total relatively) and ammonium (N-NH 4+). In particular, these relations are pronounced in contaminated water bodies, where the highest values of the correlation coefficient between the above parameters are noted. The content of carbohydrates in surface waters is a complex indicator of both organic and biogenic water pollution.

Understanding the effective breakdown of PAH s in water through the use of g–C3N4–Ag–Cu–Ni nanocomposites

The research work aimed to explore the suitability of using a novel g- C3N4–Ag–Cu–Ni nanocomposite for the simultaneous degradation of pyrene in wastewater. The outcome revealed that the g- C3N4 phase was successfully fabricated on the g–C3N4–based compound, and the existence of the g- C3N4-based compound beneficially stabilized the Ag–Cu–Ni particles. The g- C3N4–Ag–Cu–Ni nanocomposite demonstrated excellent performance in pyrene degradation under various conditions. The degradation of pyrene increased with a rise in the dosage of g- C3N4–Ag–Cu–Ni. These findings indicate that the g- C3N4–Ag–Cu–Ni nanocomposite could be a promising material for water purification, especially for the simultaneous photocatalytic and antimicrobial treatment of contaminated water bodies. The study provides a helpful guide for future research in this field.

Is natural better? An ecotoxicity study of anthraquinone dyes

The concept of sustainability has gained prominence in recent years, enhancing the need to develop products that are less harmful to the environment. Dyes are used by various industrial sectors and have a lot of market value; they are used on a large scale mainly by the textile industry that uses large volumes of water and is one of the main contributors to the contamination of water bodies. Some natural compounds, especially anthraquinones are re-emerging as possible alternatives to synthetic dyes, some of which are known for their toxic and/or mutagenic effects. The BioColour project (https://biocolour.fi/) which is interested in promoting the development of new alternative molecules to synthetic dyes, provided us highly purified anthraquinone dyes dermocybin and dermorubin (>98% purity) extracted from a specie of fungus Cortinarius sanguineus. Dyes were tested for their acute and chronic toxicity using different aquatic organisms. Dermorubin was not toxic to any of the organisms tested for the highest test concentration of 1 mg L−1 and it was the most promising dye. Dermocybin was toxic to Daphnia similis (EC50 = 0.51 mg L−1), Ceriodaphnia dubia (IC10 = 0.13 mg L−1) and Danio rerio embryos (extrapolated LC50 = 2.44 mg L−1). A safety limit, i.e, predicted no-effect concentration (PNEC) of 0.0026 mg L−1 was derived based on the toxicity of dermocybin. The PNEC value can be used to provide hazard information for future application in commercial dyeing processes. Then, we compared the toxicity of dermocybin and dermorubin with ecotoxicity data available in the literature on other anthraquinone dyes of natural and synthetic origin. Some natural dyes can be as toxic as synthetic ones, or more toxic when chronic effects are considered. Despite natural dyes being used since centuries past, there are few ecotoxicological studies available. This study is designed to help develop a more comprehensive understanding of their toxicological properties.

Environmental Sustainability and MRI: Challenges, Opportunities, and a Call for Action.

The environmental impact of magnetic resonance imaging (MRI) has recently come into focus. This includes its enormous demand for electricity compared to other imaging modalities and contamination of water bodies with anthropogenic gadolinium related to contrast administration. Given the pressing threat of climate change, addressing these challenges to improve the environmental sustainability of MRI is imperative. The purpose of this review is to discuss the challenges, opportunities, and the need for action to reduce the environmental impact of MRI and prepare for the effects of climate change. The approaches outlined are categorized as strategies to reduce greenhouse gas (GHG) emissions from MRI during production and use phases, approaches to reduce the environmental impact of MRI including the preservation of finite resources, and development of adaption plans to prepare for the impact of climate change. Co-benefits of these strategies are emphasized including lower GHG emission and reduced cost along with improved heath and patient satisfaction. Although MRI is energy-intensive, there are many steps that can be taken now to improve the environmental sustainability of MRI and prepare for the effects of climate change. On-going research, technical development, and collaboration with industry partners are needed to achieve further reductions in MRI-related GHG emissions and to decrease the reliance on finite resources. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 6.

Multifunctional carboxymethyl cellulose/graphene oxide/polyaniline hybrid thin film for adsorptive removal of Cu(II) and oxytetracycline antibiotic from wastewater

The antibiotics and metal ions in the contaminated water bodies must be removed using appropriate methods for sustainable development. In this study, the multifunctional carboxymethyl cellulose/graphene oxide/polyaniline (CMC/GO/PANI) hybrid thin film was synthesized and utilized for adsorptive scavenging of (Cu(II) and oxytetracycline (OTC) from wastewater. The prepared thin films' morphology, chemical compositions, functionality, and surface charge were analyzed by well-known physicochemical techniques. The adsorption process of the selected model pollutants was examined as a function of reaction time, Cu(II), and OTC solution pH, concentrations, and temperatures. Results showed that CMC/GO/PANI hybrid thin film had higher Cu(II) and OTC adsorption than CMC, GO/CMC, and PANI/CMP thin films due to the multifunctional synergetic effect. The adsorption kinetic data were fitted to the pseudo-second-order model. Redlich-Peterson isotherm model well interpreted Cu(II) and OTC scavenging equilibrium data. Energetically, the adsorption was spontaneous and endothermic for both pollutants. The multifunctional CMC/GO/PANI thin film was recycled and reused seven times during adsorption-desorption cycles. The study outcomes demonstrated that CMC/GO/PANI thin film could be reused multiple times for large-scale wastewater purification.

Toward better monitoring of human noroviruses and F-specific RNA bacteriophages in aquatic environments using bivalve mollusks and passive samplers: A case study.

Monitoring pathogenic enteric viruses in continental and marine water bodies is essential to control the viral contamination of human populations. Human Noroviruses (NoV) are the main enteric viruses present in surface waters and foodstuff. In a context of global change, it is currently a challenge to improve the management of viral pollutions in aquatic environments and thereby limit the contamination of vulnerable water bodies or foodstuffs. The aim of this study is to evaluate the potential of specific accumulation systems for improving the detection of NoV in water bodies, compared to direct water analyses. Passive samplers (Zetapor filters) and three species of bivalve molluscan shellfish (BMS) (Dreissena polymorpha, Mytilus edulis and Crassostreas gigas) were used as accumulation systems to determine their performance in monitoring continental and marine waters for viruses. F-specific RNA bacteriophages (FRNAPH) were also analyzed since they are described as indicators of NoV hazard in many studies. During a one-year study in a specific area frequently affected by fecal pollution, twelve campaigns of exposure of passive samplers and BMS in continental and coastal waters were conducted. Using suitable methods, NoV (genome) and FRNAPH (infectious and genome) were detected in these accumulation systems and in water at the same time points to determine the frequency of detection but also to gain a better understanding of viral pollution in this area. The reliability of FRNAPH as a NoV indicator was also investigated. Our results clearly showed that BMS were significantly better than passive samplers and direct water analyses for monitoring NoV and FRNAPH contamination in water bodies. A dilution of viral pollution between the continental and the coastal area was observed and can be explained by the distance from the source of the pollution. Viral pollution is clearly greater during the winter period, and stakeholders should take this into consideration in their attempts to limit the contamination of food and water. A significant correlation was once again shown between NoV and FRNAPH genomes in BMS, confirming the reliability of FRNAPH as a NoV indicator. Moreover, a strong correlation was observed between NoV genomes and infectious FRNAPH, suggesting recent viral pollution since infectious particles had not been inactivated at sufficient levels in the environment. More generally, this study shows the value of using BMS as an active method for improving knowledge on the behavior of viral contamination in water bodies, the ranking of the contamination sources, and the vulnerability of downstream water bodies.

Design and synthesis of silver bio-nanocomposite for photocatalytic applications.

One of the major concerns faced by humanity since Industrial Revolution is the contamination of water by the effluents released to the water bodies as a part of modernization and socio-economic development. Water purification is the most researched topic and numerous researches carried out in the past and are still going on in the present which pinpoints the seriousness of the grave issues raised by contamination of water bodies. In this work we have tried to develop a bio-nanocomposite utilizing colloidal silver nanoparticles synthesized via green protocol and arrowroot powder. Nano Silver well known for its photocatalytic properties has been incorporated into biodegradable and ecofriendly arrowroot powder for enhanced photocatalytic action and carried out degradation studies on the common contaminant dye Methylene Blue (MB). The synthesized bio nanocomposite exhibits promising photocatalytic action to be used for water purification.

Reducing nutrient loss in drainage from tomato grown in free-draining substrate in greenhouses using dynamic nutrient management

Substrate-grown crops represent approximately 10% of the cropping area of intensive greenhouse horticulture in southern Spain. The vast majority are free draining, in that they do not collect and recirculate drainage. The substantial nutrient loss in drainage contributes to contamination of water bodies. This study examined the effectiveness of dynamic management approaches to appreciably reduce the large nutrient loss associated with free-draining substrate-grown crops. For three tomato crops, grown in substrate, this study (i) compared management of N, P and K based on the ratio of the concentration in drainage to that in the nutrient solution, to conventional management, (ii) derived uptake concentration values for N, P and K throughout the crop cycle, and (iii) evaluated uptake concentration as a nutrition management tool. Ratio-based management reduced the amounts of N, P and K in drainage, in relation to conventional management by 58–61%, 65–80% and 55–77% respectively. The amounts of applied N, P and K were reduced by 22–28%, 37–43%, and 28–34% compared to conventional management. N, P and K concentrations in the applied nutrient solution slightly below the uptake concentration were associated with much lower concentrations in the drainage solution. In contrast, when the applied nutrient concentration exceeded the uptake concentration this was associated with much higher drainage nutrient concentrations. In conclusion, the two nutritional management strategies examined, ratio-based management, and use of uptake concentrations were both associated with reduced nutrient application and a considerable reduction of nutrient loss in drainage. Fruit production was maintained with the improved nutrient management practices. These strategies offer approaches that can considerably reduce the substantial nutrient loss in drainage associated with free-draining substrate cropping in greenhouse production in southern Europe.

Pharmaceutical and personal care products (PPCPs) degradation and microbial characteristics of low-temperature operation combined with constructed wetlands

Emerging contaminants (ECs), which are present in water bodies, could cause global environmental and human health problems. These contaminants originate from various sources such as hospitals, clinics, households, and industries. Additionally, they can also indirectly enter the water supply through runoff from agriculture and leachate from landfills. ECs, specifically Pharmaceutical and personal care products (PPCPs), are causing widespread concern due to their contribution to persistent water pollution. Traditional approaches often involve expensive chemicals and energy or result in the creation of by-products. This study developed a practical and environmentally-friendly method for removing PPCPs, which involved combining and integrating various techniques. To implement this method, it was necessary to establish and used a field simulator based on the real-life scenario. Based on the data analysis, the average removal rates of COD, TP, TN, and NH4+-N were 57%, 59%, 63%, and 73%, respectively. the removal rate of PPCPs by CCWs was found to be 82.7% after comparing samples that were not treated by constructed wetlands and those that were treated. Combined constructed wetlands (CCWs) were found to effectively remove PPCPs from water. This is due to the combined action of plant absorption, absorption, and biodegradation by microorganisms living in the wetlands. Interestingly, the wetland plant reed had been shown to play an important role in removing these pollutants. Microbial degradation was the most important pathway for PPCPs removal in CCWs. Carbamazepine was selected as a typical PPCP for analysis. In addition, the microbial community structure of the composite filler was also investigated. High-throughput sequencing confirmed that the dominant bacteria had good adaptability to PPCPs. This technique not only reduced the potential environmental impact but also served as a foundation for further research on the use of constructed wetlands for the treatment of PPCPs contaminated water bodies and its large-scale implementation.

Microbial approaches for pharmaceutical wastewater recycling and management for sustainable development: A multicomponent approach

A microbial-driven approach for effluent treatment, recycling, and management of Pharmaceutical and Personal Care Products (PPCPs) has been undertaken to mitigate the menace of water contamination. Bioremediation processes are mainly considered the first preference in pharmaceutical wastewater recycling and management. PPCPs are reported as one of the primary sources of emerging contaminants in various water matrices, which raises concern and requires efficient management. Their widespread utilization, persistently high level, and resistance to breaking down make them one of the potentially dangerous compounds causing harm to the ecosystem. Continually increasing PPCPs level PPCPs contaminants in water bodies raised concern for human health as they can produce potential risks with harmful and untoward impacts on our health. PPCPs are composed of multiple diverse compounds used by humans and animals, which include biopharmaceuticals, vitamins and nutritional supplements, antibiotics, counter-prescription drugs, cosmetics products, and unused pharmaceutical products. Personal care products are found to be bioaccumulative, reduce water quality and potentially impact ecological health. However, continual exposure to PPCPs in aquatic organisms, impacts their endocrine function disruption, gene toxicity, and antibiotic resistance. Decreased water quality may result in an outbreak of various water-borne diseases, which could have acute or long-term health complications and may result in an outbreak of various water-borne diseases, which could have acute or long-term effects on public and community health. Polluted water consumption by humans and animals produces serious health hazards and increased susceptibility to water-borne diseases such as carcinogenic organic or inorganic contaminants and infectious pathogens present in water bodies. Many water resource recovery facilities working on various conventional and advanced methods involve the utilization of microbes for filtration and advanced oxidation processes. Therefore, there is an immense need for bioremediation techniques facilitated by mixed cultures of bacteria, algae, and other microbes that can be used as an alternative approach for removing pharmaceutical content from effluent. This review highlights the various sources of PPCPs and their impacts on soil and water bodies, resulting in bioaccumulation. Different techniques are utilized to detect PPCPs, and various control strategies imply controlling, recycling, and managing waste.

Cyanobacterial water blooms as an environmental hazard to waters

The article describes and analyzes the problem of cyanotoxin contamination of water bodies in Ukraine and other countries of the world. Eutrophication of water bodies, which is caused by human activity, climate change lead to uncontrolled development of cyanobacteria, and thus to ecological danger in hydrosphere objects. Anthropogenic eutrophication (increasing the content of nutrients in water due to their introduction into water bodies during pollution of water bodies by flood and municipal runoff, fish farming use of water bodies), temperature rise, increase in carbon dioxide content in the atmosphere, as a result of the transformation of introduced organic matter in water, contribute to increasing the dominance of cyanobacteria in water ecosystems. Bloomforming cyanobacteria produce various neurotoxins, hepatotoxins, and dermatotoxins that can be fatal to birds and mammals (including waterfowl, cattle, and dogs) and threaten the use of water bodies for public water supply, recreation, irrigation, and fishing. Among the toxins of blue-green algae, nodularin, saxitoxin, microcystin, domoic acid, guanitoxin, anatoxins and others were found. Exceeding the critical mass of algae and their metabolites activates the selfdecomposition process. This leads to the removal of oxygen from the water, and instead the release of methane, hydrogen sulfide, ammonia, and other toxic substances. The result of this is not only the death of fish. Cyanobacteria are capable of natural genetic transformation — genetic change of the cell as a result of direct absorption and inclusion of exogenous DNA from its environment. A sufficiently effective solution to the issue of controlling the activity of cyanobacteria is the use of humic preparations. it was established that humic substances (humic acids, fulvic acids) in certain concentrations negatively affect the growth, development and activity of cyanobacteria. Humic substances, as a component of organic matter and a reserve of organic carbon in its global cycle, have a negative effect on hydrobionts by increasing their concentration in water bodies. However, humic substances are able to regulate the activity of phytoplankton. The introduction of humic substances at a concentration of 2-5 mg/l of reservoir water significantly affects the activity of phytoplankton (suppresses phytoplankton vegetation, reduces the slime formation of cyanobacteria, and, from the beginning, inactivates the synthesis of cyanotoxins). This effect is provided by the alkaline pH of humates, high content of iron and copper.

Circular Economy Approach for Treatment of Water-Containing Diclofenac Using Recyclable Magnetic Fe3o4 Nanoparticles: A Case Study of Real Water Sample from Lake Victoria

Aims: A circular economy is a concept that aims to create a sustainable future by reducing waste and promoting the reuse of resources. In the field of water treatment, this concept has been applied through the use of recyclable materials to remove pollutants from water.
 Place and Duration of Study: In this study, we investigated the use of recyclable magnetic Fe3O4 nanoparticles to remove diclofenac from a water sample from Lake Victoria. The water sample was collected once to test the application of recyclable magnetic Fe3O4 nanoparticles in real environmental samples.
 Methodology: The nanoparticles were synthesized using a coprecipitation method and characterized using various techniques, including SEM/EDX, XRD, MPMS, ImageJ, and Solid addition method for PZC determination. The removal of diclofenac experiments was designed by response surface methodology.
 Results: The optimal conditions for diclofenac removal were pH 2, concentration 500 ug/L, contact time 60 minutes, and adsorbent dose 50 mg with a removal percentage of 69.95%. The reusability of the Fe3O4 nanoparticles was evaluated for three cycles, with removal percentages of 69.95%, 60%, and 41.6% for the first, second, and third cycles, respectively. This characteristic aligns with the principles of the circular economy, promoting resource conservation and waste reduction. The nanoparticles were also tested on a real water sample from Lake Victoria, resulting in 100% removal of diclofenac.
 Conclusion: This finding suggests that the Fe3O4 nanoparticles can be adopted for drinking water treatment in the East African community, addressing the issue of pharmaceutical contamination in water bodies.

Biochemical insights into enhanced lipid production by a microalga under combined stress of salinity and arsenic

The contamination of water bodies and depleting fuel resources are the two major global concerns. Such a scenario demands a coherent approach of production of green fuels by utilizing the waste/brackish waters for a sustainable economy. Therefore, the current study investigated the adaptive response of Scenedesmus sp. IITRIND2, a halotolerant microalga under combined stress of osmolarity along with arsenic (As (III), As (V)) toxicity. The algal cells efficiently mitigated 75–89 % of As (III) and As (V) from artificial seawater (ASW) having 80 ppm of initial concentration. The ∼ 2-fold higher biosorption of As in ASW cultivated cells was mediated due to the remarkable changes in the cell size as compared to fresh water (FW) grown cells. Though uptake of As in cells significantly inhibited the growth and photosynthetic activity but the cells remodeled their biochemical pools to maintain the overall proportion of lipids (50 % of the dry cell weight). Elevated levels of superoxide dismutase, glutathione, and glutathione reductase aided major stress responsive adaptation in cells under co-toxicity of salinity and As. Further, As spiked cells grown in ASW media improved the oxidative stability and cetane number of the derived fuel. This research sheds light on the possible utilization of a halotolerant microalga, paving a viable and eco-friendly biorefinery framework to remediate As, produce green fuels while desalinating the abundant seawater for further municipal usage.

Theoretical and experimental insight into the construction of FTO/NiSe2/BiVO4 photoanode towards an efficient charge separation for the degradation of pharmaceuticals in water

The increasing contamination of water bodies by pharmaceuticals has become a major environmental concern, with traditional treatment methods often proving ineffective. In this manuscript, we present a theoretical and experimental investigation into the construction of an S-scheme FTO/NiSe2/BiVO4 (NSB) photoanode toward the photoelectrocatalytic degradation of pharmaceutical pollutants in water. The study focuses on the optimization of the photoanode structure to significantly restrain charge recombination and maximize photoelectrocatalytic performance. The photoanode achieves higher efficiency (76%) in comparison with the pristine FTO/BiVO4 (BVO) (43%) and FTO/NiSe2 (NS) (17%) for the PEC degradation of ciprofloxacin. This can be attributed to the improved band gap (1.92 eV), low charge transfer resistance (9.6 Ω), reduced flat band potential (0.24 V) and higher charge density (4.86 × 1017 cm–1) resulting from synergic interaction at the interface of the semiconductor resulting to fast transition of the charge and restraining of recombination of the charge carriers. The accumulation of the electrons majorly takes place at the NS layer as displayed by the theoretical modeling of the charge density difference. This suggests a transition of electrons from BVO to NS. The band offset as well as the built-in electric field across the NSB interface limit the recombination of the photoinduced carriers. The mechanism including the functions of different reactive species is studied, which reveals that the holes mostly dominate the degradation process. Based on density functional theory, active species capture experiment, and photoelectrochemical detection, the synthesized NSB photocatalyst conforms to an S-scheme heterojunction charge transfer mechanism. We consider the composite suitable for the treatment of water contaminated with pharmaceutical waste.

Quantum Dot-Based Fluorometric Sensor for Hg(II) in Water Customizable for Onsite Visual Detection.

An easy naked-eye detection technique for mercuric ions in water using silanized quantum dots is demonstrated. Cadmium selenide quantum dots were synthesized and rendered water soluble by silica overcoating. The quantum dot emission was instantly turned off by the mercuric ions in the analyte, enabling visual detection. The emission quenching was associated with a concomitant bathochromic shift, both in the absorption and emission profiles. The underlying mechanism is a permanent surface modification of quantum dots by mercuric ions, altering the electronic structure and, in turn, the photophysical properties. The results confirmed the potential of this simple system to be customized for on-site visual detection of mercury contamination in water bodies, biological fluids, and soil with high selectivity and sensitivity.