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.

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.

A pilot-scale study of Cryptosporidium-sized microsphere removals from swimming pools via sand filtration

2015 ◽  
Vol 14 (1) ◽  
pp. 109-120 ◽  
Author(s):  
Ping Lu ◽  
James E. Amburgey
Keyword(s):  
Filtration Rate ◽  
Pilot Scale ◽  
Cryptosporidium Species ◽  
High Rate ◽  
Organic Polymer ◽  
Recreational Water ◽  
Sand Filtration ◽  
Polyaluminum Chloride ◽  
Overall Performance ◽  
Over Time

Cryptosporidium species are the most common cause of gastrointestinal illness in treated recreational water venues. In order to protect public health during swimming, Cryptosporidium-sized microsphere removals by high-rate sand filtration with six coagulants were evaluated with a 5.5 m3 pilot-scale swimming pool. A sand filter without coagulation removed 20–63% of Cryptosporidium-sized microspheres. Cryptosporidium-sized microsphere removals exceeded 98% by sand filtration with five of the six tested coagulants. Continuously feeding coagulants A, B, and F (i.e., organic polymers) led to coagulant accumulation in the system and decreased removals over time (<2 days). Coagulant E (polyaluminum chloride) consistently removed more than 90% of microspheres at 30 m/h while the removals dropped to approximately 50% at a filtration rate of 37 m/h. Coagulant C was a chitosan-based product that removed fewer microspheres compared with other products, <75%, under the studied conditions. Results indicated aluminum-based coagulants (coagulants D and E) had an overall performance advantage over the organic polymer based coagulants primarily in terms of their tendency not to accumulate in the water and cease to be effective at improving filter efficiency.

scholarly journals The effect of cyanuric acid on the disinfection rate of Cryptosporidium parvum in 20-ppm free chlorine

2008 ◽  
Vol 7 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Joan M. Shields ◽  
Michael J. Arrowood ◽  
Vincent R. Hill ◽  
Michael J. Beach
Keyword(s):  
Public Health ◽  
Cryptosporidium Parvum ◽  
Cyanuric Acid ◽  
Free Chlorine ◽  
Swimming Pool ◽  
Swimming Pools ◽  
Log10 Reduction ◽  
Chlorine Residual ◽  
Cryptosporidium Oocysts ◽  
Reduction Current

Cyanuric acid is used to stabilize free chlorine to reduce photodegradation in outdoor swimming pools. While there have been numerous studies examining its effect on the disinfection rates of bacteria and viruses, it is not known whether cyanuric acid can significantly impact the effectiveness of hyperchlorination for inactivating Cryptosporidium oocysts present in fecally-contaminated swimming pools. This study examined the effect of cyanuric acid on the disinfection rate of Cryptosporidium parvum under swimming pool hyperchlorination conditions (20 mg/ml free chlorine). When 50 mg/L cyanuric acid was present there was a 0.70-log10 reduction in oocyst viability after 10 hours as compared to a 3.7-log10 reduction without cyanuric acid. Aids to remediation, such as decreasing the pH to enhance the germicidal efficiency of the free chlorine and doubling the amount of free chlorine residual, were still unable to achieve a 3-log10 reduction. Current public health recommendations for hyperchlorination and pool remediation are insufficient for pools using cyanurate-stabilized chlorine to achieve a three log inactivation of the parasite.

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.

scholarly journals Performance of Sand Filtration System with Different Sand Bed Depth for Polishing Wastewater Treatment

2021 ◽  
Vol 9 (2) ◽  
pp. 451-456
Keyword(s):  
Filtration Rate ◽  
Cost Effective ◽  
Treatment Method ◽  
Total Coliform ◽  
Contaminant Removal ◽  
Sand Filtration ◽  
Sand Filter ◽  
Conventional Activated Sludge ◽  
Filtration System ◽  
Filter Bed

Sand filtration is a polishing type of treatment system that is widely used as an efficient, cost-effective and simple treatment method. The efficiency of sand filtration relies mainly on the capacity of sand bed depth. Different sand bed depth affects the filtration rate and the contaminant removal differently. Hence, this study aims to investigate the effect of different sand media depth on the removal efficiency of the filtration process. An experimental sand filter with three design modifications of different sand bed depth, 30 cm, 60 cm, and 90 cm, was operated as polishing stage of an effluent from conventional activated sludge process. The highest filtration rate was recorded using sand depth of 30 cm. Higher filter bed depth result in lower filter rate which result in smaller filtrate volume. Highest E. Coli and COD removal, are 95.5% and 52.2%, respectively, recorded using 30 cm sand depth. Meanwhile, highest TSS and turbidity removal are 91.0% and 77.3%, respectively, with sand depth of 90 cm. Highest total coliform and BOD removal are 88.3% and 68.0% respectively by using sand depth of 60 cm. This study demonstrated that the sand filter is more efficient in removing suspended contaminants and coliforms compared to removing dissolved contaminants.

Effect of Pre-Ozonation on Organics Removal by In-Line Direct Filtration

1993 ◽  
Vol 27 (11) ◽  
pp. 81-90 ◽  
Author(s):  
J. E. Tobiason ◽  
J. K. Edzwald ◽  
D. A. Reckhow ◽  
M. S. Switzenbaum
Keyword(s):  
Performance Measures ◽  
Pilot Scale ◽  
Full Scale ◽  
Continuous Operation ◽  
Raw Water ◽  
Sand Filters ◽  
Water Turbidity ◽  
Sand Filter ◽  
Direct Filtration ◽  
Organics Removal

A pilot-scale study of the effects of pre-ozonation on the performance of in-line direct filtration was carried out. Performance measures included filtered water turbidity, unit filter run volumes, and organics in filtered waters: DOC, UV254, AOC and DBPs. Continuous operation of four dual media GAC/sand filters with and without pre-ozonation and chlorinated backwash and a dual media anthracite/sand filter were compared to full-scale performance. Pre-ozonation frequently results in longer filter runs, causes a twofold increase in raw water AOC and has little effect on raw water DOC. GAC/sand filters consistently reduced the AOC in the ozone train to levels below that of the full-scale plant and also provided 25 % lower DOC levels as compared to anthracite/sand filters. The effect of ozone and filtration on chlorinated DBPs followed overall DOC removal while DBPs created by ozonation followed AOC removal trends.

Removal of heavy metals in an abandoned mine drainage via ozone oxidation: a pilot-scale operation

2010 ◽  
Vol 62 (9) ◽  
pp. 2115-2120 ◽  
Author(s):  
S. H. Seo ◽  
B. W. Sung ◽  
G. J. Kim ◽  
K. H. Chu ◽  
C. Y. Um ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Mine Drainage ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Abandoned Mine ◽  
Sand Filtration ◽  
Sand Filter ◽  
Ozone Oxidation ◽  
Fe And Mn ◽  
Dissolved Heavy Metals

The objective of this study was to evaluate the ozone oxidation of dissolved heavy metals in an abandoned mine drainage (AMD) by conducting a pilot-scale operation at two different ozone doses of 7.5 and 24.0 g O3/h into an ozone reactor. A portion of the abandoned mine drainage near the Jungam Mine in Samchuck, Korea was pumped into this pilot-scale plant and used as an influent for the ozone oxidation. Some possible precipitates of metal oxides and hydroxides that resulted from the pilot-scale ozone oxidation of the dissolved Fe and Mn ions in the AMD (with a hydraulic retention time of 106 seconds in the ozone reactor) were effectively removed via sand filtration. A six-hour ozone oxidation with an ozone dose of 24.0 g O3/h and subsequent sand filtration, before backwashing the sand filter bed, can meet Korean drinking water quality standards (less than 0.3 mg/L) for Fe and Mn in the sand filter effluent under the operating conditions that were used in this study. The SO4−2 concentrations and alkalinities of the influents were not affected by the ozone oxidation. The pH values of the influents were neutral or slightly alkaline, and after the six-hour oxidation, increased very slightly. These experiment results show that the ozone oxidation of dissolved heavy metals and the subsequent sand filtration of metal precipitates are desirable alternatives to removing heavy metals in an abandoned mine drainage.

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