Assessment of Physico-Chemical Parameters and Heavy Metal of Drinking Water Samples from Some Iranian Universities and Surveyed the Efficacy of Several Water Purification Methods on Removal of Heavy Metal

Water quality is the most important factor for consumers because it has a significant impact on their health. So, monitoring and controlling water quality is of particular significance in different human communities such as universities. In this study, the physicochemical parameters such as turbidity, electrical conductivity, hardness, alkalinity, calcium and magnesium ions, and heavy metals including lead, cadmium, nickel, arsenic, and chromium in drinking water were determined in nine Iranian universities. Then, the efficacy of several treatment methods was evaluated in the removal of heavy metal, including the boiling process in two stages: 5 minutes boiling and 5 hours boiling and filtration process. The results revealed that the physicochemical quality of drinking water in all universities was appropriate. Hardness levels in drinking water samples of all universities were higher than the WHO standards. However, this parameter was lower than the national standard of Iran (500 mg/l). Nevertheless, cadmium content was not detected in any samples, nickel content was below the permissible limit, and chromium content was below the permissible limit in all samples. However, its value was higher than the allowable limit in the university with a code of 6. Lead content was higher than the limit in samples with codes 3, 5-1, and 5-4, and arsenic content was higher than the limit in samples with codes 6, 1-1, 1-2, and 2. Water purification methods, including boiling and water purifier, were satisfactory and significantly reduced pollutants. According to the present study, it is suggested to check drinking water quality in universities randomly, and the 5-minute boiling method can be recommended as a cost-effective solution for water purification.

RESEARCH ON RADON (222Rn) CONTENT IN DRINKING-WATER SAMPLES COLLECTED FROM SIBIU COUNTY

The isotope radon (222Rn), an inert water-soluble gas that may contaminate water, represents a potential risk for human health, including cancer. The present study reports the evaluation of the 222Rn concentration in drinking-water samples collected in 2020 from 10 sources located in Sibiu County, as measured using the pulse ionization chamber. Values of 222Rn varied from 0.0549 to 37.4770 Bq/l, with an average of 4.586 Bq/l. These values were below the maximum level of 100 Bq/l recommended by WHO and EU Directive/Euratom. With the exception of the sample from groundwater, the others showed 222Rn values below the maximum level of 11.1 Bq/l, as recommended by US EPA. In the case of impermeable soils, this radionuclide floats inside the cracks until it reaches the atmospheric air, so it is harmful to human health both in water and in the air. Evaluation of radon in water, in particular from groundwater sources becomes essential for the management of remedial solutions.

Detection of Virulence Genes and Biofilm Forming Capacity of Diarrheagenic E. coli Isolated from Different Water Sources

Diarrheagenic Escherichia coli (DEC) are associated with frequent incidences of waterborne infections and pose health risk to individuals who contact water for domestic or recreational uses. Detection of DEC pathotypes in drinking water can be used as an indicator of fecal contamination. This study aimed to investigate the occurrence of DEC pathotypes and their capacity to form biofilms in drinking water samples collected from different water sources. In this study, PCR analysis was used to determine the occurrence of four clinically significant virulence genes of diarrheagenic E. coli, eaeA (Enteropathogenic E. coli), stx1, stx2 (Enterohemorrhagic E. coli) and sth (Enterotoxigenic E. coli), in drinking water samples (n = 35) by using specific primers and conditions. PCR amplicons were visualized by using agarose gel electrophoresis. A total of 12/35 (34%) samples were detected as positive for at least one of the four DEC virulence genes and 11/12 (91%) E. coli isolates harbored virulence gene while 1/12 (8%) E. coli isolates harbored none. The eaeA and sth genes were the most detected genes (75%), while stx1 and stx2 genes were least detected genes (66%). Biofilm assay confirmed that ETEC pathotypes can cause damage in enteric walls by attaching and effacing to persist diarrheal conditions. This study indicated that drinking water of different sources is contaminated with potential DEC pathotypes and it can be a source of diarrheal diseases. The amplification of four virulence genes associated with DEC pathotypes (EPEC, EHEC and ETEC) in drinking water demonstrates that potentially virulent DEC pathotypes are distributed in water sources and may be a cause of health concern. There is, therefore, an urgent need to monitor DEC pathotypes in drinking water.

The health risk assessment of heavy metal concentration in drinking water samples from selected location of Kauru Local Government Area Kaduna State Nigeria

No Abstract.

A fast strategy to sequentially separate and determine 90Sr, 210Pb and 210Po in water samples using Sr resin

This study presents a rapid and novel sequential separation strategy based on extraction chromatography for determining 90Sr, 210Pb and 210Po in drinking water samples. It involves the use of Sr resin for the separation and then liquid scintillation counting and alpha spectrometry for the determination. The experimental results obtained showed that the proper acidic solution to quantitatively retain the aforementioned radionuclides is 3 M HNO3. The optimum eluents were determined for obtaining quantitative recoveries (70–80%) of 90Sr, 210Pb and 210Po. The method was validated with intercomparison water samples and is satisfactory in terms of minimum detectable activities, which are 50% lower than that established in RD 314/2016.

Iodine determination in mineral water using ICP-MS: method development and analysis of brands available in Israeli stores

Reliable iodine determination in drinking water samples has gained importance in the last few decades, mostly due to intensive use of both desalinized water that lacks several important nutritional elements, and bottled mineral water. ICP-MS is a sensitive, high-throughput method for iodine determination that must be performed under alkaline conditions because of the volatile nature of some iodine species. However, in water samples with high pH (>10), slow precipitation of calcium (Ca) and/or magnesium (Mg) carbonates leads to clogging of the ICP-MS nebulizer. We propose preventing this precipitation by adding the chelating agent ethylenediaminetetraacetic acid (EDTA) at 0.1% to a 2% ammonium hydroxide matrix. This concentration of EDTA sufficed for most drinking water samples studied, as long as a 1:1 molar ratio of EDTA to Ca+Mg concentration in the water was maintained. The limit of quantitation of the developed method for iodine was <0.1 µg L-1. The average iodine concentration in various brands of bottled mineral water sold in Israel was relatively low (7.67 ± 6.38 µg I L-1). Regular consumption of either desalinated water or bottled mineral water may induce iodine deficiency in Israeli consumers. Therefore, continuous follow-up of the iodine status in both tap and bottled water is strongly recommended.

Iodine determination in mineral water using ICP-MS: method development and analysis of brands available in Israeli stores

Reliable iodine determination in drinking water samples has gained importance in the last few decades, mostly due to intensive use of both desalinized water that lacks several important nutritional elements, and bottled mineral water. ICP-MS is a sensitive, high-throughput method for iodine determination that must be performed under alkaline conditions because of the volatile nature of some iodine species. However, in water samples with high pH (>10), slow precipitation of calcium (Ca) and/or magnesium (Mg) carbonates leads to clogging of the ICP-MS nebulizer. We propose preventing this precipitation by adding the chelating agent ethylenediaminetetraacetic acid (EDTA) at 0.1% to a 2% ammonium hydroxide matrix. This concentration of EDTA sufficed for most drinking water samples studied, as long as a 1:1 molar ratio of EDTA to Ca+Mg concentration in the water was maintained. The limit of quantitation of the developed method for iodine was <0.1 µg L-1. The average iodine concentration in various brands of bottled mineral water sold in Israel was relatively low (7.67 ± 6.38 µg I L-1). Regular consumption of either desalinated water or bottled mineral water may induce iodine deficiency in Israeli consumers. Therefore, continuous follow-up of the iodine status in both tap and bottled water is strongly recommended.

Ultra-portable, smartphone-based spectrometer for heavy metal concentration measurement in drinking water samples

Heavy metals are very toxic and hazardous for human health. Onsite screening of heavy metal contaminated samples along with location-based automation data collection is a tedious job. Traditionally high-end equipment’s such as gas chromatography mass spectrometer (GC–MS) and atomic absorption spectrometers have been used to measure the concentration of different heavy metals in water samples but most of them are costly, bulky, and time consuming, and requires expert human intervention. This manuscript reports an ultra-portable, rapid, cost-effective, and easy-to-use solution for onsite heavy metal concentration measurement in drinking water samples. Presented solution combines off-the-shelf available chemical kits for heavy metal detection and developed spectrometer-based readout for concentration prediction, quality judgment, and automatic data collection. Two chemical kits for copper and iron detection have been imported form Merck and have been used for overall training and testing. The developed spectrometer has capability to work with smartphone-based android app and also can work in standalone mode. The developed spectrometer uses white light-emitting diode as a source and commercially imported spectral sensor (AS7262) for visible radiation reception. A low-power sub-GHZ-based wireless embedded platform has been developed and interfaced with source and detector. A power management module also has been designed to monitor the battery status and also to generate low battery indication. Overall modules has been packaged in custom designed enclosure to avoid external light interference. The developed system has been trained using standard buffer samples with known heavy metal concentrations and further tested for water samples collected from institute colony and nearby villages. The obtained results have been validated with commercially imported system from HANNA instruments, and it has been observed that developed system has shown excellent accuracy to predict heavy metal concentration (tested for Fe and Cu) in water samples.

Actinobacillus pleuropneumoniae Surviving on Environmental Multi-Species Biofilms in Swine Farms

Actinobacillus pleuropneumoniae is the etiologic agent of porcine contagious pleuropneumonia, an important respiratory disease for the pig industry. A. pleuropneumoniae has traditionally been considered an obligate pig pathogen. However, its presence in the environment is starting to be known. Here, we report the A. pleuropneumoniae surviving in biofilms in samples of drinking water of swine farms from Mexico. Fourteen farms were studied. Twenty drinking water samples were positive to A. pleuropneumoniae distributed on three different farms. The bacteria in the drinking water samples showed the ability to form biofilms in vitro. Likewise, A. pleuropneumoniae biofilm formation in situ was observed on farm drinkers, where the biofilm formation was in the presence of other bacteria such as Escherichia coli, Stenotrophomonas maltophilia, and Acinetobacter schindleri. Our data suggest that A. pleuropneumoniae can inhabit aquatic environments using multi-species biofilms as a strategy to survive outside of their host.