Contamination Of Water Resources Research Articles

Quantification of water, soil and nutrient losses in the Farinha river basin, Carolina - MA, in the Cerrado biome

Natural resources, such as soil and water, play a crucial role in sustaining life on Earth. When used appropriately, these resources can mitigate environmental impacts. However, inadequate soil management practices can result in negative effects, such as the intensification of erosion processes and significant losses of soil, water and nutrients essential for plant growth. Thus, considering that the Farinha River basin - MA is located in the Cerrado biome and has a large part of its area occupied by highly erodible soils, the aim was to quantify water, soil and nutrient losses using a rainfall simulator. The experimental design adopted was entirely randomised (DIC), in a bifactorial scheme with 5 replications. Factor 1 considered two types of soil management systems (Anthropised Area and Non-Anthropised Area), while factor 2 involved three simulated rainfall intensities (80mm.h-¹, 110mm.h-¹ and 130mm.h-¹). The response variables assessed were losses of water, soil and nutrients and organic matter.The averages were subjected to analysis of variance and, if significant, the Tukey test was applied at 5% probability using Past 4.03 software. The results indicated significant losses of soil, water and nutrients associated with both the soil management system and the rainfall intensities, as well as making it possible to quantify the nutrients lost in runoff water on site. The conclusion is that the combination of inadequate soil management practices and intense rainfall can exacerbate erosion processes and the leaching of macro and micronutrients, resulting in an increasing need to incorporate fertilisers and correctives into agroforestry activities. Furthermore, it is important to emphasise that water erosion also contributes to an increase in soil and nutrient loss, which can lead to adverse environmental impacts, such as contamination of water resources and degradation of soil quality.

Application of BIM+GIS Integration Technology in the Construction of Urban Intelligent Water Informatization

Urban intelligent water informatization is the process of managing and operating urban water systems with the use of contemporary information and communication technology in order to increase productivity, security, and sustainability. Establishing the appropriate infrastructure is the initial stage in building an intelligent water system so that management can choose wisely how to manage and operate the water system. Building information modeling (BIM) is a digital depiction of a building's or infrastructure's structural and functional details. In most metropolitan regions, a fast development phase is predicted to cause several water issues, including water resource shortages, floods, poor drainage, and water resource contamination. As a result, a practical approach is required for urban intelligent water information technology with the help of artificial intelligence techniques. Intelligent water systems may be built using Building Information Modeling (BIM) software to increase the system's effectiveness, stability, and durability. By offering a potent tool for storing and analyzing geographical data connected to the water distribution system, a geographic information system (GIS) can play a crucial role in the development of urban intelligent water informatization using ArcGIS mapping Software. The Internet of Things (IoT) system is used to implement intelligent water informatization, hardware implementation using ESP32, and software development using MQTT Broker and Node-Red. As a result, we recommended utilizing BIM+GIS integration technology for building urban intelligent water informatization. The suggested system is evaluated using management efficiency, urban flood control, innovative Construction, intensive management, and computation cost. In this research, the main objective is to identify where there are water leaks broken pipes and early warning system and monitoring system for flash flood disasters in urban areas. The result findings show that the integration of BIM and GIS provides a comprehensive platform for managing complex water informatization infrastructure projects and maximizes efficiency and sustainability.

Ecological risk of metals in Andean water resources: A framework for early environmental assessment of mining projects in Peru

Metallic contaminants in Andean water resources influenced by mining activities poses risks to aquatic ecosystems and a challenge to regulatory agencies responsible for environmental compliance. In this study, the Ecological Risk Assessment (ERA) framework was adapted to assess dissolved heavy metal concentrations at 283 surface water monitoring stations near to six mining projects during the dry and wet seasons. Reports from OEFA-Peru on Early Environmental Assessment (EEA) were used to apply various criteria and non-parametric statistical tests. They included ecological, ecotoxicological, chemical, and regulatory factors. The main goal of this research was to identify, analyze, characterize, and compare the risks present at different trophic levels. These levels were categorized as T1 (Microalgae), T2 (Zooplankton and Benthic invertebrates), and T3 (Fish). Individual risk (IR) was estimated using the quotient model, while total risk (TR) was assessed using the additive probability rule. Rainbow trout (Oncorhynchus mykiss), representing trophic level T3, showed the highest sensitivity to Fe and Cu. Statistical tests ranked the IR as Fe > Cu > Zn > Mn > Pb (p < 0.01). The TR was more prevalent during the wet season compared to the dry season (p < 0.01). Notably, around 50 % of the monitoring stations (n = 142) were classified as high risk, and 9 % (n = 13) showed extremely high-risk values for Cu and Fe. The adapted ERA framework demonstrated great effectiveness in identifying critical points of metal contamination in high Andean aquatic ecosystems under mining influence. However, specialized studies are suggested that allow the sources of pollution to be associated with specific regulatory actions.

Single and binary adsorption of paracetamol and diclofenac onto biochar produced from pepper stem: Which adsorption properties change in the binary system?

The importance of combating the contamination of water resources with emerging pollutants must be kept all the more in view by scientists, since such pollutants are harmful and pose challenges for traditional water treatment methods. The current study was designed to scrutinize the adsorption properties of a low-cost biochar for two pharmaceuticals in both single and binary systems. The work was focused on understanding how paracetamol (PARA) and diclofenac (DIC) co-adsorb, and it can serve as a beacon for similar studies, especially in modeling the adsorption processes of such systems. Using a low-cost biochar from pepper stem (PS) with a high surface area = 727.5 m2/g as adsorbent, experiments were carried out in both the single and binary systems to investigate the adsorption behavior of the mentioned pharmaceuticals. Results showed that, in the single system, the PS biochar demonstrates a slightly greater adsorption capability for both PARA and DIC, with a capacity of 354.66 and 256.10 mg/g, respectively, compared to its capacity for each pharmaceutical in the presence of the other in the solution. Interestingly, the effect of the presence of one of the pharmaceuticals on the thermodynamic parameters (ΔGº, ΔSº, and ΔHº) of the other was ignorable, and interactions such as hydrogen bonding, π-π, n-π, and anion-π interactions were at work for the adsorption processes, with different extends in each pharmaceutical-biochar case. On the other hand, the presence of one of the pharmaceuticals was effective on the kinetics of the adsorption process of the other and caused a decrease in its adsorption rate, especially in the initial stage of the process. Overall, in addition to the suitability of pepper stem biochar for PARA and DIC, results showed that the presence of one pharmaceutical is not influential on all the adsorption properties of the other, and the results can be exploited for studding similar systems.

Utilizing Waste Cooking Oil for Sustainable Biodiesel Production: A Comprehensive Review

The environmental and economic challenges posed by the over-reliance on fossil fuels have driven the search for alternative and sustainable energy sources. Waste cooking oil (WCO) presents a viable feedstock for biodiesel production, offering a dual solution to waste management and renewable energy generation. This comprehensive review examines the current state of biodiesel production from waste cooking oil, exploring the benefits, challenges, and processes involved. Biodiesel derived from WCO has several environmental advantages, including lower greenhouse gas emissions, biodegradability, and enhanced engine lubricity compared to traditional fossil fuels. Moreover, utilizing it for biodiesel addresses waste disposal issues, reducing the contamination of land and water resources. Despite these benefits, several challenges remain, such as the variability in its composition, contamination, and the need for efficient purification and transesterification processes. The review explores various methods for converting WCO into biodiesel, highlighting the key stages of the transesterification process, including the use of catalysts, alcohols, and reaction conditions. Additionally, advanced techniques such as ultrasound-assisted and microwave-assisted transesterification are discussed for their potential to increase efficiency and reduce processing time. This paper also addresses the sustainability aspects of biodiesel production from it, emphasizing its role in promoting a circular economy and reducing waste. The use of its contributes to a closed-loop system, where waste is transformed into a valuable resource. Furthermore, the review explores the economic and social impacts of biodiesel production, noting its potential to create jobs, reduce import dependence, and support local communities. In conclusion, this review underscores the significant potential of waste cooking oil in sustainable biodiesel production. It calls for continued research and technological innovation to optimize processes, enhance efficiency, and overcome existing challenges, thereby contributing to a cleaner and more sustainable energy landscape.

Nitrogen-doped carbon dots as fluorescent probes for sensitive and selective determination of Fe3+

At present, the contamination of water resources by heavy metal ions has posed a significant threat to human survival. Therefore, it is particularly critical to develop low-cost, easy-to-use, and highly efficient heavy metal detection technologies. In this work, a fast and cost-effective fluorescent probe for nitrogen-doped carbon dots (N-CDs) was prepared using one-step hydrothermal method with citric acid (CA) as carbon source, and melamine as nitrogen source. The structural and optical characterizations of the resulting N-CDs were investigated in details. The results showed that the quantum yield of the prepared fluorescent probe was as high as 45 %, and an average fluorescence lifetime was about 7.80 ns. N-CDs have excellent water solubility and dispersibility, with an average size of 2.58 nm. N-CDs exhibited excellent specific responsiveness to Fe3+ and can be used as an effective method for detecting Fe3+ at low-concentrations (the concentrations of N-CDs as low as 0.24 μg/mL) using fluorescent probes. The linear response of the fluorescent probe N-CDs to Fe3+ was formed in the concentration range of 20–80 μM, and the detection limit was 3.18 μM. In addition, in the actual water samples analysis, the recovery rate reached 97.05–100.58 %. The prepared of N-CDs provide available Fe3+ fluorescent probes in the environment.

Screening of Atrazine Tolerant Aquatic Plant and Roles of Plant Growth Regulators on Plant Growth and Atrazine Tolerance

The extensive use of atrazine to control weeds in agricultural areas has contaminated atrazine in surface water and groundwater. Atrazine contamination in water resources causes human health concerns. Thus, this study investigated the possible use of aquatic plants for removing atrazine from contaminated water. The experiment was performed under plant nursery conditions and divided into two parts: (1) the atrazine-tolerant plants were screened, and (2) the most atrazine-tolerant plant was used for atrazine phytoremediation stimulated by plant growth regulators. The results showed that atrazine was toxic to all aquatic plants, as the dry weight of the plants was significantly decreased when exposed to 20 mg/L of atrazine (P&lt;0.05). Based on five aquatic plants grown under 2.5–20 mg/L atrazine-contaminated water, &lt;i&gt;Azolla microphylla&lt;/i&gt; Kaulf. was the most tolerant aquatic plant and was more suitable for use in atrazine phytoremediation than the other aquatic plants (&lt;i&gt;Ceratophyllum demersum&lt;/i&gt; L., &lt;i&gt;Eichhornia crassipes&lt;/i&gt; (Mart.) Solms, &lt;i&gt;Hydrilla verticillata&lt;/i&gt; (L. f.) Royle, and &lt;i&gt;Salvinia cucullata&lt;/i&gt; Roxb. ex Bory). The total chlorophyll, carotenoid, and proline contents in the biomass of &lt;i&gt;A. microphylla&lt;/i&gt; cultured in 2.5–20 mg/L of atrazine did not significantly differ between the atrazine concentrations (P&gt;0.05). Meanwhile, the proline contents in the other four aquatic plants increased with increasing atrazine concentrations, and the chlorophyll content significantly decreased with an increase in the atrazine concentration. However, &lt;i&gt;A. microphylla&lt;/i&gt; could not remove atrazine from contaminated water, and the application of plant growth regulators (6-benzyladenine, gibberellic acid, indole-3-butyric acid, and salicylic acid) did not improve the atrazine removal from water. Atrazine in the water was around 21–26 mg/L on day five of &lt;i&gt;A. microphylla&lt;/i&gt; cultivation compared to the initial concentration (25 mg/L). Using a plant growth regulator was ineffective for stimulating growth and atrazine removal by &lt;i&gt;A. microphylla&lt;/i&gt;. Future research should explore other potential mechanisms for enhancing atrazine removal by &lt;i&gt;A. microphylla&lt;/i&gt;.

Health Effects of Heavy Metal Contamination in Drinking Water

Water is essential for life, be it the life of animals, plants or human beings. It’s our prime duty to protect, manage and preserve the quality of water. Uncontrolled anthropogenic activities have resulted in contamination of fresh water resources thereby affecting the health of living beings. Rampant industrialization is a major environmental problem on the global scale for the pollution of fresh water with toxic effluents containing heavy metals. Contamination of surface water by heavy metals is the greatest quality issues because of their toxic nature, increased release and negative impact on the health of human beings. Water-borne diseases remain one of the major health concerns in the world. Heavy metals are individual metals and metal compounds that can impact human health. Exposure of humans to metals such as antimony, arsenic, barium, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, selenium, silver, tin, zinc, etc results in chronic and acute toxicities. The toxicity of heavy metals depends on their concentration, period of exposure and route of exposure. Humans are exposed to heavy metals either by inhalation from the atmosphere, intake through drinking water, or by ingestion through the skin by dermal contact. The present review describes the analysis of ‘heavy metal contamination in drinking water’ with reference to definition, sources, health effects on humans and preventive measures. This study suggests that, the best way to get rid of heavy metal contamination in drinking water is to remove toxic heavy metals by using the best water purification system. Also, the ground water resources must be monitored for quality assessment, source identification and bioremediation of heavy metals.

Coliform Bacteria Contamination of Water Resources and Implications on Public Health in Fako Division, South West Region, Cameroon

Coliform Bacteria Contamination of Water Resources and Implications on Public Health in Fako Division, South West Region, Cameroon

Versatile superhydrophobic magnetic biomass aerogel for oil/water separation and removal of multi-class emerging pollutants

Water resources contamination by both oil and microplastics (MPs) stands as a pressing environmental concern. To tackle this challenge, we have devised a superhydrophobic magnetic biomass aerogel, synthesized from PDMS-modified carbonized ZIF-67/chitosan (PDMS@CZIF-67/CS). This aerogel exhibits remarkable proficiency in effecting oil/water separation and adsorbing a wide range of emerging pollutants, owing to its inherent superhydrophobicity, stability, and self-cleaning capabilities. Furthermore, the aerogel demonstrates efficient absorption of viscous oils and facilitates self-driven oil absorption through the synergistic photothermal conversion and magnetic properties of CZIF-67, respectively. Following ten consecutive separation cycles, the aerogel consistently upholds its efficacy in oil/water separation, regardless of the employed method, be it gravity-driven or facilitated by a peristaltic pump. Notably, the PDMS@CZIF-67/CS aerogel manifests a high adsorption capacity for various emerging pollutants, specifically MPs, achieving an almost complete adsorption efficiency. This paper introduces an innovative, eco-friendly approach aimed at mitigating oil-contaminated wastewater and emerging pollutants, highlighting its potential for widespread application.

Effects of agriculture and urbanization on the geochemistry of the Scioto River, Ohio

Despite efforts to reduce nonpoint source contamination of water resources, agriculture and urbanization remain primary sources that impair surface water quality. The Scioto River in Ohio, USA has headwaters in land dominated by primarily row-crop agriculture, then flows through metropolitan Columbus, the 14th largest city in the U.S. The river serves as a major drinking water source for the city and is dammed to form two reservoirs. The Scioto River was sampled for major ions, nutrients, and select trace elements weekly to monthly at five locations along changing agricultural and urban land use. Dissolved concentrations of many analytes were highest at the most upstream agricultural location, decreased to downtown Columbus, and increased at the location furthest downstream in agricultural land. The same trend was observed in discharge-weighted yields. Because much of the study area is underlain by carbonate bedrock, correlations with Ca2+ were likely to indicate a primarily geogenic source of the solute. Elements with moderate to strong positive correlations with Ca2+ included SO42-, Ni2+, Rb+, Mo6+, and Ba2+. Inorganic N species, emanating primarily from an agricultural source, had negative relationships with Ca2+. Concentration-discharge relationships revealed chemostatic to weak dilution of analytes positively correlated with Ca2+, suggesting a geogenic source of these elements that was weakly diluted with increasing discharge. Cu2+ showed a positive concentration-discharge slope, suggesting an anthropogenic input, but a defined source was not identified. Dams on the Scioto River that form drinking water reservoirs dampened chemical correlations and concentration-discharge relationships. Both agricultural and urban sources influence the river’s chemistry based on hydroclimatic conditions and land use. Higher frequency sampling of the Scioto River during high flows allowed for a more nuanced understanding of sources of solutes to the river compared to previous work. Continued water quality monitoring is imperative to maintain and protect water quality resources, especially as urban populations are predicted to grow significantly in the next century.

Purification process and mechanism analysis of low-concentration phosphorus wastewater with novel electrodeposition - biochar filter bed

Phosphate‑phosphorus (PO43−-P) is a non-renewable resource. Rapid agricultural activities and inefficient use of phosphate fertilizers contribute to the contamination of natural water resources due to PO43−-P accumulation. PO43−-P recovery in natural water with a low PO43−-P concentration, is conducive to the sustainable utilization of phosphate. Electrodeposition using Ca2+ to recover PO43−-P in natural water has great potential. However, the limitations of low-concentration PO43−-P recovery need to be addressed. This study designed a novel electrodeposition-biochar filter bed (E-BFB) to investigate the removal and recovery ability of PO43−-P at low concentrations. Efficient removal and recovery of PO43−-P was achieved through electrodeposition, biochar adsorption, and accumulation by microorganisms. Effects of different parameters on the performance of E-BFB for PO43−-P removal were studied, including influent PO43−-P concentration, voltage, and electrode spacing. Results showed that 69.4 % PO43−-P was removed when the influent PO43−-P concentration was 0.8 mg/L by E-BFB, as the average removal rate in the biochar filter bed (BFB) was only 11 %. The PO43−-P recovery rate of cathodic electrodeposition was as high as 37.22 %, accounting for 57 % of the total PO43−-P removal amount. The PO43−-P electrodeposition precipitate mainly was amorphous calcium phosphate (ACP) through analysis. 16S rRNA results demonstrated that electrodeposition altered the microbial communities. At the genus level, such as Acinetobacter (26.6 %), Acidocella (11.7 %), and Pelomonas (7.2 %) were promoted in the biochar substrate of E-BFB. Overall, this novel E-BFB can remove PO43−-P at low concentrations effectively. It has great application prospects in the treatment of surface water by biofilters or constructed wetlands.

Prevalence and concentration of pesticides in European waters: A protocol for systematic review and meta-analysis.

There is currently a growing interest in the so-called emerging pollutants, such as pesticides, pharmaceuticals, personal hygiene care products, drugs, etc., whose presence in natural ecosystems is not necessarily recent, but the development in latest years of new and more sensitive methods of analysis has allowed their detection. They can be present in the natural environment, food, and many products of everyday origin, which suggests that human exposure to them is massive and universal. Therefore, the study of this type of substances is becoming one of the priority lines of research of the main agencies dedicated to the protection of public and environmental health, such as the World Health Organization (WHO), United States Environmental Protection Agency (USEPA) or European Union (EU). In this sense, it is of vital importance to know the nature and quantity of this type of contaminants, to establish preventive mechanisms that minimize its presence in aquatic systems, with special requirements for human consumption. This study aimed to describe a protocol for a systematic review and meta-analysis to assess the status of pesticides in European waters. We will search for original studies in the PubMed/Medline, Scopus, Web of Science, EMBASE, ScienceDirect databases. Prevalence studies of emerging contaminants (pesticides) in water resources (watersheds, aquifers, rivers, marine and springs), wastewaters (influent and effluent), and drinking water should be included. Two reviewers will independently screen and assess the included studies, with any disagreements being resolved by a third reviewer. We will summarize the findings using a narrative approach and, if possible, conduct a quantitative synthesis (meta-analysis). We will conduct the protocol following the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols (PRISMA-P) guidelines. The review will summarize the current evidence on the presence of pesticides in European waters such as glyphosate, chlorpyrifos, pyrethroid pesticides, neonicotinoid pesticides, and/or fungicides, in samples of different water resources like wastewaters and drinking water. We expect that this systematic review will establish preventive mechanisms that minimize the presence of pesticides in water in the environment.

The Contribution of Open Source Software in Identifying Environmental Crimes Caused by Illicit Waste Management in Urban Areas

This study focuses on the analysis, implementation and integration of techniques and methods, also based on mathematical algorithms and artificial intelligence (AI), to acquire knowledge of some phenomena that produce pollution with an impact on environmental health, and which start from illicit practices that occur in urban areas. In many urban areas (or agroecosystems), the practice of illegal waste disposing by commercial activities, by abandoning it in the countryside rather than spending economic resources to ensure correct disposal, is widespread. This causes an accumulation of waste in these areas (which can also be protected natural areas), which are then also set on fire to reduce their volume. Obviously, the repercussions of such actions are many. The burning of waste releases contaminants into the environment such as dioxins, polychlorinated biphenyls and furans, and deposits other elements on the soil, such as heavy metals, which, by leaching and percolating, contaminate water resources such as rivers and aquifers. The main objective is the design and implementation of monitoring programs against specific illicit activities that take into account territorial peculiarities. This advanced approach leverages AI and GIS environments to interpret environmental states, providing an understanding of ongoing phenomena. The methodology used is based on the implementation of mathematical and AI algorithms, integrated into a GIS environment to address even large-scale environmental issues, improving the spatial and temporal precision of the analyses and allowing the customization of monitoring programs in urban and peri-urban environments based on territorial characteristics. The results of the application of the methodology show the percentages of the different types of waste found in the agroecosystems of the study area and the degree of concentration, allowing the identification of similar areas with greater criticality. Subsequently, through network and nearest neighbour analysis, it is possible to start targeted checks.

Evaluating the efficiency of modified hydrophobic PVDF membrane for the removal of PFOA substances from water by direct contact membrane distillation

This study addresses the global issue of the contamination of water resources by per- and poly-fluoroalkyl substances (PFAS). PFAS are notoriously difficult to remove due to their resilient alkyl-fluorinated chains. We examined the potential of hydrophobic PVDF membranes in direct contact membrane distillation (DCMD) to eliminate perfluorooctanoic acid (PFOA) from Water. For desalination, both commercial and custom-made PVDF membranes exhibited a permeate flux of approximately 13 LMH, with salt rejections of 98.39 % and 99.95 %, respectively. In the case of PFOA removal, the fabricated PVDF membrane outperformed its commercial counterpart. It boasted an initial permeate flux of 16 LMH and a PFAS rejection of 95.8 %, compared to the commercial membrane's 13 LMH and 67.31 %. Furthermore, the custom membrane exhibited superior resistance to fouling, experiencing less flux decline. Employing response surface methodology (RSM), we identified the optimal combination of feed concentration (30 ppm), (60 °C), and flow rate (1.5 LPM) to yield a flux of 9 LMH and a PFOA rejection of 95.41 %. Feed temperature emerged as the most influential factor in DCMD performance. This study offers a novel approach to concentrating and removing emerging contaminants from wastewater and highlights the efficacy of tailored membrane technology in addressing pressing environmental challenges.

Influence of karst conduit’s geometry and morphology on 3D flow and transport processes: Insights from 3D tracer tests and numerical modelling

In karst, the characterization of subsurface solute and contaminant transport is a major issue that has been widely investigated due to the high vulnerability of these hydrosystems. In former studies, several researchers addressed these needs with different approaches such as laboratory experiments, field experiments, or groundwater flow and transport simulations. The objective of such approaches is to improve knowledge of transport processes in karst hydrosystems, and propose solutions to limit the downstream hydrogeological risks (contamination of water resources). In this study, we performed the 3D mapping of the karst conduit, which outlet is the Lez spring (southern France) to get the precise geometry and morphology of this fully water-filled karst conduit. Then we injected a dye in the water-filled karst conduit and performed a continuous monitoring of dye tracer recovery at three different cross-sections located downstream the injection spot, at a distance of 40 m, 90 m and 160 m, respectively. In each cross-section, five submersible fluorometer probes were positioned at different locations (top, right, down, left and central parts) along the cross-section of the karst conduit. Experimental data allowed to reconstruct the transient spatial distribution of concentration for each cross-section, which allowed assessing the propagation and evolution of solute plume over time. Monitored data also provided information about dye mixing along the karst conduit and were used to investigate the effect of karst conduit geometry, flow turbulences and velocity profiles on the mixing processes and propagation of solute plume along the conduit with numerical models. Modelling results showed that the consideration of 3D mapped karst conduit geometry and morphology allows a much better reproduction of observed transport processes and breakthrough curves, than the one obtain when considering simplified conduit geometry and morphology.

A novel method for the remediation of o‐ and p‐aminophenol from industrial wastewater by hexacyanoferrate (III) ions using Ir‐complex catalyst

AbstractIn this manuscript o‐ and p‐aminophenols model environmental pollutants are being remedied by catalytic oxidation process. A kinetic‐spectrophotometric technique was used to study the remediation of o‐ and p‐aminophenol by hexacyanoferrate (III) ions as an oxidant and synthesized Ir‐DTPy complex as a catalyst in aqueous alkaline medium. The optimum pH for these experiments was 9.0 and 11.0 for o‐ and p‐aminophenol respectively at the constant temperature 25°C. It has been studied how variations in the concentration of the catalyst (Ir‐DTPy), the hexacyanoferrate (III) ions, and substrate affect the rate of the reaction. At four different temperatures, ranging from 25 to 40°C, the change in reaction rate has been analyzed with thermodynamic variables like free energy of activation, enthalpy, frequency factor, and activation energy. FTIR, UV‐Vis, and ESI‐MS spectroscopic analytical methods have been used to identify the oxidized products. 2‐aminophenoxazin‐3‐one and NN'‐bis‐(p‐hydroxyphenyl)‐2‐hydroxy‐5‐amino‐1, 4‐benzoquinone di‐imine are the main products of oxidation of o‐and p‐aminophenol, respectively. Therefore, this technique for removing o‐ and p‐aminophenol from contaminated water resources is very effective and environmentally safe.

Computational study on organochlorine insecticides extraction using ionic liquids

Insecticides pose hazardous environmental effects and can enter the food chain and contaminate water resources. Ionic liquids (ILs) have recently drawn much interest as environmentally friendly solvents and have been an efficient choice for extracting pesticides because of their outstanding thermophysical characteristics and tunable nature. In this study, ILs were screened using COSMO-RS (Conductor-like Screening Model for Real Solvents) to extract organochlorine insecticides from water at 289 K. A total of 165 ILs, a combination of 33 cations with five anions, were screened by COSMO-RS to predict the selectivity and capacity of the organochlorine insecticides at infinite dilution. The Organochlorine insecticide compounds, such as benzene hexachloride (BHC), Heptachlor, Aldrin, Gamma-Chlordane (γ-Chlordane), Endrin, and Methoxychlor are selected for this study. Charge density profiles show that Endrin and Methoxychlor compounds are strong H-bond acceptors and weak H-bond donors, while the rest of the compounds are H-bond donors with no H-bond acceptor potential. Moreover, it has been shown that ILs composed of halides and heteroatomic anions in conjunction with cations have enhanced selectivity and capacity for insecticides. Moreover, the hydrophobic phosphonium-based ILs have enhanced selectivity and capacity for insecticides. In BHC extraction, the selectivity of 1,3-dimethyl-imidazolium chloride was found to be the highest at 1074.06, whereas 2-hydroxyethyl trimethyl ammonium chloride exhibited the highest capacity being 84.0.1,3-dimethyl-imidazolium chloride exhibits the highest performance index, which is 57064.77. In addition, the ILs that have been chosen are well-recognized as environmentally friendly and very effective solvents to extract insecticides from water. As a result, this study evaluated that ILs could be promising solvents that may be further developed for the extraction of insecticides from contaminated water.

Cu and Zn metal particles modified nanocathode based electrocatalytic nitrate reduction: Effective, selective and mechanism

Nitrate contamination of water resources not only endangers ecological environment, but also poses a threat to human health. Electrochemical removal of nitrate is limited by poor electrode efficiency and high levels of by-products. Herein, Cu and Zn nanoparticles were loaded onto the surface of TiO2 nanoelectrodes by electrodeposition to improve the electrochemical activity of the electrodes. The fabricated Cu/TiO2 and Cu/Zn/TiO2 nanoelectrodes achieved nitrate removal efficiencies of 83.5 % and 93.6 %, respectively, indicating a significant improvement in nitrate removal efficiency. The physicochemical and electrochemical characteristics of the Cu/TiO2 and Cu/Zn/TiO2 electrode revealed that the TiO2 nanotube structure formed on the electrode surface increased the specific surface area of the electrode, while the uniformly attached Cu and Zn nanoparticles augmented the active sites on the electrode surface. Additionally, the loaded Zn nanoparticles enhanced the conversion of NO2−-N to N2, effectively suppressing byproducts production. The synergistic effect of TiO2 nanotubes with Cu and Zn nanoparticles made it possible to completely electrochemical remove nitrate. Under the condition of 0.5 g/L NaCl as the electrolyte, these two electrochemical systems can achieve cathodic reduction of NO3−-N and effectively inhibit the formation of NH4+-N and NO2−-N, thereby achieving the goal of harmless removal of NO3−-N. This work provides theoretical and technical support for efficient and clean removal of nitrate from environmental water bodies by electrochemistry.

Interceptor sewer for abatement of pollution in surface water

Abstract Unplanned population growth in urban cities has largely caused unplanned habitations called slums. Due to various complexities, service providers are unable to provide basic amenities, i.e., water, roads, sanitation, and sewerage in these slums. Water, being the basic need for human survival, is either managed by these residents by extracting groundwater or the minimum required water is provided by the government through water tankers or tube wells. In the absence of sewerage facilities, sewage is discharged directly into stormwater drains, rivers, ponds, lakes, etc. It contaminates the freshwater of these water bodies. The Yamuna River (22 km stretch) from the Wazirabad Barrage to the Okhla Barrage, and about 600 lakes in Delhi, India, are highly polluted. To avoid such severe events of contamination of water resources, it is necessary to develop a system to intercept wastewater at the source, transfer it to the nearest sewage treatment plant, and treat it to the required discharge standard, called the interceptor sewer. This case study is an outcome of a successful mega project of an interceptor sewer along three major drains (Najafgarh, Supplementary, and Shahadra) for the abatement of pollution in river Yamuna, Delhi.