Eutrophication Of Water Bodies Research Articles

Purification Effect of Water Eutrophication Using the Mosaic System of Submerged-Emerged Plants and Growth Response.

Aquatic plants play a crucial role in the sustainable management of eutrophic water bodies, serving as a valuable tool for water purification. However, the effectiveness of using aquatic plants for improving water quality is influenced by landscape considerations. In practical applications, challenges arise concerning low purification efficiency and compromised aesthetic appeal when utilizing plants for water purification. To address these issues, this study aimed to examine the impact of aquatic plants on the purification of simulated landscape water bodies, specifically focusing on the effectiveness of the mosaic system of submerged-emerged plants in remediating eutrophic water bodies. Our findings indicated that individual aquatic plants exhibited limited efficacy in pollutant (total nitrogen, total phosphorus, ammonia nitrogen, and chemical oxygen demand) removal. However, when combined in appropriate proportions, submerged plants could enhance species growth and improve the purification efficiency of polluted water bodies. Notably, the mosaic system of submerged-emerged plants neither significantly promoted nor inhibited the growth of each other, but it effectively removed pollutants from the simulated water bodies and inhibited turbidity increase. The comprehensive evaluation ranked the purification capacity as Canna indica-submerged plants combination (C + S) > Thalia dealbata-submerged plants combination (T + S) > Iris pseudacorus-submerged plants combination (I + S) > Lythrum salicaria-submerged plants combination (L + S). Both C + S and T + S configurations effectively mitigated the rise of water turbidity and offered appealing landscape benefits, making them viable options for practical applications in urban landscape water bodies. Our study highlights that a submerged-emerged mosaic combination is a means of water purification that combines landscape aesthetics and purification efficiency.

Identification of potentially harmful bacterial genera of veterinary relevance in the Llanquihue urban wetlands

Water bodies constitute natural, social, and ecological heritage under constant threat from the footprint of human action. They are the habitats of many species and play a key role in sustaining biodiversity in different ecosystems. However, anthropogenic activity can result in eutrophication of water bodies, favoring the excessive growth of microorganisms, which can be a risk factor for animal, human, and environmental health. The Agricultural and Livestock Service [Servicio Agrícola y Ganadero, (SAG)] of Chile developed a list of Mandatory Reportable Diseases (MRD) to report suspected contagious diseases of veterinary relevance. In this sense, the detection of microorganisms in water bodies for the characterization of their sanitary status is important for the development of monitoring strategies and the prevention of possible diseases. This study aimed to determine the presence of potentially harmful bacteria in Llanquihue urban wetlands. Here, we used metagenomic sequencing of amplicons to characterize the composition of microorganisms in three urban wetlands in the city of Llanquihue, which could be a risk factor for animal health. Our main finding was the detection of genera that may be associated with MRD, in addition to other microbial genera that have pathogenic potential. On the other hand, we also report the presence of cyanobacteria genera that can be involved in toxin production in water bodies as another potential source of risk. This is the first study to use massive sequencing techniques to analyze the sanitary status of urban wetlands in the city of Llanquihue.

The cytotoxicity of microcystin-LR: ultrastructural and functional damage of cells.

Microcystin-LR (MC-LR) is a toxin produced by cyanobacteria, which is widely distributed in eutrophic water bodies and has multi-organ toxicity. Previous cytotoxicity studies have mostly elucidated the effects of MC-LR on intracellular-related factors, proteins, and DNA at the molecular level. However, there have been few studies on the adverse effects of MC-LR on cell ultrastructure and function. Therefore, research on the cytotoxicity of MC-LR in recent years was collected and summarized. It was found that MC-LR can induce a series of cytotoxic effects, including decreased cell viability, induced autophagy, apoptosis and necrosis, altered cell cycle, altered cell morphology, abnormal cell migration and invasion as well as leading to genetic damage. The above cytotoxic effects were related to the damage of various ultrastructure and functions such as cell membranes and mitochondria. Furthermore, MC-LR can disrupt cell ultrastructure and function by inducing oxidative stress and inhibiting protein phosphatase activity. In addition, the combined toxic effects of MC-LR and other environmental pollutants were investigated. This review explored the toxic targets of MC-LR at the subcellular level, which will provide new ideas for the prevention and treatment of multi-organ toxicity caused by MC-LR.

A method for quantifying the contribution of algal sources to CODMn in water bodies based on ecological chemometrics and its potential applications

In natural water bodies, especially in eutrophic or waterbloom water bodies, algal sources are an important source of the permanganate index (CODMn), and their contribution ratio and analytical methods for rapid and quantitative require more research. In this study, continuous monitoring sampling was conducted in the Jiuqu River Basin of the Tuojiang River, and the response relationship between the algal community structure and the CODMn of the overlying water was analysed by detecting and analysing algal biomass, river water quality indicators, algal source organic matter characteristics and the component characteristics of river CODMn. A rapid quantitative analysis model of algal-source CODMn contribution was established based on ecological chemometrics with coupled chlorophyll indicators. Studies have shown that algal abundance is closely related to the dynamic changes in CODMn in water bodies, especially Cyanobacteria, which have a significant advantage in water bodies with high concentrations of CODMn and can be indicating oxygen-depleted polluted water bodies. The contribution of nascent humic substances in algal source material to the CODMn of the overlying water was greater than that of protein substances. The contribution of chlorophyll-a to the estimate of CODMn from algal sources in this study watershed was modeled as CODMn%=[(0.1077Chla−0.1483)/Overlying waterCODMn]×24.50%, and the components and the methods for establishing of an automatic algal sources CODMn monitoring and analysis system were proposed. This study provides technical support for the research and quantitative control of oxygen depletion pollution in rivers, lakes and reservoirs during the waterbloom period.

Young-of-the-year fish as bioindicators of eutrophication and temperature regime of water bodies.

Young-of-the-year fish communities are widely used as bioindicators of various environmental disturbances. This study was conducted from 1997 to 2015 and aims to develop fish trait-based indices of changes in the temperature regime and eutrophication of water bodies in the Dnipro River basin. We identified fish traits that significantly correlate with both temperature and chlorophyll-a concentration optimum: reproduction habitat, oxygen tolerance, and toxicity tolerance. Compared to other ecological groups, lithophilic species exhibited the lowest degree of thermal and eutrophication optimum, indicating this species' greater vulnerability to environmental alteration. Fish species that are intolerant to water quality and low oxygen concentration were the most sensitive to changes in temperature regime and eutrophication level. Salinity preferences and water quality tolerance emerged as reliable predictors of temperature optimum. Freshwater fish had an average temperature optimum that was 4.5% higher than that of freshwater-brackish and freshwater-brackish-marine fish. Species tolerance to the temperature factors and nutrient loads correlated only with rheophily, with rheophilic species having an average 13.8% higher temperature tolerance than other fish species and a 10.4% higher chlorophyll-a concentration tolerance. The fish temperature index increased over time during the study period in all the studied water bodies, consistent with ongoing warming affecting all sites. In contrast, the Fish Eutrophication Index showed greater temporal heterogeneity in studied water bodies, indicating various adaptative potentials of fish communities to eutrophication. These indices can be relevant for assessing disturbed situations caused by changes in climatic and anthropogenic impacts on water bodies.

Controlling Phosphorus Transport in Poyang Lake Basin under the Constraints of Climate Change and Crop Yield Increase

Phosphorus, as a key nutrient, plays an essential role in both algal growth in surface waters and crop development on land. Its presence in inorganic fertilizers is crucial for maximizing crop yields. However, an excessive accumulation of phosphorus in soils can lead to its loss and exacerbate eutrophication in water bodies. This study highlights the complex interplay among phosphorus management, agricultural productivity, and environmental health, particularly in the context of climate change’s influence on sediment transport and water pollution. We focus on the Poyang Lake Basin (PLB) and use a sophisticated process-based phosphorus model to forecast phosphorus load trends from 2020 to 2049. Our predictions indicate a significant increase in the total phosphorus load of the PLB due to the impact of climate change. To address these challenges, we explore a novel strategy combining organic and inorganic phosphorus fertilizers. This approach aims to improve crop yields while reducing non-point source phosphorus pollution through adjusted anthropogenic inputs. Our findings reveal that a synergistic application of these fertilizers, coupled with a controlled use of inorganic phosphate, can reduce its usage by more than 2.5% annually. This method not only contributes to a 2.2% average annual increase in livestock and poultry production but also promotes a 0.6% yearly growth in grain output. Consequently, it effectively diminishes non-point source phosphorus pollution, offering a sustainable solution to the dual challenge of enhancing agricultural productivity and protecting environmental health.

Efficacy of point source legislation quantified for a 64-year river water quality trajectory of phosphorus loading

Changes in river water quality often follow typical trajectories characterized by sequential phases of degradation and recovery induced by management measures, typically achieved with combinations of legislative and technological interventions. However, the key question about the effectiveness of the different types of legal interventions – source control, use-related, and end-of-pipe – remains poorly understood. With the case of phosphorus (P), which is a valuable indicator of surface water quality and a widespread target of legislation at various governance levels in order to control eutrophication of water bodies, we quantified the relation between point source loading of P and resulting river water quality for a multidecadal trajectory of the river Ruhr (Germany). In particular, we analysed P-related legislation targeting point source pollution enforced at EU, national, state, and local level and linked their development with measured total phosphorus (TP) concentrations in the river Ruhr (Germany). To this end, we combined archival data with information in the literature and conducted interviews with contemporary witnesses to describe and quantify the efficacy of each legislative approach. Although not specifically targeted at P reduction, end-of-pipe measures (sewer systems and wastewater treatment plants (WWTP)) reduced TP inputs to surface waters already in the 1960s and 1970s, curbing TP inputs to the Ruhr by 38% in 1980. The first targeted source control legislation – the banning of phosphates in textile detergents in 1981 – effectively reduced TP concentrations in WWTP influents by 36% since 1990. In combination with stronger end-of-pipe legislation focusing on P elimination in WWTP since the 1990s, TP concentrations in WWTP effluents were reduced by 86% at the end of the 1990s and by 92% in 2021. Complete and successful source control for textile detergents made use-related legislation redundant. Our study demonstrates that source control measures should be prioritized, because they are the fastest way to curb emissions. These findings provide insights that can inform efficient decision-making regarding water quality in a trajectory perspective of hierarchical governance and technological needs, as well as effective policy-making and management for other pollutants requiring control from point sources.

Z-scheme Ag2MoO4/BiVO4 photocatalyst using Ag as charge transfer mediator: Performance optimization and Microcystis aeruginosa inactivation application

Eutrophication in water bodies has caused harmful algal blooms (HABs) to occur worldwide, resulting in significant impacts on both the environment and human well-being. In this work, a Z-scheme Ag2MoO4/BiVO4 (AMB) photocatalyst with Ag as the charge transfer mediator was constructed by depositing Ag2MoO4 on BiVO4 through a simple in-situ generation method and characterized by various techniques. In addition, AMB-30% has the best photocatalytic performance, removing 99% of chlorophyll a within 3 h and performing well under different conditions. The physiological characteristics of algal cells were also investigated. The results showed that AMB-30% could not only destabilize the stability, membrane permeability and physiological function of algal cells, but also degrade the intracellular organic matter leaked out from the algal cells, effectively avoiding the secondary pollution of the water body while inactivating algae. Based on the identification of the active substance, the possible algal removal mechanism of Ag2MoO4/BiVO4 under the photocatalytic system was further proposed. Finally, the results of the five-cycle experiments and XRD characterization of AMB-30% demonstrated that it has great recyclability and stability, thus offering a favorable prospect in mitigating HABs.

Metals and biogenic substances’ migration ability in the «bottom sediments – water» system under natural and experimental conditions


 
 
 The paper considers the results of long-term studies on some chemical elements’ migration (Al, Fe, Ti, Mn, Cu, Zn, Pb, N, P, Si) in the «bottom sediments – water» system of surface water bodies under the effect of different aquatic environment factors. The greatest effect is made by water bodies’ oxygen regime, pH, and presence of dissolved organic substances, in particular humic substances. The migration of manganese, iron, inorganic nitrogen and phosphorus from bottom sediments is controlled mostly by oxygen regime. Migration of these chemical elements significantly increases, when there is oxygen deficiency and anaerobic conditions are formed in the bottom water layer. It has been observed in both natural and experimental conditions. Man- ganese concentration increases in bottom water in 25–50 times, iron – in 1.3–13, inorganic nitrogen – in 5.3–19.3, and inorganic phosphorus – in 2.8–23 times. The dissolved oxygen concentration hardly has any effect on the migration of aluminium, titanium, copper, zinc, lead, and silicon from bottom sediments into the water. The chemical elements’ migration is significantly affected by a decrease in pH of water contacting with bottom sediments and the presence of humic substances in it. High humic substances concentrations promote a reduction in water pH and oxygen content, which is consumed for their oxidation. A case study of several water bodies illustrates the cumulative effect of water pH lowering, anaerobic conditions at the solid and liquid phases’ interface, as well as complexation with humic substances on chemical elements’ migration from bottom sediments. Experimental modeling has shown that the metal migration from bottom sediments occurs both due to their labile fractions and complex compounds with dissolved organic matter, especially with humic substances of low molecular weight (≤2.0 kDa). The share of the metal labile fraction gets higher, when water pH decreases. Under recent climate change, the probability of water’s secondary pollution with different chemicals increases significantly in summer. This is mainly caused by oxygen deficiency, water pH lowering, and reducing conditions at the «bottom sediments – water» interface with hydrogen sulphide being formed. This is especially true for highly eutrophic water bodies subject to human impact. The aquatic environment toxicity can get considerably higher due to the migration of chemicals with strong toxic properties from bottom sediments, as well as labile metal fractions, marked by higher bioavailability for hydrobionts.
 
 

Assessing the performance of polyphosphate accumulating organisms in a full-scale side-stream enhanced biological phosphorous removal.

Phosphorous (P) removal in wastewater treatment is essential to prevent eutrophication in water bodies. Side-stream enhanced biological phosphorous removal (S2EBPR) is utilized to improve biological P removal by recirculating internal streams within a side-stream reactor to generate biodegradable carbon (C) for polyphosphate accumulating organisms (PAOs). In this study, a full-scale S2EBPR system in a water resource recovery facility (WRRF) was evaluated for 5 months. Batch experiments revealed a strong positive correlation (r = 0.91) between temperature and C consumption rate (3.56-8.18 mg-COD/g-VSS/h) in the system, with temperature ranging from 14°C to 18°C. The anaerobic P-release to COD-uptake ratio decreased from 0.93 to 0.25 mg-P/mg-COD as the temperature increased, suggesting competition between PAOs and other C-consumers, such as heterotrophic microorganisms, to uptake bioavailable C. Microbial community analysis did not show a strong relationship between abundance and activity of PAO in the tested WRRF. An assessment of the economic feasibility was performed to compare the costs and benefits of a full scale WRRF with and without implementation of the S2EBPR technology. The results showed the higher capital costs required for S2EBPR were estimated to be compensated after 5 and 11 years of operation, respectively, compared to chemical precipitation and conventional EBPR. The results from this study can assist in the decision-making process for upgrading a conventional EBPR or chemical P removal process to S2EBPR. PRACTITIONER POINTS: Implementation of S2EBPR presents adaptable configurations, exhibiting advantages over conventional setups in addressing prevalent challenges associated with phosphorous removal. A full-scale S2EBPR WRRF was monitored over 5 months, and activity tests were used to measure the kinetic parameters. The seasonal changes impact the kinetic parameters of PAOs in the S2EBPR process, with elevated temperatures raising the carbon demand. PAOs abundance showed no strong correlation with their activity in the full-scale S2EBPR process in the tested WRRF. Feasibility assessment shows that the benefits from S2EBPR operation can offset upgrading costs from conventional BPR or chemical precipitation.

Experimental studies of the effect of lighting on eutrophication of water bodies and the operation of drip irrigation systems

Experimental studies of the effect of lighting on eutrophication of water bodies and the operation of drip irrigation systems

Efficiency and driving factors for the retention of exogenous inorganic nitrogen in different forest soils

Forest soils play a vital role in purifying exogenous nitrogen ions and mitigating eutrophication in downstream water bodies. However, the heterogeneity of nitrogen ion removal efficiency in different forest soils and the underlying driving mechanisms remain not fully known. In our research, we selected soils from four typical forest stands, namely, Pinus massoniana-Quercus variabilis mixed forest (MF), Quercus variabilis forest (QF), Pinus massoniana forest (PF), and Citrus reticulata forest (CF), surrounding China’s second largest reservoir in the Yangtze River Basin. Using laboratory simulation experiments, we observed variations in concentration of ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3−-N) in soil leachate after addition of exogenous NH4+-N and NO3−-N solutions, along with the corresponding physical, chemical, and microbial factors. The results showed that on Day 21, all soils exhibited comparable removal rates of approximately 93% for NH4+-N and 70% for NO3−-N. On Day 4, 6–15, PF and QF demonstrated significantly higher removal efficiencies for NH4+-N and NO3−-N, respectively. Combining direct with indirect effects from Partial Least Squares Path Modeling (PLS-PM), NH4+-N removal efficiency was promoted by total organic carbon (TOC), soil NO3−-N and NO2−-N, while it was inhibited by soil water content (SWC), urease activity, soil NH4+-N, and ammonia-oxidizing archaea (AOA). NO3−-N removal efficiency was facilitated by SWC, TOC, and urease, while it was restrained by soil NO3−-N and ammonia-oxidizing bacteria (AOB). Notably, TOC was the only factor that had a comprehensive promoting effect on both NH4+-N and NO3−-N removal efficiency. Our study indicates that soil in coniferous forest excels in NH4+-N removal while broadleaf forest in NO3−-N, and the spatial layout of water source forests should consider water replenishment time, the form of nitrogen ion pollutants, and the nitrogen purification features of different forest types when the prime objective is to purity the water. Additionally, enhancing soil organic carbon could be an effective forest management approach to improve soil nitrogen ion purification and mitigate agricultural and nitrogen deposition pollution.

A portable EIS-based biosensor for the detection of microcystin-LR residues in environmental water bodies and simulated body fluids.

Due to the eutrophication of water bodies around the world, there is a drastic increase in harmful cyanobacterial blooms leading to contamination of water bodies with cyanotoxins. Chronic exposure to cyanotoxins such as microcystin leads to oxidative stress, inflammation, and liver damage, and potentially to liver cancer. We developed a novel and easy-to-use electrochemical impedance spectroscopy-based immunosensor by fabricating stencil-printed conductive carbon-based interdigitated microelectrodes and immobilising them with cysteamine-capped gold nanoparticles embedded in polyaniline. It has been also coupled with a custom handheld device enabling regular on-site assessment, especially in resource-constrained situations encountered in developing countries. The sensor is able to detect microcystin-LR up to 0.1 μg L-1, having a linear response between 0.1 and 100 μg L-1 in lake and river water and in serum and urine samples. In addition to being inexpensive, easy to fabricate, and sensitive, it also has very good selectivity.

Construction and Evaluation of The Wind Tunnel Technique for Estimating Ammonia Volatilization from Land

Agriculture is mainly responsible for ammonia (NH3) volatilization. Among all agricultural activities, livestock and especially animal manures are the most important sources of NH3 emissions. Manure application which not only exacerbate greenhouse gas emissions, but also leads to eutrophication of water bodies. Many studies have shown that surface application of manure can lead to large ammonia losses and run off, on the other hand that tillage can substantially reduce these losses. It is necessary to determine ammonia flux from manure-amended soils to improve management manure handling practices for minimizing agriculture’s impact on the environment. From this point of view, one of the direct measured method was used to determine this volatilization. The objections of this work were: i) The design, construction, physical calibration, and operation of the little wind tunnels. ii) Recover ammonia loss from bovine slurry by little wind tunnel method. iii) Determine the effect of slurry application depth on ammonia emission. The little wind tunnel system consisted of plastic canopy covering the treatment area (2 m long by 0.5 m wide). By was using a fan, it was imitated the natural wind speed in the test area (1-1.5 m/s). Nitrogen losses were measured with this method in surface application, 50 mm and 100 mm subsurface. In the surface application, the highest ammonia emission was observed. It was approximately 68% higher in compared to another methods. There is significantly (P=0.05) different in the ammonia emission, between the surface apply method and injection manure in soil methods. But There isn’t any significantly different between ammonia emission amount in injection subsurface methods (100 mm and 50 mm deep).

ANALYSIS OF THE IMPACT OF THE PETROCHEMICAL INDUSTRY ON THE CONDITION OF SURFACE WATER BODIES

The purpose of the study is to assess the consequences of the impact of the petrochemical industry on the condition of water bodies; studying the level of anthropogenic eutrophication and toxicity of a water body. The article presents the results of using the developed method for determining the eutrophication coefficient for surface rivers, which was carried out on water bodies experiencing the maximum impact of anthropogenic and technogenic factors.The development of research in this area will create the basis for the development of a model for predicting the processes of eutrophication and toxication of water bodies, which is important not only for the industrial hub of the city of Sterlitamak, but also for many regions with a high technogenic load.In this work, the Sterlya River was chosen as the object of study, as a water body located in the zone of influence of chemical and petrochemical enterprises. The laboratory experiment was carried out in accordance with the approved methodology for determining the toxicity of various water bodies and solutions of chemical substances PND F T 14.1: 2: 4.19-20131. During the experiment, indicators such as germination, average length and average dry weight of watercress seedlings were measured.The use of integral methods, which include biotesting methods used to diagnose the state of environmental components in areas with high anthropogenic load, makes it possible to obtain a comprehensive assessment of the object being studied, taking into account many factors, such as natural conditions, environmental parameters, etc.The experimental data obtained confirm both the stimulating and inhibitory effects of the test sample on the analyzed parameters of the test object, which is caused by simultaneous toxic effects and eutrophication processes.It is shown that the proposed method can be used to study the integral toxicity of not only surface and groundwater, but also wastewater, and also to record the dynamics of toxicity in space and time.

Enrichment of Water Bodies with Phenolic Compounds Released from Betula and Pinus Pollen in Surface Water.

Betula and Pinus pollen, which are dispersed in natural surface waters, release biologically active compounds into the water bodies. This study aims to evaluate variations in the distribution and composition of phenolic compounds in suspended particles in natural water bodies during pollen spreading. Samples taken from water bodies of different trophic levels were analyzed by microscopy, UV/VIS spectroscopy, HPTLC, and HPLC/DAD. The study revealed that the total phenolic content in water-suspended particles varied from 3.0 mg/g to 11.0 mg/g during Betula and Pinus pollen spreading. It was also observed that the surface water of dystrophic natural lakes had a higher content of phenolic compounds than the eutrophic, hypereutrophic, and mesotrophic water bodies. Chlorogenic, trans-ferulic, vanillin, and 3,4-dihydroxybenzoic acids were frequently detected in the surface water samples. Experimental measurements have shown variations in the release of phenolic compounds from Betula pollen into water (p < 0.05). After the exhibition of pollen, the distilled water predominantly contained bioactive chlorogenic acid. Further in situ investigations are necessary to gain a more comprehensive understanding of the function of phenolic compounds in aquatic ecosystems. The exploration of the release of bioactive compounds from pollen could provide valuable insights into the potential nutritional value of pollen as a nutrient source for aquaculture.

Developing upflow filters operated in a cascade sequence to compare two green sorption media for phosphorus removal

Finding solutions to treat stormwater runoff and wastewater effluent that contain phosphorus is an important effort due to the potential harmful algal bloom impacts on both human health and the environment, such as red tide in coastal regions, eutrophication of waterbodies, and fish kills. However, many of the remaining phosphorus reserves are becoming depleted. Finding low-cost, energy-efficient, and low-maintenance solutions that incorporate green sorption media (GSM) mixed with natural and recycled materials to treat nutrient-laden water, with potential for recovery, is of critical importance for sustainable material development. Biochar and zero-valent iron (ZVI) have received significant attention as low-cost, low-impact adsorbents for the removal of heavy metals, pathogens, and nutrients due to their ability to aid in structural support and reasonable removal efficiencies in GSM. In this study, phosphorus removal efficiencies were studied using two new recipes of GSM within a unique passive cascade upflow filtration system. The two new GSM include zero-valent iron and perlite green environmental media (ZIPGEM) composed of 85% sand, 5% clay, 5% ZVI, and 5% perlite by volume, and biochar zero-valent iron and perlite green environmental media (BIPGEM) containing 80% sand, 5% biochar, 5% clay, 5% perlite, and 5% ZVI by volume. Results indicate that the ZIPGEM-based filtration system achieved an average removal of 78.9% to 97.9% in the initial 60-min to 300-min range, whereas BIPGEM exhibited an average 67.1% to 86.9% removal during this same time interval. At the time of shutdown as a system, BIPGEM showed an average 52.8% removal at the 5480-min mark, and ZIPGEM exhibited an average 69.1% removal at the 11,180-min mark. After examining three isotherm models, the dose-response model estimated the adsorption capacity of ZIPGEM as 6.5 mg·g−1. Further comparison of the material structures and compositions of both raw and spent media samples using X-ray diffraction, X-ray fluorescence spectrometry, and a scanning electron microscope helped confirm part of the removal mechanisms.

Evaluation of Accumulation Potency of Arka Plant Varieties for Metals and Nutrients through Natural Biological Treatment

This study aims to evaluate the effectiveness of a natural biological treatment system for wastewater using Red soil, Arka Darshan, Arka Tilak, Arka Nirantara, and Arka Prajwal plants. The system employs clay as a natural nanomaterial for adsorption of substances such as nitrates, phosphates, potassium, and heavy metals. The soil contains numerous microorganisms that decompose organic matter into simpler compounds, while the plants use phytoremediation to uptake heavy metals and nutrients. The study measured the system’s efficiency in reducing Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Phosphate, Magnesium, Zinc, Nitrate, Sodium, and Potassium. The results showed that the system had an average efficiency of 98% in COD and 96% in BOD removal, and contributed an efficiency of 99% TSS and 46% TDS. The system also removed nitrates and phosphates, which cause eutrophication in water bodies, by 76% and 72%, respectively. Additionally, heavy metals like chromium, Nickel and Zinc were reduced by up to 81%, 71% and 59%. The study suggests that the natural biological treatment system is a sustainable and effective alternative to conventional wastewater treatment, particularly in sparsely populated rural areas. Therefore, we can conclude that this system has potential for wider adoption in treating wastewater.

Removal of Nitrate Nitrogen from Municipal Wastewater Using Autotrophic Denitrification Based on Magnetic Pyrite

As the problem of eutrophication of water bodies and nitrate pollution of surface and groundwater is becoming more and more prominent, deep denitrification of wastewater can effectively reduce the amount of nitrate nitrogen (NO3−-N) discharged into natural water bodies. To solve this problem, in this research, the autotrophic denitrifying bacteria were incorporated in an autotrophic denitrification simulator equipped with magnetic pyrite to remove NO3−-N and total nitrogen (TN) from wastewater. The purified strains were inoculated into municipal sewage. When the ratio of magnetic pyrite to quartz sand was 1:1 and the particle size of the filler was 0.5–1 mm, the removal rate of NO3−-N and TN was optimized, at 93.52% and 83.22%, respectively. Sulphate (SO42−) concentrations will level off during stable system operation, and SO42− concentrations show a positive correlation with NO3−-N and TN removal. The 16s rDNA sequencing analysis of the screened sludge showed that the main phyla in the screened and purified sludge were Epsilonbacteraeota and Proteobacteria, with an abundance of 65.83% and 26.88%, and the final enriched products were dominated by Sulfurimonas and Thiobacillus, with an abundance of 64.91% and 9.32%, respectively. The results showed that autotrophic denitrifying bacteria could be screened and purified using thiosulfate as a substrate, and that the use of magneto pyrite as an electron donor reduced most of the NO3−-N to N2, while reducing the TN content.

"Needle" hidden in silk floss: Inactivation effect and mechanism of melamine sponge loaded bismuth oxide composite copper-metal organic framework (MS/Bi2O3@Cu-MOF) as floating photocatalyst on Microcystis aeruginosa

Photocatalytic technology showed significant potential for addressing the issue of cyanobacterial blooms resulting from eutrophication in bodies of water. However, the traditional powder materials were easy to agglomerate and settle, which led to the decrease of photocatalytic activity. The emergence of floating photocatalyst was important for the practical application of controlling harmful algal blooms. This study was based on the efficient powder photocatalyst bismuth oxide composite copper-metal organic framework (Bi2O3 @Cu-MOF), which was successfully loaded onto melamine sponge (MS) by sodium alginate immobilization to prepare a floating photocatalyst MS/Bi2O3 @Cu-MOF for the inactivation of Microcystis aeruginosa (M. aeruginosa) under visible light. When the capacity was 0.4 g (CA0.4), MS/Bi2O3 @Cu-MOF showed good photocatalytic activity, and the inactivation rate of M. aeruginosa reached 74.462% after 120 h. MS/Bi2O3 @Cu-MOF-CA0.4 showed a large specific surface area of 30.490 m2/g and an average pore size of 22.862 nm, belonging to mesoporous materials. After 120 h of treatment, the content of soluble protein in the MS/Bi2O3 @Cu-MOF-CA0.4 treatment group decreased to 0.365 mg/L, the content of chlorophyll a (chla) was 0.023 mg/L, the content of malondialdehyde (MDA) increased to 3.168 nmol/mgprot, and the contents of various antioxidant enzymes experienced drastic changes, first increasing and then decreasing. The photocatalytic process generated·OH and·O2-, which played key role in inactivating the algae cells. Additionally, the release of Cu2+ and adsorption of the material also contributed to the process.