Contamination Of Water Systems Research Articles

Adsorption of amoxicillin by chitosan and alginate biopolymers composite beads.

Due to its widespread use and incomplete breakdown in the human body, amoxicillin has been detected in receiving water bodies. This raises significant concerns, like the promotion of antibiotic resistance, toxicity towards aquatic life, disruption of the natural balance of microbial communities within these water bodies, and the struggle of effectively removal by the traditional wastewater treatment plants. Consequently, exploring new processes to complement the existing methods is crucial. Adsorption, a promising highly efficient, selective, and versatile technique, can effectively remove contaminants, making it useful in various industries such as water treatment, pharmaceuticals, and environmental remediation. Several adsorbents are documented in the literature for drug adsorption; however, their fabrication often involves more complex steps and substances compared to chitosan and alginate, which are natural polymers that are biocompatible, non-toxic, and biodegradable. Their tunable properties and ease of modification enhance their efficacy in environmental remediation. Therefore, the novelty of this article is to understand the interaction of amoxicillin with chitosan and alginate adsorbents easily synthetized using the dripping technique. This approach allows us to explore basic principles that can be applied to more complex systems in future studies. The optimal pH for both beads was found to be 4, with adsorption capacities of 74.2 ± 0.3mgg-1 for alginate and 80.4 ± 0.2mgg-1 for chitosan, using 1g of adsorbent. Kinetics studies indicated that external diffusion governs adsorption for alginate, while internal diffusion governs adsorption for chitosan. This approach underscores the potential of chitosan and alginate beads as effective adsorbents for mitigating antibiotic contamination in water systems, offering a sustainable complement to traditional treatment methods.

Fabrication and application of magnetic MgFe2O4-OH@biochar composites decorated with β-ketoenamine for Pb(II) and Cd(II) adsorption and immobilization from aqueous solution

The excessive discharge of water contaminated by lead (Pb(II)) and cadmium (Cd(II)) seriously jeopardizes ecological security and needs to be addressed urgently. Herein, a novel, efficient and highly stable biochar-based magnetic adsorbent of KEA-MgFe2O4-OH@RSBC was fabricated via loading MgFe2O4-OH nanoparticles (NPs) on reed straw biochar (RSBC) surface followed by decorating with β-ketoenamine (KEA) to boost the capture efficiency of Pb(II)/Cd(II) from wastewater. Adsorption behavior and mechanism studies indicated that the abundant and diverse functional groups of KEA-MgFe2O4-OH@RSBC were favorable for Pb(II)/Cd(II) removal. The binding of KEA-MgFe2O4-OH@RSBC with Pb(II)/Cd(II) was increased mainly via complexation, electrostatic attraction, cation-π coordination, ion exchange and pore filling. Due to the incorporation of MgFe2O4-OH and KEA, the Pb(II) /Cd(II) uptake capacity by KEA-MgFe2O4-OH@RSBC reached up to 238.06/226.76 mg/g (pH=5.0, C0 = 180 mg/L). The XPS analysis showcased that the strong interactions between Pb(II)/Cd(II) and oxygen/nitrogen atoms in the composites played an important role for the adsorption of Pb(II)/Cd(II) by KEA-MgFe2O4-OH@RSBC. In addition, the evaluation study on the practical application potential of KEA-MgFe2O4-OH@RSBC manifested that the material exhibited strong resistance to ionic interference (R> 93 % in collected actual metal smelting wastewater). KEA-MgFe2O4-OH@RSBC had a good regeneration and reapplication capability (R> 82 % after 5 cyclic regeneration experiments). Besides, the stronger magnetism overcome the separation difficulty after adsorption from wastewater. In conclusion, KEA-MgFe2O4-OH@RSBC will be an ideal candidate for Pb(II)/Cd(II) removal from contaminated water systems. The present study would greatly contribute to the effective and sustainable progress of heavy metal remediation strategies.

Heteroatom doped cellulose nanocrystals (CNC) with chiral nematic liquid crystal interface for high efficiency removal of ciprofloxacin

The increasing contamination of water systems by ciprofloxacin (CIP) has become a growing concern. The photocatalysis approach offers a promising strategy for the effective removal of CIP. In this study, MSx/CNC (MSx, M = Co, Ni, Cu) binary composites with chiral catalytic interfaces were prepared by chemical precipitation and the composite M0-MSy/CNC was prepared by energetic β-particle bombardment. The XPS results confirmed the successful construction of C–O−M bonds. TEM results clearly revealed the generation of sulfur vacancies (Sv) in the composites. The M0-MSy/CNC/peroxymonosulfate (PMS) photocatalytic system was also constructed in this study. The results of the application experiments showed that the Co0-CoSy/CNC/PMS system had an excellent degradation effect on CIP, which reached 100 % at 1.5 h of open light. The degradation kinetic constants of Co0-CoSy/CNC/PMS were 4.26 times higher than those of CoSx/CNC/PMS. In addition, EPR showed that the Co0-CoSy/CNC/PMS system generates ‧OH, ‧SO4−, ‧O2−, and h+ radicals to co-remove CIP. This study also elucidated the major intermediates of photocatalytic degradation of CIP at the chiral catalytic interface using LC-MS analysis. This work provides insights into the coupled application of photocatalysis and PMS activation in the remediation of aqueous environments.

Efficient removal of chromate from wastewater using a one-pot synthesis of chitosan cross-linked ceria incorporated hydrous copper oxide bio-polymeric composite

Remediating hexavalent chromium [Cr(VI)] from contaminated water systems is a significant concern due to its harmful effects on human health, aquatic life, and plants. To tackle this issue, scientists have created a chitosan cross-linked hydrous ceria incorporated cupric oxide bio-polymeric composite (CHCCO) by combining chitosan biopolymer with corresponding metal ions using glutaraldehyde as a cross-linker. The composite was characterized using advanced analytical instruments such as FTIR, p-XRD, SEM, XPS, etc. The synthesized composite (CHCCO) was then tested for its efficiency in removing Cr(VI) from synthetic Cr(VI) aqueous samples. The parameters examined included pH, material dose, contact time, concentration, temperature, and co-existing ions. The experimental data showed that the kinetics and equilibrium data fit well with the pseudo-second-order and the Freundlich isotherm models, respectively. Thermodynamic analysis demonstrated that the investigated surface adsorption process is spontaneous and endothermic. Except for the SO42− ion, no other species imparts adverse influence significantly on the reaction. The CHCCO bio-composite surfaces were refreshed using a dilute NaOH (1.0 M) solution and effectively recycled five times for Cr(VI) adsorption, indicating no significant surface activity deterioration. This study highlights the high effectiveness of CHCCO bio-polymeric composites in Cr(VI) remediation and the potential for this technology as an easy-to-use technique for environmental restoration.

D-limonene-based polymeric adsorbent for effective Pb(II) ion removal: A comprehensive study on sorption behaviour and environmental applicability

In response to the pressing global health concern posed by lead contamination in water systems, we introduce a novel green synthesis polymer, LIM-co-DVB-co-VIM, derived from D-Limonene, a natural terpene. This polymer offers high surface area and tenability making it a promising solution for Pb(II) ion removal. Our study involves a thorough characterization of the adsorbent and optimization of operational parameters for selective Pb(II) ion removal. Adsorption follows Langmuir isotherm and pseudo-second-order kinetics, with an adsorption capacity of 31.8 mg g⁻¹ and rapid removal efficiency. Thermodynamic analysis reveals the exothermic and spontaneous nature of the adsorption process. Selectivity studies confirm the polymer's ability to selectively adsorb Pb(II) ions. Desorption experiments with 0.1 M HCl achieve a quantitative recovery of 95.7%, demonstrating efficient regeneration. Application to real water samples validates the method's effectiveness, highlighting the importance of environmentally friendly solutions in addressing water contamination challenges.

Ru@Co3O4@g-C3N4 as a novel adsorbent for enhanced copper and cadmium abolition

Elimination of heavy metals from contaminated water systems is of prime distress due to their capacity to prompt toxic impact on the flora and fauna. The usage of innovative nano-engineered materials predominantly opens up smart prospects for the treatment of persistent heavy metal adulterated water resources. This study presents an ultrasonic-assisted sol-gel production of Ru@Co3O4@g-C3N4 nanostructure that was utilized to remove Cu+2 and Cd+2 ions from aqueous solutions. The X-ray diffraction investigation revealed the development of RuO2, Co2O3 and g-C3N4 phases, and the relevant elemental composition was verified by the photoelectron spectroscopy and EDX. The dispersion of the metal oxides within the nitride sheets was evidenced by scanning and transmission electron microscopy. The initial metal ions concentration, pH, and contact time effects were investigated through batch experiments. The adsorption isotherm models matched the Langmuir isotherm well, whereas the kinetics model data perfectly fitted the pseudo-second-order model. The maximum adsorption capacities of Cu+2 and Cd+2 ions on the nanocomposite Ru@Co3O4@g-C3N4 were 696.9 and 564.5 mg/g, respectively. A mechanism based on a viable covalent type of bonding developed by the delocalized -conjugated electrons of the triazine ring and functional groups were efficiently involved in the metal ions anchoring and ultimate elimination. Thus, the suitability of the Ru@Co3O4@g-C3N4 nanocomposite for eradicating heavy metals, including Cu+2 and Cd+2, was established.

Sustainable approaches for removing toxic heavy metal from contaminated water: A comprehensive review of bioremediation and biosorption techniques

In this comprehensive study, highlights emerging environmentally friendly methods to eliminating hazardous heavy metals from contaminated water, with an emphasis on bioremediation and biosorption. Breakthroughs, such as the combination of biological remediation and nanotechnology to improve the elimination of metals effectiveness and the use of genetically modified microbes for targeted pollutant breakdown. Developing biosorption materials made from agricultural waste and biochar, this indicates interesting areas for future research and emphasizes the necessity of sustainable practices in tackling heavy metal contamination in water systems. There seems to be a surge in enthusiasm for the utilization of biological remediation and biosorption methods as sustainable and viable options for eliminating heavy metals from contaminated water in the past couple of decades. The present review intends to offer an in-depth review of the latest understanding and advances in the discipline of biological remediation methods like bioaccumulation, biofiltration, bio-slurping, and bio-venting. Biosorption is specifically explained and includes waste biomass as biosorbent with the removal mechanisms and the hindrances caused in the process are detailed. Advances in biosorption like microbes as biosorbents and the mechanism involved in it. Additionally, novel enhancement techniques like immobilization, genetic modification, and ultrasound-assisted treatment in microbial sorbent are clarified. However, the review extended with analyzing the future advances in the overall biological methods and consequences of heavy metal pollution.

Emerging nitrogen-fixing cyanobacteria for sustainable cotton cultivation

Amid growing environmental concerns and the imperative for sustainable agricultural practices, this study examines the potential of nitrogen-fixing cyanobacteria as biofertilizers, particularly in cotton cultivation. The reliance on synthetic nitrogen fertilizers (SNFs), prevalent in modern agriculture, poses significant environmental challenges, including greenhouse gas emissions and water system contamination. This research aims to shift this paradigm by exploring the capacity of cyanobacteria as a natural and sustainable alternative. Utilizing advanced metabarcoding methods to analyze the 16S rRNA gene, we conducted a comprehensive assessment of soil bacterial communities within cotton fields. This study focused on evaluating the diversity, structure, taxonomic composition, and potential functional characteristics of these communities. Emphasis was placed on the isolation of native N2-fixing cyanobacteria strains rom cotton soils, and their subsequent effects on cotton growth. Results from our study demonstrate significant plant growth-promoting (PGP) activities, measured as N2 fixation, production of Phytohormones, Fe solubilization and biofertilization potential of five isolated cyanobacterial strains, underscoring their efficacy in cotton. These findings suggest a viable pathway for replacing chemical-synthetic nitrogen fertilizers with natural, organic alternatives. The reintegration of these beneficial species into agricultural ecosystems can enhance crop growth while fostering a balanced microbial environment, thus contributing to the broader goals of global sustainable agriculture.

Synthesis and characterization of nanocomposite based polymeric membrane (PES/PVP/GO-TiO2) and performance evaluation for the removal of various antibiotics (amoxicillin, azithromycin & ciprofloxacin) from aqueous solution

The escalating global concern regarding antibiotic pollution necessitates the development of advanced water treatment strategies. This study presents an innovative approach through the fabrication and evaluation of a Polyethersulfone (PES) membrane adorned with GO-TiO2 nanocomposites. The objective is to enhance the removal efficiency of various antibiotics, addressing the challenge of emerging organic compounds (EOCs) in water systems. The nanocomposite membranes, synthesized via the phase inversion method, incorporate hydrophilic agents, specifically GO-TiO2 nanocomposites and Polyvinylpyrrolidone (PVP). The resultant membranes underwent comprehensive characterization employing AFM, EDS, tensile strength testing, water contact angle measurements, and FESEM to elucidate their properties. Analysis revealed a substantial improvement in the hydrophilicity of the modified membranes attributed to the presence of hydroxyl groups within the GO-TiO2 structure. AFM images demonstrated an augmentation in surface roughness with increasing nanocomposite content. FESEM images unveiled structural modifications, leading to enhanced porosity and augmented water flux. The pure water flux elevated from 0.980 L/m2.h−1 for unmodified membranes to approximately 6.85 L/m2.h−1 for membranes modified with 2 wt% nanocomposites. Membrane performance analysis indicated a direct correlation between nanocomposite content and antibiotic removal efficiency, ranging from 66.52% to 89.81% with 4 wt% nanocomposite content. Furthermore, the nanocomposite-modified membrane exhibited heightened resistance to fouling. The efficacy of the membrane extended to displaying potent antibacterial properties against microbial strains, including S. aureus, E. coli, and Candida. This study underscores the immense potential of GO-TiO2 decorated PES membranes as a sustainable and efficient solution for mitigating antibiotic contamination in water systems. The utilization of nanocomposite membranes emerges as a promising technique to combat the presence of EOC pollutants, particularly antibiotics, in water bodies, thus addressing a critical environmental concern.

Adsorption capacity of pollutants from water by graphene and graphene-based materials: a bibliographic review

The increase in the contamination of water systems by endocrine disruptive chemicals is of great concern once they pose risk to human and animal lives. The need for materials to adsorb these pollutants are of great concern. Graphene, a newly discovered material from the carbonaceous group, has been demonstrating interesting applications in contaminants removal from water. Therefore, this study aimed to review manuscripts regarding the adsorption capacity of herbicides and pesticides, bisphenol A, and carbamazepine from water using graphene or graphene-based materials as an adsorbent. Research of manuscripts was performed in Science Direct, Wiley Online Library, and Periódicos Capes database regarding the application of this nanomaterial in the removal of these pollutants from water. This review demonstrated that graphene itself or hybrid with other materials is very efficient in removing these contaminants, with high-efficiency rates. However, new studies can be performed to improve graphene applications and effectiveness.

A comprehensive study on the co-removal of Cr (VI) and ciprofloxacin via microbial-photocatalytic coupling: Mechanistic insights and performance evaluation

The increasing contamination of water systems by antibiotics and heavy metals has become a growing concern. The intimately coupled photocatalysis and biodegradation (ICPB) approach offers a promising strategy for the effective removal of mixed pollutants. Despite some prior research on ICPB applications, the mechanism by which ICPB eliminates mixed pollutants remains unclear. In our current study, the ICPB approach achieved approximately 1.53 times the degradation rate of ciprofloxacin (CIP) and roughly 1.82 times the reduction rate of Cr (VI) compared to photocatalysis. Remarkably, after 30 days, the ICPB achieved a 96.1% CIP removal rate, and a 97.8% reduction in Cr (VI). Our investigation utilized three-dimensional fluorescence analysis and photo-electrochemical characterization to unveil the synergistic effects of photocatalysis and biodegradation in removal of CIP and Cr (VI). Incorporation of B–Bi3O4Cl (B-BOC) photocatalyst facilitated electron-hole separation, leading to production of ·O2−, ·OH, and h+ species which interacted with CIP, while electrons reduced Cr (VI). Subsequently, the photocatalytic products were biodegraded by a protective biofilm. Furthermore, we observed that CIP, acting as an electron donor, promoted the reduction of Cr (VI). The microbial communities revealed that the number of bacteria favoring pollutant removal increased during ICPB operation, leading to a significant enhancement in performance.

BIOCHAR FROM LIGNOCELLULOSIC BIOMASS: A SUSTAINABLE CIRCULAR ECONOMY APPROACH FOR REMOVING ORGANIC AND INORGANIC CONTAMINANTS

Metals, pharmaceuticals, personal care products, pesticides, and dyes constitute contaminants widely detected in aquatic ecosystems. Adsorption is an important technology for addressing these noxious contaminants in water systems. Its widespread employment stems from its uncomplicated design, environmentally benign nature, heightened sensitivity to contaminants, and mechanical robustness. These inherent advantages render it a highly promising solution for such challenges. Within this framework, biochar embodies key physicochemical properties akin to activated carbon, the foremost adsorbent globally recognized for its efficacy in water contaminant removal. Moreover, biochar derives from the repurposing of biomass waste, thereby presenting an opportunity to enhance the value chain of numerous agricultural byproducts across Brazil. Therefore, this review article aims to present the most commonly studied lignocellulosic residues from Brazil as adsorbents, the methods used to convert them into biochar, the factors influencing the adsorption of contaminants on biochar, and their environmental applications. The main results related to lignocellulosic biomass were presented, including sugarcane, soybean, corn, rice, cotton, coffee, açaí, tucumã, coconut, Brazil nut, cupuaçu, nuts, murumuru, orange, cassava, banana, malt, macaúba, and guava. It was concluded that chemical activation is more common than physical activation, especially using ZnCl2. Finally, the materials have been employed for the removal of metals and a few organic contaminants, mainly dyes, from synthetic solutions.

Preferential separation of a radioactive TcO4- surrogate from a mixture of oxoanions by a cationic MOF.

Preferential trapping of a selected metal-oxoanion from a mixture of other metal-oxoanionic toxic pollutants in water has been demonstrated by implementing energy-efficient adsorption followed by the ion-exchange method, utilizing a hydrolytically stable cationic metal-organic framework (MOF). The cationic MOF exhibits ultrafast and selective extraction efficiency towards ReO4- (a surrogate anion of radioactive TcO4-) over other metal-oxoanions in contaminated water systems.

Molecular level investigation of interactions between pharmaceuticals and β-cyclodextrin (β-CD) functionalized adsorption sites for removal of pharmaceutical contaminants from water

This study describes a novel application of the use of molecular modeling tools for investigating the adsorption of organic micropollutants (OMPs) from water by nanocomposites. The partitioning of pharmaceuticals onto β-Cyclodextrin (β-CD) functionalized adsorbents was investigated at the molecular level to explore the atomistic interactions of pharmaceutical contaminants in water systems with β-CD and to provide insight into possible approaches for removal of pharmaceuticals from water. Molecular electrostatic surface potential mapping of β-CD derivatives was employed to examine the impact of substitution degree of β-CD and type of grafting agent on host-guest complexation. The stability of the complexes of selected pharmaceuticals and β-CD derivatives were assessed via molecular dynamics simulations to evaluate competitive adsorption between organic micropollutants (OMPs) and between OMPs and fulvic acid, a representative natural organic material (NOM) component found in water systems. Molecular electrostatic surface potential maps showed that grafting agents with aromatic and amine functional groups were found to provide attractive interactions for negatively charged OMPs. In addition, optimization of substitution degree of β-CD is necessary to enhance adsorption of target OMPs. Furthermore, it was found that aromatic ring bearing grafting agents can provide additional electrostatic attractions by π-π interactions with the aromatic ring of the OMPs. The impact of common water quality characteristics on adsorption was assessed and it was revealed that the effect of pH and calcium on adsorption depends on the ionizable functional groups present on the grafting agent. Molecular dynamics simulations showed that adsorption of target OMPs does not solely depend on hydrophobicity but is affected by electrostatic interactions. The simulations revealed that fulvic acid which is commonly present in environmental waters can be a competitor with ibuprofen for the β-CD cavity. Ultimately, this study showed that molecular level simulation can be effectively employed to investigate adsorption of OMPs by β-CD functionalized adsorbents and could be employed to enhance their design and subsequent environmental applications.

Recent Advances in Metal-Organic Framework (MOF)-Based Photocatalysts: Design Strategies and Applications in Heavy Metal Control.

The heavy metal contamination of water systems has become a major environmental concern worldwide. Photocatalysis using metal-organic frameworks (MOFs) has emerged as a promising approach for heavy metal remediation, owing to the ability of MOFs to fully degrade contaminants through redox reactions that are driven by photogenerated charge carriers. This review provides a comprehensive analysis of recent developments in MOF-based photocatalysts for removing and decontaminating heavy metals from water. The tunable nature of MOFs allows the rational design of composition and features to enhance light harvesting, charge separation, pollutant absorptivity, and photocatalytic activities. Key strategies employed include metal coordination tuning, organic ligand functionalization, heteroatom doping, plasmonic nanoparticle incorporation, defect engineering, and morphology control. The mechanisms involved in the interactions between MOF photocatalysts and heavy metal contaminants are discussed, including light absorption, charge carrier separation, metal ion adsorption, and photocatalytic redox reactions. The review highlights diverse applications of MOF photocatalysts in treating heavy metals such as lead, mercury, chromium, cadmium, silver, arsenic, nickel, etc. in water remediation. Kinetic modeling provides vital insights into the complex interplay between coupled processes such as adsorption and photocatalytic degradation that influence treatment efficiency. Life cycle assessment (LCA) is also crucial for evaluating the sustainability of MOF-based technologies. By elucidating the latest advances, current challenges, and future opportunities, this review provides insights into the potential of MOF-based photocatalysts as a sustainable technology for addressing the critical issue of heavy metal pollution in water systems. Ongoing efforts are needed to address the issues of stability, recyclability, scalable synthesis, and practical reactor engineering.

Legionellosis in Poland in 2018-2021.

The aim of this study is to compare the epidemiological situation of legionellosis in Poland in 2018-2021 to prior years, taking into account the impact of the COVID-19 pandemic in 2020-2021. The assessment is based on national surveillance data published in the annual bulletin "Infectious Diseases and Poisons in Poland" from 2013 to 2021, as well as data from Legionnaires' disease case reports collected and sent to the Department of Epidemiology of Infectious Diseases and Surveillance NIPH NIH - NRI by sanitary and epidemiological stations or submitted to EpiBase. In Poland, both Legionnaires' disease (an acute infection that progresses to pneumonia) and Pontiac fever (a mild, flu-like sickness) are reported. In 2018-2021, a total of 255 cases of legionellosis were registered, including 236 cases of Legionnaires' disease and 19 cases of Pontiac fever. Each year, there was an increase in the number of notifications compared to the annual median number of cases from 2013-2017. The annual incidence rate in 2019 (0.23 per 100,000 population) was the highest since the start of legionellosis case registration in Poland. It declined again during the years of the COVID-19 pandemic. The notifications occurred throughout the country, but the highest notification rate was observed in the western belt of voivodeships. Pomorskie reported the highest incidence, accounting for more than 20% of all registered cases. The median incidence of Legionnaires' disease in men (0.23 per 100,000) was more than twice that of women (0.10), with the highest incidence (0.58) recorded in men 65 years of age or older. All indigenous cases of Legionnaires' disease were sporadic; all but three patients were hospitalized. State Sanitary Inspection reported 26 fatal cases of Legionnaires' disease (mortality = 11%). Twenty-four cases were linked to contaminated water systems in health-care settings, and 21 cases were likely associated with travel abroad. Although the number of notifications has increased in recent years, Legionnaires' disease is still an infrequently diagnosed respiratory infection in Poland, and the reported incidence remains one of the lowest in the entire EU. The most affected demographic group is men aged 65 and older. Improving the early diagnosis of Legionnaires' disease in healthcare settings remains a priority.

Sources of antimony contamination and its migration into water systems of Xikuangshan, China: Evidence from hydrogeochemical and stable isotope (H, O, S, and Sr) signatures

The Xikuangshan (XKS) mine was selected for a comprehensive Sb-related hydrogeochemical study because of its significant Sb contamination in water systems. Hydrochemical data, specifically multi-isotope (H, O, S, and Sr) data, were conducted to elucidate the primary sources and migration processes of Sb responsible for water system contamination. At the XKS Sb mine, water is near-neutral to alkaline and is characterized by high concentrations of SO42− and Sb. Sb occurs as Sb(OH)6− (the dominant species) in these oxidized waters. The hydrochemistry is mainly controlled by carbonate dissolution and silicate weathering. δ2HH2O and δ18OH2O values indicate that the infiltration recharge of mine water and mining activities regulate the migration of Sb in groundwater. δ34SSO4 and δ18OSO4 values indicate that dissolved SO42− and Sb primarily come from stibnite oxidation, bacterial SO42− reduction has either not occurred or is extremely weak, and the reductive dissolution of Fe (III) hydroxides does not significantly affect Sb migration in water. The 87Sr/86Sr ratios further indicate that the discharge of solid mine wastes leaching and smelting water is a crucial source of Sb contamination in groundwater. In addition, the relationship between δ34SSO4 and δ87Sr values suggests the complexity of the contamination source and migration of Sb in water. Finally, a robust conceptual hydrogeochemical model was developed using isotopic tools in combination with detailed hydrogeological and hydrochemistry characterization to describe the contamination source and migration of Sb in water systems at the XKS Sb mine.

Biofilms Controlling in Industrial Cooling Water Systems: A Mini-Review of Strategies and Best Practices.

Biofilm formation and growth is a significant concern for water treatment professionals, as it can lead to the contamination of water systems and pose a threat to public health. Biofilms are complex communities of microorganisms that adhere to surfaces and are embedded in an extracellular matrix of polysaccharides and proteins. They are notoriously difficult to control, as they provide a protective environment for bacteria, viruses, and other harmful organisms to grow and proliferate. This review article highlights some of the factors that favor biofilm growth, as well as various strategies for controlling biofilm in water systems. Adopting the best available technologies, such as wellhead protection programs, proper industrial cooling water system maintenance, and filtration and disinfection, can prevent the formation and growth of biofilms in water systems. A comprehensive and multifaceted approach to biofilm control can reduce the occurrence of biofilms and ensure the delivery of high-quality water to the industrial process.

Prevalence and Characterization of Legionella pneumophila and Related Species from Water-Based Recreational Sites

Abstract Background and Objectives Legionella is a genus of gram-negative bacteria common in soil and aquatic systems and is associated with protists. They have emerged as a pathogenic group due to the increased use and poor maintenance of artificial water environments. This study aims at phenotypic and molecular identification of Legionella in water and swab samples collected from water-based recreational sites. The biofilm-forming ability of Legionella on exposure to various temperatures and iron concentrations was also studied. Methods A total of 60 samples including 30 swab samples and 30 water samples (decorative fountain ponds, swimming pools, garden sprinklers, drip irrigation system) were collected from in and around Mangalore, Karnataka, India. From each source, swab and water samples were collected as per the Indian standard IS: 1622. The collected samples were processed within 4 hours of collection. The samples were subjected to microbiological and chemical estimation followed by filtration through a 0.2 µm membrane filter. Isolation of Legionella from collected samples was performed as per US Centers for Disease Control and Prevention guidelines 2005. The positive isolates were then checked for biofilm-forming ability at various temperatures (25°C, 35°C, and 45°C) and iron concentration (3 mg/L, 30 mg/L, and 300 mg/L) using crystal violet assay. Results Out of 30, water and swab samples tested, one water sample from a garden sprinkler, swimming pool, and one from both water and swab samples from a decorative fountain showed the presence of Legionella. A biofilm study of Legionella at various temperatures and iron concentrations categorized the bacteria as a moderate biofilm former. Conclusion This study revealed that most of the water and swab samples were found to be negative for Legionella that is quite encouraging and the contamination of water systems in recreational facilities can be reduced by decontamination techniques and proper hygienic practices.

Identification, prevention, and treatment of Legionella in bath facility water systems in South Korea

Legionella bacteria infect people via aerosol transmission. These pathogens can meaningfully affect people with weak immune systems and the older adult population. Legionella proliferate in water systems at temperatures between 25 and 45 °C, the optimum range for bath facilities. Here, we discuss how and where water systems can be contaminated by Legionella in bath facility water systems in South Korea. An epidemiological investigation of Legionella detection data from the Korea Disease Control and Prevention Agency was conducted to understand the tendencies of general outbreaks of water system types in building groups. Onsite investigations were then conducted to identify the causes of contamination in water systems in actual Legionella detection cases. According to annual Legionella detection data, the highest rate of Legionella was detected in hot bathtub water. Onsite investigations revealed that sand filter circulation systems for bathtubs are susceptible to Legionella growth. Overall, this study examined the mechanisms of buidling water systems from a building engineering perspective in order to provide valuable information for future studies and strategies to control Legionella growth in bath facility water systems.