Running Water Samples Research Articles

Electrolysis‐Mediated Rapid Synthesis of Highly Fluorescent and pH Responsive Congo Red Carbon Nanodots for Cu2+ Sensing

AbstractCopper ion (Cu2+) is a highly toxic environmental pollutant with bioaccumulative properties, making its rapid and selective detection important for environmental and health monitoring. In this study, highly fluorescent carbon nanodots by the electrolysis of Congo Red are developed, which are denoted as CR‐CDs and exhibit high quantum yield and pH‐responsive character. The pH response behavior is applied for pH test in soft drinks with high accuracy. Cu2+ causes dramatic fluorescence quenching due to the formation of cupric amine complex and the occurrence of inner filter effect. The signal changes in fluorescence spectroscopy allow a detection limit of Cu2+ at 0.13 μM. The response is highly specific toward Cu2+ over other metal ions. In addition, the practicability of the sensor is validated by accurate Cu2+examination in running water samples.

Detection and Genotyping of Toxoplasma gondii in the Environmental matrices (Soil and Water) in Gaza-Palestine

BACKGROUND AND AIM: The aim of the present study was to detect the prevalence as well genotyping of T. gondii oocysts, which is the environmental infectious stage, in Gaza- Palestine. METHODS: For this purpose, 290 environmental samples were collected for T. gondii oocysts detection and genotyping through the use of sheather’s solution and PCR techniques. More specifically, soil samples were collected from five sites, which were Wadi-Gaza, Near trash dumpsters, residential house yards, open-air markets, public squares and gardens. RESULTS: The results of the present study revealed that from the 290 environmental samples, 22 (7.58%) and 31 (10.68%) were contaminated with T. gondii oocyst according to the test methods of PCR and Sheather’s solution, respectively. The highest rate of contamination detected was from samples collected from residential house yards, while public squares and gardens represented the lowest rate. Moreover, 26 (13%) from the 200 soil samples pool were contaminated according to the Sheather’s solution method, while under the PCR, 18 (9.99%) samples were contaminated. Regarding the prevalence of contamination in water samples, only samples collected from Wadi-Gaza reported contamination levels. CONCLUSIONS: The present study revealed that the contamination of T. gondii oocyst in soil is higher than water. The highest rate of soil contamination detected were from samples collected from residential house yards, while public squares and gardens represented the lowest rate. On another hand, the contaminated water samples are only from running water samples collected from Wadi- Gaza, while water which collected from other sources are free of contamination. Finally, this study concluded that all samples that were genotyped belong to T. gondii type I. It is recommended that the Gaza Municipality should take measure towards the sanitation of the contaminated sites. KEY WORDS : Toxoplasma gondii – oocysts – Environment – Soil- Water – PCR- Sheather’s - Gaza

An ultrahigh‐throughput screening platform based on flow cytometric droplet sorting for mining novel enzymes from metagenomic libraries

Uncultivable microbial communities provide enormous reservoirs of enzymes, but their experimental identification by functional metagenomics is challenging, mainly due to the difficulty of screening enormous metagenomic libraries. Here, we propose a reliable and convenient ultrahigh-throughput screening platform based on flow cytometric droplet sorting (FCDS). The FCDS platform employs water-in-oil-in-water double emulsion droplets serving as single-cell enzymatic micro-reactors and a commercially available flow cytometer, and it can efficiently isolate novel biocatalysts from metagenomic libraries by processing single cells as many as 108 per day. We demonstrated the power of this platform by screening a metagenomic library constructed from domestic running water samples. The FCDS assay screened 30 million micro-reactors in only 1 h, yielding a collection of esterase genes. Among these positive hits, Est WY was identified as a novel esterase with high catalytic efficiency and distinct evolutionary origin from other lipolytic enzymes. Our study manifests that the FCDS platform is a robust tool for functional metagenomics, with the potential to significantly improve the efficiency of exploring novel enzymes from nature.

Assessment of the Virological Quality of Marine and Running Surface Waters in NW Greece: A Case Study.

The virological quality of surface marine and running water samples collected from Igoumenitsa gulf and Kalamas river (NW Greece) was assessed from October 2012 to September 2013. Sampling sites were exposed to different land and/or anthropogenic effects. Seawater samples were collected monthly from five sampling stations (new harbor, old harbor, wastewater treatment plant outlet, protected Natura area, Drepano beach). Viral targets included human adenoviruses (hAdVs), as index human viruses, while noroviruses (NoVs) and hepatitis A virus (HAV) were also studied. Kalamas river samples were collected seasonally, from three sampling stations (Soulopoulo, Dam, Sagiada-estuaries), while viral targets included also porcine adenoviruses (pAdVs) and bovine polyoma viruses (bPyVs), as additional index viruses. All water samples were analyzed for standard bacterial indicators, as well. Physicochemical and meteorological data were also collected. Based on the standard bacterial indices, both sea and river water samples did not exceed the limits set according to Directive 2006/7/EU. However, positive samples for hAdVs were found occasionally in all sampling sites in Igoumenitsa gulf (23.3%, 14/60) showing fecal contamination of human origin. Moreover, HAV was detected once, in the sampling site of the old port (at 510 GC/L). Most of the Kalamas water samples were found positive for hAdVs (58.3%, 7/12), while human noroviruses GI (NoVGI) (8.3%, 1/12) and GII (NoVGII) (16.7%, 2/12) were also detected. HAV, pAdVs, and bovine polyomaviruses (bPyVs) were not detected in any of the analyzed samples. No statistically significant correlations were found between classic bacterial indicators and viral targets, nor between viruses and meteorological data. Overall, the present study contributed to the collection of useful data for the biomonitoring of the region, and the assessment of the overall impact of anthropogenic activities. It provided also valuable information for the evaluation of the risk of waterborne viral infections and the protection of public health. It was the first virological study in the area and one of the few in Greece.

Epidemiological investigation of the village with iodine in drinking water on Qianbian village and the adjacent villages in Xiamen city,Fujian province in 2008

Objective To investigate the current conditions of water iodine,childrens'iodine nutrition and residents'edible circumstance of iodized salt in the villages with high iodine in drinking water and the adjacent three villages in Xiamen city of Fujian province.Methods Four natural villages of Qianbian,Donglian,Dazhong and Dongshan of Xiangan county were chosen as survey spots in 2008.In each village,one running water sample and all well water samples were collected to obtain the benchmark for each location.All children aged 7-13 year in the four villages underwent thyroid palpation and were selected to measure the urine iodine and the salt iodine.The water iodine and urine iodine were determined by As3+-Ce4+ catalytic spectrophotometry digestion,salt iodine was determined by direct titration.Results In four investigated villages,iodine of four running water samples were all 1.5μg/L.The range of 237 well water iodine samples was from 0.1 μg/L to 506.0 μg/L.There were 18.6% (44/237)specimens in which the well water iodine less than 10 μg/L,73.4%(174/237)between 10 μg/L and 150 μg/L and 8%(19/237)more than 150μg/L.The median of urinary iodine was 153.3 μg/L in 79 urine samples,which was 114%(9/79)more than 200μg/L and less than 300μg/L,12.7%(10/79)equal or more than 300 μg/L and less than 500μg/L,7.6%(6/79)equal or more than 500μg/L and less than 800 μg/L in all samples.Seventy-nine students were examined by palpation and the total goiter rate of children measured was 11.4% (9/79).Seventy-one samples of iodine salt were detected and the coverage rate of iodized salt was 77.5%(55/71).Conclusions The well water iodine contents have a wide distribution in the investigated villages.We should enhance the community awareness by educating them on the damage of iodine excess and iodine deficiency. Key words: Water; Iodine; Urine; Epidemiology

The bioassessment of fish and macroinvertebrates in a Mediterranean–Atlantic climate: Habitat assessment and concordance between contrasting ecological samples

Abstract Human intervention and drought conditions in Mediterranean rivers may necessitate the collection of organisms from a different habitat type to that specified by the original bioassessment protocol; it is therefore critical to understand the consequences of adaptive sampling strategies in these lotic systems. In a survey of 31 streams (2nd–4th order) in northern Portugal we collected separate macroinvertebrate samples from running-water and standing-water habitats and fish samples from a delineated reach, inclusive of all habitat types. In addition to collecting habitat data specific to macroinvertebrates and fish we conducted a generalized River Habitat Survey (RHS) and derived scores designed to report habitat quality and habitat degradation. Ecological data were described in terms of taxonomic structure, functional organization and by biotic indices and interpreted in relation to habitat data, comparing samples within and between sites for concordance. Macroinvertebrates from respective habitats differed in their relationship with habitat variable with running-water samples more strongly related to substrate and water quality and standing-water samples more strongly reflecting habitat characteristics at the reach scale. Running- and standing-water samples from the same-site varied widely, indicating that substituting standing-water for running-water samples in macroinvertebrate-based bioassessment carries a high risk of misclassification. However, a consistent bias in index scores suggests that a habitat-adjusted interpretation of biotic indices could be employed to improve measurement precision. Variation in key parameters of the fish community corresponded to changes in water quality and habitat structure and to reach-scale features recorded by the RHS. Trends between macroinvertebrate and fish measurements indicated common patterns for oxygen/flow sensitive taxa and for trophic organization that were related to similar habitat preferences. Whilst macroinvertebrates demonstrated no relationship with derived scores of habitat quality, the fish-based Index of well-being (Iwb) was strongly related to the Habitat Modification Score. Overall these data indicate how different ecological samples can be used to focus on different aspects of habitat quality and are suggestive of strategies for both the collection and interpretation of ecological data that would improve assessment performance. This study emphasizes the need to adapt assessment methods not only to the species pool but also to the differences in the managed and natural habitat characteristics of these types of Mediterranean streams.

Properties of in situ Escherichia coli -D-glucuronidase (GUS): evaluation of chemical interference on the direct enzyme assay for faecal pollution detection in water

A study of the activity of Escherichia coli
-D-glucuronidase (GUS) in polluted stagnant and running water samples was performed with an objective of assessing the viability of a direct marker enzyme assay as a suitable alternative to membrane filtration for the indication of faecal pollution in water intended for drinking purposes. The effects of temperature, pH and the presence of different ions on enzyme activity were investigated. GUS exhibited optimal activity at 40oC over a broad pH range (5-9). In general, CO3 2- (as Na2CO3), Cl- (NaCl) and NO3 - (KNO3) increased GUS activity, while ferric chloride (FeCl3), OCl- (as NaOCl) and ferulic acid were inhibitory. However, the enzymatic response to these effectors differed with the source of the sample. Therefore, when these compounds are present in water intended for drinking purposes they can either exaggerate or give false negatives with regards to GUS activity. Environmental GUS properties are different from those of the commercially available (and pure) E. coli GUS. This helps to explain difficulties encountered in applying laboratory methods (developed through seeding of pure water samples with pure enzymes and cultures) to environmental analyses.

Seasonal variations in the occurrence of environmental mycobacteria in potable water.

A fluctuation in the prevalence of environmental mycobacteria in relation to nutritional conditions in nature has been repeatedly described in the literature. A seasonal difference in the potable water supply system has not yet been documented. Potable water samples from the supply systems of 16 identical localities were analyzed. Samples of running water and tap swabs or tap scrapings were collected twice a year, in the spring and in the autumn. The samples were processed as stipulated by the international standards. McNemar's test was used to analyze the difference in the occurrence of environmental mycobacteria between the vernal and the autumnal samples. A significant change in the presence of environmental mycobacteria in the potable water supply system was observed, the vernal samples yielding more positive results. This finding supports other observations respecting surface water. We suggest that this effect on the potable water supply system may be caused by the change in temperature. Contamination rates were similar, with no statistically significant differences between running water samples and those from swabs or scrapings. No time trend in the period 1984-1989 respecting the prevalence of mycobacteria was detected. Direct microscopy showed massive colonization with environmental mycobacteria of the potable water supply system. The public health consequences of these findings should be further evaluated, as colonization of water pipes can be associated with outbreaks of mycobacterial disease in immunocompromised patients. There has also been an increase in the incidence of mycobacterioses in the North Moravian region in recent years.

Effect of plumbing systems on lead content of drinking water and contribution to lead body burden

Stable lead isotopes and lead contents in drinking water from a number of Australian cities have been measured to determine the contribution of drinking water to body burden. Lead contents are generally < 2 μg/l and thus contribute an insignificant amount to the lead budget in humans in Australia. First-flush and running water samples taken at intervals of up to 10 min show that equilibrium is reached within 1 min or ∼ 10 1 by volume. There is, however, large variability in both lead content and isotopic composition within the first minute which brings into question the reliability of the recommended sampling time of 30 s. Extremely large isotopic differences between individual dwellings within the one city and between dwellings and the storage tanks for the water supply are attributed to differences in lead residing in the plumbing within the dwellings, usually from lead solder in brass fittings. Isotopic analysis of solder and water from two dwellings confirm this relationship.

Degradation of softwood [14C lignin] lignocelluloses and its relation to the formation of humic substances in river and pond environments

The fate of lignin in water and sediment of the Garonne river (France) and of a pond in its floodplain was examined using specifically labeled [14C-lignin] lignocelluloses. No significant differences appeared in the mineralization rate of alder, poplar or willow [14C-lignin] in running water samples. Conversion of total radioactivity to 14CO2 ranged between 18.7% and 24.4% after 120 days of incubation. Degree of 14C-labeled lignin mineralization in standing water and sediments was clearly lower, especially in submerged sediments, and was correlated with oxygen supply. After 60 days of incubation 3.3% to 7.9% of the 14C-labeled lignin was recovered in water samples as dissolved organic carbon originating from microbial metabolism. In water extracts from sediment the percentage of dissolved organic 14C was only 0.4% to 1.3% of the applied activity. In the humic fraction extracted from sediments it did not exceed 4.4% which was much lower than in soils. No significant difference appeared between river and pond conditions for humic substances formation.

Quality of drinking water in the Aligarh Muslim University Campus, Aligarh, U.P. (India) with respect to heavy metals

The physico-chemical characteristics of the drinking water in nine residential halls of the Aligarh Muslim University, Aligarh, U.P. (India), were studied. Nine samples each of running and standing water were taken four times over a period of one month at weekly intervals from all of the residential halls and were analysed for physico-chemical characteristics and heavy metal contents. The temperature, pH and electrical conductivity of water samples ranged between 20.0-26.0°C; 7.00-8.00 and 116.00-199.04 micromhos cm(-1) respectively whereas the values of total alkalinity, total hardness, Cl(-), SO 4 (-) , F(-), NH3-N, NO2-N; NO3-N were found between 261.00-396.00; 128.00-200.00; 8.00-69.00; 12.00-46.00; 0.90-1.35; 0.20-0.44; ND; 1.60-6.50 mg l(-1) respectively. The ranges of heavy metal concentrations in the running water samples were as follows: Cd (0.70-3.75); Cr (ND-5.00); Co (9.50-18.75); Cu (0.75-15.00); Fe (ND-13.50); Mn (3.50-51.00); Ni (7.00-17.50); Pb (0.50-2.50) and Zn (10.00-176.50) μg l(-1). The heavy metal concentrations in standing water samples were found to be: Cd (1.20-4.90); Cr (ND-10.00); Co (10.25-19.00); Cu (1.75-20.00); Fe (ND-18.00); Mn (5.00-66.50); Ni (8.75-19.75); Pb (0.75-5.50) and Zn (28.60-364.00) μg l(-1). The concentrations of heavy metals in drinking water supplies of the Aligarh Muslim University campus were well below the guidelines for drinking water quality as prescribed by World Health Organisation (1984). It is evident from the results that the drinking water may not cause any significant health hazard to water consumers due to heavy metals but these may be hazardous if they get accumulated in the body due to continuous consumption of water.