Untreated Water Samples Research Articles

Advanced Carbon Nanoparticle-Based Filtration Systems for Water Disinfection and Microplastics Removal

Providing clean and safe water is an inherent entitlement of every individual, underscoring the imperative for efficient water disinfection methods. Nevertheless, the increasing prevalence of microplastics in water sources has presented intricate obstacles for current treatment methodologies. Microplastics present significant challenges to both human health and ecosystems, hence requiring the development of novel and inventive solutions. This study suggests introducing a Nanoparticle-Based Water Filtration System (NP-WFS) specifically developed to tackle the combined issue of water disinfection and microplastic elimination. This technique presents a viable alternative to traditional methods by utilizing the distinctive characteristics of Carbon Nanoparticles (CNP) in conjunction with a precisely engineered membrane. At a wavelength of 450 nm, there was a noticeable absorption peak with an absorbance of 1.81%. This discovery demonstrates the existence of CNP. The peak suggests the presence of microplastic particles at 2901.4 cm-1, which coincides with the value found in the untreated water sample. The continuous range of 2798.6 cm-1 in the microfilm indicates that the CNP-infused microfilm effectively collects minuscule plastic beads. This finding implies that the CNP microfilm successfully captured the microorganisms and microplastics. These results serve as evidence of the efficacy of the NP-WFS in the field of water purification. Compared to conventional approaches, NP-WFS demonstrates superior performance in removing microplastics and establishes a novel benchmark for water disinfection. This initiative effectively tackles pressing concerns about water safety, safeguarding ecosystems, and human well-being. This study advances water filtration technology, offering a viable solution to sustainably address the ever-changing waterborne issues.

An assessment of HgII to preserve carbonate system parameters in organic‐rich estuarine waters

AbstractThis work assesses the effectiveness of sample preservation techniques for measurements of pHT (total scale), total dissolved inorganic carbon (CT), and total alkalinity (AT) in organic‐rich estuarine waters as well as the internal consistency of measurements and calculations (e.g., AT, pHT, and CT) in these waters. Using mercuric chloride (HgCl2)‐treated and untreated water samples, measurements of these carbonate system parameters were examined over a period of 3 months. Respiration of dissolved organic matter in untreated samples created large discrepancies in CT concentrations (~37 μmol kg−1 increase, p < 0.0001), while CT was effectively constant in treated samples (3095.0 ± 1.14 μmol kg−1). AT changes were observed for both treated and untreated samples, with HgCl2‐treated samples showing the greatest variation (~ 26 μmol kg−1 decrease, p < 0.001). In response to changing AT/CT ratios, pHT changes occurred in both treated and untreated samples but were relatively small in treated samples. Results in organic‐rich estuarine waters that reflect the in situ carbonate system characteristics of the samples at the time of collection can be improved when samples obtained for CT and AT analysis are collected and stored separately. Accurate analyses of CT can be obtained by filtration and preservation with HgCl2. Accuracy of AT analyses can be improved by filtration and storage without adding HgCl2. The quality of pHT measurements can be improved by prompt analysis in the field and, if this cannot be accomplished, then samples can be preserved with HgCl2 and measured in the laboratory within 1 week.

Annual Assessment of Physico Chemical Parameters of The Untreated and Treated Sewage Water Fed Ponds of CHRIST (Deemed to Be University) Campuses, Bengaluru, Karnataka, India

Annual assessment and comparative investigation on six sewage water bodies, among six of the study areas, three were of untreated sewage water bodies and the rest three were of treated sewage water bodies namely MU ( Main campus Untreated sewage water), MT(main campus Treated water), BU (Bannerghatta campus untreated sewage water), BT(Bannerghatta campus Treated Sewage water), KU(Kengeri campus untreated sewage water) and KT(Kengeri campus Treated sewage water) were conducted to assess the water characteristics and the effect of water treatment process. Water characteristics were presented in terms of physico-chemical parameters.Twenty physico-chemical parameters of sewage water, were examined on a monthly basis for the time period of November 2019-November 2020. During the analysis, waters of treated sewage samples showed a larger difference and more suitable for daily usage when compared to untreated sewage water samples which were heavily loaded with pollution. As per Two Way ANOVA there was highly significant variation in physico-chemical parameters between the untreated and treated sewage water samples(P<0.01).

Cyperus scariosus extract based greenly synthesized gold nanoparticles as colorimetric nanoprobe for Ni2+ detection and as antibacterial and photocatalytic agent

Nanoparticles (NPs) having diameter in the range of 1–100 nm has been extensively studied for their broad range applications in the field of catalysis, sensing, energy storage and biology. The NPs can be synthesized utilizing multiple approaches, such as sol–gel method, hydrothermal, chemical reduction and green synthesis etc. However, green synthesis utilizing the plant extract as reducing and capping agent has grabbed the special attention due to its eco-friendly, non-hazardous and cost-effective nature. Herein, green synthesis of gold nanoparticles (AuNPs) is being reported utilizing aqueous extract of Cyperus scariosus roots (CSRE) under sunlight irradiation. CSRE@AuNPs have been successfully characterized by UV–Visible and FTIR spectroscopy, Scanning electron microscopy (SEM), Energy-dispersive X-rayspectroscopy (EDX), zeta potential (ZP), dynamic light scattering (DLS) and powder diffraction analysis (PXRD). Average size of the CSRE@AuNPs has been found ∼50 nm. Due to appropriate band gap of CSRE@AuNPs in the range of visible light, these NPs have evaluated for the photocatalytic potential to degrade hazardous organic dye i.e., methylene blue (MB). The NPs were proved to be efficient catalyst by 80% degradation of MB dye in just 90 min exposure to sunlight. These NPs have also been screened for the selective sensing of heavy metal ions in spiked water. CSRE@AuNPs had shown selective colorimetric response for the detection of Ni2+ with limit of detection (LOD) of 118.5 nM and a linear range of 0–300 µM at optimized temperature of 40 °C at wide range of pH (3–9). The zeta potential and hydrodynamic size measurements were carried out to study the effect of Ni2+ on nanoparticle aggregation. A decrease in value of zeta potential from −34.4 to −0.116 mV (ignore the sign) and increase in value of DLS size from 53.2 to 7553 nm of the AuNPs was observed with an increase in concentration of Ni2+ ions from 0 to 300 µM. Furthermore, over 93% recovery and a relative standard deviation (RSD) of roughly 4% proved the effectiveness of this colorimetric nano-probe for Ni2+ detection in untreated natural water samples, such as river and tap water.

Multivariate Analysis of Harvested Rainwater Quality Utilizing Sustainable Solar-Energy-Driven Water Treatment

The rising importance of utilizing rainwater as a sustainable and viable alternative water source is evident amid increasing urbanization and the mounting global apprehensions about water scarcity. This research aims to develop a comprehensive and sustainable approach to rainwater treatment by effectively utilizing the recently constructed solar panels at the University of Engineering and Technology (UET) in Pakistan. The study’s distinctiveness lies in its comprehensive examination of treatment plant efficiency under various weather conditions in a water-scarce region. The main objective of this work is to maximize the harvested rainwater in order to provide safe drinking water while lessening the carbon footprint of treatment operations. The proposed University of Engineering and Technology water purification process (UETWPP) method involves a sequence of four essential rainwater filtration stages, namely aeration, absorption, sediment filtration, and finally, UV disinfection, all powered by solar energy. Water samples were collected monthly for a year to assess the quality of untreated and treated rainwater, including physical, chemical, and biological parameters. Multivariate analysis techniques were used to assess these parameters, including the Friedman test and principal component analyses. By reducing the initial set of twenty components down to the four most critical ones identified in the untreated water samples, the interrelationships among these components were investigated. The results indicate that the quality of treated water using the UETWPP process was found to be suitable for human consumption, aligning with the local standards as well as those established by the World Health Organization (WHO), highlighting the effectiveness of the process in transforming rainwater into potable water. Ultimately, this pilot project showcases the viability and economic efficiency of the proposed system, rendering it easily implementable in other regions.

Regulation Transcriptional of Antibiotic Resistance Genes (ARGs) in Bacteria Isolated from WWTP

The incidence of antibiotics and transcriptional regulation of ARGs in isolated bacteria from wastewater needs to be explored. By HPLC, in samples of untreated wastewater, ampicillin (49.74 ± 5.70 µg/mL), chloramphenicol (0.60 ± 0.03 µg/mL), tylosin (72.95 ± 2.03 µg/mL), and oxytetracycline (0.22 ± 0.01 µg/mL) was determined. Through metagenomic analysis identified 58 bacterial species belonging to 9 phyla and at least 14 species have shown resistance to a variety of antibiotics. Twenty-two bacterial isolates were proved to be resistant to fifteen antibiotics of new generation and used in medical research to combat infectious diseases. Fourteen strains were shown to harbor plasmids in size ranges of 2–5 Kb, 6–10 Kb and plasmids with size greater than 10 Kb. By quantitative PCR it was possible to identify genes sul, qnr, cat1, aadA1, and sat-1 gene were shown to be present in gDNA samples from treated and untreated samples of wastewater and by relative expression analysis, differential expression of cat1, ermB, act, and tetA genes was demonstrated in strains that showed identity with Escherichia coli, Bacteroides fragilis, and Salmonella thyphi, and that were stressed with different concentrations of antibiotics. The presence of ARGs in untreated water samples, as well as in bacterial isolates, was indicative that in these habitats there are microorganisms that can resist β-lactams, aminoglycosides, tetracyclines, sulfonamides, and quinolones.

A novel culture-enriched metagenomic sequencing strategy effectively guarantee the microbial safety of drinking water by uncovering the low abundance pathogens

Assessing the presence of waterborne pathogens and antibiotic resistance genes (ARGs) is crucial for managing the environmental quality of drinking water sources. However, detecting low abundance pathogens in such settings is challenging. In this study, a workflow was developed to enrich for broad spectrum pathogens from drinking water samples. A mock community was used to evaluate the effectiveness of various enrichment broths in detecting low-abundance pathogens. Monthly metagenomic surveillance was conducted in a drinking water source from May to September 2021, and water samples were subjected to five enrichment procedures for 6 h to recover the majority of waterborne bacterial pathogens. Oxford Nanopore Technology (ONT) was used for metagenomic sequencing of enriched samples to obtain high-quality pathogen genomes. The results showed that selective enrichment significantly increased the proportions of targeted bacterial pathogens. Compared to direct metagenomic sequencing of untreated water samples, targeted enrichment followed by ONT sequencing significantly improved the detection of waterborne pathogens and the quality of metagenome-assembled genomes (MAGs). Eighty-six high-quality MAGs, including 70 pathogen MAGs, were obtained from ONT sequencing, while only 12 MAGs representing 10 species were obtained from direct metagenomic sequencing of untreated water samples. In addition, ONT sequencing improved the recovery of mobile genetic elements and the accuracy of phylogenetic analysis. This study highlights the urgent need for efficient methodologies to detect and manage microbial risks in drinking water sources. The developed workflow provides a cost-effective approach for environmental management of drinking water sources with microbial risks. The study also uncovered pathogens that were not detected by traditional methods, thereby advancing microbial risk management of drinking water sources.

Prevalence and Genetic Diversity of Cross-Assembly Phages in Wastewater Treatment Plants in Riyadh, Saudi Arabia.

The most common DNA virus found in wastewaters globally is the cross-assembly phage (crAssphage). King Saud University wastewater treatment plant (KSU-WWTP); Manfoha wastewater treatment plant (MN-WWTP); and the Embassy wastewater treatment plant (EMB-WWTP) in Riyadh, Saudi Arabia were selected, and 36 untreated sewage water samples during the year 2022 were used in the current study. The meteorological impact on crAssphage prevalence was investigated. CrAssphage prevalence was recorded using PCR and Sanger sequencing. The molecular diversity of crAssphage sequences was studied for viral gene segments from the major capsid protein (MCP) and membrane protein containing the peptidoglycan-binding domain (MP-PBD). KSU-WWTP and EMB-WWTP showed a higher prevalence of crAssphage (83.3%) than MN-WWTP (75%). Phylogenetic analysis of MCP and MP-PBD segments depicted a close relationship to the Japanese isolates. The MCP gene from the current study's isolate WW/2M/SA/2022 depicted zero evolutionary divergence from 3057_98020, 2683_104905, and 4238_99953 isolates (d = 0.000) from Japan. A significant influence of temporal variations on the prevalence of crAssphage was detected in the three WWTPs. CrAssphage displayed the highest prevalence at high temperatures (33-44 °C), low relative humidity (6-14%), and moderate wind speed (16-21 Km/h). The findings provided pioneering insights into crAssphage prevalence and its genetic diversity in WWTPs in Riyadh, Saudi Arabia.

Chemical Analysis of Essential Trace Elements in Wastewater Samples Collected from Four Different Mines

Mine water contains trace heavy metals which are some essential trace elements in high concentrations causing the pollution of nearby water bodies, related ground waters and soils degradation. The aim of the study is to identify and quantify the essential trace elements present in the different mine water samples and their level of toxicity. Digestion technique was employed to pretreat the mine wastewater before analysis. Physicochemical analysis was conducted for pH, electrical conductivity (EC), total dissolved solids (TDS), and salinity. The samples collected from four different locations are Sample A (Gold mine), Sample B (Copper mine), Sample C (Iron mine), Sample D (Tin mine). The raw or untreated mine water samples were analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The results showed the essential trace elements present in all the mine water samples are Mn, Cu, Fe and Zn. Cu is highly concentrated in copper (73.87 mg/L) and tin (2.09 mg/L) mine water while Fe is dominant in water samples collected from gold (7.19 mg/L) and iron (13.12 mg/L) mine. In conclusion, the essential trace elements Mn, Cu, and Fe present in all the mines are very high and can be harmful to human life in the environment but the concentrations of Zn in the entire mine water samples are within the permissible level of standard drinking water and hence it can pose no threat to human life.

Phytoremediation Effectiveness Azolla sp. and Ipoemea Aquatica Towards Amonia Levels Reduction in Tilapia (Oreochromis niloticus) Water Cultivation

Tilapia is one type of freshwater fish that has a lot of demand in the market. Therefore, the production of tilapia aquaculture is increasing. Increased production of aquaculture causes a decrease in water quality due to the large number of metabolic wastes. Fish farmers usually require a large amount of money to overcome the decline in the quality of aquaculture pond water. For this reason, it is necessary to apply techniques to improve the quality of aquaculture pond water at an affordable cost. Azolla sp and Ipoemea aquatica are plants that can absorb environmental contaminants. The research method used was experimental method with untreated pool water samples (control), pool water samples treated with kale (Treatment 1), pool water samples treated with Azolla sp. (Treatment 2) and pond water samples with the combination treatment of kale and Azolla sp. (Treatment 3). Ammonia levels in Tilapia pond water samples were statistically analyzed using the SPSS application. The results showed that kale and Azolla sp. tends to be effective in reducing ammonia levels in Tilapia rearing pond water. The water spinach treatment had a higher value in reducing ammonia levels in the sample water of the tilapia rearing pond, which was 5.99 compared to the Azolla sp. of 3.22 and the combination treatment of 5.95.

Efficacy of electrolytic treatment on degrading microplastics in tap water

Microplastics, or plastic fibers less than five millimeters in length, are a significant environmental problem and are extremely difficult to remove from water. In this experiment, we quantified the effect of electrolysis on the degradation of microplastics in tap water and explored electrolysis as a potential solution to this issue. We hypothesized that an electrolytic treatment would disassemble microplastic molecules, as it does with water. Treated water consisted of samples electrolyzed for 30 minutes in an electrolysis machine, while samples of untreated tap water were the control. We examined filters under a microscope before and after filtration of the water samples to determine the number of net microplastics in every sample. Overall, control samples demonstrated a greater number of net microplastics than experimental samples (Mann-Whitney U, p = 0.047). Thus, we conclude that electrolysis is a valid and practical method to degrade microplastics in tap water because of its high efficiency within a short duration of time. These findings could be of great value as they have the potential to improve the quality of drinking water, and by extension, public health. This research indicates electrolysis could be advantageous over many other methods of water purification in respect to microplastics.

Application of Bio-Treatment Agent for Waste Water Remediation using Moringa Olifera Seed powder

This study is aimed at determining the efficacy of using Moringa oleifera seed powder (MOSP) in wastewater treatment process (domestic and industrial). The effectiveness of MOSP was evaluated on the microbial and physiochemical characteristics of water. The experimental results of the properties of the treated and untreated water samples from industrial and domestic water sources revealed significant improvement after treatment with MOSP. The findings observed that generally, Moringa oleifera seeds treated both industrial and domestic waste water well as an alternative to commercial coagulating agents.  The study, therefore recommended that Moringa oleifera seed powder be utilized in industries and homes for the treatment of waste water and re-use. In addition, these processes are environmentally friendly and offer a wide variety of other benefits, such as reducing costs, reducing the generation of by-products, and providing greater biodegradability.

Isolation and Phenotypic Characterization of Lytic Bacteriophage with Activity against Pseudomonas aeruginosa

Aims: To perform the isolation and phenotypic characterization of bacteriophage with lytic activity against Pseudomonas aeruginosa. To demonstrate that this type of viral agent can be isolated from the environment and used for the biocontrol of resistant bacterial types, such as  Pseudomonas aeruginosa.
 Study Design: This study was an experimental study.
 Place and Duration of Study: The study was conducted at, Bacteriology and Mycology Laboratory in the Veterinary Hospital at the School of Agricultural Sciences, Innovation and Business  of the University of Passo Fundo (ESAN/UPF) and Center for Diagnosis and Research in Animal Health of the University of Passo Fundo (CDSA/UPF), between April 2022 and June 2022.
 Methodology: Samples of untreated water were inoculated with the host bacterium strain Pseudomonas aeruginosa ATCC 27853 in an enriched media After the incubation period in, a phage filtrate was obtained by centrifugation followed by filtration. We verified the presence of bacteriophages using spot test and we carried out its purification by the method of sterile toothpick plate transfer on bacterial overlay semi-solid agar. Amplification was performed using an SM buffer elution procedure to produce a stock of viral material. Through assays in Petri dishes with bacterial overlay, we performed titration and phenotypic characterization regarding the lysis spectrum and efficiency of phage infection in the host.
 Results: We managed to isolate a morphologically characterized lytic bacteriophage with approximately 1 mm of diameter, high clarity in the inhibition area, the presence of halo and well-demarcated edges. The bacteriophage, named as Pseudomonas aeruginosa Phage UPF_PaBP1, demonstrated the infection capacity of the target bacteria in all tested dilutions and a stock preparation with a titre of 6.5 x 10⁸ PFU/ml was obtained for future use.
 Conclusion: The isolated phage showed strong lytic activity against the bacterial host, a finding that nourishes our expectations regarding the use of this phage as a biocontrol agent and phage therapy.

Biochar for the removal of pathogens from waste water

Waste water contains various pollutants and pathogens which is harmful to all the living organisms. This waste water without any treatment if released directly to water bodies or soil causes pollution of water and soils. Various agroindustry by-products viz., sawdust, corn cob, wheat husk, bagasse, rice bran, etc. are generated in huge amount which are disposed directly to the landfills or incinerated which causes pollution. The agroindustry by-products can be used to prepare biochar. In this work, wheat husk was used to prepare biochar. This wheat husk based biochar was used for the study of removal of pathogens from waste water. The biochar was also used to check if it can be used for treatment of water by study of total suspended and dissolved solids. The reduction of pathogens in waste water samples A and B using wheat husk based biochar observed was 90 and 80% respectively when compared to untreated waste water samples. Also, no colonies of E. coli were observed after treating the waste water samples A and B with wheat husk based biochar. The reduction in total suspended and dissolved solids observed was 97.7 and 76.3% respectively when compared to the untreated water sample. Wheat husk based biochar can be used for the removal of pathogens such as E. coli from waste water. The biochar can also be sued for the treatment of waste water. The use of biochar for the removal of pathogens, solids and other pollutants from waste water will be very cheap and eco-friendly.
  

Cherenkov Radiation Detection on a LS Counter for 226Ra Determination in Water and Its Comparison with Other Common Methods.

Reliable determination of 226Ra content in drinking water, surface water and groundwater is required for radiological health-risk assessment of populations and radiation-dose calculations after ingestion and inhalation. This study aimed to determine 226Ra presence in the untreated water samples on a liquid scintillation counter via Cherenkov radiation detection. Cherenkov counting is a faster, simpler, less expensive technique than other commonly used methods for 226Ra determination. Step-by-step optimization of this technique on the Quantulus detector is presented in this paper. Improvement of detection limit/efficiency in the presence of sodium salicylate was investigated in this study. The main parameters of the method obtained were detection efficiency 15.87 (24)% and detection limit 0.415 Bq/L achieved for 1000 min of counting in 20 mL of sample volume. When 1 g of sodium salicylate was added, efficiency increased to 38.1 (5)%, with a reduction in the detection limit to 0.248 Bq/L for 500 min of counting. A satisfactory precision level of Cherenkov counting was obtained, the results deviating between 5% and 20% from reference values. The precision and accuracy of the Cherenkov counting technique were compared to liquid scintillation counting (EPA Method 913.0 for radon determination) and gamma spectrometry (the direct method for the untreated water samples on HPGe spectrometer). An overview of the advantages/disadvantages of each technique is elaborated in this paper.

Physicochemical and microbial pollution of a reservoir in South India and role of bacteriophage treatment to curtail drug-resistant bacterial pollution in water

This study aimed to assess the physicochemical and microbiological pollution of water samples collected from Bellandur Lake, Bengaluru, South India, and to study the potential of bacteriophage treatment to curtail drug-resistant bacterial pathogens. The water samples were collected from the lake during four time periods in 2018–19. The physicochemical, heavy metal, and bacteriological analyzes were studied by standard protocol. The antibiotic sensitivity profiles of the major isolates from the water samples were assessed by disk diffusion assay, and two isolates that showed resistance to the highest percentage of the tested antibiotics were characterized by 16S rRNA gene sequencing. The lake water samples were treated with the isolated bacteriophages with controls, and the reduction of viable bacterial count in the treated water samples was estimated. This study revealed that the physicochemical, heavy metal and microbiological qualities of water samples were exceeded the permissible limits set by the standard authorities ( p ≤ 0.05). When tested against 44 antibiotics, most of the isolates were found to be multidrug-resistant in which IS1 and IS2 showed resistance to the highest percentage of antibiotics, which were confirmed to be Pseudomonas aeruginosa strain DSCEbt-Bellandur01 and Pseudomonas sp. strain DSCEbt-Bellandur022, respectively. When the lake water samples were treated with the isolated bacteriophages, the study showed a 99.99 % reduction in the viable bacterial count (CFUL/ml) when compared to untreated water samples ( p ≤ 0.05). Thus, the present study suggests that bacteriophage-based therapy is one of the promising approaches to treat various water bodies to reduce microbial pollution, and the approach can be used to curtail the emergence of multi-drug resistant pathogens in the water samples. • Assessing the physicochemical and microbial pollution of lake water in South India. • Bacteriophage therapy as a potential approach in reducing MDR pathogens in water. • Lake water quality found to be poor with heavy metal and MDR bacterial pathogens. • IS1 and IS2 belonged to Pseudomonas spp. and showed 100 % antibiotic resistance. • 99.9 % reduction of CFU/ml in the treated samples with isolated bacteriophage.

Chlorine taste can increase simulated exposure to both fecal contamination and disinfection byproducts in water supplies

Expanding drinking water chlorination could substantially reduce the burden of disease in low- and middle-income countries, but the taste of chlorinated water often impedes adoption. We developed a Monte Carlo simulation to estimate the effect of people's choice to accept or reject drinking water based on chlorine taste and their subsequent exposure to E. coli and trihalomethanes, a class of disinfection byproduct (DBP). The simulation used empirical data from Dhaka, Bangladesh, a megacity with endemic waterborne disease. We drew on published taste acceptability thresholds from Dhaka residents, measured residual chlorine and thermotolerant E. coli inactivation following the addition of six chlorine doses (0.25–3.0 mg/L as Cl2) to untreated piped water samples from 100 locations, and analyzed trihalomethane formation in 54 samples. A dose of 0.5 mg/L, 75% lower than the 2 mg/L dose typically recommended for household chlorination of low-turbidity waters, minimized overall exposure to E. coli. Doses of 1–2 mg/L maximized overall exposure to trihalomethanes. Accounting for chlorine taste aversion indicates that microbiological exposure increases and DBP exposure decreases above certain doses as a higher proportion of people reject chlorinated water in favor of untreated water. Taken together with findings from other modeling analyses, empirical studies, and field trials, our results suggest that taste acceptability should be a critical consideration in establishing chlorination dosing guidelines. Particularly when chlorination is first implemented in water supplies with low chlorine demand, lower doses than those generally recommended for household water treatment can help avoid taste-related objections while still meaningfully reducing contaminant exposure.

The Industrial Production of Water Dedicated to Absorption of Gases

The paper presents a flow plasma reactor permitting modification of the properties of water/aqueous solutions by stochastic resonance amplification of vibrations of selected chemical species in water with electromagnetic noise generated during a plasma discharge. The main parameters characterizing the quality for super-pure water, tap water and water from the intake in Besko (Poland) before and after the process in the plasma reactor were presented for comparison. In addition, the 17O NMR (the full width at half maximum) and electrospray ionization mass spectrometry (ESI MS) methods were used to determine differences in physicochemical parameters between the untreated and plasma-treated water. It has been established that the water subjected to plasma treatment shows much different gas absorption properties than the untreated water samples, as a function of temperature and pressure, in this paper we report exemplary data for CO2, oxygen and acetylene. The improved gas absorption properties of the plasma-treated water make it attractive for the use in industrial processes. It is worth pointing to a great capacity of the new reactor (4000 l/h), and low energy consumption (20 MJ/h) for the treatment of the above mentioned volume flow rate of water.

New Strategies for the Simple and Sensitive Voltammetric Direct Quantification of Se(IV) in Environmental Waters Employing Bismuth Film Modified Glassy Carbon Electrode and Amberlite Resin.

An analytical procedure regarding the determination of selenium(IV) by anodic stripping voltammetry exploiting the in situ plated bismuth film electrode is described. Since organics are commonly present in untreated natural water samples, the use of Amberlite XAD-7 resin turns out to be quite important to avoid problems such as the adsorption of these compounds on the working electrode. The optimum circumstances for the detection of selenium in water using differential pulse voltammetry techniques were found to be as follows: 0.1 mol L−1 acetic acid, 1.9 × 10−5 mol L−1 Bi(III), 0.1 g Amberlite XAD-7 resin, and successive potentials of −1.6 V for 5 s and −0.4 V for 60 s, during which the in situ formation of the bismuth film on glassy carbon and the accumulation of selenium took place. The current of the anodic peak varies linearly with the selenium concentration ranging from 3 × 10−9 mol L−1 to 3 × 10−6 mol L−1 (r = 0.9995), with a detection limit of 8 × 10−10 mol L−1. The proposed procedure was used for Se(IV) determination in certified reference materials and natural water samples, and acceptable results and recoveries were obtained.

Zinc oxide coated regenerated spent FCC catalyst for water purification

Introduction: Zeolites are microporous aluminosilicates, commonly used as commercial adsorbents and catalysts. As an adsorbent, zeolite can adsorb gram-positive bacteria when compared with gram-negative bacteria (1,2). Ultrafine zinc oxide nanoparticles in colloidal medium is toxic to E. coli bacteria (3). ZnO-coated zeolite adsorbent can effectively remove of humic acid and E. coli from water when compared to zeolite adsorbent (4-5). The spent FCC (SFCC) catalyst is very harmful to the human health by being absorbed mainly into the respiratory tract and lungs due to its tiny particles of size 60-100 micrometer (1). Most of the spent FCC catalysts are currently disposed as landfills, which leads to the wastage of valuable metal resources and the environmental pollution. In this work the spent zeolite catalyst is regenerated and coated with zinc oxide and this zinc oxide coated regenerated spent FCC catalyst (ZOCRSC) is used to remove E. coli from water. Methods: In this work, decoking is done to burning off the deposited carbon by roasting in air at 550°C for 2 hours. Then SFCC catalyst is leached with HCl and oxalic acid. Activated SFCC catalyst, obtained as a leaching residue is separated. Zinc oxide is coated on the regenerated catalyst to develop zinc oxide coated zeolite adsorbents. Coating procedure follows activated catalyst modified by HNO3 and then Zn(NO3)2 solution. To characterize crystal structure of zeolite and ZOCRSC, XRD, SEM, and BET analysis were carried out. The water from the treatment plant after secondary treatment was used for the experiments and the E. coli content was estimated using plate counting technique. ZOCZ is added to the E-coli containing water and after proper mixing the suspension is allowed to settle. Sample is collected from treated water at different intervals for determining E. coli content. The treatment procedure was also done using the spent coated sample, acid activated sample and spent FCC catalyst and are used as a comparison with ZOCZ. Results & Discussions: The XRD pattern shows that the ZOCRSC exhibited similar characteristic diffraction peaks to that of the uncoated samples which indicates that the modification did not affect the mineralogy of the zeolite and in addition it also exhibited similar characteristic diffraction peaks to those of ZnO. Thus, the XRD pattern and the SEM images of ZnO coated spent catalyst and ZnO coated regenerated catalyst shows that coatings of ZnO on zeolites were done effectively. The surface area and pore volume of zinc oxide coated regenerated spent FCC catalyst is determined from BET analysis. The removal of E. coli from water was quantified by plate counting. The E. coli count of the untreated water sample is 560 cfu/ml and treated sample after 30 minutes is less than 1 cfu/ml. Water treated using spent FCC catalyst without any modification did not show any change in the E. coli count. The acid activated catalyst and spent FCC catalyst coated with ZnO reduce the E. coli content in the water to 11 cfu/ml and 6 cfu/ml respectively after 90 minutes. Conclusions: ZnO coated regenerated spent FCC catalyst is developed from waste spent catalysts is utilized for the removal of E. coli from water. The ZOCRSC removes E. coli effectively when compared with spent FCC catalyst coated with ZnO, acid activated catalyst, and spent FCC catalyst in a short period. The spent FCC catalyst coated with ZnO cannot be directly used for treating purpose as it contains various contaminant metals which should not be present in treated water. Keywords: Escherichia coli, Spent FCC catalyst, Zinc oxide, ZOCRSC