scholarly journals AOC removal and accumulation of bacteria in experimental sand filters

2005 ◽  
Vol 5 ◽  
pp. 17-32 ◽  
Author(s):  
W. A.M. Hijnen, ◽  
D. Van Der Kooij
Keyword(s):  
Tap Water ◽  
Microbiological Activity ◽  
Filtration Process ◽  
Sand Filters ◽  
Biological Filtration ◽  
Acetate Concentration ◽  
Assimilable Organic Carbon ◽  
Filter Bed ◽  
Reduction Capacity

Using small sand filets under well defined laboratory conditions, filtration experiments were performed with tap water supplemented with acetate. The objective of these experiments was to determine the effect of different acetate concentrations on (i) the removal of easily assimilable organic carbon (AOC) in the filter (ii), the clogging of the tiller and (iii) the bacteriological quality of the filtrate. The results of the experiments revealed that the reduction capacity of biological filtration processes for acetate is relatively high. Acetate removal resulted in an increased microbiological activity in the top layer (< 1cm) of the filter bed and accumulation of bacterial matter was observed at an influent AOC concentration as low as 0.005 mg of ac-C eq/l. Clogging of the filter bed occurred at an influent acetate concentration of 0.01 mg C/l. Based on these observations it was concluded that the AOC concentration of water used for infiltration in recharge wells should be less thon 0.01 mg ac-C eq/l. This level is similar to the level advised for biologically-stable drinking water. A linear relationship was found between the acetate removal in the experimental filters and the colony count in the filtrate. It was recommended that the AOC load in the final filtration process in water treatment therefore should be limited to prevent high colony counts in the filtrate, thus leading to the use of post disinfection.

scholarly journals Evaluation of Anaerobic Filter Bed-Biological Filtration Process with Physicochemical Phosphorus Removal Methods.

2002 ◽  
Vol 38 (1) ◽  
pp. 47-55 ◽  
Author(s):  
YASUHIRO YAMAMOTO ◽  
YUJI MIURA ◽  
MITSURU INOUE ◽  
NAOSHI FUJIMOTO ◽  
YUHEI INAMORI ◽  
...  
Keyword(s):  
Phosphorus Removal ◽  
Filtration Process ◽  
Biological Filtration ◽  
Anaerobic Filter ◽  
Filter Bed

Empirical models of bio-sand filter to calculate the design parameters

2009 ◽  
Vol 9 (6) ◽  
pp. 723-734 ◽  
Author(s):  
Mohamad Ali Fulazzaky ◽  
Norshuhaila Mohamed Sunar ◽  
Ab Aziz Abd Latiff ◽  
Amir Hashim Mohd Kassim
Keyword(s):  
Empirical Models ◽  
Physical Models ◽  
Design Parameters ◽  
Sand Filtration ◽  
Process Technology ◽  
Filtration Process ◽  
Sand Filters ◽  
Sand Filter ◽  
Quality Of Water

The performance of bio-sand filters (BSF) should be monitored periodically to ensure the quality of water produced for the safety of consumers. An engineering design of BSF is proposed to achieve the desired efficacy of the treatment system. Accurate designs to achieve bio-sand filtration are not available in detail for most BSFs since present physical models were not originally able to calculate design's parameters. This paper develops the mathematical models to calculate the depth of sand filter and water velocity in operating the proposed BSF especially to remove organic and suspended matter simultaneously. Parameters in the equations are all physically meaningful, experimental data validation shows the equations remained accurate. The baseline design's parameters are analyzed to contribute to bio-sand filtration process technology. The filtration rates and depths of sand filter proposed in designing of the BSF system are justified.

Removal of geosmin and 2-methylisoborneol by biological filtration

2004 ◽  
Vol 49 (9) ◽  
pp. 273-280 ◽  
Author(s):  
S.L.N. Elhadi ◽  
P.M. Huck ◽  
R.M. Slawson
Keyword(s):  
Activated Carbon ◽  
Tap Water ◽  
Threshold Concentration ◽  
Biological Filtration ◽  
Treatment Processes ◽  
Odour Threshold ◽  
Parallel Filter ◽  
Sand Source ◽  
By Products

The quality of drinking water is sometimes diminished by the presence of certain compounds that can impart particular tastes or odours. One of the most common and problematic types of taste and odour is the earthy/musty odour produced by geosmin (trans-1, 10-dimethyl-trans-9-decalol) and MIB (2-methylisoborneol). Taste and odour treatment processes including powdered activated carbon, and oxidation using chlorine, chloramines, potassium permanganate, and sometimes even ozone are largely ineffective for reducing these compounds to below their odour threshold concentration levels. Ozonation followed by biological filtration, however, has the potential to provide effective treatment. Ozone provides partial removal of geosmin and MIB but also creates other compounds more amenable to biodegradation and potentially undesirable biological instability. Subsequent biofiltration can remove residual geosmin and MIB in addition to removing these other biodegradable compounds. Bench scale experiments were conducted using two parallel filter columns containing fresh and exhausted granular activated carbon (GAC) media and sand. Source water consisted of dechlorinated tap water to which geosmin and MIB were added, as well as, a cocktail of easily biodegradable organic matter (i.e. typical ozonation by-products) in order to simulate water that had been subjected to ozonation prior to filtration. Using fresh GAC, total removals of geosmin ranged from 76 to 100% and total MIB removals ranged from 47% to 100%. The exhausted GAC initially removed less geosmin and MIB but removals increased over time. Overall the results of these experiments are encouraging for the use of biofiltration following ozonation as a means of geosmin and MIB removal. These results provide important information with respect to the role biofilters play during their startup phase in the reduction of these particular compounds. In addition, the results demonstrate the potential biofilters have in responding to transient geosmin and MIB episodes.

The fate of formaldehyde in sugar manufacture and in products

2015 ◽  
pp. 692-696
Author(s):  
Remi Aubry ◽  
Laurence Gasnot
Keyword(s):  
Sugar Industry ◽  
Common Knowledge ◽  
Microbial Populations ◽  
Optimal Dosage ◽  
Consumer Health ◽  
Microbiological Activity ◽  
Specific Process ◽  
Beet Sugar ◽  
Series Of Experiments

A study was carried out in six beet sugar factories in France during the 2012/13 sugar campaign. The objective was to assess the optimal dosage of formaldehyde solutions at specific process stages and in different existing factory set-ups in order to obtain the desired effect on microbial populations, without interference with the quality of the products. In addition harmlessness regarding consumer health was to be demonstrated. A series of experiments was conducted resulting in new data allowing refreshment of common knowledge and references existing regarding the use of formaldehyde solutions in the sugar industry. The effectiveness and convenience for controlling microbiological activity in beet sugar manufacture was assessed. Formaldehyde reduces sugar losses and protects in-process products without harming their further use, such as for ethanol production.

scholarly journals Tap Water Quality: Seasonal User Surveys in Poland

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3841
Author(s):  
Józef Ober ◽  
Janusz Karwot
Keyword(s):  
Water Quality ◽  
World Literature ◽  
Mixed Methods Research ◽  
Tap Water ◽  
Quality Parameters ◽  
Subjective Perception ◽  
Quality Of Water ◽  
Profit Analysis ◽  
Tap Water Quality

Security of supply of water, which meets the quality parameters specified in applicable standards, is now the basis for the functioning of most societies. In addition to climatic, biological, chemical, and physical hazards, it is worth paying attention to consumers’ subjective perception of the quality of tap water supplied in the area of Poland. The article discusses various activities related to water resources management and analyses the results of an evaluation of selected quality parameters of tap water in Poland. A novelty on a European scale here is an examination of the evaluation of these parameters based on potential seasonal differences (spring, summer, autumn, winter). For the first time in the world literature, PROFIT analysis was used to evaluate selected parameters of tap water quality. The aim of the article was to present a model for the evaluation of the parameters of tap water supplied in different seasons of the year in Poland. Due to the complexity of the research aspects, a mixed-methods research procedure was used in which a literature review was combined with a survey and statistical analysis. For the purpose of the survey, an original survey questionnaire called “Survey of customer opinions on selected parameters of tap water supplied in Poland” was developed especially for this study. The conducted research confirmed the adopted hypothesis that the results of evaluation of selected tap water parameters vary depending on the period (spring, summer, autumn, winter) in Poland. The model developed by means of PROFIT analysis makes it possible to highlight to water suppliers the specific quality parameters in particular seasons of the year (spring, summer, autumn, winter), which may improve the quality of water supplied in Poland and thus, in the long-term perspective, increase the level of satisfaction of water recipients and confidence in drinking tap water in Poland.

Quality of algal material produced on a fertilizer-tap water medium in outdoor plastic-enclosed systems

Aquaculture ◽  
1988 ◽  
Vol 68 (2) ◽  
pp. 157-164 ◽  
Author(s):  
D.J. Geldenhuys ◽  
R.D. Walmsley ◽  
D.F. Toerien
Keyword(s):  
Tap Water ◽  
Water Medium ◽  
Algal Material

Elimination of viruses, bacteria and protozoan oocysts by slow sand filtration

2004 ◽  
Vol 50 (1) ◽  
pp. 147-154 ◽  
Author(s):  
W.A.M. Hijnen ◽  
J.F. Schijven ◽  
P. Bonné ◽  
A. Visser ◽  
G.J. Medema
Keyword(s):  
Pilot Plant ◽  
Pathogenic Bacteria ◽  
Laboratory Experiments ◽  
Full Scale ◽  
Sand Filters ◽  
E Coli ◽  
Thermotolerant Coliforms ◽  
Filter Bed ◽  
Scale Data ◽  
Bacteria Removal

The decimal elimination capacity (DEC) of slow sand filters (SSF) for viruses, bacteria and oocysts of Cryptosporidium has been assessed from full-scale data and pilot plant and laboratory experiments. DEC for viruses calculated from experimental data with MS2-bacteriophages in the pilot plant filters was 1.5-2 log10. E. coli and thermotolerant coliforms (Coli44) were removed at full-scale and in the pilot plant with 2-3 log10. At full-scale, Campylobacter bacteria removal was 1 log10 more than removal of Coli44, which indicated that Coli44 was a conservative surrogate for these pathogenic bacteria. Laboratory experiments with sand columns showed 2-3 and &gt;5-6 log10 removal of spiked spores of sulphite-reducing clostridia (SSRC; C. perfringens) and oocysts of Cryptosporidium respectively. Consequently, SSRC was not a good surrogate to quantify oocyst removal by SSF. Removal of indigenous SSRC by full-scale filters was less efficient than observed in the laboratory columns, probably due to continuous loading of these filter beds with spores, accumulation and retarded transport. It remains to be investigated if this also applies to oocyst removal by SSF. The results additionally showed that the schmutzdecke and accumulation of (in)organic charged compounds in the sand increased the elimination of microorganisms. Removal of the schmutzdecke reduced DEC for bacteria by ±2 log10, but did not affect removal of phages. This clearly indicated that, besides biological activity, both straining and adsorption were important removal mechanisms in the filter bed for microorganisms larger than viruses.

scholarly journals Identifying the Optimal Application Rate of Three Fertilizers Used to Grow New Guinea Impatiens

2016 ◽  
Vol 34 (4) ◽  
pp. 118-122
Author(s):  
A.K. Ostrom ◽  
C.C. Pasian
Keyword(s):  
Controlled Release ◽  
Consumer Preferences ◽  
Tap Water ◽  
Consumer Preference ◽  
New Guinea ◽  
Water Soluble ◽  
Plant Weight ◽  
Preference Ratings ◽  
New Guinea Impatiens

This manuscript describes the effect of controlled-release, and water-soluble fertilizers on the growth and quality of New Guinea impatiens (NGI) (Impatiens hawkeri Bull.). Three different fertilizers were applied at three rates each in order to investigate their effect on growth and quality of ‘Paradise New Red.’ NGI. Fertilizer treatments included 1) a 20-4.4-16.6 water-soluble fertilizer (WSF), 2) a 10-1.8-2.5 soybean-based fertilizer (SBF), and 3) a 15-4-10, three-to four-month longevity controlled-release fertilizer (CRF). CRF was applied as a pre-plant at 1×, 0.75×, and 0.5× the label rate. WSF and SBF fertigation rates of 75, 150, and 250 mg·L−1 N (75, 150, and 250 ppm N), respectively, were used based on a common range of fertigation rates in a greenhouse setting from what is considered relatively low, moderate, and high for NGI production. Plants were irrigated or fertigated by hand every 1 to 5 days as needed, based on environmental conditions and plant size, with either approximately 300 mL (10.4 oz) of either tap water or a fertilizer solution. SPAD readings, above ground plant weight, consumer preference ratings, and cumulative flower number were measured and used to calculate a quality index (QI). Optimal fertilizer rates as determined by the QI were found to be 1) CRF at 7.11 kg·m−3 (11.8 lb·yd−3), 2) SBF at 150 mg·L−1 (150 ppm) N, and 3) WSF at 75 mg·L−1 (75 ppm) N. With the application method used in this work, the WSF was more efficient than the SBF because it produced high quality plants with less fertilizer applied. While for the most part overall consumer preference ratings coincided with plant dry weight, there were some exceptions, indicating that consumers can prefer plants that are not necessary the largest as indicated by their dry weights. Consumer preferences may not coincide with typical plant parameters of plant growth all the time. Consumer preferences should be always considered in an industry that sell its products based mainly on their appearance.

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