ASTM D4188-17 Standard Practice for Performing Pressure In-Line Coagulation-Flocculation-Filtration Test in Water.pdf

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1、Designation: D4188 17Standard Practice forPerforming Pressure In-Line Coagulation-Flocculation-Filtration Test in Water1This standard is issued under the fixed designation D4188; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the

2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the procedure used to performpressure in-line coagulation-flocculation-filtration of wate

3、r andwaste water. It is applicable to water and waste water withrelatively low suspended solids (30 mg/L). The practice isapplicable for any size filter greater than 100 mm (4 in.) indiameter.1.2 This practice for performing pressure in-linecoagulation-flocculation-filtration tests in water relies o

4、n tur-bidity measurement to assess the water quality, referring to TestMethods D7315, D6698,orD6855 to perform the turbiditymeasurement.1.3 This practice can be used to determine the effectivenessof flocculants or coagulants, or both, and filter medium(a) inremoving suspended and colloidal material

5、from water andwaste water.1.4 Interval between filter backwashing, backwashrequirements, rinse requirements, and effect of filtration rate oneffluent quality can also be obtained with this practice.1.5 The values stated in SI units are to be regarded asstandard. The values given in parentheses are m

6、athematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate

7、safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment

8、 of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD2035 Practice for Coagulation-Flocculation Jar Test ofWaterD3370 Practices for Sam

9、pling Water from Closed ConduitsD4189 Test Method for Silt Density Index (SDI) of WaterD6698 Test Method for On-Line Measurement of TurbidityBelow 5 NTU in WaterD6855 Test Method for Determination of Turbidity Below 5NTU in Static ModeD7315 Test Method for Determination of Turbidity Above 1Turbidity

10、 Unit (TU) in Static Mode3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTerminology D1129.4. Summary of Practice4.1 A flocculant or coagulant, or both, is added to apressurized flowing water or waste water stream, and the flocthat forms is removed, using

11、a filter medium(a).4.2 The effectiveness of the system in removing suspendedand colloidal matter is determined by monitoring the quality ofthe filter effluent.4.3 A holding tank for floc formation or floc growth isoptional.4.4 The practice also provides information on intervalbetween filter backwash

12、ing, backwash requirements, rinserequirements, and effect of filtration rate on effluent quality.5. Significance and Use5.1 Pressure in-line coagulation-flocculation followed byfiltration is an effective process to remove suspended andcolloidal matter from water and waste water.1This practice is und

13、er the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits, Analysis of Water for Power Generation and Process Use,On-Line Water Analysis, and Surveillance of Water.Current edition approved Dec. 15, 2017. Publi

14、shed January 2018. Originallyapproved in 1982. Last previous edition approved in 2013 as D4188 13. DOI:10.1520/D4188-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer

15、 to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization establishe

16、d in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.2 The effectiveness of this process is dependent on thetype and concentration of the flocculant or coagulant

17、, or both,the pH, the temperature, the filtration medium(a), and thefiltration rate. This practice permits the evaluation of thesevarious parameters.5.3 This practice can also be used to determine filterbackwash and rinse requirements.5.4 The results obtained from this practice can be used forplant

18、design of large systems.6. Apparatus6.1 Installation:6.1.1 To prevent contamination by corrosion products, usestainless steel, plastic, or coated (rubber or epoxy-lined) steelfor all wetted parts.6.1.2 Take care to ensure that no contamination will occurfrom oil films on new metal piping, release ag

19、ents on rawplastic components, or from solutions previously used in thesystem. Thoroughly clean or degrease, or both, any materialsthat are suspect.6.1.3 Design all pressurized components based on themanufacturers working pressure rating. Review the manufac-turers rating for compliance with standard

20、 engineering prac-tice.6.1.4 Assemble the system as shown in Fig. 1. The holdingtank just preceding the filter is optional. Use a manual flowcontrol valve to regulate the filter effluent flow.NOTE 1Since the filter is intended to be operated at constant flow withdifferential pressure changes across

21、the filter, manual flow adjustmentsmay be required periodically. For streams that yield a high filter loadingrate, an automatic flow control valve might be required.NOTE 2If a holding tank is used, it should be designed to obtainuniform flow to minimize stagnant zones and to keep the floc suspended.

22、It should also be sized to obtain the desired retention and contain an airvent.6.1.5 Operate the apparatus by drawing water from thewater supply and pumping it through the system under pres-sure. Use a gauge pressure of 275 to 345 kPa (40 to 50 psi) asthe filter inlet pressure.NOTE 3If the water sup

23、ply is already sufficiently pressurized, thepressurizing centrifugal pump is not required.6.1.6 Use a single calibrated pressure gauge equipped witha “quick-connect” fitting to measure the filter inlet pressure andfilter pressure drop. Individual gauges are also satisfactory butnot as reliable as a

24、single “quick-connect” pressure gauge.6.1.7 Use either a flowmeter or a calibrated volume con-tainer and stopwatch to measure the filter effluent flow.6.1.8 Use an accurate metering pump to inject the flocculantor coagulant, or both. Use an injector with a check valve andlocate the teat of the injec

25、tor in the center of the flowing streamand in the vertical position.6.1.9 Use a calibrated volume container and stopwatch tomeasure the injection pump rate.NOTE 4If the suction line of the metering pump is placed into thevolume container, it is necessary to subtract the volume displaced by thesuctio

26、n line.6.1.10 With small inside diameter piping (12-in. nominal),use five or six right-angle elbows for mixing. With large insidediameter piping, use in-line static mixing to obtain goodmixing.6.1.11 Valve the filter so the raw water supply can be usedfor backwashing.6.1.12 To protect the pump, inst

27、all a flow-sensor switch toshut the system down if the water supply to the pump isinterrupted.NOTE 5If a centrifugal pump is used, excessive pressure is usually noproblem provided the pump or piping or both are properly sized. Either ahigh-pressure limit control switch or a pressure-relief device ca

28、n beinstalled after the pump, if there are any doubts about excessive pressure.FIG. 1 Typical Pressure In-Line Coagulation-Flocculation Filtration SystemD4188 1726.1.13 If the system pressure fluctuates by more than 635kPa (65 psi), install a pressure regulator immediately down-stream of the pressur

29、e control valve.6.2 To minimize wall effects, use a filter with a minimumdiameter of 100 mm (4 in.).7. Reagents7.1 For a list of typical coagulants and the preparation ofpolyelectrolyte solutions, refer to Practice D2035.8. Procedure8.1 Start-Up Procedure:8.1.1 First, backwash the filter with the su

30、pply water tothoroughly clean the filter medium. Use the backwash raterecommended by the filter medium supplier, which is usually20 to 50 m3/(hm2) of filter area (8 to 20 gal/(minft2).Backwash the filter until the turbidity (as determined by TestMethod D7315) of the backwash is equal (within 10 %) t

31、o theturbidity of the supply water. For all sampling, follow theprocedure given in Practices D3370.NOTE 6New medium usually contains many fines which need to beremoved for the best filter performance. During backwash approximately2 to 3 % of the medium can be siphoned off at the top of bed to remove

32、fines.8.1.2 After backwashing, operate the filter in the servicemode and adjust the flow rate and pressure by adjusting boththe flow control valve and the pressure control valve.8.1.2.1 Set the inlet pressure to the filter at a gauge pressureof 275 to 345 kPa (40 to 50 psi).8.1.2.2 Set the flow rate

33、 based on filter medium suppliersrecommendation, which is usually 5 to 15 m3/(hm2) of filterarea (2 to 6 gal/(minft2).8.2 Operating Procedure:8.2.1 To determine the effectiveness of the filter medium inremoving colloidal and suspended particles with addition offlocculants or coagulants, or both, pro

34、ceed to 8.2.3. To deter-mine the ability of the filter medium in removing colloidal andsuspended particles without addition of flocculants orcoagulants, or both, operate the filter for 30 min. Then,measure the water quality of the filter effluent and compare itto the quality of the supply water. Whe

35、re possible measure theturbidity of the filter effluent on line using Test Method D6698,otherwise use Test Method D6855 or D7315 to measure thewater quality. Repeat the water quality measurements every 30min until results indicate equilibration of the filter.8.2.2 Repeat 8.1.1 and 8.1.2.8.2.3 Start

36、the flocculant or coagulant injection pump toinject a previously prepared solution. Initially, set the injectionpump rate to obtain 2 mg/L of the flocculant or coagulant in thesupply water.8.2.3.1 Set the concentration of flocculant or coagulant inthe supply water using the injection pump curves (pu

37、mpingrate against back pressure), concentration of flocculant orcoagulant in the chemical feed tank, and the flow rate of waterthrough the filter. For example, for a 250-mm (10-in.) diameterfilter operating at 3.785 L/min (1 gal/min) and a polyelectrolytefeed solution concentration of 200 mg/L, the

38、injection pumpshould be adjusted to the following rate to obtain 2 mg/L in thesupply water: Dilution of polyelectrolyte feed solution of 100to 1 will give 2 mg/L.Therefore:3.785 L/min! / X L/min! 5 100 (1)X 5 0.03785 L/min 5 37.85 mL/min (2)Therefore, set injection pump rate at 37.8 mL/min.8.2.3.2 I

39、f polyelectrolyte from supplier is a liquid, assume100 % active ingredient.8.2.4 After the injection rate has been set, measure theinjection rate (see 6.1.9).8.2.5 Allow 5 min of operation to equilibrate the mixingsection then obtain a water sample just after the mixing sectionand measure the zeta p

40、otential, if applicable.NOTE 7For most natural waters, optimum coagulation-flocculationwill occur at a zeta potential of 0 6 2 mV. Zeta potential measurementsare only useful for cationic polyelectrolytes and inorganic coagulants(alum and iron). If a nonionic or anionic polyelectrolyte is used, omit

41、thezeta potential measurement.NOTE 8For waters with high total dissolved solids, for example,seawater, zeta potential measurements are not meaningful.8.2.6 Adjust the concentration of flocculant or coagulant, orboth, either up or down to obtain the desired zeta potential.8.2.7 After the desired zeta

42、 potential has been obtained,allow the system to operate for 15 to 20 min, and then measurethe filter effluent water quality and compare to the supply waterquality (before flocculant or coagulant, or both, addition) usingturbidity, suspended solids, or silt density index. Repeatmeasurements (both ef

43、fluent water quality and zeta potential)every 30 to 45 min until equilibration of the system hasoccurred. (For further information about slit density index, seeTest Method D4189.)8.2.8 If the desired zeta potential value is unknown or if zetapotential measurements are not made, then the coagulantcon

44、centration must be varied and equilibrated values of theeffluent water quality obtained at each concentration to deter-mine the optimum concentration, that is, that concentration offlocculant or coagulant, or both, which gives acceptableeffluent water quality.NOTE 9Exercise care since excess coagula

45、nt or flocculant, or both,can be adsorbed by the filter medium, and several hours may be requiredbefore true equilibration of the system occurs.8.2.9 Measure the pH and the temperature of the filtereffluent for future reference.NOTE 10For some coagulants, for example, alum, the pH is animportant par

46、ameter and control of the pH within certain limits is usuallydesirable.8.2.10 In operating the system, periodically measure andmake appropriate adjustment of the filter inlet pressure, filterflow rate, and injection pump rate.8.2.11 To determine the effect of filtration rate on effluentwater quality

47、, repeat 8.1.1 to 8.2.9 but set the flow rate in8.1.2.2 at different values.8.2.12 To determine the effect of different flocculants orcoagulants, or both, on the effluent water quality, repeat 8.1.1to 8.2.9, using different flocculants or coagulants, or both.8.2.13 To evaluate different medium, repl

48、ace filter or filtermedium with new medium and repeat 8.1.1 to 8.2.9.D4188 1738.2.14 To determine the need for backwashing for a givenmedium, and flocculant or coagulant, or both, operate thesystem as in 8.2.7 for extended time periods and monitor theeffluent quality. When the effluent quality deter

49、iorates or whenthe pressure drop across the filter reaches the suppliersrecommended maximum limit, backwash the filter.NOTE 11The interval between backwashings can vary from a fewhours to several weeks, depending on the quantity of suspended andcolloidal material in the supply water, the filter flow rate, the type offlocculant or coagulant, or both, used, and the filter design.8.2.15 To determine the filter rinse time, first determine theoptimum concentration of flocculant or coagulant, or both, at agiven filter flow rate. Then backwash the filter as in 8.1