Untreated Water Samples Research Articles

Genotyping of Cryptosporidium spp. in environmental water in Turkey.

This research was undertaken to study the molecular detection and characterization of Cryptosporidium spp. in environmental water sources at Samsun and Giresun Provinces of The Black Sea in Turkey. Two-hundred forty and one-hundred eighty environmental samples were collected from a total of twenty and twenty-five sampling sites of Giresun and Samsun Provinces. One hundred twenty untreated drinking water samples were also detected for Cryptosporidium spp. in both investigated areas. 101 (%42), 92 (%38.3) of 240 and 74 (41.1%), 70 (38.8%) of 180 environmental samples have been found positive for Cryptosporidium spp. by Loop mediated isothermal amplification (LAMP) targeting the S-adenosyl-L-methionine synthetase (SAM) gene and nested PCR targeting small subunit (SSU)rRNA gene in Samsun and Giresun Provinces, respectively. Of the tested untreated drinking water samples collected from the investigated area, one sample was positive for Cryptosporidium spp. Six and twelve samples were clearly sequenced for the Cryptosporidium (SSU)rRNA gene among the highest positive samples selected from each of the twenty and twenty-five sampling sites of Giresun and Samsun Provinces, respectively. Genetic characterization of Cryptosporidium isolates from water samples represented Cryptosporidium bovis for five samples, Cryptosporidium parvum for six samples and one sample for Cryptosporidium felis in Samsun Province, where C. parvum for five samples and C. bovis for one sample were sequenced in Giresun Province. According to accessible information sources, this is the first research about genotyping of Cryptosporidium spp. in water samples collected from Samsun and Giresun Provinces of Turkey.

Bioremediation of different types of polluted water using microalgae

The present investigation was attempted to reduce the toxic pollutants from the different mixtures of water samples (sewage, sea and well) using the freshwater alga, Chlorella vulgaris and the marine alga Chlorella salina. The results revealed that both algae species were highly efficient and having a potential to reduce pH, total dissolved solids (TDS), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrate, ammonia, phosphate, sulphate, calcium, magnesium, sodium, potassium, heavy metals (Zn, Cu, Mn, Ni, Co, Fe and Cr) and the number of total Coli-form bacteria after 10 days of treatment compared to the untreated water samples. The removal efficiency of heavy metals was 13.61–100 %. In general, C. vulgaris shows higher removal efficiency in most of parameters than C. salina.

Highly selective and sensitive fluorescent chemosensor for femtomolar detection of silver ion in aqueous medium

The chemical sensing for the trace level detection of silver ion in aqueous solution still remains a challenge using simple, rapid, and inexpensive method. We report that thionine can be used as a fluorescent probe for the detection of Ag+ ion. The successive addition of Ag+ ion to the solution containing thionine quenches (turns-off) the fluorescence intensity of thionine. Association and quenching constants have been estimated by the Benesi–Hildebrand method and Stern–Volmer plot, respectively. From the plot, the nature of the fluorescence quenching was confirmed as static quenching. An important feature of our chemosensor is high selectivity towards the determination of silver ion in aqueous solution over the other competitive metal ions. The detection limit of the sensor achieved 5fM for Ag+ ion, which is superior to all previously reported chemosensors. The NMR and FT-IR studies were also carried out to support the complex formation between thionine and Ag+ ion. The practicality of the proposed chemosensor for determination of Ag+ ion was carried in untreated water samples.

Drinking water safety in recreational parks in northern New South Wales, Australia

The objective of this study was to assess whether the drinking water supplies in northern New South Wales (NSW) recreational parks conformed to the recommendations of the NSW Private Water Supply Guidelines. Water supplies in 57 recreational parks were surveyed to assess implementation of the Guidelines. A random sample of five parks (excluding reticulated town water supply or rainwater) was selected for microbiological sampling over a 12-month period. Additional nine samples were collected from carted water supplies. Forty-four of the 57 water supplies were untreated. Escherichia coli was detected in 16 of 59 monthly samples. Two of 36 treated water samples showed contamination by E. coli compared to 14 of 23 untreated water samples. Three of nine carted water supplies had E. coli at initial sampling. Thirty-four supplies had warning signs posted somewhere in the park. Twenty-one drinking water tanks had evidence of physical deterioration. No supply had a risk-based drinking water management plan. Treated water supplies had lower rates of E. coli detection and presented a lower risk than untreated water supplies. Survey and sampling results indicated the need for reviewing existing water quality warning signs in the recreational parks and implementation of risk-based drinking water management plans.

Inactivation of Phytoplankton in Ship’s Ballast Water by Pulsed Electric Field and Thermal Treatment

Invasive aquatic species discharged through ship ballast water is one of the most serious problems posed nowadays in the marine environment. The effect of inactivation of phytoplankton by pulsed electric field and thermal treatment was studied. Effect factors such as pulsed voltage, electrode gap, pulse width and preheating temperature were explored, and its mechanism of inactivation was analyzed. The combined effect of mild thermal and PEF treatments was shown to give more effective damage of phytoplankton than application of PEF treatment alone. The untreated ballast water sample pretreated at moderate temperature (323 K) and moderate PEF (E ≈10kV/cm) showed a noticeable enhancing of inactivation.

Status of some trace elements in water samples from University of Ilorin Campus

This study was carried out to monitor the quality of the drinking water in University of Ilorin (UNILORIN) main Campus. Water samples were collected from seven different sources within the University Main Campus, which include a ground water (borehole), untreated surface water and tap water (treated surface water). The metals investigated were Copper (Cu), Manganese (Mn), Zinc (Zn), Iron (Fe) and Lead (Pb). Total Cu concentration ranged from 0-0.04 mg/L, total iron concentration from 0.12-3 mg/L and Zinc concentration from 0.02-35 mg/L. Manganese concentration was within the range of 0.2-3.8 mg/L. No trace of Lead was discovered in the water samples.  The Zn value for most samples was below WHO and the Nigerian Standards of 3 mg/L. The ground water sample was found to be the least polluted, thereby making it suitable for drinking. The treated water samples were also within the laid down limits, with a minimal level of pollution while the untreated surface water sample was recorded as the most polluted water sample and unfit for drinking.

Cryptosporidium spp. and Giardia duodenalis as pathogenic contaminants of water in Galicia, Spain: the need for safe drinking water.

The objectives of this cross-sectional study were to detect the presence of Cryptosporidium spp. and Giardia duodenalis in drinking water treatments plants (DWTPs) in Galicia (NW Spain) and to identify which species and genotype of these pathogenic protozoans are present in the water. Samples of untreated water (surface or ground water sources) and of treated drinking water (in total, 254 samples) were collected from 127 DWTPs and analysed by an immunofluorescence antibody test (IFAT) and by PCR. Considering the untreated water samples, Cryptosporidium spp. were detected in 69 samples (54.3%) by IFAT, and DNA of this parasite was detected in 57 samples (44.8%) by PCR, whereas G. duodenalis was detected in 76 samples (59.8%) by IFAT and in 56 samples (44.0%) by PCR. Considering the treated drinking water samples, Cryptosporidium spp. was detected in 52 samples (40.9%) by IFAT, and the parasite DNA was detected in 51 samples (40.1%) by PCR, whereas G. duodenalis was detected in 58 samples (45.6%) by IFAT and in 43 samples (33.8%) by PCR. The percentage viability of the (oo)cysts ranged between 90.0% and 95.0% in all samples analysed. Cryptosporidium andersoni, C. hominis, C. parvum and assemblages A-I, A-II, E of G. duodenalis were identified. The results indicate that Cryptosporidium spp. and G. duodenalis are widespread in the environment and that DWTPs are largely ineffective in reducing/inactivating these pathogens in drinking water destined for human and animal consumption in Galicia. In conclusion, the findings suggest the need for better monitoring of water quality and identification of sources of contamination.

Evaluation of A Point-Of Use Water Purification System (Llaveoz) in a Rural Setting of Chiapas, Mexico

Access to potable water is a priority for highly-marginalized rural communities of Chiapas, Mexico where consumption of poorly sanitized water has fostered severe diarrheal diseases among children. Interventions aimed to reduce contaminants present in water are necessary to reduce morbidity and mortality rates. In this work we evaluated the efficiency of a point of use water purification system, Llaveoz, to eradicate total coliform (TC) bacteria and diarrheagenic E. coli (DEC) strains in 62 paired water samples obtained from households during the dry and rainy season. TC was determined by the membrane filtration method whereas DEC strains were evaluated by a multiplex PCR approach. After Llaveoz treatment, water samples collected during the dry season (N=20) had an 80.3% reduction of TC counts (p<0.05). Similarly, TC were significantly reduced (72.3%, (p<0.05)) in water samples treated during the rainy season (N=42). A total of 28 E. coli strains were isolated of which 14.3% (N=4) were identified as DEC strains (ETEC (N=2), EAEC (N=1) or EIEC (N=1)) in untreated water samples. Llaveoz-treated water did not contain DEC strains. Thus, the Llaveoz system represents an alternative method to obtain more pure water in regions where potable water sources are not available.

An evaluation of the effect of four herbicides on some aquatic organisms

Studies were carried out on the effect of four commonly used herbicides (2,4-D atrazine, atrazine + metolachlor and paraquat) on some aquatic organisms in simulated aquatic ecosystem at 100 ppm, 150 ppm and 200 ppm of the herbicides active ingredients (ai). The effects of the herbicides on pH, blue-green alga – Aphanocapsa sp, aquatic weed – Lemna sp, tadpole ( Bufo regularis ) and bacterial species were investigated. While 2,4-D resulted in significant decreases in pH value; paraquat resulted in significant increases (p < 0.05). Atrazine and atrazine + metolachlor treatments impacted the most on the lysis of Aphanocapsa sp as all the cells were lysed at 2 days after application. Paraquat treatments at all concentrations resulted in the death of all (20) tadpoles at 2 days after application. Complete tadpole death in atrazine + metolachlor was observed at 8 days after application at 150 ppm and at 12 days after application at 100 ppm. A general decrease in bacterial counts relative to concentrations and days of treatment was observed with paraquat impacting the most on decreases in bacterial counts. Bacterial species isolated from untreated water samples (control) included- Proteus sp, Enterobacter aerogenes, E. coli, Bacillus sp, Pseudomanas sp, Citrobacte r sp, Staphylococcus aureus and Flavobacterium sp; while Bacillus (41.2%) and Pseudomonas (56.3%) species were the most frequently isolated bacteria from herbicide treated water samples after 14 days of treatment. Conclusively, herbicides from agricultural run-offs can impair the normal balance of the flora and fauna of the aquatic ecosystem. Keywords: Herbicides, aquatic ecosystem, pH, bacteria

Graphene quantum dots and the resonance light scattering technique for trace analysis of phenol in different water samples

A novel, highly selective resonance light scattering (RLS) method was researched and developed for the analysis of phenol in different types of industrial water. An important aspect of the method involved the use of graphene quantum dots (GQDs), which were initially obtained from the pyrolysis of citric acid dissolved in aqueous solutions. The GQDs in the presence of horseradish peroxidase (HRP) and H2O2 were found to react quantitatively with phenol such that the RLS spectral band (310nm) was quantitatively enhanced as a consequence of the interaction between the GQDs and the quinone formed in the above reaction. It was demonstrated that the novel analytical method had better selectivity and sensitivity for the determination of phenol in water as compared to other analytical methods found in the literature. Thus, trace amounts of phenol were detected over the linear ranges of 6.00×10−8–2.16×10−6M and 2.40×10−6–2.88×10−5M with a detection limit of 2.20×10−8M. In addition, three different spiked waste water samples and two untreated lake water samples were analysed for phenol. Satisfactory results were obtained with the use of the novel, sensitive and rapid RLS method.

Removal of halogenated by-products precursors in photocatalysis process enhanced with membrane filtration

In the article, the results of the research on removal of halogenated by-products precursors in a photocatalysis (PC) process enhanced with membrane filtration have been presented. In the research, the following by-products were analyzed as follows: trihalomethanes (trichloromethane, bromodichloromethane, dibromochloromethane, tribromomethane), haloacetic acids (monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, bromochloroacetic acid, dibromoacetic acid, trichloroacetic acid), haloacetonitriles (bromochloroacetonitrile, dibromoacetonitrile, dichloroacetonitrile, trichloroacetonitrile), haloketones (1,1-dichloro-2-propanone, 1,1,1-trichloro-2-propanone), chloropicrin, and chloral hydrate. The analyses were conducted on the model solutions of humic and fulvic acids and also on the samples of surface water taken from the Goczalkowice Reservoir. These water samples were treated in a sequence of PC and membrane filtration. The PC process was conducted using TiO2 and low-pressure monochromatic UV lamps. The samples of untreated water and the one obtained as a result of those processes were chlorinated with sodium hypochlorite in a dose which resulted in 3–5 mg/L of free chlorine after 24 h. After that time, the formed chlorination by-products were analyzed with gas chromatography, and the formation potential was calculated for each considered group of halogenated organic compounds.

A fast fluorescence imaging flow cytometer for phytoplankton analysis

We report a fast fluorescence imaging flow cytometer for phytoplankton analysis that can achieve a volume flow rate up to 1ml/min. The instrument shows a high immunity to motion blur in image captured with a lateral resolution of 0.75 ± 0.06 μm for a wide size range ~1 μm to ~200 μm. This is made possible by suppressing the out-of-focus light using thin light sheet illumination and image deconvolution, and by precluding the motion-blur with a unique flow configuration. Preliminary results from untreated coastal water samples show the technique has high potential as a practical field instrument for monitoring phytoplankton abundance and species composition.

Outcompeting GC for the detection of legacy chlorinated pesticides: online-SPE UPLC APCI/MSMS detection of endosulfans at part per trillion levels

Endosulfan, the last remaining organochlorine pesticide, has been the subject of a number of international regulations and restriction/banning action plans worldwide. Occurrence of endosulfan residues in South Florida environments has been widely described in the literature for more than two decades. This work describes a selective, sensitive, and fast online solid-phase extraction (SPE) method coupled with liquid chromatography separation and tandem mass spectrometry (LC-MS/MS) for the determination of endosulfan isomers and endosulfan sulfate in water samples at low part per trillion levels with very little sample preparation. A negative atmospheric pressure chemical ionization source was carefully optimized to produce reproducible spectra of the target compounds with no adduct ion formation. Selected reaction monitoring transitions were monitored and quantitation was performed against a per-deuterated internal standard β-endosulfan (d4). The automated online SPE clean-up was performed using only 20mL of untreated water sample prior to LC-MS/MS analysis. The method was capable of separating and quantifying endosulfan within a 24-min run using acetonitrile and water as mobile phases and presenting statistically calculated method detection limits of 3, 10, and 7ng/L for endosulfan sulfate, α-endosulfan, and β-endosulfan, respectively. In addition, a QuEChERS method was successfully developed and applied for endosulfan determination in sediments/soils, floating and submerged algal mats, and small fish. Minimal matrix effects were observed in all matrices analyzed and recoveries for all analytes ranged from 50-144%. The developed methodology was applied to monitor the occurrence and to assess the potential transport of endosulfan in the Loveland Slough watershed, an area adjacent to Everglades National Park showing long-term contamination with endosulfans.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) in mineral water and tap water

The aims of the present study were to determine PFAS (perfluoroalkyl and polyfluoroalkyl substances) concentrations in various sources of water intended for human consumption, use these data to calculate the possible uptake via water as well as to estimate the water related health risk to consumers. A total of 177 water samples (119 mineral waters, 26 tap water samples, 18 spring water samples and 14 raw (untreated) water samples) were analyzed using liquid chromatography tandem mass spectrometry for the presence of 10 or 19 PFASs, respectively. PFAS concentrations above the limit of detection of 1 ng/L were found in 52% of all samples. Short-chain PFASs with less than 8 carbon atoms were responsible for 58% of the total PFAS contamination. The highest concentration (sum of PFASs) of 42.7 ng/L was detected in tap water. The calculated maximum uptake of both components for which a tolerable daily intake (TDI) level exists were 0.17 ng/kg bodyweight/day for PFOS (perfluorooctane sulfonic acid) and 0.21 ng/kg bodyweight/day for PFOA (perfluorooctane carboxylic acid). In regard to the model calculations made here (TDI for adults and for infants), the uptake of PFOS and PFOA via consumption of water can be considered negligible. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Environmental Science and Health, Part A to view the supplemental file.

Unknown Quantity: Regulating Radionuclides in Tap Water

Radioactivity surrounds us; each day we are exposed to a certain amount by virtue of being alive on planet Earth. Some of this exposure comes from radioactive substances (radionuclides) that occur naturally in a wide variety of geologic and soil formations. Occasionally these naturally occurring substances become more concentrated or accessible through human activities such as mining and nuclear energy production, resulting in greater potential for exposure than their original natural occurrence would suggest. Other radionuclides are artificially created. Residents in almost all parts of the United States live on lands that contain minor to substantial concentrations of radionuclides of one type or another.1 These substances often make their way into tap water, leading to exposures by ingestion, inhalation, or dermal pathways during showering or other contact with the water. Although radionuclides are widespread, there are large gaps in our knowledge about sources of these materials, their distribution, associated health risks, and mitigation measures. However, the information we do have suggests that current drinking water standards for radionuclides established by the U.S. Environmental Protection Agency (EPA) may not adequately protect health. The EPA is set to review these standards relatively soon, and the next two years are prime time for filling in numerous information gaps and doing other legwork to make sure the review is as well informed as possible.

Pollution Trees: Identifying Similarities among Complex Pollutant Mixtures in Water and Correlating Them to Mutagenicity

There are relatively few tools available for computing and visualizing similarities among complex mixtures and in correlating the chemical composition clusters with toxicological clusters of mixtures. Using the "intersection and union ratio (IUR)" and other traditional distance matrices on contaminant profiles of 33 specific water samples, we used "pollution trees" to compare these mixtures. The "pollution trees" constructed by neighbor-joining (NJ), maximum parsimony (MP), and maximum likelihood (ML) methods allowed comparison of similarities among these samples. The mutagenicity of each sample was then mapped to the "pollution tree". The IUR-distance-based measure proved effective in comparing chemical composition and compound level differences between mixtures. We found a robust "pollution tree" containing seven major lineages with certain broad characteristics: treated municipal water samples were different from raw water samples and untreated rural drinking water samples were similar with local water sources. The IUR-distance-based tree was more highly correlated to mutagenicity than were other distance matrices, i.e., MP/ML methods, sampling group, region, or water type. IUR-distance-based "pollution trees" may become important tools for identifying similarities among real mixtures and examining chemical composition clusters in a toxicological context.

Chemical mixtures in untreated water from public-supply wells in the U.S. — Occurrence, composition, and potential toxicity

Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources.

Microbiologic quality of an untreated water sample analyzed by a novel DNA chip for simultaneous detection of microorganisms

Consumption of contaminated drinking water heavily contributes to the burden of gastrointestinal waterborne diseases. Conventional detection methodologies present several shortcomings, such as indirect measure of indicator species, low throughput and time consume. DNA chips have the potential to serve as surveillance systems for the simultaneous detection of pathogens overcoming these limitations. We have developed a DNA chip for simultaneous detection of multiple waterborne pathogens. Species specific DNA probes were implemented on a microarray, for microorganism detection. Present study reports the results of one untreated water sample analyzed by conventional methods and by the DNA chip. The results were concordant for the mandatory organisms (total coliforms, &lt;em&gt;Escherichia coli&lt;/em&gt;, fecal enterococci) using both methods, reinforcing the utility and proof-ofconcept of the DNA chip. However, it is necessary a prior enrichment in a culture medium in order to obtain a positive signal using the DNA chip. The DNA chip may be a valuable distinctive tool for waterborne pathogens detection

Determining the Maximum Cumulative Ratios for Mixtures Observed in Ground Water Wells Used as Drinking Water Supplies in the United States

The maximum cumulative ratio (MCR) developed in previous work is a tool to evaluate the need to perform cumulative risk assessments. MCR is the ratio of the cumulative exposures to multiple chemicals to the maximum exposure from one of the chemicals when exposures are described using a common metric. This tool is used to evaluate mixtures of chemicals measured in samples of untreated ground water as source for drinking water systems in the United States. The mixtures of chemicals in this dataset differ from those examined in our previous work both in terms of the predicted toxicity and compounds measured. Despite these differences, MCR values in this study follow patterns similar to those seen earlier. MCR values for the mixtures have a mean (range) of 2.2 (1.03–5.4) that is much smaller than the mean (range) of 16 (5–34) in the mixtures in previous study. The MCR values of the mixtures decline as Hazard Index (HI) values increase. MCR values for mixtures with larger HI values are not affected by possible contributions from chemicals that may occur at levels below the detection limits. This work provides a second example of use of the MCR tool in the evaluation of mixtures that occur in the environment.

High prevalence of enteric viruses in untreated individual drinking water sources and surface water in Slovenia

Waterborne infections have been shown to be important in outbreaks of gastroenteritis throughout the world. Although improved sanitary conditions are being progressively applied, fecal contaminations remain an emerging problem also in developed countries. The aim of our study was to investigate the prevalence of fecal contaminated water sources in Slovenia, including surface waters and groundwater sources throughout the country. In total, 152 water samples were investigated, of which 72 samples represents groundwater from individual wells, 17 samples from public collection supplies and 63 samples from surface stream waters. Two liters of untreated water samples were collected and concentrated by the adsorption/elution technique with positively charged filters followed by an additional ultracentrifugation step. Group A rotaviruses, noroviruses (genogroups I and II) and astroviruses were detected with real-time RT-PCR method in 69 (45.4%) out of 152 samples collected, of which 31/89 (34.8%) drinking water and 38/63 (60.3%) surface water samples were positive for at least one virus tested. In 30.3% of drinking water samples group A rotaviruses were detected (27/89), followed by noroviruses GI (2.2%; 2/89) and astroviruses (2.2%; 2/89). In drinking groundwater samples group A rotaviruses were detected in 27 out of 72 tested samples (37.5%), genogroup I noroviruses in two (2.8%), and human astroviruses in one (1.4%) samples. In surface water samples norovirus genogroup GII was the most frequently detected (41.3%; 26/63), followed by norovirus GI (33.3%; 21/63), human astrovirus (27.0%; 17/63) and group A rotavirus (17.5%; 11/63). Our study demonstrates relatively high percentage of groundwater contamination in Slovenia and, suggests that raw groundwater used as individual drinking water supply may constitute a possible source of enteric virus infections. In the future, testing for enteric viruses should be applied for drinking water sources in waterborne outbreaks.