Mechanism of silver incorporated in biosand zeolite clay granular filters for the removal of Cryptosporidium parvum and Giardia lamblia from surface water at point of use

2020 ◽  
Vol 205 ◽  
pp. 286-295
Author(s):  
Resoketswe Charlotte Moropeng ◽  
Maggie Ndombo Benteke Momba
Keyword(s):  
Surface Water ◽  
Cryptosporidium Parvum ◽  
Giardia Lamblia ◽  
Point Of Use ◽  
Granular Filters

Depressed filtration ripening enhances removal of Cryptosporidium parvum

2002 ◽  
Vol 2 (3) ◽  
pp. 159-168 ◽  
Author(s):  
V. Gitis ◽  
R.C. Haught ◽  
R.M. Clark ◽  
E. Radha Krishnan
Keyword(s):  
Surface Water ◽  
Cryptosporidium Parvum ◽  
Pilot Scale ◽  
Kaolin Clay ◽  
Clay Particles ◽  
Physico Chemical ◽  
Cryptosporidium Parvum Oocysts ◽  
Granular Filtration ◽  
Electrostatic Adhesion ◽  
Innovative Concept

Pilot-scale experiments were conducted to investigate removal of Cryptosporidium parvum by contact granular filtration. The research demonstrated enhanced removal of Cryptosporidium parvum in the presence of kaolin particles. This is believed to be due electrostatic adhesion of Cryptosporidium parvum oocysts to the kaolin clay particles. The elementary physico-chemical interactions between filter granules and suspension particles will be discussed. This innovative concept was successfully implemented to reduce the ripening sequence of subsequent filtration experimental test runs by the addition of large surface area particles to slurry of kaolin and Cryptosporidium parvum in surface water.

Survival of cryptosporidium parvum, escherichia coli, faecal enterococci and clostridium perfringens in river water: influence of temperature and autochthonous microorganisms

1997 ◽  
Vol 35 (11-12) ◽  
pp. 249-252 ◽  
Author(s):  
G. J. Medema ◽  
M. Bahar ◽  
F. M. Schets
Keyword(s):  
Surface Water ◽  
River Water ◽  
Cryptosporidium Parvum ◽  
Health Hazard ◽  
Influence Of Temperature ◽  
E Coli ◽  
Untreated Water ◽  
Time Required ◽  
Micro Organisms

Oocysts of Cryptosporidium parvum can survive for several months in surface water, one of the main factors determining their success in environmental transmission and thus their health hazard via water. Several factors in the environment, e.g. temperature, presence of predators and exo-enzymes will probably influence oocyst survival. The high persistence of oocysts may also limit the value of traditional faecal indicator bacteria. The aim of this study was to determine the rate at which C parvum oocysts, E coli, faecal enterococci and C perfringens spores die in surface water and the influence of temperature and the presence of autochthonous (micro)organisms on the die-off rate. Microcosms with autoclaved river water were inoculated with the organisms. Microcosms with untreated river water were inoculated with concentrated primary effluent containing the bacteria and with C parvum oocysts. Microcosms were incubated at 5°C or 15°C at 100rpm. Viability of oocysts was monitored by in vitro excystation and dye-exclusion; viability of the bacteria was determined on appropriate selective media. When pseudo first-order die-off kinetics were assumed, the die-off rate of oocysts at 5°C was 0.010 log10/d and at 15°C, 0.006–0.024 log10/d. These rates underestimate die-off since oocyst disintegration was not accounted for. Incubation in autoclaved or untreated water did influence the die-off rate of oocysts at 15°C but not at 5°C. The die-off rate of E coli and enterococci was faster in the non-sterile river water than in autoclaved water at both temperatures. At 15°C, E coli (and possibly E faecium) even multiplied in autoclaved water. In untreated river water, the die-off of E coli and enterococci was approximately 10x faster than die-off of oocysts but die-off rates of C perfringens were lower than those of oocysts. As for oocysts, die-off of the bacteria and spores was faster at 15°C than at 5°C. Oocysts are very persistent in river water: the time required for a 10x reduction in viability being 40–160d at 15°C and 100d at 5°C. Biological/biochemical activity influenced oocyst survival at 15°C and survival of both vegetative bacteria at 5 and 15°C. The rapid die-off of E coli and enterococci makes them less suitable as indicators of oocyst presence in water. As C perfringens survived longer in untreated river water than oocysts, it may prove useful as an indicator of the presence of C parvum.

scholarly journals Serological responses to Cryptosporidium antigens among women using riverbank-filtered water, conventionally filtered surface water and groundwater in Hungary

2005 ◽  
Vol 3 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Floyd Frost ◽  
Tim Muller ◽  
Gunther Craun ◽  
Kádár Mihály ◽  
Berencsi György ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Cryptosporidium Parvum ◽  
Conventional Treatment ◽  
Riverbank Filtration ◽  
Well Water ◽  
Confined Aquifer ◽  
Surface Water And Groundwater ◽  
The Mean ◽  
Intensity Of Response

We compared serological responses to Cryptosporidium parvum antigens using surplus sera from females undergoing routine screening for pregnancy from three counties in Hungary where bank-filtered surface water, conventionally filtered and disinfected surface water, and groundwater from either a karst or confined aquifer are commonly used for drinking water. The primary purpose was to determine whether the prevalence and intensity of serological responses, indicators of prior Cryptosporidium infection were similar for these populations. Women using groundwater from a confined aquifer had significantly lower mean serological responses for both the 15/17-kDa and 27-kDa (p<0.0001) antigen groups than women using conventionally filtered and disinfected surface water or karst well water. This is suggestive of less frequent infections. Women using bank-filtered water also had lower mean responses for both antigen groups. Among women using bank-filtered water, the mean intensity of response for both antigen groups was almost one-third of the mean response observed for women using conventionally filtered and disinfected surface water. These findings suggest that riverbank filtration may be an effective alternative to conventional treatment for reducing Cryptosporidium exposures and infection from surface drinking water sources.

scholarly journals Dairy Calves in Uruguay Are Reservoirs of Zoonotic Subtypes of Cryptosporidium parvum and Pose a Potential Risk of Surface Water Contamination

2020 ◽  
Vol 7 ◽  
Author(s):  
Rubén Darío Caffarena ◽  
Marcelo Vasconcelos Meireles ◽  
Leonidas Carrasco-Letelier ◽  
Catalina Picasso-Risso ◽  
Bruna Nicoleti Santana ◽  
...  
Keyword(s):  
Surface Water ◽  
Cryptosporidium Parvum ◽  
Potential Risk ◽  
Water Contamination ◽  
Dairy Calves ◽  
Surface Water Contamination

Detecting Cryptosporidium parvum and Giardia lamblia by coagulation concentration and real-time PCR quantification

2012 ◽  
Vol 7 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Huining Zhang ◽  
Xiaohu Zhang ◽  
Shuting Zhang ◽  
Bo Wei ◽  
Qipei Jiang ◽  
...  
Keyword(s):  
Real Time ◽  
Cryptosporidium Parvum ◽  
Real Time Pcr ◽  
Giardia Lamblia

scholarly journals Development of a Diagnostic Kit to Detect Cryptosporidium parvum and Giardia lamblia

2013 ◽  
Vol 4 (3) ◽  
pp. 146-151 ◽  
Author(s):  
Hyeng-Il Cheun ◽  
Byung-Suk Chung ◽  
Da-Won Ma ◽  
Bo-La Goo ◽  
Shin-Hyeong Cho ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Giardia Lamblia
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