Efficacy of SODIS in turbid waters
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Campbell, Dan
Jun 24, 2009, 9:56:19 AM6/24/09
to household-wa...@googlegroups.com, Therese Dooley, Borrazzo, John, Campbell, D., Campbell, Dan, Gavin, John, Grahman, J., Hafner, Craig, Jay, Kolb, Anthony, Rainey, Rochelle, Weinger, Merri
Below are
citations and abstracts to 4 recently published aricles on SODIS, household
water treatment in India, greywater management in South Africa and bamboo
wells:
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Tropical
Medicine & International Health, 14
(6): 620-627
2009
Efficacy
of the solar water disinfection method in turbid waters experimentally
contaminated with Cryptosporidium parvum oocysts under real field
conditions
H. Gómez-Couso, et al.
Objective -
To investigate the efficacy of the solar water disinfection (SODIS)
method for inactivating Cryptosporidium parvum oocysts in turbid waters using
1.5 l polyethylene terephthalate (PET) bottles under natural
sunlight.
Methods -
All experiments were performed at the Plataforma Solar de Almería,
located in the Tabernas Desert (Southern Spain) in July and October 2007. Turbid
water samples [5, 100 and 300 nephelometric turbidity units (NTU)] were prepared
by addition of red soil to distilled water, and then spiked with purified C.
parvum oocysts. PET bottles containing the contaminated turbid waters were
exposed to full sunlight for 4, 8 and 12 h. The samples were then
concentrated by filtration and the oocyst viability was determined by
inclusion/exclusion of the fluorogenic vital dye propidium iodide.
Results - After an exposure time of 12 h
(cumulative global dose of 28.28 MJ/m2; cumulative UV dose of 1037.06
kJ/m2) the oocyst viabilities were 11.54%, 25.96%, 41.50% and 52.80% for
turbidity levels of 0, 5, 100 and 300 NTU, respectively, being significantly
lower than the viability of the initial isolate
(P < 0.01).
Conclusions - SODIS method significantly reduced the
potential viability of C. parvum oocysts on increasing the percentage of oocysts
that took up the dye PI (indicator of cell wall integrity), although longer
exposure periods appear to be required than those established for the bacterial
pathogens usually tested in SODIS assays.
-------------------------------
Tropical Medicine & International
Health, forthcoming
article
Virological evaluation of domestic water
purification devices commonly used in India emphasizes inadequate quality and
need for virological standards
Vikram Verma, Vidya A. Arankalle. National Institute of Virology, Pune,
India.
Objectives -
To evaluate the performance of domestic water purification units with
respect to contaminating enteric viruses.
Methods Eight domestic water purification
systems widely used in India were evaluated using hepatitis E virus (HEV) as a
model virus. For HEV concentration and detection, membrane filtration and
real-time PCR were used respectively. Viral log reduction value (LRV) was
calculated for each unit.
Results Viral log reduction value was 0.21
for unit 6 (polyester + carbon), 1.45 for unit 4 (filter + UV), 1.52 for unit 3
(filter + chlorine), 1.70 for a carbon + exhaust indication contact disinfection
unit, 2.20 for an iodine resin unit, 2.51 for a dual filter unit and 6.53 for a
hollow fibre membrane unit and a gravity-fed filter unit. Thus, only the
technologies employed by the latter two were efficient in complete removal of
HEV.
Conclusions -
The majority of the water purifiers under use are inadequate. Virological
standards in evaluating such devices need to be established urgently, in order
to help manufacturers to improve the performance of such products and most
importantly, to help consumers.
-------------------------------
Water Sci Technol.
2009;59(12):2341-50.
Community-focused greywater management in two informal settlements in South Africa.
Armitage NP, Winter K, Spiegel A, Kruger E.
Department of Civil Engineering, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa E-mail: Neil.A...@uct.ac.za.
South Africa is struggling to provide services to the millions of poor people migrating to the major centres and living in informal settlements (shanty towns). Whilst the local authorities are generally able to provide potable water from the municipal network to communal taps scattered around the settlements, there is usually inadequate provision of sanitation and little or no provision for the drainage of either stormwater or greywater. This paper describes an investigation into ways of engaging with community structures in the settlements with a view to encouraging "self-help" solutions to greywater management requiring minimal capital investment as an interim "crisis" solution until such time that local and national government is able to provide formal services to everyone. The work was carried out in three settlements encompassing a range of different conditions. Only two are described here. It has become clear that the management of greywaterhas a low priority amongst the residents of informal settlements. The lack of effective political structures and the breakdown in communication with Ward Councillors and local government officials have contributed to the lack of progress. As the project progressed it became evident that greywater cannot be considered separately from stormwater, sanitation and refuse removal.
Community-focused greywater management in two informal settlements in South Africa.
Armitage NP, Winter K, Spiegel A, Kruger E.
Department of Civil Engineering, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa E-mail: Neil.A...@uct.ac.za.
South Africa is struggling to provide services to the millions of poor people migrating to the major centres and living in informal settlements (shanty towns). Whilst the local authorities are generally able to provide potable water from the municipal network to communal taps scattered around the settlements, there is usually inadequate provision of sanitation and little or no provision for the drainage of either stormwater or greywater. This paper describes an investigation into ways of engaging with community structures in the settlements with a view to encouraging "self-help" solutions to greywater management requiring minimal capital investment as an interim "crisis" solution until such time that local and national government is able to provide formal services to everyone. The work was carried out in three settlements encompassing a range of different conditions. Only two are described here. It has become clear that the management of greywaterhas a low priority amongst the residents of informal settlements. The lack of effective political structures and the breakdown in communication with Ward Councillors and local government officials have contributed to the lack of progress. As the project progressed it became evident that greywater cannot be considered separately from stormwater, sanitation and refuse removal.
--------------------------------
Ground Water. 2009
Mar-Apr;47(2):310-3.
Design of a low-cost bamboo well.
Shakya SK, Singh SR, Anjaneyulu B, Vashisht AK.
Department of Soil and Water Engineering, Punjab Agricultural University, Ludhiana, Punjab, India.
Bamboo wells are an economical alternative for water supply wells in developing countries. The design of the bamboo well described in this article was developed based on field tests. Following field experiments, the screen in the bamboo well was fabricated with seven 3-m-long bamboo strips, each 2 cm wide and 1 cm thick. The strips were bolted on 1-cm-wide mild steel rings spaced 30 cm along the length of the bamboo strips, with 9-cm-long galvanized iron pipe end pieces.Pipes used in the bamboo well were fabricated by wrapping polythene sheets on the bamboo screens. Excellent performance, low cost, and good service life justify the use of a bamboo well for ground water withdrawal in developing countries.
Design of a low-cost bamboo well.
Shakya SK, Singh SR, Anjaneyulu B, Vashisht AK.
Department of Soil and Water Engineering, Punjab Agricultural University, Ludhiana, Punjab, India.
Bamboo wells are an economical alternative for water supply wells in developing countries. The design of the bamboo well described in this article was developed based on field tests. Following field experiments, the screen in the bamboo well was fabricated with seven 3-m-long bamboo strips, each 2 cm wide and 1 cm thick. The strips were bolted on 1-cm-wide mild steel rings spaced 30 cm along the length of the bamboo strips, with 9-cm-long galvanized iron pipe end pieces.Pipes used in the bamboo well were fabricated by wrapping polythene sheets on the bamboo screens. Excellent performance, low cost, and good service life justify the use of a bamboo well for ground water withdrawal in developing countries.
Dan Campbell, Web
Manager
Environmental Health at USAID
1611 North Kent St., Suite 300
Arlington, VA 22209
Ph:
703-247-8722
Email: dcam...@usaid.gov
Environmental Health at USAID: http://www.ehproject.org
IRC/USAID Sanitation Updates: http://sanitationupdates.wordpress.com
Urban Health Updates: http://urbanhealthupdates.wordpress.com
Cholera Google Group: http://groups.google.com/group/cholera-control
Household Water Treatment Google Group: http://groups.google.com/group/household-water-treatment
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