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.

scholarly journals Removals of cryptosporidium parvum oocysts and cryptosporidium-sized polystyrene microspheres from swimming pool water by diatomaceous earth filtration and perlite-sand filtration

2017 ◽  
Vol 15 (3) ◽  
pp. 374-384 ◽  
Author(s):  
Ping Lu ◽  
James E. Amburgey ◽  
Vincent R. Hill ◽  
Jennifer L. Murphy ◽  
Chandra L. Schneeberger ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Filtration Rate ◽  
Diatomaceous Earth ◽  
Pilot Scale ◽  
Full Scale ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Sand Filtration ◽  
Sand Filter ◽  
Cryptosporidium Parvum Oocysts

Removal of Cryptosporidium-sized microspheres and Cryptosporidium parvum oocysts from swimming pools was investigated using diatomaceous earth (DE) precoat filtration and perlite-sand filtration. In pilot-scale experiments, microsphere removals of up to 2 log were obtained with 0.7 kg·DE/m2 at a filtration rate of 5 m/h. A slightly higher microsphere removal (2.3 log) was obtained for these DE-precoated filters when the filtration rate was 3.6 m/h. Additionally, pilot-scale perlite-sand filters achieved greater than 2 log removal when at least 0.37 kg/m2 of perlite was used compared to 0.1–0.4 log removal without perlite both at a surface loading rate of 37 m/h. Full-scale testing achieved 2.7 log of microspheres and oocysts removal when 0.7 kg·DE/m2 was used at 3.6 m/h. Removals were significantly decreased by a 15-minute interruption of the flow (without any mechanical agitation) to the DE filter in pilot-scale studies, which was not observed in full-scale filters. Microsphere removals were 2.7 log by perlite-sand filtration in a full-scale swimming pool filter operated at 34 m/h with 0.5 kg/m2 of perlite. The results demonstrate that either a DE precoat filter or a perlite-sand filter can improve the efficiency of removal of microspheres and oocysts from swimming pools over a standard sand filter under the conditions studied.

scholarly journals A full-scale study of Cryptosporidium parvum oocyst and Cryptosporidium-sized microsphere removals from swimming pools via sand filtration

2015 ◽  
Vol 52 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Ping Lu ◽  
James E. Amburgey ◽  
Vincent R. Hill ◽  
Jennifer L. Murphy ◽  
Chandra Schneeberger ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Initial Dosage ◽  
Pilot Scale ◽  
Full Scale ◽  
Swimming Pool ◽  
High Rate ◽  
Swimming Pools ◽  
Sand Filtration ◽  
Continuous Feeding ◽  
Cryptosporidium Parvum Oocysts

Removal of Cryptosporidium parvum oocysts and Cryptosporidium-sized microspheres was evaluated in full-scale swimming pools via high-rate sand filtration (31–34 m/h) with coagulation. Results showed that at least 90% of C. parvum oocysts and microspheres were removed by filtration with an initial dosage of coagulant B (1.56 mg/L), D (1.9 mg/L or 305 g/m2), or F (1.56 mg/L) from each swimming pool. Filtration with an initial dosage of coagulant E (0.1 mg·Al/L) achieved 82% C. parvum oocyst removal and 97% microsphere removal. Coagulants B and F had a tendency to overdose over time with continuous feeding (based on corresponding pilot-scale experiments) and did not consistently achieve removals greater than 90% in the full-scale trials. As high as 99% of C. parvum oocysts and 98% of microspheres were removed with a continuous dosage of coagulant D. Up to 98% (1.7 log) of C. parvum oocysts and 93% (1.1 log) of microspheres were removed by continuous dosing of coagulant E at 27 m/h. Consistent oocyst and microsphere removal by aluminum-based coagulants (D and E) was achieved under the tested swimming pool conditions.

Rapid sand filtration of Cryptosporidium parvum: effects of media depth and coagulation

2008 ◽  
Vol 8 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Vitaly Gitis
Keyword(s):  
Cryptosporidium Parvum ◽  
Pilot Scale ◽  
Ripening Stage ◽  
Sand Filtration ◽  
Run Time ◽  
Efficient Transport ◽  
Effects Of Media ◽  
Granular Filtration ◽  
Rapid Sand Filtration

Pilot-scale experiments were conducted to investigate the removal of C. parvum by contact granular filtration. The experiments indicated efficient transport of C. parvum oocysts and limitations posed by attachment conditions. The required 99% oocyst removal was achieved during the operable period. Insufficient 95% removal was attributed to a reduced amount of accumulated material at ripening stage. Coagulation, filter depth and run time were found to be important in the removal of C. parvum oocysts.

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

Nanofiltration of colored surface water: Quebec's experience

2003 ◽  
Vol 3 (5-6) ◽  
pp. 15-22
Author(s):  
P. Kouadio ◽  
M. Tétrault
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Quebec City ◽  
Water Regulation ◽  
Eastern Canada

Three colored surface water nanofiltration pilot-scale projects were conducted in the province of Quebec (eastern Canada), between November 2000 and March 2002, by the company H2O Innovation (2000) inc., for the municipalities of Lac Bouchette, Latulipe-et-Gaboury and Charlesbourg (now part of Quebec City). Results indicated that nanofiltration permeate quality has an advance on present drinking water regulation standard in Quebec, but important membrane fouling occurred. Fouling can be controlled by pretreatment and optimization of the operating conditions.

Survival of giardia, cryptosporidium, poliovirus and salmonella in marine waters

1997 ◽  
Vol 35 (11-12) ◽  
pp. 261-268 ◽  
Author(s):  
D. C. Johnson ◽  
C. E. Enriquez ◽  
I. L. Pepper ◽  
T. L. Davis ◽  
C. P. Gerba ◽  
...  
Keyword(s):  
Water Quality ◽  
Salmonella Typhimurium ◽  
Cryptosporidium Parvum ◽  
Common Method ◽  
Waterborne Pathogens ◽  
Protozoan Parasites ◽  
Marine Waters ◽  
Untreated Sewage ◽  
Cryptosporidium Parvum Oocysts ◽  
Giardia Muris

Discharge of sewage into the ocean is still a common method of disposal worldwide. Both treated and untreated sewage may contain significant concentrations of waterborne pathogens, such as Giardia, Cryptosporidium, poliovirus and Salmonella. Limited studies exist on the survival of poliovirus and Salmonella in marine waters; however, almost no information exists on the survival of protozoan parasites in marine waters. This study examined the survival of Giardia muris cysts, Cryptosporidium parvum oocysts, poliovirus-1 and Salmonella typhimurium in marine waters. The survival of the microorganisms varied according to the presence of light, salinity and water quality (as determined by quantity of enterococci). All microorganisms survived longer in the dark than in sunlight, the order of survival in sunlight being: Cryptosporidium > poliovirus > Giardia > Salmonella.

Viability of nematode eggs in high rate algal ponds: the effect of physico-chemical conditions

2000 ◽  
Vol 42 (10-11) ◽  
pp. 371-374 ◽  
Author(s):  
S. Araki ◽  
J. M. González ◽  
E. de Luis ◽  
E. Bécares
Keyword(s):  
Hydraulic Retention Time ◽  
Pilot Scale ◽  
High Rate ◽  
Sterile Water ◽  
Egg Viability ◽  
High Rate Algal Ponds ◽  
Helminth Eggs ◽  
Physico Chemical ◽  
Nematode Eggs ◽  
Chemical Conditions

The viability of Parascaris equorum eggs was studied in two experimental pilot-scale high-rate algal ponds (HRAPs) working in parallel with 4 and 10 days hydraulic retention time respectively. Semi-permeable bags of cellulose (15000 daltons pore size) were used to study the effect of physico-chemical conditions on the survival of these helminth eggs. Three thousand eggs were used in each bag. Replicates of these bags were submerged for 4 and 10 days in the HRAPs and egg viability was compared with that in control bags submerged in sterile water. After 4 days exposure, 60% reduction in viability was achieved, reaching 90% after 10 days, much higher than the 16% and 25% found in the control bags for 4 and 10 days respectively. Ionic conditions of the HRAP may have been responsible for up to 50–60% of the egg mortality, suggesting that mortality due to the ionic environment could be more important than physical retention and other potential removal factors.

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