scholarly journals Comparison of crushed rock sand and natural river sand as filter media for rapid filtration

2020 ◽  
Author(s):  
Bruno Moreno Ramos da Silva ◽  
Rafael Kopschitz Xavier Bastos ◽  
Pedro Kopschitz Xavier Bastos
Keyword(s):  
Water Treatment ◽  
Pilot Scale ◽  
Head Loss ◽  
Crushed Rock ◽  
Filter Media ◽  
Particle Size Range ◽  
River Sand ◽  
Run Length ◽  
Acid Solubility ◽  
Filter Bed

Abstract The objective of this work was to evaluate the crushed rock sand (CRS) as a filter bed in rapid filtration for water treatment. The experiments were carried out using pilot-scale filtration units: one with a CRS filter bed and the other with natural river sand (NRS). Both filter media were prepared in accordance with typical standards for rapid sand filtration (particle size range and distribution, and filter bed depth), and were further characterized in terms of chemical composition, particles and bulk density, porosity, acid solubility and sphericity coefficient. Over four months, 14 filter runs using filtration rates of 90, 180, 270 and 360 m3 m−2 d−1 were monitored and characterized in terms of run length, head loss increase along filter bed depth, turbidity removal along filter bed depth. Overall, the performance of the CRS filter was similar to or even better than that of the NRS filter, producing filtered water with turbidity lower than 0.50 NTU along the entire run, with head loss increasing rates and run length similar to those of the NRS filter. It is concluded that CRS presents a high potential for use as filter media for rapid filtration in water treatment, without technical or operational disadvantages.

scholarly journals Cause of rapid monochloramine decay observed in treated water

2016 ◽  
Vol 17 (3) ◽  
pp. 752-758 ◽  
Author(s):  
Sam Hancock ◽  
Martin Harris ◽  
David Cook
Keyword(s):  
Water Treatment ◽  
Water Samples ◽  
Pilot Scale ◽  
The Other ◽  
Biological Degradation ◽  
Filter Media ◽  
Rapid Decay ◽  
Treated Water ◽  
Water Treatment Plants ◽  
The Impact

Rapid monochloramine decay has been observed in the product water of three River Murray water treatment plants (WTPs). Previous investigations identified that rapid monochloramine decay was microbiological in nature and observed in samples taken after media filtration but was absent in filtered water samples from a fourth WTP of similar design. The filters at the WTP not exhibiting rapid decay are backwashed with filtered non-disinfected water whereas the other WTPs backwash with treated chloraminated water. It was therefore hypothesised that backwashing filters with chloraminated water was the cause of the rapid monochloramine decay. A pilot-scale study was conducted to investigate the impact of backwashing with chloraminated water on the occurrence of microbiologically accelerated monochloramine decay. Additional samples were analysed to assess the impact of chloraminated backwash water on N-Nitrosodimethylamine (NDMA) formation and biological degradation of taste and odour compounds 2-methyl isoborneol (MIB) and geosmin in the filter media. Backwashing with chloraminated filtered water was concluded to be the cause of the observed rapid monochloramine decay, with rapid decay observed within 8 weeks for the filters backwashing with chloramines. Additionally, backwashing with chloraminated filtered water was observed to increase NDMA formation and impair the biological degradation performance of MIB and geosmin.

scholarly journals Improving Filtrate Quality Using Agrobased Materials as Coagulant Aid

2002 ◽  
Vol 37 (4) ◽  
pp. 745-756 ◽  
Author(s):  
Pramod Kumar Raghuwanshi ◽  
Monika Mandloi ◽  
Arvind J. Sharma ◽  
Hanumat S. Malviya ◽  
Sanjeev Chaudhari
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Granular Media ◽  
Moringa Oleifera ◽  
Head Loss ◽  
Turbid Water ◽  
Filter Performance ◽  
Treatment Train ◽  
Strychnos Potatorum ◽  
Filter Bed

Abstract In the present study, an evaluation of agrobased materials (ABM) as a coagulant aid in conjunction with alum has been conducted to determine their efficacy in water treatment. The agrobased materials evaluated are Surjana seed (Moringa oleifera), Nirmali seed (Strychnos potatorum) and maize (Zeemays). Experiments have been conducted simulating a conventional water treatment train consisting of coagulation-flocculation-settling and granular media filtration. Emphasis has been given to the filtration aspect of the treatment train using synthetic turbid water. The filter performance was defined by water quality and head loss development across the filter bed. When Nirmali seed or maize was used as a coagulant aid, the alum dose required was 25 and 15 mg/L, respectively, and the filtrate turbidity achieved was less than 0.2 NTU, whereas alum alone with a dose of 45 mg/L achieved filtrate turbidity levels higher than 1 NTU. Thus, the use of ABM improved the filtrate quality. Head loss in filter with Surjana seed and Maize as coagulant aids was comparable to that of alum alone, whereas it was higher when Nirmali seed was used as a coagulant aid.

Particles Capturing and Correlation with Head Loss in a Pilot-Scale Biological Aerated Filter

2013 ◽  
Vol 409-410 ◽  
pp. 279-286
Author(s):  
Ting Li ◽  
Wen Yi Dong ◽  
Hong Jie Wang ◽  
Jin Nan Lin ◽  
Feng Ouyang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Pilot Scale ◽  
Head Loss ◽  
Biological Aerated Filter ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Lower Velocity ◽  
Aerated Filter ◽  
Filter Bed

Experimental observations of particle capturing through the biological aerated filter bed indicated that air flow rate plays an important role in head loss development by influencing the suspended solids distribution along the depth of the bed as well as the morphology of the deposits. The active height for the SS removal prolonged with the increasing of the air velocity based on the mechanism of first-order kinetics. With the increasing of the superficial air velocity, the effluent SS concentration and the time need to reach the stead-states after backwash both increased. The value of the SS spike in the effluent after backwash at superficial air velocity of 27 m/hr was nearly twice as much as that of 5.4m/hr. Distribution of the deposits at higher air velocity was more uniform. Deposits at lower velocity with air flow rate produced higher head loss gradient. The headloss increased with the increasing of deposits and the increase rate was faster when the deposits exceeded higher value.

scholarly journals Mineral Materials Coated with and Consisting of MnOx—Characteristics and Application of Filter Media for Groundwater Treatment: A Review

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2232 ◽  
Author(s):  
Magdalena M. Michel ◽  
Lidia Reczek ◽  
Dorota Papciak ◽  
Maria Włodarczyk-Makuła ◽  
Tadeusz Siwiec ◽  
...  
Keyword(s):  
Water Treatment ◽  
Research Needs ◽  
Groundwater Treatment ◽  
Filter Media ◽  
Manganese Ores ◽  
Metals Removal ◽  
Treatment Research ◽  
Sand And Gravel ◽  
Filter Bed ◽  
The Relationship

For groundwater treatment, the technologies involving oxidation on MnOx filter bed are beneficial, common, and effectively used. The presence of MnOx is the mutual feature of filter media, both MnOx-coated mineral materials like quartz sand and gravel, chalcedonite, diatomite, glauconite, zeolite, or anthracite along with consisting of MnOx manganese ores. This review is based on the analysis of research and review papers, commercial data sheets, and standards. The paper aimed to provide new suggestions and useful information for further investigation of MnOx filter media for groundwater treatment. The presented compilations are based on the characteristics of coatings, methods, and conditions of its obtaining and type of filter media. The relationship between the properties of MnOx amendments and the obtained purification effects as well as the commonly used commercial products, their features, and applications have been discussed. The paper concludes by mentioning about improving catalytic/adsorption properties of non-reactive siliceous media opposed to ion-exchange minerals and about possible significance of birnessite type manganese oxide for water treatment. Research needs related to the assessment of the use MnOx filter media to heavy metals removal from groundwater in field operations and to standardize methodology of testing MnOx filter media for water treatment were identified.

Pilot plant study of alternative filter media for rapid gravity filtration

2012 ◽  
Vol 66 (12) ◽  
pp. 2779-2784 ◽  
Author(s):  
P. D. Davies ◽  
A. D. Wheatley
Keyword(s):  
Particle Size ◽  
Pilot Plant ◽  
Low Cost ◽  
Pilot Scale ◽  
Head Loss ◽  
Filter Media ◽  
Sand Filters ◽  
Extensive Experience ◽  
Recycled Glass ◽  
Pilot Plant Study

Sand has been the main filter media used in rapid gravity filtration since its introduction. The dominance of sand has been due to its low cost and availability. Extensive experience has led to sand filters with a dependable and predictable performance. Sand remains the preferred filter medium but usually with a larger sized anthracite capping to reduce the onset of head loss. Other approved filter media are now commercially available and this paper compares sand with recycled glass, Filtralite® and slate at pilot scale. The results have reaffirmed the basic importance of particle size on head loss and turbidity performance rather than surface activity or specific surface area. The results did suggest, however, that particle shape and packing exerted a stronger influence on performance than previously acknowledged. These could be used to improve the design and the contribution to sustainability made by rapid gravity filters.

Effect of ozone injection location on filter performance in direct filtration

2002 ◽  
Vol 46 (9) ◽  
pp. 171-177 ◽  
Author(s):  
E. Yüksel ◽  
Ö Akgiray ◽  
A.M. Saatçi ◽  
H.Z. Sarikaya ◽  
I. Koyuncu
Keyword(s):  
Pilot Scale ◽  
Head Loss ◽  
Sand Filters ◽  
Injection Point ◽  
Particle Count ◽  
Direct Filtration ◽  
Filter Performance ◽  
Detention Tank ◽  
Filter Bed ◽  
Ozone Injection

Two identical pilot scale sand filters were operated in parallel to study the effects of preozonation in direct filtration. No coagulants were used. The influent of one filter was ozonated, whereas the influent to the second filter was aerated. Significantly improved reduction in turbidity, particle count, and iron was observed with the filter receiving preozonated water. The head loss development rate was increased as a result of using ozone. In a second set of experiments, the effects of ozone injection point on filter performance were investigated. Two identical filters both receiving preozonated water were operated. With one of the filters, the raw water was ozonated immediately before it entered the filter. The entrance of the preozonated water to the other filter was delayed by using a detention tank between the ozone contact chamber and the filter. In addition to effluent turbidity and particle count values, zeta potentials of the waters entering the two filters were measured. Head loss development at several locations within each filter bed was also observed and recorded. Slightly better effluent quality (turbidity and particle count) was observed with the filter receiving preozonated water without delay. It was observed that the zeta potential of the prezonated water became more negative with increasing delay time.

scholarly journals Testing Metallic Iron Filtration Systems for Decentralized Water Treatment at Pilot Scale

Water ◽  
2015 ◽  
Vol 7 (12) ◽  
pp. 868-897 ◽  
Author(s):  
Raoul Tepong-Tsindé ◽  
Richard Crane ◽  
Chicgoua Noubactep ◽  
Achille Nassi ◽  
Hans Ruppert
Keyword(s):  
Water Treatment ◽  
Metallic Iron ◽  
Pilot Scale

scholarly journals Strength Analysis of Concrete Containing Crushed Rock Particles AS Partial and Total Replacement of Sand

2019 ◽  
Vol 8 (4) ◽  
pp. 8092-8099
Keyword(s):  
Environmental Issues ◽  
Tensile Tests ◽  
Crushed Rock ◽  
Experimental Investigations ◽  
Strength Analysis ◽  
River Sand ◽  
Natural Sand ◽  
Conventional Concrete ◽  
Stone Dust ◽  
Compressive Strength Test

In recent past, the demand for natural river sand has rapidly increased for constructional purposes. This high demand led to extraction of sand from river beds. Depletion of natural sand creates the environmental issues and hence sand excavating is restricted by government which resulted in shortage and substantial increase in its cost. In this context, there is a need to recognize reasonable elective material from mechanical waste instead of stream sand. The usage of squashed shake sand which is a waste material has been acknowledged as building material in numerous nations for as long as three decades. In this paper, attempt is being made to replace natural river sand partially and completely with stone dust. The cube compressive strength test and split tensile tests were conducted. Experimental investigations have revealed that the mechanical properties of concrete using stone dust are almost similar to the conventional concrete. Hence the detrimental effects on environment caused due to excessive mining of river sand can be minimized.

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