1、Designation: D 4188 08Standard Practice forPerforming Pressure In-Line Coagulation-Flocculation-Filtration Test1This standard is issued under the fixed designation D 4188; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 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. Scope*1.1 This practice covers the procedure used to performpressure in-line coagulation-flocculation-filtration of water andw
3、aste 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 can be used to determine the effectivenessof flocculants or coagulants, or both, and filter medi
4、um(a) inremoving suspended and colloidal material from water andwaste water.1.3 Interval between filter backwashing, backwash require-ments, rinse requirements, and effect of filtration rate oneffluent quality can also be obtained with this practice.1.4 This standard does not purport to address all
5、of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1129 Terminology Rel
6、ating to WaterD 2035 Practice for Coagulation-Flocculation Jar Test ofWaterD 3370 Practices for Sampling Water from Closed ConduitsD 4189 Test Method for Silt Density Index (SDI) of WaterD 6698 Test Method for On-Line Measurement of TurbidityBelow 5 NTU in WaterD 6855 Test Method for Determination o
7、f Turbidity Below5 NTU in Static ModeD 7315 Test Method for Determination of Turbidity Above1 Turbidity Unit (TU) in Static Mode3. Terminology3.1 Definitions: For definitions of terms used in this prac-tice, refer to Definitions D 1129.4. Summary of Practice4.1 A flocculant or coagulant, or both, is
8、 added to apressurized flowing water or waste water stream, and the flocthat forms is removed, using 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
9、 floc growth isoptional.4.4 The practice also provides information on intervalbetween filter backwashing, 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 effect
10、ive process to remove suspended andcolloidal matter from water and waste water.5.2 The effectiveness of this process is dependent on thetype and concentration of the flocculant or coagulant, or both,the pH, the temperature, the filtration medium(a), and thefiltration rate. This practice permits the
11、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 design of large systems.1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direc
12、t 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 July 1, 2008. Published August 2008. Originallyapproved in 1982. Last previous edition
13、 approved in 2003 as D 4188 82 (2003).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 to the standards Document Summary page onthe ASTM website.1*A Summary of Changes
14、section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Apparatus6.1 Installation:6.1.1 To prevent contamination by corrosion products, usestainless steel, plastic, or coated (rubber or epoxy-lin
15、ed) steelfor all wetted parts.6.1.2 Take care to ensure that no contamination will occurfrom oil films on new metal piping, release agents 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 p
16、ressurized components based on themanufacturers working pressure rating. Review the manufac-turers rating for compliance with standard 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
17、 the filter effluent flow.NOTE 1Since the filter is intended to be operated at constant flow withdifferential pressure changes across the filter, manual flow adjustmentsmay be required periodically. For streams that yield a high filter loadingrate, an automatic flow control valve might be required.N
18、OTE 2If a holding tank is used, it should be designed to obtainuniform flow to minimize stagnant zones and to keep the floc suspended.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 throug
19、h the system under pres-sure. Use a gage pressure of 275 to 345 kPa (40 to 50 psi) asthe filter inlet pressure.NOTE 3If the water supply is already sufficiently pressurized, thepressurizing centrifugal pump is not required.6.1.6 Use a single calibrated pressure gage equipped with a“quick-connect” fi
20、tting to measure the filter inlet pressure andfilter pressure drop. Individual gages are also satisfactory butnot as reliable as a 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 accur
21、ate metering pump to inject the flocculantor coagulant, or both. Use an injector with a check valve andlocate the teat of the injector 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
22、suction line of the metering pump is placed into thevolume container, it is necessary to subtract the volume displaced by thesuction 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 mixi
23、ng 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, install 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 noproble
24、m provided the pump or piping or both are properly sized. Either ahigh-pressure limit control switch or a pressure-relief device can beinstalled after the pump, if there are any doubts about excessive pressure.6.1.13 If the system pressure fluctuates by more than6 35kPa (65 psi), install a pressure
25、regulator immediately down-stream of the pressure 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 D 2035.8. Procedure8.1 Start-Up Proce
26、dure:8.1.1 First, backwash the filter with the supply water tothoroughly clean the filter medium. Use the backwash raterecommended by the filter medium supplier, which is usuallyFIG. 1 Typical Pressure In-Line Coagulation-Flocculation Filtration SystemD 4188 08220 to 50 m3/(hm2) of filter area (8 to
27、 20 gal/(minft2).Backwash the filter until the turbidity (as determined by TestMethod D 7315) of the backwash is equal (within 10 %) to theturbidity of the supply water. For all sampling follow theprocedure given in Practices D 3370.NOTE 6New medium usually contains many fines which need to beremove
28、d for the best filter performance. During backwash approximately2 to 3 % of the medium can be siphoned off at the top of bed to removefines.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 co
29、ntrol valve.8.1.2.1 Set the inlet pressure to the filter at a gage pressureof 275 to 345 kPa (40 to 50 psi).8.1.2.2 Set the flow rate 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 ef
30、fectiveness of the filter medium inremoving colloidal and suspended particles with addition offlocculants or coagulants, or both, proceed to 8.2.3. To deter-mine the ability of the filter medium in removing colloidal andsuspended particles without addition of flocculants or coagu-lants, or both, ope
31、rate the filter for 30 min. Then, measure thewater quality of the filter effluent and compare it to the qualityof the supply water. Where possible measure the turbidity ofthe filter effluent on line using Test Method D 6698, otherwiseuse Test Method D 6855 or D 7315 to measure the waterquality. Repe
32、at the water quality measurements every 30 minuntil results indicate equilibration of the filter.8.2.2 Repeat 8.1.1 and 8.1.2.8.2.3 Start 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 co
33、agulant in thesupply water.8.2.3.1 Set the concentration of flocculant or coagulant inthe supply water using the injection pump curves (pumpingrate against back pressure), concentration of flocculant orcoagulant in the chemical feed tank, and the flow rate of waterthrough the filter. For example, fo
34、r 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 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.
35、Therefore,3.785 L/min.!/X L/min!5100X 5 0.03785 L/min 5 37.85 mL/minTherefore, set injection pump rate at 37.8 mL/min.8.2.3.2 If 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 m
36、in of operation to equilibrate the mixingsection then obtain a water sample just after the mixing sectionand measure the zeta potential, 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
37、 for cationic polyelectrolytes and inorganic coagulants(alum and iron). If a nonionic or anionic polyelectrolyte is used, omit 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 concen
38、tration of flocculant or coagulant, orboth, either up or down to obtain the desired zeta potential.8.2.7 After the desired zeta 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 f
39、locculant or coagulant, or both, addition) usingturbidity, suspended solids, or silt density index. Repeatmeasurements (both effluent water quality and zeta potential)every 30 to 45 min until equilibration of the system hasoccurred.8.2.8 If the desired zeta potential value is unknown or if zetapoten
40、tial measurements are not made, then the coagulantconcentration 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 w
41、ater quality.NOTE 9Exercise care since excess coagulant 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 coa
42、gulants, for example, alum, the pH is animportant parameter 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 t
43、he effect of filtration rate on effluentwater quality, 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 coagulan
44、ts, or both.8.2.13 To evaluate different medium, replace filter or filtermedium with new medium and repeat 8.1.1 to 8.2.9.8.2.14 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 theefflu
45、ent quality. When the effluent quality deteriorates 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 m
46、aterial 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
47、 in 8.1.1.Afterbackwashing operate the filter in the service direction with theaddition of the optimum flocculant or coagulant, or both,D 4188 083concentration and monitor the effluent water quality versustime to obtain acceptable water quality. Depending on thedesired water quality and nature of co
48、lloidal material in thesupply water, the rinse time can vary from 15 min to severalhours.8.3 Shutdown Procedure:8.3.1 Shut off the injection pump and push the stop buttonon the pressurizing pump motor.8.3.2 Allow the pressure to reach zero before disconnectingthe system or carrying out maintenance o
49、n the piping system.9. Calculation and Report9.1 Report the following data and information:9.1.1 Filter medium(a), depth of medium, filter area, filterflow rate, filter backwash rate, filter rinse rate, rinse time,backwash time, time between backwashings (service run time),pressure of filter influent, and pressure drop across filter duringservice run.9.1.2 Flocculant or coagulant, or both used, concentration offlocculant or coagulant, or both in chemical feed tank, concen-tration of flocculant or coagulant, or both in filter influent,injection pump flow rat
