ISPE預(yù)處理選項(xiàng)

1、PRETREATMENTOPTIONS預(yù)處理選項(xiàng)4. PRETREATMENTOPTIONS預(yù)處理選項(xiàng)4.1 INTRODUCTION簡介Pretreatmentisallprocessstepsorunitoperationspriortothelast(final)watertreatmentstep.Pretreatmentisaseriesofunitoperationstomodifythefeedwaterqualitysothatitwillbeofadequatequalitytobefedtoafinaltreatmentstep.ThisfinalstepmaybeReve

2、rseOsmosis,Ultrafiltration,MultiorMixedBedDeionizationorDistillation.ThesefinalstepsarediscussedinChapters5and6.預(yù)處理是指最后(最終)水處理步驟之前的所有加工步驟或單元操作。預(yù)處理是一系列的單元操作，用來改善給水水質(zhì)以使其水質(zhì)足夠好而進(jìn)入終處理步驟。最終步驟可以是反滲透、超濾、多或混合床去離子或蒸儲(chǔ)。第5、6章中將詳細(xì)討論這些最終步驟。ReverseOsmosisisuniquesinceitcanbeapretreatmentstep,inadditiontobeingafinal

3、treatmentstep.ReverseOsmosisapplicationsinpretreatmentarediscussedinthischapterandChapter11,butReverseOsmosisasatechnologyisdiscussedinChapters5and6.反滲透很特別，因?yàn)樗纯梢允且粋€(gè)預(yù)處理步驟，另外還能是一個(gè)終處理步驟。本章和第11章將討論反滲透作為預(yù)處理的情況，而將其作為一門技術(shù)的情況將在5、6章中詳述。Theinitialsectionsofthischapterdiscusstheprocessdesign(programmingissues

4、)forpretreatmentdesignincludingfeedwaterqualityandoutputwaterqualityfrompretreatment.Thechapterthendiscussestheselectionoftreatmentoptions(i.e.unitoperations)forfourgroupsofimpurities:本章的開始部分討論預(yù)處理設(shè)計(jì)的過程設(shè)計(jì)(程序設(shè)計(jì)問題)，包括給水水質(zhì)和經(jīng)過預(yù)處理后出來的水質(zhì)。然后討論針對(duì)四種雜質(zhì)所做選擇的處理選項(xiàng)(即單元操作)：?Controloffouling-removalofturbidityandpar

5、ticulates渾濁度和粒子的除垢控制?Controlofscaling-removalofhardnessandmetals硬度和金屬的除氧化皮控制?Removaloforganicsandmicrobiologicalimpurities有機(jī)物和微生物雜質(zhì)的去除?Removalofmicrobialcontrolagents微生物防治因子的去除Pre-treatmentoptionsaresummarizedinFigure4-1attheendofthechapter.本章結(jié)尾處的圖4-1中總結(jié)了預(yù)處理的可選方案。Thefinalsectionsofthechapterdiscusst

6、heimportanceofanioncomposition/concentration,pH,materialsofconstruction,andpretreatmentsystemcontrol.本章的最后討論了陽離子的構(gòu)成/深度、pH、組成材料以及預(yù)處理系統(tǒng)控制的重要性。ThisdiscussionisbasedonthedescriptionofthesetechnologiespresentedinChapter11.這些討論是建立在11章中出現(xiàn)的對(duì)這些技術(shù)的敘述基礎(chǔ)之上的。4.2 PROCESSDESIGNOFPRETREATMENT預(yù)處理的過程設(shè)計(jì)Processdesignof

7、thepretreatmentsystemisthespecificationoftheunitoperationsorprocessstepstotreatthefeedwater.Typicalinformationincludesflowrates,temperatures,pressure,andcompositionofallstreams.DetailedmechanicaldesignoftheequipmentforagivenunitoperationorprocessstepisbeyondthescopeofthisGuide.預(yù)處理系統(tǒng)的過程設(shè)計(jì)是對(duì)處理給水的單元操作或

8、加工步驟的規(guī)范。典型信息包括流速、溫度、壓力以及所有水流的組合。為給出的單元操作或加工步驟的設(shè)備做詳細(xì)的機(jī)械設(shè)計(jì)不在此指南范圍內(nèi)。Theprocessdesign(programmingissues)forapretreatmentsystemmayinclude:預(yù)處理系統(tǒng)的過程設(shè)計(jì)(程序設(shè)計(jì)問題)可能包括：a) Requiredquantityandqualityofthewaterfromthefinaltreatmentprocess.經(jīng)過終處理程序出來的必須的水量和水質(zhì)。b) Temperatureconstraintsonthewaterusedinapharmaceuticalp

9、rocessandtheapproachtomicrobialcontrol.對(duì)用于制藥工藝的水溫和防治微生物所需的溫度限制。c) Thefinaltreatmentoptionthathasbeenchosen,asthisdefinestherequiredwaterqualityleavingpre-treatment.已經(jīng)選定的終處理選項(xiàng)，這就規(guī)定了離開了預(yù)處理步驟所需達(dá)到的水質(zhì)。d) Qualityofthefeedwaterthatistheinputtothepretreatmentsystem(waterqualitytobevalidatedoveraoneyearperio

10、d).預(yù)處理系統(tǒng)的給水水質(zhì)(驗(yàn)證水質(zhì)需要一年以上的期限)e) Differencebetweeninputwaterqualityanddesiredoutputwaterquality.Thedifferencedeterminesimpritiesthatmustberemovedbythepretreatmentsystem.Thedifferenceisdeterminedbyperformingamaterialbalance.Attentionshouldbepaidtoimpuritiesandminorcomponents.輸入水水質(zhì)和希望得到的輸出水水質(zhì)之間的差異。此差異確定

11、了必須要用預(yù)處理系統(tǒng)去除的雜質(zhì)。此差異是通過執(zhí)行一個(gè)物料平衡來決定的。應(yīng)當(dāng)特別注意雜質(zhì)和較小的組分。f) Pretreatmentoptionstoprovidethedesiredremovalofimpuritiesconsideringotherfactorssuchascapabilitiesofthelaborforce,economics,wastedisposal,environmentalconsiderations,validation,andtheavailablespaceandutilities.鑒于勞動(dòng)力、經(jīng)濟(jì)、廢物處理、環(huán)境因素、驗(yàn)證以及或用的空間和設(shè)施之類的因素，

12、預(yù)處理選項(xiàng)要能理想地去除雜質(zhì)。Inadditiontodefiningtheoptionsforremovalofimpurities,theapproachtakentomicrobialcontrolisanintegralpartoftheprocessdesignofthepretreatmentsystem.Considerationsinclude:除了規(guī)定去除雜質(zhì)這一項(xiàng)以外，用于防治微生物的途徑也是預(yù)處理系統(tǒng)過程設(shè)計(jì)需要整合的部分?？紤]包括：a) Ifthedrinkingqualitywatertothepretreatmentsystemcomesfromamunicipal

13、ityintheUnitedStates,itwilltypicallycontainchlorine,orchloramines,asamicrobialcontrolagent.InEurope,ozoneisthemorecommonmicrobialcontrolagent.Theconcentrationoftheagentshouldbesufficienttoprotecttheinitialstepsofthepretreatment.如果預(yù)處理系統(tǒng)的飲用水是來源于美國市區(qū)，那么它都會(huì)含有用作微生物防治因子氯或氯胺。在歐洲，臭氧是最普遍的微生物防治因子。因子的濃度應(yīng)當(dāng)足夠用來防

14、護(hù)預(yù)處理的最初步驟。b) Ifthequantityofmicrobialcontrolagentisinsufficient,additionalmicrobialcontrolagentmaybeaddedorprovisionmadetoperiodicallysanitizetheinitialequipmentinthepretreatmentsystem.Thisislikelyifwatercomesfromasourceotherthanamunicipality.Increasedmonitoringoffeedwaterandtheinitialstepsmaybewarr

15、anted.如果微生物防治因子的量不夠，那么可以添加額外的微生物防治因子或者在預(yù)處理系統(tǒng)的首個(gè)設(shè)備進(jìn)行定期消毒。如果水是來源于市政以外，這種情況是很有可能的。希望能夠保證增加對(duì)給水和最初步驟的監(jiān)控。c) Atsomepointinthepretreatmentprocess,themicrobialcontrolagentmustberemovedbeforegoingtothefinaltreatment.Atthispoint,ameansofeithercontinuousorperiodicsanitizationneedstobeselectedforthetreatmentstep

16、sfollowingthisremoval.在預(yù)處理過程的某些點(diǎn)上，進(jìn)行終處理前必須去除微生物防治因子。在這種點(diǎn)上，必須為去除之后的步驟選擇連續(xù)或定期消毒兩種方式其中之一。TheUSPrequirementthatcompedialwatersshouldcontainnoaddedsubstancd"eliminatesadditionofchemicalsto"PurifiedWater"orWaterForInjection.However,additionofchemicalagentsisnotprohibitedinpretreatment.Subst

17、ancesarefrequentlyaddedinpretreatmentandsubsequentlyremovedinthepretreatmentorfinaltreatment.Someexamplesare:USP規(guī)定法定水應(yīng)當(dāng)含有“非添加物質(zhì)”，這就排除了向“純化水”或注射用水中添加化學(xué)物質(zhì)的可能性。但是，在預(yù)見處理中并不禁止添加化學(xué)助劑。預(yù)處理時(shí)經(jīng)常會(huì)加入一些物質(zhì)，而它們又會(huì)在預(yù)處理或終處理中被去除。比如：?Chlorine(tocontrolmicrobialgrowth,removedinlaterstagesofpretreatment)氯(為了防治微生物生長，會(huì)在預(yù)處理的

18、最后階段去除)?Sodiumions(insoftenerwithexchangeformultivalentions,removedinionremovalprocess）鈉離子（在軟化器中和多價(jià)離子進(jìn)行交換，在去離子工序中被去除）?Acid（fordegasificationtoremovecarbondioxide,counterions,removedinasubsequentionremovalprocess）酸（為了脫除二氧化碳?xì)狻⒎措x子，在隨后的去離子工序中被去除）?Sulfite（toreducechlorinetochloride,orchloramihes,toammoni

19、umandchloridewhileformingsulfate,removalbysofteningorionremovalprocess）亞硫酸鹽（在形成硫酸鹽的同時(shí)將氯轉(zhuǎn)化為氯化物，或者將氯胺轉(zhuǎn)化為鏤和氯化物，通過軟化或去離子工序去除）?Sequestrants（topreventscalinginfinaltreatment,removedbyROinfinaltreatment）螯合劑（在終處理中防止結(jié)垢，通過終處理中的RO去除）?pHcontrolagents（removedinionremovalprocess）pH控制因子（在去離子工序中去除）Addedsubstancesar

20、eanissueiftheyresultinanincreaseinmicrobialgrowthorendotoxins.如果添加的物質(zhì)導(dǎo)致微生增長或內(nèi)毒素增加，那么它們就是一個(gè)問題。Afinalconsiderationistherelationshipbetweeninvestmentandoperatingdollarsinpretreatment,andtheperformanceandcostofthefinaltreatmentprocess.Thefollowingaregenerallytrue:最后需要考慮的是預(yù)處理的投資和開發(fā)費(fèi)用與終處理工藝的性能和成本之間的關(guān)系。?Af

21、inaltreatmentsystemwillnotoperatereliablyoverthelongterm,withoutreliableoperationofthepretreatmentsystem.如果預(yù)處理系統(tǒng)操作性不可靠，那么終處理系統(tǒng)的長期操作也不會(huì)可靠。?Inadequateoperationinpretreatment（breakthroughofparticulates,hardness,orchlorine）maynotimmediatelyaffectwaterqualityfromfinaltreatment,butitwillbereflectedinlongt

22、ermmaintenanceandoperatingreliability,andpossiblyinwaterquality.預(yù)處理中操作不充分（有粒子、硬度或氯漏過）或能不會(huì)立即影響到終處理的水質(zhì)，但是會(huì)反映在長期維護(hù)和操作可靠性上，也有可能是水質(zhì)。?Investmentinpretreatmentcapabilityandreliabilitycanreturnmanytimestheinvestmentinfinaltreatmentmaintenancecosts.在預(yù)處理能力和可靠程度上的投資得到的回饋會(huì)是花費(fèi)的終處理維護(hù)上的幾倍。?Pharmaceuticalwatersyste

23、msareexpectedtogeneratewatermeetingfinalpharmaceuticalproductwaterstandards.Thesystemshouldbedesignedtocontrolimpurityspikesintheincomingwaterquality,orseasonalimpurityprofilechanges.Arobustpretreatmentsystemdesignhandlesimpurityspikesdetrimentaltofinaltreatment.我們期望制藥用水系統(tǒng)生成的水能夠達(dá)到最終藥品的水質(zhì)標(biāo)準(zhǔn)。設(shè)計(jì)系統(tǒng)時(shí)應(yīng)當(dāng)控制

24、給水水質(zhì)中的雜質(zhì)峰，或者雜質(zhì)表現(xiàn)出的周期性變化。設(shè)計(jì)一個(gè)堅(jiān)固耐用的預(yù)處理系統(tǒng)來處理那些終處理不易去除的雜質(zhì)峰。Thereisnosingle"right"answertotheprocessdesignofthepretreatmentsystem.Pretreatmentsystemprocessdesignisaseriesofchoicesandoptions,eachwithadvantagesanddisadvantages.預(yù)處理系統(tǒng)的過程設(shè)計(jì)并沒有唯一的“正確”答案。預(yù)處理系統(tǒng)的過程設(shè)計(jì)是一系統(tǒng)的選擇，每個(gè)都有各自的利弊。4.3 FEEDWATERTOPRET

25、REATMENTQUALITY:TESTINGANDDOCUMENTATION預(yù)處理給水水質(zhì)：測(cè)試和文件記錄Compendialpharmaceuticalwatersystemsarerequiredtousefeedwatercomplyingwith"DrinkingWater"standards.法定的藥用給水系統(tǒng)應(yīng)當(dāng)用符合“飲用水”標(biāo)準(zhǔn)的給水。Mostpharmaceuticalmanufacturersutilizemunicipalwatersupplies.Thiswatergenerallymeets"DrinkingWater"qua

26、litystandardsandistreatedwithamicrobialcontrolagent.HistoricallyintheUS,themicrobialcontrolagentischlorine,butchloramineisnowusedwithincreasingfrequency.Eitherfeedwatercompositionormicrobialcontrolagentconcentrationmaybesubjecttooccasionalandseasonalvariations.Thesevariationsmaynegativelyimpactwater

27、quality,andcanbedetectedonlybyextensivesampling.Inaddition,waterqualityattheplantsitemaynotbeequivalenttothatfromamunicipaltreatmentfacility,duetopotentialforcontaminationorlossofmicrobialcontrolagentinthedistributionsystem.Documentationoffeedwaterqualityisrecommendedeitherbyuseofmunicipalitytesting

28、(ifapplicable)supplementedbysometestingattheplantsideorbyextensivetestingoffeedwaterquality.大多數(shù)的藥品制造商都是使用的市政供水。這個(gè)水一般都滿足“飲用水”的質(zhì)量標(biāo)準(zhǔn)，并用微生物防治因子處理過。在美國歷史上，微生物防治因子是氯、但是現(xiàn)在使用氯胺的頻率也在增加。給水成份或微生物防治因子的濃度都會(huì)受偶然因素或季節(jié)變化的影響。這種變化對(duì)水質(zhì)會(huì)有不利影響，而且只有用擴(kuò)大抽樣才能檢查出來。此外，在工廠里的水質(zhì)也有可能和市政處理廠出來的不一樣，這是因?yàn)樵诜峙湎到y(tǒng)中微生物防治因子在污染或丟失的可能性。給水的水質(zhì)文件推

29、薦用市政測(cè)試結(jié)果(如果適用的話)，再補(bǔ)充一些在工廠里所做的測(cè)試結(jié)果，也可以對(duì)給水水質(zhì)做全面的測(cè)試。Typicalcontaminantsinfeedwaterinclude:給水中含有的典型成分有：?ParticulatesSilt,dust,pollen,pipescale,ironandsilica,undissolvedmineralsandorganics粒子泥沙、灰塵、花粉、管垢、鐵和二氧化硅、不溶的礦物質(zhì)和有機(jī)物?InorganicsCalciumandmagnesiumsalts,heavymetals(iron,aluminum,andsilica)withtheircorre

30、spondinganions無機(jī)物鈣鹽和鎂鹽、帶有相應(yīng)離子的重金屬（鐵、鋁和硅）?OrganicsNATURALLYOCCURRINGBYPRODUCTSOFVEGETATIVEDECAY,I.E.,HUMICANDFULVICACIDSAND"MAN-MADEORGANICS"SUCHASPESTICIDESANDAUTOMOTIVEPOLLUTION（OILS）有機(jī)物自然存在的植物腐爛后的副產(chǎn)物，即腐殖酸和富里酸，以及“人造有機(jī)物”如殺蟲劑和汽車污染物（油）?BacteriaBACTERIALCONTAMINATIONANDITSBYPRODUCTS,ENDOTOXIN

31、S,ANDPYROGENS細(xì)菌細(xì)菌污染及其副產(chǎn)物，內(nèi)毒素和熱原Testingrecommendationsinclude:推薦的測(cè)試包括：?Documentationthatfeedwatermeetsdrinkingwaterquality.Thismaybebasedonresultsoftestingbythemunicipality,possiblysupplementedbylocalorin-processtesting.Frequencyofin-processtestingwillbeaffectedbyreliabilityofthemunicipality,importan

32、ceofmonitoredvariables,andcompanyphilosophy.給水符合飲用水水質(zhì)的文件。這可能是根據(jù)市政的測(cè)試結(jié)果，也有可能是由當(dāng)?shù)鼗蜻^程中測(cè)試結(jié)果補(bǔ)充的。市政當(dāng)局的可信度、監(jiān)控變量的重要性以及公司的理念都會(huì)影響過程中測(cè)試的頻率。?Monitoringformicrobialcontrolagentlevelsatthestartofthepretreatmentsystem.ChlorinelevelisaffectedbypH.Achlorinelevelof0.2-1.0ppmisgenerallyconsideredadequatetocontrolmicro

33、bialgrowthandgenerallyhasnegligibleeffectsonpretreatmentequipmentorperformance.在預(yù)處理系統(tǒng)初始處對(duì)微生物防治因子水平的監(jiān)控。氯的水平會(huì)受到pH的影響。一般認(rèn)為0.2-1.0ppm的氯完全能夠防治微生物生長，而且它對(duì)預(yù)處理設(shè)備和性能的影響也可以忽略不計(jì)。?Specifictestingforcontaminantsknownorsuspectedofbeingpresentinthefeedwater.Thisistodetermineifdatafromthemunicipalityisadequate;e.g.,

34、feedwaterfromasurfacesourceforpesticidesinanagriculturalareawhererunofffromfarmsmaybeseasonal.存在于給水中的已知或可疑污染物的特效試驗(yàn)。這個(gè)試驗(yàn)取決于市政方面的數(shù)據(jù)是否充分；例如來源于地表的給水，因?yàn)閺募覙I(yè)地區(qū)的農(nóng)田中流出的殺蟲劑可能是季節(jié)性的。QUALITYOF4.4 OUTPUTWATERFROMPRETREATMENT:FEEDWATERTOFINALTREATMENT預(yù)處理輸出水：終處理的給水水質(zhì)Thegoalsforpretreatmentaretoprovidewaterqualityth

35、atminimizestheoperatingandmaintenanceproblemsinthefinaltreatmentequipmentandtopermitthefinaltreatmentsteptoproducewatermeetingthedesiredspecificationsforfinaltreatment.預(yù)處理的目的是供水，所供的水質(zhì)應(yīng)當(dāng)能夠減少對(duì)終處理設(shè)備的操作和維護(hù)，并使終處理步驟生產(chǎn)出來的水符合終處理預(yù)期的要求。Theimpuritiesthatmustberemovedinthepretreatmentprocesstopermitreliableoper

36、ationofthefinaltreatmentstepdependonthefinaltreatmentstepselectedandthetoleranceofafinaltreatmentstepfortheimpurities.Ifpretreatmentisinadequate,resultingproblemscanbecomeverylargeinmagnitude,asseeninTable4-1below:那些必須在預(yù)處理過程中去除從而保證終處理步驟可靠的雜質(zhì)取決于所選擇的終處理步驟以及終處理步驟對(duì)雜質(zhì)的耐受程度。如果預(yù)處理不充分，最終導(dǎo)致的問題可能會(huì)非常嚴(yán)重，參見下表4-1

37、:Table4-1表4-1MAGNITUDEOFPROBLEMSINFINALTREATMENTCAUSEDBYTYPEOFIMPURITY由雜質(zhì)類型引起的終處理中的問題大小程度IMPURITY雜質(zhì)FOULING:causedbyparticulates污垢：由粒子引起SCALING:causedbyhardnessandminerals結(jié)垢：由硬度和礦物引起CORROSION:causedbychlorides府蝕：由氯化物引起DEGRADATION:causedbychlorine分解：由氯引起ReverseOsmosis反滲透Large大Large大None無Large*大*OtherM

38、embraneProcesses其它膜工藝Large-moderate大-中Large-moderate大-中None無Large*大*SingleEffectDistillation單效蒸儲(chǔ)Moderate中Moderate中Moderate-large大-中Large大Multi-effectDistillation多效蒸儲(chǔ)Large-moderate大-中Large-moderate大-中Moderate-large大-中Large大VaporCompressionDistillation蒸汽壓縮蒸儲(chǔ)Moderate中Moderate中Small小Large大*Membranedepen

39、dent*取決于膜Pretreatmentrequirementsforfeedwatertothefinaltreatmentprocessusuallyinclude:終處理的給水所做的預(yù)處理要求通常包括：FORMEMBRANES相對(duì)于膜Theconcernsarefoulingbysuspendedsolids(particulates)andscaling(precipitatingsolids)aswaterisremoved.Atypicalgoalforcontrolinpretreatmentmightbeasiltdensityindex(SDl)of3-5andhardne

40、ssof<1grain/gallonforon-siteanalysis.Membranestoleratechloridesbutonlysomemembranestoleratechlorine.它所擔(dān)心的是水移開后由懸浮固體(粒子)引起的污垢和結(jié)垢(致沉淀的固體)。在預(yù)處理中控制的最典型目標(biāo)是在線分析的泥沙密度指數(shù)(SDI)為3-5,硬度<1格令/加侖。膜能夠耐受氯化物，但是僅有一些膜能夠耐受氯。FORDISTILLATION相對(duì)于蒸儲(chǔ)Theconcernsarescaleformationduetohardnessandcorrosionduetochlorides.Typ

41、icalwaterqualitymightbeashighas1.0Mohm/cm,whichoftenrequiresadditionaltreatmentbeyondpretreatment,i.e.ROorultrafiltration.Distillationhasnotoleranceforchlorineduetocorrosionandcarryovertotheproduct.Distillationhassometoleranceforparticulates.它所擔(dān)心的是由硬度引起的結(jié)垢以及由氯化物引起的腐蝕。代表性的水質(zhì)可能有1.0Mohm/cm那么高，除了預(yù)處理以外經(jīng)常

42、還需要一些附加處理，即RO或超濾。由于腐蝕和帶給產(chǎn)品污染的原因，蒸儲(chǔ)并不耐氯。但是蒸儲(chǔ)對(duì)粒子卻有一些耐受力。Pretreatmentgenerallyhaslittleeffectontheotherparametersindicativeofwaterqualitysuchasanions,microbiallevels,conductivity,totalorganiccarbons(TOC),andvolatiles.預(yù)處理一般來說會(huì)對(duì)影響水質(zhì)的其它參數(shù)有一點(diǎn)影響，比如陰離子、微生物水平、電導(dǎo)率、總有機(jī)碳(TOC)和揮發(fā)性。Selectingpretreatmenttoreliablyp

43、rovidetherequiredfeedwaterqualitytofinaltreatment,inspiteofspikesinfeeddrinkingwaterquality,willreduceoperatingandmaintenancecostsinfinaltreatment.選擇預(yù)處理來為終處理提供所需水質(zhì)的給水，將會(huì)減少在終處理中的操作和維護(hù)費(fèi)用，盡管供給的飲用水中有雜質(zhì)峰。4.5 CONTROLOFFOULING:REMOVALOFTURBIDITYANDPARTICULATES污垢的防治：渾濁度和粒子的去除Theprincipalmethodsforremovingpa

44、rticulatesandreducingturbidityare:去除粒子以及降低渾濁度的主要方法是：?Clarificationandtheaccompanyingoperationsofflocculation,coagulation,andsedimentation澄清以及絮凝、凝結(jié)和沉淀的附隨操作?DepthorMediafiltrationincludingsingleandmultimediafiltration(particlesretainedbythemedia)深層和介質(zhì)過濾，包括單一過濾和多重過濾(介質(zhì)中所含的粒子)Thedefinitions,filtrationme

45、chanismsandtypicalremovalprocessesfortheseareoutlinedinChapter11.第11章中將概述它的定義，過濾機(jī)制和這些雜質(zhì)的典型去除工藝。Clarificationisnotapplicable,asfeedwatersourcesarepotablequalityorbetter.澄清是不適用的，當(dāng)給水水源是適合飲用或更好時(shí)。Depthormediafiltrationisusedinpharmaceuticalwatersystemsandisoftenthefirststepinapretreatmentsystem.Multi-siz

46、edsandisthemostcommonmedia,butothermediamayprovidebetterperformancewithsomefeedwaters.Removalofparticulatesdownto10micronsispossibleanddependsonselectionofmedia.Microbialgrowthisakeyconcerninamediafilter,unlessthefeedwatercontainsamicrobialcontrolagent.Otherwise,microbialcontrolinthedepthfilterisreq

47、uired(e.g.,periodicsanitizationusingeitherheatorachemicalsanitizingagent).深層和介質(zhì)過濾用于制藥給水系統(tǒng)，通常也是預(yù)處理系統(tǒng)的第一步。大小不一的沙子是最普遍介質(zhì)，但是其它介質(zhì)可能會(huì)為某些給水提供更好的性能。去除10微米以上的粒子是有可能的，這取決于所選的介質(zhì)。在介質(zhì)過濾中，微生物的生長是擔(dān)心的關(guān)鍵，除非給水中含有微生物防治因子。否則，深層過濾中就需要對(duì)微生物進(jìn)行防治(例如，用加熱或化學(xué)消毒劑進(jìn)行定期滅菌)。4.6 CONTROLOFSCALING:REMOVALOFHARDNESSANDMETALS水垢的控制：硬度和金屬

48、的去除Whenwaterisseparatedfromitsimpuritiesinthefinaltreatmentprocess,thosecompoundswithlowsolubilityareconcentratedtothepointwheretheyprecipitate.Thisprecipitation,orscaling,istheresultofexceedingthesolubilityofthedivalentandtrivalentcations,usuallyasasparinglysolublesaltsuchascarbonateorsulfate.Theme

49、thodsofcontrolare:在最終的處理工藝中將水和雜質(zhì)分離開后，那些微溶性的化合物就會(huì)濃縮到它們的深沉點(diǎn)。這些沉淀或水垢，通常是一種像碳酸鹽或硫酸鹽之類的微溶性的鹽超過了它二價(jià)和三價(jià)陽離子溶解度的結(jié)果。控制方法有：?Removalbyionexchange.Theseareprincipallycalciumandmagnesiumandmayincludedivalentandtrivalentionssuchasiron,aluminumandsilica.Pretreatmentisusuallywatersoftening,(exchangingtheionscausingh

50、ardnessandscalingforsodiumions).用離子交換去除。這些主要是鈣和鎂，也有可能包括一些二價(jià)和三價(jià)離子，像鐵、鋁及硅。通常的預(yù)處理是水軟化(將鈉離子與引起硬度和水垢的離子進(jìn)行交換)?Removalofcarbonatebyacidification.Acidificationconvertsthecarbonatetocarbondioxide,whichisremovedbysubsequentdegasification.加酸去除碳酸鹽。酸會(huì)使碳酸鹽轉(zhuǎn)化成二氧化碳，它在后面的脫氣中即可去除。?Removaloftheoffendingcompoundbyabarr

51、ierfiltrationprocesssuchasnanofiltration.Waterpassesthroughthemembraneandcompoundsareretainedbythemembraneandremovedasapurgestream.用鈉濾之類的屏障過濾過程去除引起困擾的化合物。讓水通過膜，化合物作為一個(gè)凈化流就被留在膜上去除掉了。TheseremovalprocessesaredetailedinChapter11.這些去除工藝將在第11章詳細(xì)討論。Watersofteningionexchange,whichremovesdivalentandtrivalent

52、ionsandreplacesthemwithsodium,isaverycommonprocessusedinpretreatmentofpharmaceuticalwater.Itisapplicableforallflowratesandallhardnesslevels,andiswellunderstoodandeasytooperate.Itinvolvesthehandlingofsaltonly,andproducesanon-hazardouswastestream.However,thehightotaldissolvedsolids(TDS)inthewastestrea

53、mmaylimitdisposaloptions.WatersofteningisalsoeasilycontrolledmanuallyorwithaPLC.水軟化離子交換是用鈉代替水中的二價(jià)和三價(jià)離子，它是制藥用水預(yù)處理中非常常用的方法。它可用于各種流率和各種硬度水平，并且易于掌握和操作。它只涉及鹽的處理，并且排出的廢液是無害的。然而，廢水中高的總?cè)芙夤腆w(TDS)量可能會(huì)限制處理選項(xiàng)。水軟化也易于用手動(dòng)或PLC控制。Forlargeflowrates(>50gpmor0.18m3/min)andhighhardness(>50ppm)degasification(aftera

54、cidification)maybetheprocessofchoice.ThisdegasificationprocessisoftenemployedbetweenthetwostagesofanROandinvolvesthehandlingofacidandbasefortwopHadjustments:對(duì)于大流率(>50gpm或0.18m3/min)以及高硬度(>50ppm)的水，可選則脫氣(酸化后)。該脫氣過程常用于兩級(jí)反滲透之間，并涉及酸堿處理的兩個(gè)pH調(diào)節(jié)：LoweringofpHbeforefirststageofRO一級(jí)反滲透前降低pHIncreasingofp

55、HbeforesecondstageofRO二級(jí)反滲透前增加pHTheprincipaladvantageisthatthecarbondioxideisreleasedtotheatmosphereratherthanbeingaliquidwastestreamrequiringdisposal.主要優(yōu)點(diǎn)是：二氧化碳釋放到大氣中而不是留在需處理的廢液中。Nanofiltrationisamembraneprocessthatmaybeapplicablewithcertainfeedwatersandspecializedsituations.Thefiltrationisusuallyc

56、ross-flowandinvolvesasignificantpurgestream.ItismuchlikeRO,thedifferencesbeingporesizeinthemembraneandthecorrespondingeffectonionremoval.Removalofdivalentionscanbegreaterthan98%.納米過濾是一種膜處理，它可能用于特定的給水和特殊的情況。該過濾通常是錯(cuò)流，并涉及一個(gè)重要的除污流。它和反滲透非常相似，它們之間的差別是膜的孔徑不同，以及相應(yīng)的去除離子的效果的不同。二價(jià)離子的去除水平可大于98%。Chemicalinjectio

57、nisanalternatemethodtocontroltheionsorcompoundsthatcontributetoscaling.Thisprocessinjectsacompound(usuallyaproprietaryorganiccompound)tothefinaltreatmentfeedwater.Thesecompoundsarecalledsequestrantsandact"totieupandcomplex"theoffendingionsorcompoundstoformacomplex,orcompound,thatismoresolu

58、bleandwillnotprecipitateinthefinaltreatmentprocess.The"complexedionandsequestrant"havealargemolecularweightandareremovedasapurgestreaminthefinaltreatmentprocess.Sequestrantsarealmostalwaysproprietarycompounds,whichrequiretestingtoverifyapplicabilityanddosagelevelfortheparticularfeedwater,andanalysistoverifyremovalinthefinaltreatmentprocess.可選擇用添加化學(xué)藥品的方法來控制離子或易于結(jié)垢的化合物。該處理是在給水的最后處理時(shí)，向其中添加化合物(通常是專用有機(jī)化合物)。該化合物被稱為多價(jià)螯合劑，它的作用是將需去除的離子或化合物“連接或復(fù)合”起來形成一個(gè)復(fù)合