Contaminated Water Research Articles

Synthetic bacteria designed using ars operons: a promising solution for arsenic biosensing and bioremediation.

The global concern over arsenic contamination in water due to its natural occurrence and human activities has led to the development of innovative solutions for its detection and remediation. Microbial metabolism and mobilization play crucial roles in the global cycle of arsenic. Many microbial arsenic-resistance systems, especially the ars operons, prevalent in bacterial plasmids and genomes, play vital roles in arsenic resistance and are utilized as templates for designing synthetic bacteria. This review novelty focuses on the use of these tailored bacteria, engineered with ars operons, for arsenic biosensing and bioremediation. We discuss the advantages and disadvantages of using synthetic bacteria in arsenic pollution treatment. We highlight the importance of genetic circuit design, reporter development, and chassis cell optimization to improve biosensors' performance. Bacterial arsenic resistances involving several processes, such as uptake, transformation, and methylation, engineered in customized bacteria have been summarized for arsenic bioaccumulation, detoxification, and biosorption. In this review, we present recent insights on the use of synthetic bacteria designed with ars operons for developing tailored bacteria for controlling arsenic pollution, offering a promising avenue for future research and application in environmental protection.

A MXene Hydrogel-Based Versatile Microrobot for Controllable Water Pollution Management.

The urgent demand for addressing dye contaminants in water necessitates the development of microrobots that exhibit remote navigation, rapid removal, and molecular identification capabilities. The progress of microrobot development is currently hindered by the scarcity of multifunctional materials. In this study, a plasmonic MXene hydrogel (PM-Gel) is synthesized by combining bimetallic nanocubes and Ti3C2Tx MXene through the rapid gelation of degradable alginate. The hydrogel can efficiently adsorb over 60% of dye contaminants within 2 min, ultimately achieving a removal rate of >90%. Meanwhile, the hydrogel exhibits excellent sensitivity in surface enhanced Raman scattering (SERS) detection, with a limit of detection (LOD) as low as 3.76 am. The properties of the plasmonic hydrogel can be further adjusted for various applications. As a proof-of-concept experiment, thermosensitive polymers and superparamagnetic particles are successfully integrated into this hydrogel to construct a versatile, light-responsive microrobot for dye contaminants. With magnetic and optical actuation, the robot can remotely sample, identify, and remove pollutants in maze-like channels. Moreover, light-driven hydrophilic-hydrophobic switch of the microrobots through photothermal effect can further enhance the adsorption capacity and reduced the dye residue by up to 58%. These findings indicate of a broad application potential in complex real-world environments.

Water physicochemical quality as driver of spatial and temporal patterns of microbial community composition in lake ecosystems

This study aimed at monitoring and management of the surface water and potentially pathogenic microbes of Lake Tonga (Algeria) with respect to. It characterized the main bacterial diversity patterns of Lake Tonga and predicted from water physicochemical parameters and water quality index (WQI) the distribution of bacterial species and the main indicator groups of faecal water contamination. Water samples were taken monthly at three sampling sites of different water depths. Several physicochemical parameters were measured; of which some were included in computing WQI to characterize the water quality of the lake. Counting, isolation and bacterial identification methods were used to characterize the existing aerobic heterotrophic bacteria. The composition of the microbial community of the waterbody of Lake Tonga included an abundant culturable bacterial flora belonging to several bacterial families and whose specific richness varied between water depths of the sites sampled. Species richness of the bacteria identified phenotypically varied between 7 and 11 per sample. The site with shallow water was the richest in bacterial species, compared to moderate and deep waters. The redundancy analysis showed the main physicochemical drivers of the microbial community composition. Our findings showed that high WQI scores indicated the water quality deterioration which triggered the increase in total load of faecal indicator bacterial groups. This study identified in Lake Tonga an important culturable aerobic bacterial flora whose specific richness and distribution varied spatially following the effects of water physicochemical parameters. Lake Tonga needs an integrated management plan to mitigate human disturbances declining water quality.

Green synthesis of nZVI-modified biochar significantly enhanced the removal of Cr(VI) from aqueous solution.

Water contamination by hexavalent chromium (Cr(VI)) seriously jeopardizes human health, which is a pressing environmental concern. Biochar-loaded green-synthesized nZVI, as a green and environmentally friendly material, can efficiently reduce Cr(VI) to Cr(III) while removing Cr(VI) from water. Therefore, in this study, an efficient green-modified biochar material (TP-nZVI/BC) was successfully prepared using tea polyphenol (TP) and sludge biochar (BC) using a low-cost and environmentally friendly green synthesis method. The preparation conditions of TP-nZVI/BC were optimized using response surface methodology (RSM), revealing that the dosage of tea polyphenols plays a crucial role in the removal performance (R2 = 1271.09), followed by reaction time and temperature. The quadratic regression model proved accurate. The optimal preparation conditions are as follows: tea polyphenols (TP) dosage at 48 g/L, reaction temperature at 75 ℃, and a reaction time of 3 h. TP-nZVI/BC removed Cr(VI) from water at a rate 7.6 times greater than BC. The pseudo-second-order kinetic model (R2 = 0.987) accurately describes the adsorption process, suggesting that chemical adsorption predominantly controls the removal process. The adsorption of Cr(VI) by TP-nZVI/BC can be well described by the Langmuir model, and the maximum adsorption capacity reached 105.65 mg/g. FTIR and XPS analyses before and after adsorption demonstrate that nZVI plays a crucial role in the reduction process of Cr(VI), and the synergistic effects of surface adsorption, reduction, and co-precipitation enhance Cr(VI) removal. In summary, using green-modified biochar for Cr(VI) removal is a feasible and promising method with significant potential.

Optimizing removal of antiretroviral drugs from tertiary wastewater using chlorination and AI-based prediction with response surface methodology

Chemical and pharmaceutical chemicals found in water sources create substantial risks to human health and the environment. The presence of pharmaceutical contaminants in water can cause antibiotic resistance development, toxicity to aquatic organisms, and endocrine disruption. Hence, the elimination of chemicals and other contaminants from wastewater prior to its release is a burgeoning concern in the domains of engineering and science. The use of treatment technologies in wastewater treatment plants can remove pharmaceutical contaminants through the oxidation process. However, many traditional wastewater treatment plants lack the advanced monitoring tools required to detect low concentrations of pharmaceuticals. Without the ability to detect these compounds, it's challenging to treat them effectively. The goal of this study was to use Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) algorithms to model and improve how Nevirapine and Efavirenz break down in different chlorination conditions. The RSM analysis revealed statistically significant models (F-values: Nevirapine, pH-t: 108.15, T-t: 76.55, ICC-t: 110.84), indicating a strong correlation between operational parameters (pH, temperature, and initial chlorine concentration) and degradation behavior. The ANN model accurately predicted the degradation of both Nevirapine and Efavirenz under various chlorination conditions, as confirmed by analyzing actual-predicted graphs, residual plots, and Mean Squared Error (MSE) values. The ANN model using ICC-t achieved the highest MOD value of 31.31 % for Nevirapine. The ANN model based on ICC-t yielded a maximum MOD value of 16.06 % for Efavirenz. These findings provide valuable insights into optimizing chlorination processes for better removal of these pharmaceutical contaminants from water.

Photocatalytic Removal of Emerging Contaminants from Water using Metal Oxide-based Nanoparticles

Abstract: Water contamination resulting from industrial and anthropogenic activities is a major problem in many countries throughout the world. Effective water treatment technologies are necessary to address this issue. Emerging pollutants (EPs) are reaching the aquatic environments from point and diffuse sources constantly. These are the substances that are not regularly monitored, yet have the potential to infiltrate the environment and harm the ecosystem and human health. Because of their ecological and sustainable properties, interest in improved photocatalytic technologies based on metal oxide-based nanomaterials has grown tremendously over the years to address this water contamination. Pollutant degradation, water splitting, carbon dioxide reduction, nitrogen reduction, and microbial inactivation are just a few of the applications of photocatalysis. However, to maintain its environmentally favourable status, new solutions must be found to assure long-term viability. Here we review, emerging organic pollutants, conventional water treatment, advanced oxidation methods, photocatalytic mechanisms, photocatalyst support materials, synthesis, and characterization of metal oxides and metal oxide nanoparticles in the removal of emerging contaminants. The purpose of this review is to reach a broader readership by giving a simple comprehension of the fundamentals and advances of metal-oxide-driven photocatalysis for environmental clean-up.

Innovations and challenges in adsorption-based wastewater remediation: A comprehensive review

Innovations and challenges in adsorption-based wastewater remediation: A comprehensive review

Nitrogen and me - How little did we, and do we know about “stikstof – azote – nitrogen”?

This retrospective article reflects on the complex and evolving relationship between humans and nitrogen over several decades. Raised on a Flemish farm, the author's early experiences with nitrogen in agriculture – both its benefits and dangers – laid the foundation for a lifelong interest in this element. The article traverses a broad range of topics related to nitrogen, highlighting its critical role in various historical, agricultural, environmental, and industrial contexts. The narrative begins with a historical overview of nitrogen's role in agriculture and warfare. The development of industrial processes like the Haber and Ostwald methods transformed nitrogen into a key ingredient for both fertilizers and explosives. The dual nature of nitrogen – as a life-giver in agriculture and a destructive component in warfare and also in biodiversity – is an important theme. The article delves into the environmental impacts of nitrogen, particularly in the context of modern agriculture and industrialization. Issues like fertilization, water contamination, and the challenges of managing nitrogenous waste highlight the complex interplay between human activities and environmental health. Technological advancements are explored, including the development of bioaugmentation methods and the potential of genetic engineering in optimizing nitrogen fixation. Throughout the narrative, personal anecdotes are weaved with scientific information, offering a unique perspective on the historical and contemporary challenges of managing nitrogen. The discussion extends to the broader implications of nitrogen management in the context of sustainability, climate change, and global food security and its overall regulatory space. All these considerations call for a re-evaluation of our relationship with nitrogen, advocating for innovative solutions and systemic thinking to address the multifaceted challenges posed by this essential, yet often problematic element.

An assessment of the potential health hazards associated with metal contamination in a variety of consumable species living along the industrialized coastline of East Java, Indonesia

The massive industrial growth in Gresik, East Java, Indonesia has the potential to result in metal contamination in the nearby coastal waters. The purpose of this study was to analyze the metal concentrations in edible species from the Gresik coastal waters and evaluate the potential health risks linked to this metal contamination. Metal concentrations (Cu, Fe, Pb, Zn, As, Cd, Ni, Hg, and Cr) in fish and shrimp samples mostly met the maximum limits established by national and international regulatory organizations. The concentrations of As in Scatophagus argus exceed both the permissible limit established by Indonesia and the provisional tolerable weekly intake (PTWI). The As concentration in Arius bilineatus is equal to the PTWI. The target cancer risk (TCR) values for both As and Cr in all analyzed species exceed the threshold of 0.0001, suggesting that these two metals possess the potential to provide a cancer risk to humans.

Unregulated contaminants in drinking water: Evidence from PFAS and housing prices

Our understanding of individuals’ response to information about unregulated contaminants is limited. We leverage the highly publicized social discovery of unregulated PFAS (per- and polyfluoroalkyl substances) contamination in public drinking water to study the impact of information about unregulated contaminants on housing prices. Using residential property transaction data, we employ a difference-in-differences research design and show that high profile media coverage about PFAS contamination significantly decreased property values of affected homes. We also find suggestive evidence of residential sorting that may have worsened environmental inequality.

Unregulated drinking water contaminants and adverse birth outcomes in Virginia

Unregulated drinking water contaminants and adverse birth outcomes in Virginia

Risk-based public health impact assessment for drinking water contamination emergencies.

Chemical spills in surface waters pose a significant threat to public health and the environment. This study investigates the public health impacts associated with organic chemical spill emergencies and explores timely countermeasures deployable by drinking water facilities. Using a dynamic model of a typical multi-sourced New England drinking water treatment facility and its distribution network, this study assesses the impacts of various countermeasure deployment scenarios, including source switching, enhanced coagulation via poly‑aluminum chloride (PACl), addition of powdered activated carbon (PAC), and temporary system shutdown. This study reveals that the deployment of multiple countermeasures yields the most significant reduction in total public health impacts, regardless of the demand and supply availability. With the combination PAC deployed first with other countermeasures proving to be the most effective strategies, followed by the combination of facility shutdowns. By understanding the potential public health impacts and evaluating the effectiveness of countermeasures, authorities can develop proactive plans, secure additional funding, and enhance their capacity to mitigate the consequences of such events. These insights contribute to safeguarding public health and improving the resilience of drinking water systems in the face of the ever-growing threat of chemical spills.

Trace compounds in the urban water cycle in the Freiberg region, Germany

Urban water contamination has become a pressing concern due to the surge in urbanization, industrialization, and population growth, resulting in increased pollution levels and the introduction of emerging contaminants (ECs) into the environment. The widespread use of pharmaceuticals (PhACs), driven by medical advancements and economic progress, has led to their presence in aquatic systems, posing risks to both ecosystems and human health. These compounds are released into the environment via effluent of wastewater treatment plants (WWTPs) as they are inefficient in totally removing PhACs. This study focused on PhACs in wastewater, surface water and groundwater of a small city like Freiberg region in Germany. Samples were collected along Münzbach’s path, encompassing hospital discharges and WWTP. Analysis for the measurement of PhACs was conducted via Ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS). Results revealed that about 46 out of 54 analyzed PhACs were detected across matrices, with positive findings of 46 substances in wastewater, 37 in surface water, and 19 in groundwater. Among 54 analyzed PhACs, six of the active pharmaceutical ingredients (APIs) like atenolol (ATL), carbamazepine (CBZ), caffeine (CAF), diclofenac (DCF), metformin (MET), and sulfamethoxazole (SMX) were focused in this study. Five of the six APIs were present in all matrices, with MET and CAF widely distributed in an aqueous system. CBZ and DCF were found in wastewater and surface water, ATL was scarce in surface water, while SMX was absent in groundwater. It was observed that PhAC concentration was reduced from wastewater to groundwater, with the highest levels near the WWTP, decreasing as effluents flowed through surface water Münzbach and Freiberger Mulde. It was also observed that the groundwater near the surface water shows the presence of APIs mainly due to the hyporheic zone connecting the surface water and groundwater. Overall, PhAC compounds reflect the city population and their age, the water cycle, and the hydrochemical processes of the compounds themselves.

Consumer willingness to pay for improved drinking water in District Buner

AbstractThis study investigates households' willingness to pay (WTP) for better water systems, clean water availability, and water quality in Gadaizi tehsil, District Buner, Pakistan. This research aims to shed light on various aspects of water quality, health impacts, and socioeconomic factors influencing households' ability to pay for superior water services. This research also looks into waterborne infection and water purification methods residents utilize to mitigate the risk of water pollution. Utilizing a mixed‐method approach with a structured questionnaire, data from 62 households were collected. SPSS was used for data analysis. Findings reveal awareness of water contamination issues, primarily attributed to marble industries. Most households use untreated water, boiling, chemicals, or candle filters. Water purification methods are influenced by media exposure and higher income. Common waterborne diseases, such as typhoid and diarrhea, are treated in private hospitals. Consumer WTP for better water systems depends on income, education, and media exposure, in which income has a statistically significant positive effect on WTP for improved water services. Although 76% of households do not use any water purification method. 84% of households are willing to adopt a private sector‐provided system. Importantly, this study highlights the necessity for public health initiatives and a thorough understanding of socioeconomic issues to guide political choices for better water delivery. These insights can inform policies that prioritize public health and ensure better access to clean water for all.

High-resolution mapping and multivariate technique (factor analysis) to support hydrogeochemical analysis and identification of surface water contamination

High-resolution mapping and multivariate technique (factor analysis) to support hydrogeochemical analysis and identification of surface water contamination

The study of environmental impact from fabric dyeing process in Lahanam area, Songkhone district, Lao PDR

The aim of this research was to examine water contamination resulting from the fabric dyeing process in the Lahanam area, located in Songkhone district, Lao PDR. Lahanam is a famous village known for its fabric dyeing and weaving activities, utilizing both natural and chemical dyes which result in the discharge of colors into local water resources. Water samples were collected from three different sources: household dyeing water (HD), community wastewater (CW) and the nearby river, Xebanghieng (XR). Qualitative and quantitative analyses were performed on the water samples. Atomic Absorption Spectroscopy (AAS) was employed to measure the presence of heavy metals such as lead (Pb), arsenic (As), cadmium (Cd) and mercury (Hg). Additionally, tests were conducted to determine the biological oxygen demand (BOD), dissolved oxygen (DO), ammonia contents and pH in the water of Xebanghieng. The results revealed that HD samples contained significantly higher amounts of all four heavy metals (lead 0.217 mg L–1, cadmium 0.105 mg L–1, arsenic 0.029 mg L–1 and mercury 0.0014 mg L–1), with lead, cadmium and arsenic exceeding standard limits. These data indicate potential environmental impact of chemical dyeing in the village in the future. Therefore, it is recommended to replace the current dyeing process with more sustainable alternatives, such as natural dyes. GRAPHICAL ABSTRACT HIGHLIGHTS The water quality of the river in the dyeing village in Lao PDR Heavy metals in wastewater after dyeing process. The impact of chemical dyeing.

Comparative transcriptomics combined with physiological and functional analysis reveals the regulatory mechanism of rainbow trout (Oncorhynchus mykiss) under acute hypoxia stress

Hypoxia, largely triggered by global warming and water contamination, has become an environmental issue of great concern, posing a great threat to aquatic ecosystem. As one of the world's most economically important fish, rainbow trout (Oncorhynchus mykiss) is extremely intolerant of hypoxic environments, however, little is known about the roles of non-coding RNAs (ncRNAs) in the response of rainbow trout to hypoxia stress. Herein, effects of moderate (Tm12L) and severe hypoxia for 12 h (Ts12L) and 12 h reoxygenation on histology, biochemical parameters (antioxidant, metabolism and immunity) and transcriptome (lncRNA, miRNA and mRNA) in rainbow trout liver were investigated. We further validated the regulatory relationships between LOC110519952, novel-m0023-5p and glut1a via dual‑luciferase reporter, overexpression and silencing assays. Compared with Tm12L, the liver in Ts12L showed more severe oxidative damage. Anaerobic, lipid and protein metabolism was enhanced under hypoxia stress, especially in Ts12L. We also found that Tm12L could strengthen innate immune response, which was inhibited in Ts12L. Besides, several hypoxia-related genes (glut1a, vegfaa, hmox, epoa, foxo1a and igfbp1) and ceRNA networks were identified from 1824, 427 and 545 differentially expressed mRNAs, miRNAs and lncRNAs, including LOC118965299-novel-m0179-3p-epoa, LOC110519952-novel-m0023-5p-glut1a, MSTRG.7382.2-miR-184-y-hmox and LOC110520012-miR-206-y-vegfaa. Through in vitro and in vivo functional analysis, we demonstrated that glut1a is a target of novel-m0023-5p, and LOC110519952 can positively regulate glut1a by targeting novel-m0023-5p. Introduction of LOC110519952 could attenuate the promoting effects of novel-m0023-5p on rainbow trout liver cell viability and proliferation. This study highlights the differences in the regulatory mechanism of rainbow trout under different concentrations of hypoxia stress and provides valuable data for further research on the molecular mechanisms of fish adaptation to hypoxic environments.

IoT-based Design and Implementation of an Intelligent Water Quality Monitoring System

Abstract: Water is an essential requirement for human survival, and a scarcity of water renders us unable to sustain our lives. The issue of water pollution and shortage is a pressing worldwide concern that necessitates the adaptation of water resources and the establishment of guiding principles at both the international and individual levels. Water contamination is the primary contributor to global disease outbreaks. In the past, the process of monitoring water quality relied on the physical collection of data, lacking the implementation of a smart sensor system. This resulted in inefficiencies, particularly in the areas of real-time data retrieval, device surveillance, and less precise data gathering. The integration of a real-time water quality monitoring method is important in order to guarantee the provision of a secure drinking water supply. Therefore, the concept of the Internet of Things (IoT), which facilitates the interconnection of diverse devices for the purpose of data interchange and collection, has emerged

Eco-friendly biosorbent based on local raw material: application to dye removal

Eco-friendly biosorbent based on local raw material: application to dye removal

Assessing heavy metal and physiochemical pollution load of Danro River and its management using floating bed remediation

River Danro in Garhwa (India) plays a vital role as a significant source of surface water and a crucial tributary of the North Koel River, ultimately joining the Ganga River Basin. Serving both urban-industrial and rural areas, the region faces challenges, including sand mining near Belchampa Ghat. This study aimed to assess physicochemical and heavy metals pollution at nine sampling locations, utilizing the Overall Index of Pollution (OIP), Nemerow Pollution Index (NPI), and Heavy Metal Pollution Index (HPI). OIP values indicated excellent surface water quality (0.71) in non-monsoon and slight pollution (6.28) in monsoon. NPI ranged from 0.10 to 1.74 in non-monsoon and from 0.22 (clean) to 27.15 (heavily polluted) in monsoon. HPI results suggested groundwater contamination, particularly by lead. Principal component analysis (PCA) and geospatial mapping showed similar outcomes, highlighting the influence of adjacent land use on water quality. Recognizing the significance of the Danro River in sustaining life, livelihoods, and economic growth, the study recommends implementing measures like floating bed remediation and regulatory actions for effective river management. The study acknowledges weaknesses in the current practical assessment methods for water contamination. These weaknesses make it difficult to put plans for cleaning up and controlling contamination into action. Because of this, future research on developing new in-place remediation techniques should focus on creating better ways to measure how effective the cleanup is.