Kumar Gunda N.S.,University of Alberta |
Naicker S.,University of Alberta |
Shinde S.,Tata Consultancy Services Ltd. |
Kimbahune S.,Tata Consultancy Services Ltd. |
And 2 more authors.
Analytical Methods | Year: 2014
In this work, we have developed and demonstrated a rapid and low-cost water monitoring sensor that can simultaneously detect total coliform and Escherichia coli (E. coli) bacteria in contaminated drinking water samples. The test method, called Mobile Water Kit (MWK), comprises a set of custom chemical reagents that would serve as colorimetric or fluorometric chemosensors, syringe filter units and a smartphone platform that would serve as the detection/analysis system. The MWK provides information about the presence/absence of total coliform and E. coli in water samples. The MWK has preliminarily been tested for its selectivity, sensitivity and accuracy, with samples of known concentrations of bacteria. The MWK has also been tested with contaminated water samples collected during the two field trials conducted in Canada and India, and the obtained results were confirmed with conventional laboratory methods. With this MWK, we were able to detect the total coliform and E. coli bacteria in water samples within 30 min or less, depending on the concentration of the bacteria. For one of the field samples, the MWK was able to detect the total coliform within 35 s, which is faster than any rapid test methods available in the market. This new technology can dramatically improve the response times for the outbreak of water-borne diseases and will help water managers and individuals to assess the quality of water sources. This journal is © the Partner Organisations 2014.
Bhathena Z.P.,Bhavans Research Center |
Shrivastava S.,Bhavans Research Center |
Londhe P.,Bhavans Research Center |
Brown J.,Georgia Institute of Technology
Water Science and Technology: Water Supply | Year: 2014
Commercial innovation of household-scale water treatment (HWT) devices is rapid in India, where unsafe drinking water contributes to the high burden of disease and death associated with diarrhoeal diseases. Performance testing data for novel devices are not publicly available and there has been no systematic attempt to independently verify manufacturer effectiveness claims. We purchased three gravity-driven HWT devices available on the Indian market to evaluate their performance in reducing bacteria, viruses, and protozoan surrogates in the laboratory according to World Health Organization testing protocols. Results indicated that technologies were moderately effective in reducing Escherichia coli (1.6-2.9 log10) and MS2 (1.4-2.8 log10), and less effective against Bacillus subtilis spores (0.73-2.2 log10) and 3 μm microspheres (0.33-0.56 log10), as means over the testing period (750-4,000 l). Effectiveness declined sharply over the duration of testing for each device, suggesting that the manufacturer-specified effective lifespans were overestimated for all devices. Moderate variability was observed across challenge conditions intended to represent actual use conditions, but performance was not significantly different between challenge waters or ambient testing temperature. Our results suggest that these novel devices do not meet international minimum performance recommendations and that manufacturer effectiveness claims are misleading. Further technological innovation and regulation in this sector may serve to protect public health.© IWA Publishing 2014.