A2O工藝計(jì)算講解

,A2/O工藝計(jì)算,,,,,,,,,,,,

一、工藝流程,,,,,,,,,,,,,

二、主要設(shè)計(jì)參數(shù),,,,,,,,,,,,,

三、設(shè)計(jì)計(jì)算,,,,,,,,,,,,,

項(xiàng)目,設(shè)計(jì)流量(m3/d),COD(mg/l),BOD5S0(mg/l),TSS（mg/l),VSS(mg/l),MLVSS/MLSS,TN(mg/l),NH3-N(mg/l),TP(mg/l),堿度S(mg/l),PH,最底水溫（℃）,最高水溫（℃）

進(jìn)水,3600,300,150,150,105,0.7,30,25,3,280,7.0～7.5,14,25

出水,,60,20,20,,,15,8,1.5,,,,

（活性污泥法）,,,,,,,,,,,,,

（1）判斷是否可采用A2O法（用污泥負(fù)荷法）,,,,,,,,,,,,,

,COD/TN=,10,>,8,,,,,,,,,

,TP/BOD5=,0.02,<,0.06,,,,,,,,,

,符合要求,,,,,,,,,,,,

(2)有關(guān)設(shè)計(jì)參數(shù),,,,,,,,,,,,,

,1、BOD5污泥負(fù)荷N=,,,,0.13,kgBOD5/(kgMLSS·d),,,,,,,

,2、回流污泥濃度XR=,,,,6600,mg/L,,,,,,,

,3、污泥回流比R=,,,,100,%,,,,,,,

,4、混合液懸浮固體濃度X=RXR/(1+R),,,,3300,mg/L,,,,,,,

,5、混合液回流比R內(nèi),,,,,,,,,,,,

,TN去除率ηtx=(TN0-TNe)/TN0×100%=,,,,50,%,,,,,,,

,混合液回流比R內(nèi)＝ηTN/(1-ηTN)×100%=,,,,100,%,,,,,,,

,,,,取R內(nèi)＝,150,%,,,,,,,

"（3）反應(yīng)池容積V,m3",,,,,,,,,,,,,

,V=QS0/NX=,1258.74,m3,,,,,,,,,,

反應(yīng)池總水力停留時(shí)間：,,,,,,,,,,,,,

,t=V/Q=,0.35,(d)=,8.40,(h),,,,,,,,

各段水力停留時(shí)間和容積：,,,,,,,,,,,,,

,厭氧：缺氧：好氧＝1：1：3,,,,,,,,,,,,

,,,厭氧池水力停留時(shí)間t厭=,1.68,(h),,,,,,,,

,,,池容V厭＝,251.7,(m3),,,,,,,,

,,,缺氧池水力停留時(shí)間t缺=,1.68,(h),,,,,,,,

,,,池容V缺＝,251.7,(m3),,,,,,,,

,,,好氧池水力停留時(shí)間t好=,5.04,(h),,,,,,,,

,,,池容V好＝,755.2,(m3),,,,,,,,

(4)校核氮磷負(fù)荷，kgTN/(kgMLSS·d),,,,,,,,,,,,,

,好氧段總氮負(fù)荷=Q·TN0/（XV好）＝,,,0.043335901,[kgTN/(kgMLSS·d)],,,<0.05,符合要求,,,,

,厭氧段總磷負(fù)荷=Q·TP0/（XV厭）＝,,,0.013002492,[kgTP/(kgMLSS·d)],,,<0.06,符合要求,,,,

(5)剩余污泥量△X，kg/d,,,,,,,,,,,,,

,△X=Px+Ps,,,,,,,,,,,,

,Px=YQ(S0-Se)-kdVXR,,,,,,,,,,,,

,Ps=(TSS-TSSc)*50%,,,,,,,,,,,,

,,取污泥增殖系數(shù)Y=,0.6,,,,,,,,,,

,,污泥自氧化率kd=,0.05,,,,,,,,,,

,,將各值代入：Px=,135,kg/d,,,,,,,,,

,,Ps=,234,kg/d,,,,,,,,,

,,△X=,369,kg/d,,,,,,,,,

(6)堿度校核,,,,,,,,,,,,,

,每氧化1mgNH3-N需消耗堿度7.14mg；每還原1mgNO3--N產(chǎn)生堿度3.57mg；去除1mgBOD5產(chǎn)生堿度0.1mg。,,,,,,,,,,,,

,剩余堿度SΔLK1＝進(jìn)水堿度-硝化消耗堿度+反硝化產(chǎn)生堿度+去除BOD5產(chǎn)生堿度,,,,,,,,,,,,

,假設(shè)生物污泥中含氮量以,,12.40%,計(jì)，則：,,,,,,,,,

,每日用于合成的總氮,,16.79,kg/d,,,,,,,,,

,即，進(jìn)水總氮中有,,4.66,mg/l用于合成。,,,,,,,,,

,,,,,,被氧化的NH3-N=進(jìn)水總氮-出水總氮量-用于合成的總氮量=,17.34,mg/l,,,,,

,,,,,,所需脫硝量＝,10.34,mg/l,,,,,

,需還原的硝酸鹽氮量NT=,,37.21,(mg/L),,,,,,,,,

,將各值代入：,,,,,,,,,,,,

,剩余堿度SALK1=,,206.1215963,(mg/l),>100mg/l,(以CaCO3計(jì)）,,,,,,,

,可維持PH≥7.2.,,,,,,,,,,,,

（7）反應(yīng)池主要尺寸,,,,,,,,,,,,,

,反應(yīng)池總?cè)莘eV＝,,1258.74,,m3,,,,,,,,

,設(shè)反應(yīng)池,2,組，單組池容V單＝,,629.37,m3,,,,,,,

,有效水深h=,4,m；,,,,,,,,,,

,單組有效面積S單=,,157.3425,m2,,,,,,,,,

,采用,5,廊道式推流式反應(yīng)池，廊道寬b=,,,2.5,m=,2500,mm,,,,

,單組反應(yīng)池長度L＝S單/B=,,18,(m)=,18000,mm,(實(shí)?。?,,,,,

,單組反應(yīng)池長度L＝S單/B=,,13,(m),,,（計(jì)算需要）,,,,,,

,校核：b/h=,0.6,(不能滿足b/h=1～2）,,,,,,,,,,

,L/b=,7.2,(滿足L/B=5～10）,,,,,,,,,,

,取超高為：,1,"m,則反應(yīng)池總高H=",,5,(m),,,,,,,

(8)反應(yīng)池進(jìn)、出水系統(tǒng)計(jì)算,,,,,,,,,,,,,

,1、進(jìn)水管,,,,,,,,,,,,

,,,單組反應(yīng)池進(jìn)水管設(shè)計(jì)流量Q1＝,0.021,(m3/s),,,,,,,,

,,,管道流速V=,0.8,m/s；,,,,,,,,

,,,管道過水?dāng)嗝娣eA=,0.02625,(m2),,,,,,,,

,,,管徑d=,0.182864678,(m),,,,,,,,

,,,取進(jìn)水管管徑DN,200,mm,,,,,,,,

,2、回流污泥管,,,,,,,,,,,,

,,,單組反應(yīng)池回流污泥管設(shè)計(jì)流量Qk＝,0.020833333,(m3/s),,,,,,,,

,,,管道流速V=,0.8,m/s；,,,,,,,,

,,,管道過水?dāng)嗝娣eA=,0.026041667,(m2),,,,,,,,

,,,管徑d=,0.182137579,(m),,,,,,,,

,,,取進(jìn)水管管徑DN,200,mm,,,,,,,,

,3、進(jìn)水井,,,,,,,,,,,,

,反應(yīng)池進(jìn)水孔尺寸：,,,,,,,,,,,,

,,,進(jìn)水孔過流量Q2＝,0.041666667,(m3/s),,,,,,,,

,,,孔口流速V=,0.6,m/s,,,,,,,,

,,,孔口過水?dāng)嗝娣eA＝,0.069444444,(m2),,,,,,,,

,,,孔口尺寸取為,0.4,m×,0.2,m=,0.08,(m2),,,,

,,,進(jìn)水井平面尺寸取為1m×2.5m,,,,,,,,,,

,4、出水堰及出水井,,,,,,,,,,,,

,按矩形堰流量公式計(jì)算：,,,,,,,,,,,,

,式中,,Q3=(1+R+R內(nèi))*Q/n=,0.072916667,(m3/s),,,,,,,,

,,b—堰寬，,b=,2.5,m；,,,,,,,,

,,H—堰上水頭，m。,H＝,0.062649254,(m),,,,,,,,

,,,出水孔過流量Q4=Q3=,0.072916667,(m3/s),,,,,,,,

,,,孔口流速v=,0.6,m/s,,,,,,,,

,,,孔口過水?dāng)嗝娣eA＝Q/V=,0.121527778,(m2),,,,,,,,

,,,孔口尺寸取為,0.7,m×,0.2,m=,0.14,(m2),,,,

,,,出水井平面尺寸取為1m×2.5m,,,,,,,,,,

,5、出水管,,,,,,,,,,,,

,,,反應(yīng)池出水管設(shè)計(jì)流量Q5＝Q2＝,0.041666667,(m3/s),,,,,,,,

,,,管道流速v=,0.8,m/s,,,,,,,,

,,,管道過水?dāng)嗝娣eA=,0.052083333,(m2),,,,,,,,

,,,管徑d=,0.257581434,(m),,,,,,,,

,,,取進(jìn)水管管徑DN,300,mm,,,,,,,,

,,,校核管道流速v=Q5/A=,0.589761736,m,,,,,,,,

9、曝氣系統(tǒng)設(shè)計(jì)計(jì)算,,,,,,,,,,,,,

,1、設(shè)計(jì)需氧量AOR,,,,,,,,,,,,

,AOR=去除BOD5需氧量-剩余污泥中BOD5氧當(dāng)量+NH3-N硝化需氧量-剩余污泥中NH3-N的氧當(dāng)量-反硝化脫氮產(chǎn)氧量,,,,,,,,,,,,

,碳化需氧量,,,=,492.56,(kgO2/d),,,,,,,

,硝化需氧量,,,,,=,287.0789817,(kgO2/d),,,,,

,反硝化脫氮產(chǎn)生的氧量,,,,,,,,,,,,

,,D3＝2.86NT=,106.4162364,(kgO2/d),,,,,,,,,

,總需氣量AOR＝D1+D2-D3=,,673.22,(kgO2/d)=,28.05086574,(kgO2/h),,,,,,,

,"最大需氧量與平均需氧量之比為1.4,則",,,,,,,,,,,,

,,AORmax=1.4R=,942.509089,(kgO2/d)=,39.27121204,(kgO2/h),,,,,,,

,,,去除每1kgBOD5的需氧量=AOR/[Q(S0-S)]=,1.438505936,(kgO2/kgBOD5),,,,,,,,

,2、標(biāo)準(zhǔn)需氧量,,,,,,,,,,,,

,采用鼓風(fēng)曝氣，微孔曝氣器。曝氣器敷設(shè)于池底，距池底0.2m，淹沒深度,,,,,,3.8,m，氧轉(zhuǎn)移效率EA=,,20%,計(jì)算溫度T＝,25,℃。

,將實(shí)際需氧量AOR換算成標(biāo)準(zhǔn)狀態(tài)下的需氧量SOR。,,,,,,,,,,,,

,,,,,,工程所在地區(qū)實(shí)際大氣壓為,,,1.02,×105,Pa,,

,,,ρ＝,1.006910168,；,,,,,,,,

,,,,CL—曝氣池內(nèi)平均溶解氧，取CL=,2,mg/L；,,,,,,,

,查表得水中溶解氧飽和度：,,Cs(20)=,9.17,"mg/l,",Cs(25)=,8.38,mg/l.,,,,,

,空氣擴(kuò)散氣出口處絕對(duì)壓為：,,Pb=,1.3854,×105,（Pa),,,,,,,

,空氣離開好氧反應(yīng)池時(shí)氧的百分比：,,,,,,,,,,,,

,,,,,17.53653445,%,,,,,,,

,好氧反應(yīng)池中平均溶解氧飽和度,,,,,,,,,,,,

,,=,9.118342412,(mg/l),,,,,,,,,

,標(biāo)準(zhǔn)需氧量：,,,,,,,,,,,,

,,SOR=,978.2095122,(kgO2/d)=,40.75872968,(kgO2/h),,,,,,,

,相應(yīng)最大時(shí)標(biāo)準(zhǔn)需氧量：,,,,,,,,,,,,

,,SORmax=,1.4SOR=,1369.493317,(kgO2/d)=,57.06222155,(kgO2/h),,,,,,

,好氧反應(yīng)池平均時(shí)供氣量：,,,,,,,,,,,,

,,,,679.3121613,(m3/h),,,,,,,,

,最大時(shí)的供氣量,,,,,,,,,,,,

,,Gsmax=1.4Gs=,951.0370258,(m3/h)=,15.8506171,(m3/min),,,,,,,

,3、所需空氣壓力p(相對(duì)壓力）,,,,,,,,,,,,

,,p＝h1+h2+h3+h4+Δh,,,,,,,,,,,

,式中,h1+h2,——,供風(fēng)管道沿程與局部阻力之和，取h1+h2=,,,,0.2,m；,,,,

,,h3,——,曝氣器淹沒水頭，,,,h3=,4.5,m；,,,,

,,h4,——,曝氣器阻力，取,,,h4=,0.4,m；,,,,

,,Δh,——,"富余水頭,",,,Δh=,0.5,m；,,,,

,,P=,5.6,(m),,,,,,,,,

,4、曝氣器數(shù)量計(jì)算(以單組反應(yīng)池計(jì)算）,,,,,,,,,,,,

,按供氧能力計(jì)算所需曝氣器數(shù)量。,,,,,,,,,,,,

,式中,"h1—按供氧能力所需曝氣器個(gè)數(shù),個(gè)；",,,,,,,,,,,

,,"qc—曝氣器標(biāo)準(zhǔn)狀態(tài)下，與好氧反應(yīng)池工作條件接近時(shí)的供氧能力,kgO2/(h·個(gè)）",,,,,,,,,,,

,"采用微孔曝氣器，參照有關(guān)手冊(cè)，工作水深4.3m，在供風(fēng)量1～3m2/(h·個(gè)）時(shí)，曝氣器氧利用率EA＝20%，服務(wù)面積0.3～0.75m2,充氧能力qc=0.14kgO2/(h·個(gè)）。則：",,,,,,,,,,,,

,,h1=,204,(個(gè)）,,,,,,,,,

,以微孔曝氣器服務(wù)面積進(jìn)行校核：,,,,,,,,,,,,

,,f=F/h1=,0.441176471,(m2),<0.75(m2),符合要求,,,,,,,

,5、供風(fēng)管道計(jì)算,,,,,,,,,,,,

,供風(fēng)干管采用環(huán)狀布置。,,,,,,,,,,,,

,,流量Qs=0.5Gsmax=,475.5185129,(m3/h)=,0.132088476,(m3/s),,,,,,,

,流速v=,10,m/s；,,,,,,,,,,

,,,0.129717221,(m),,,,,,,,,

,,取干管管徑為DN,150,mm,,,,,,,,,

,單側(cè)供氣（向單側(cè)廊道供氣）,,,,,,,,,,,,

,,流量Qs單=0.5Gsmax/3=,158.506171,(m3/h)=,0.044029492,(m3/s),,,,,,,

,流速v=,10,m/s；,,,,,,,,,,

,,,0.074892272,(m),,,,,,,,,

,,取支管管徑為DN,60,mm,,,,,,,,,

,雙側(cè)供氣（向兩側(cè)廊道供氣）,,,,,,,,,,,,

,,流量Qs雙=Gsmax/3=,317.0123419,(m3/h)=,0.088058984,(m3/s),,,,,,,

,流速v=,10,m/s；,,,,,,,,,,

,,,0.105913667,(m),,,,,,,,,

,,取支管管徑為DN,100,mm,,,,,,,,,

,10、厭氧池設(shè)備選擇（以單組反應(yīng)池計(jì)算）,,,,,,,,,,,,

,厭氧池設(shè)導(dǎo)流墻，將厭氧池分成3格，每格內(nèi)設(shè)潛水?dāng)嚢铏C(jī)1臺(tái)，所坱功率按5W/m3池容計(jì)算。,,,,,,,,,,,,

,,厭氧池有效容積V厭＝,,180,m3,,,,,,,,

,,混合全池污水所需功率為,,900,w,,,,,,,,

,11、缺氧池設(shè)備選擇（以單組反應(yīng)池計(jì)算）,,,,,,,,,,,,

,缺氧池設(shè)導(dǎo)流墻，將缺氧池分成3格，每格內(nèi)設(shè)潛水?dāng)嚢铏C(jī)1臺(tái)，所坱功率按5W/m3池容計(jì)算。,,,,,,,,,,,,

,,缺氧池有效容積V缺＝,,180,m3,,,,,,,,

,,混合全池污水所需功率為,,900,w,,,,,,,,

,12、污泥回流設(shè)備,,,,,,,,,,,,

,污泥回流比,R＝,100,%,,,,,,,,,

,污泥回流量,QR=,RQ=,3600,m3/d,,,,,,,,

,,,=,150,(m3/h),,,,,,,,

,,設(shè)混合液回流泵房,1,座,,,,,,,,,

,,每座泵房內(nèi)設(shè),3,臺(tái)潛污泵,2,用,1,備,,,,,

,,單泵流量QR單＝0.5QR=,75,(m3/h),,,,,,,,,

,水泵揚(yáng)程,,,,,,,,,,,,

,,,,,,,,,,,,,,

,,污泥回流總管設(shè)計(jì)流量Q污回＝,150,(m3/h),,,,,,,,,

,,污泥回流管設(shè)計(jì)流速采用V＝,1.2,m/s,,,,,,,,,

,,總管道過水?dāng)嗝娣eA＝Q污回/v=,0.034722222,m2,,,,,,,,,

,,管徑d=,0.21031436,(m),,,,,,,,,

,,污泥回流管徑管徑DN,200,mm,,,,,,,,,

,,校核管道流速v=,1.326963907,(m/s),,,,,,,,,

,,,,,,,,,,,,,,

,,,