Comparison and verification of four field-based microbiological tests: H2S test, Easygel®, Colilert®, Petrifilm™

2011 ◽  
Vol 1 (1) ◽  
pp. 68-85 ◽  
Author(s):  
Patty Chuang ◽  
Stephanie Trottier ◽  
Susan Murcott
Keyword(s):  
Water Quality ◽  
Developing Countries ◽  
Standard Method ◽  
Low Cost ◽  
Field Tests ◽  
Single Test ◽  
Total Water ◽  
Microbiological Test ◽  
Technical Capacity ◽  
Larger Sample

The UN defines water supplies as ‘improved’ or ‘unimproved.’ These indicators are easy to measure, but do not reflect water quality, which requires laboratory or field tests. Laboratory and test availability, expense and technical capacity are obstacles for developing countries. This research compares and verifies four low-cost, field-based microbiological tests: the EC-Kit (Colilert® and Petrifilm™ tests), the H2S bacteria test, and Easygel®, against a standard method (Quanti-Tray®). The objectives are to: (1) verify the accuracy of the four field-based tests, (2) study the accuracy of these tests as a function of improved and unimproved sources; (3) recommend a single microbiological test, if appropriate, based on accuracy and cost, and/or (4) recommend a testing combination, if appropriate, based on accuracy and cost. The tests of 500+ total water samples from Capiz Province, Philippines and Cambridge, MA indicate that two-tests systems gave better results than a single test. Both the 100-mL H2S test + Petrifilm™ and the 20-mL H2S test + Easygel® combinations yield promising results, in addition to being inexpensive. None of the field-based tests should be used on their own. We recommend further verification of a larger sample size and scale be undertaken before these testing combinations are recommended for wider use.

scholarly journals OpenOBS: Open-source, low-cost optical backscatter sensors for water quality and sediment-transport research

2021 ◽  
Author(s):  
Emily Eidam ◽  
Theodore Langhorst ◽  
Evan Goldstein ◽  
McKenzie McLean
Keyword(s):  
Water Quality ◽  
Environmental Management ◽  
Sediment Transport ◽  
Open Source ◽  
Printed Circuit Boards ◽  
Low Cost ◽  
Field Tests ◽  
Sediment Concentration ◽  
Industrial Applications ◽  
Sensing Technology

Optical backscatter sensors (OBSs) are commonly used to measure the turbidity, or light obscuration, of water in fresh and marine environments and various industrial applications. These turbidity measurements are commonly calibrated to yield total suspended solids (TSS) or suspended sediment concentration (SSC) measurements for water quality, sediment transport, and diverse other research and environmental management applications. Commercial sensors generally cost >$1000-3000. Here we leveraged simple, low-cost microprocessors, electronics, and housing components to design and construct open-source OBSs for <$150 per unit. The circuit relies on a photodiode to sense the backscattered light, two stages of signal amplification, and a high resolution analogue-to-digital convert to read the detected value. The instrument and logger utilize inexpensive, custom-printed circuit boards with through-hole soldering mounts; micro-SD card reader and real-time clock modules; and PVC housings with commercial end caps and epoxy-potted diode emitter and receiver. All parts are readily and publicly available, and minimal experience in soldering and coding is required to build and deploy the sensor. In lab and field tests, standard deviations were comparable to those measured by commercial sensors (~2-3% of the mean for suspended muds and 20-30% for suspended sands). These open-source sensors represent a useful advance in inexpensive sensing technology with broad applications across scientific and environmental management disciplines.

Low-Cost Technology for Water Pollution Control in Developing Countries

1982 ◽  
Vol 14 (9-11) ◽  
pp. 1337-1352 ◽  
Author(s):  
G G Cillié
Keyword(s):  
Water Pollution ◽  
Developing Countries ◽  
United Nations ◽  
Pollution Control ◽  
Low Cost ◽  
Water Pollution Control ◽  
Local Labour ◽  
International Water ◽  
Design And Methods ◽  
Local Materials

An estimated 80 % of all illnesses in developing countries is in one way or another related to water. In order to alleviate this most serious condition, the united Nations has initiated the “International Water Decade”, for which the estimated costs are $600 000 million, a sum which is far beyond any available means. By application of “low-cost technology” this sum could be reduced to $100 000 million which brings the objective within the reach of possibility. Details are given of the design and methods of construction of units which are best suited to the specific requirements and which would be simple, reliable and economical to operate. These can be constructed largely from local materials and by local labour. The need for appropriate training of both operators and the user population is stressed.

Water Quality and Health

1991 ◽  
Vol 23 (1-3) ◽  
pp. 201-209 ◽  
Author(s):  
W. Kreisel
Keyword(s):  
Water Quality ◽  
Developing Countries ◽  
Drinking Water ◽  
Water Supply ◽  
Human Health ◽  
Pollution Control ◽  
Wastewater Reuse ◽  
Water Supplies ◽  
Minimum Quality Standards ◽  
Quality Guidelines

Water quality can affect human health in various ways: through breeding of vectors, presence of pathogenic protozoa, helminths, bacteria and viruses, or through inorganic and organic chemicals. While traditional concern has been with pathogens and gastro-intestinal diseases, chemical pollutants in drinking-water supplies have in many instances reached proportions which affect human health, especially in cases of chronic exposure. Treatment of drinking-water, often grossly inadequate in developing countries, is the last barrier of health protection, but control at source is more effective for pollution control. Several WHO programmes of the International Drinking-Water Supply and Sanitation Decade have stimulated awareness of the importance of water quality in public water supplies. Three main streams have been followed during the eighties: guidelines for drinking-water quality, guidelines for wastewater reuse and the monitoring of freshwater quality. Following massive investments in the community water supply sector to provide people with adequate quantities of drinking-water, it becomes more and more important to also guarantee minimum quality standards. This has been recognized by many water and health authorities in developing countries and, as a result, WHO cooperates with many of them in establishing water quality laboratories and pollution control programmes.

scholarly journals Low-cost hybrid design of masonry structures for developing countries: Shaking table tests

2021 ◽  
Vol 146 ◽  
pp. 106675
Author(s):  
Anastasios Tsiavos ◽  
Anastasios Sextos ◽  
Andreas Stavridis ◽  
Matt Dietz ◽  
Luiza Dihoru ◽  
...  
Keyword(s):  
Developing Countries ◽  
Low Cost ◽  
Shaking Table ◽  
Hybrid Design ◽  
Masonry Structures ◽  
Shaking Table Tests

scholarly journals Development and Characterization of a Novel Low-Cost Water-Level and Water Quality Monitoring Sensor by Using Enhanced Screen Printing Technology with PEDOT:PSS

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 474 ◽  
Author(s):  
Bei Wang ◽  
Manuel Baeuscher ◽  
Xiaodong Hu ◽  
Markus Woehrmann ◽  
Katharina Becker ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Level ◽  
Sheet Resistance ◽  
Screen Printing ◽  
Low Cost ◽  
Conductive Polymer ◽  
Water Quality Monitoring ◽  
Physical Treatment ◽  
Printing Technology ◽  
Screen Printing Technology

A novel capacitive sensor for measuring the water-level and monitoring the water quality has been developed in this work by using an enhanced screen printing technology. A commonly used environment-friendly conductive polymer poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) for conductive sensors has a limited conductivity due to its high sheet resistance. A physical treatment performed during the printing process has reduced the sheet resistance of printed PEDOT:PSS on polyethylenterephthalat (PET) substrate from 264.39 Ω/sq to 23.44 Ω/sq. The adhesion bonding force between printed PEDOT:PSS and the substrate PET is increased by using chemical treatment and tested using a newly designed adhesive peeling force test. Using the economical conductive ink PEDOT:PSS with this new physical treatment, our capacitive sensors are cost-efficient and have a sensitivity of up to 1.25 pF/mm.

Smart and Low Cost Real Time Water Quality Monitoring System Using IoT

2019 ◽  
Author(s):  
Jeba Anandh S ◽  
Anandharaj M ◽  
Aswinrajan J ◽  
Karankumar G ◽  
Karthik P
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Monitoring System ◽  
Low Cost ◽  
Water Quality Monitoring ◽  
Quality Monitoring

MECHANIZATION OF POTATO GRADING ON SMALL-SCALE FARMS: A CASE STUDY FROM PERU

2005 ◽  
Vol 41 (1) ◽  
pp. 81-92 ◽  
Author(s):  
G. P. BUTLER ◽  
T. BERNET ◽  
K. MANRIQUE
Keyword(s):  
Developing Countries ◽  
Market Integration ◽  
Low Cost ◽  
Farming System ◽  
Agricultural Products ◽  
Small Scale ◽  
Critical Aspect ◽  
Small Scale Farmers ◽  
Important Cash Crop

Potatoes are an important cash crop for small-scale producers worldwide. The move away from subsistence to commercialized farming, combined with the rapid growth in demand for processed agricultural products in developing countries, implies that small-scale farmers and researchers alike must begin to respond to these market changes and consider post-harvest treatment as a critical aspect of the potato farming system. This paper presents and assesses a low cost potato-grading machine that was designed explicitly to enable small-scale potato growers to sort tubers by size for supply to commercial processors. The results of ten experiments reveal that the machine achieves an accuracy of sort similar to commercially available graders. The machine, which uses parallel conical rollers, has the capacity to grade different tuber shapes and to adjust sorting classes, making it suitable for locations with high potato diversity. Its relatively low cost suggests that an improved and adapted version of this machine might enhance market integration of small-scale potato producers not only in Peru, but in other developing countries as well.

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