原液補(bǔ)碳模式對(duì)豬場(chǎng)厭氧消化液SFSBR處理特性的影響

馮 濤,李 平*,吳 靜,馬金珍,黃宇圣,徐 錳,吳錦華

原液補(bǔ)碳模式對(duì)豬場(chǎng)厭氧消化液SFSBR處理特性的影響

馮 濤1,2,李 平1,2*,吳 靜1,2,馬金珍1,2,黃宇圣1,2,徐 錳3,吳錦華1,2

(1.華南理工大學(xué)環(huán)境與能源學(xué)院,工業(yè)聚集區(qū)污染控制與生態(tài)修復(fù)教育部重點(diǎn)實(shí)驗(yàn)室,廣東 廣州 510006；2.華南理工大學(xué)環(huán)境與能源學(xué)院,污染控制與生態(tài)修復(fù)廣東省普通高等學(xué)校重點(diǎn)實(shí)驗(yàn)室,廣東 廣州 510006；3.博天環(huán)境集團(tuán)股份有限公司,北京 100082)

針對(duì)豬場(chǎng)糞尿厭氧消化液在后續(xù)生物處理過(guò)程中碳源,堿度的嚴(yán)重失衡問(wèn)題,采用“缺氧(A1)+曝氣(O1)+缺氧(A2)+曝氣(O2)”的分步進(jìn)水序批式反應(yīng)器(SFSBR)處理,以實(shí)現(xiàn)碳源,堿度的體系內(nèi)自平衡利用.通過(guò)改變A1,A2段的補(bǔ)碳量(采用定量的豬場(chǎng)糞尿原液,分別以1:1,1:3和3:1的體積比在反應(yīng)器每個(gè)周期的A1,A2階段啟動(dòng)時(shí)補(bǔ)碳,分別簡(jiǎn)稱(chēng)工況I,II,III),研究原液補(bǔ)碳模式對(duì)處理過(guò)程脫氮除磷特性的影響.結(jié)果表明,3種補(bǔ)碳模式均實(shí)現(xiàn)了短程硝化反硝化脫氮,反應(yīng)器內(nèi)pH值均穩(wěn)定在8.5左右,NH4+-N去除率均達(dá)到95%以上.原液補(bǔ)碳直接影響反硝化過(guò)程,工況I,II條件下A2段反硝化速率分別為2.19和2.15mg/(g·h),均約為工況III A2段的1.6倍.不同工況下原液補(bǔ)碳對(duì)A段釋磷和O段吸磷有顯著差異,工況I和III條件下SFSBR除磷效果更佳,出水TP濃度分別為7.9和6.4mg/L,去除率分別達(dá)到84.4%和87.3%,相較于工況II分別提高了9.5%和12.4%.綜合考慮脫氮除磷,有機(jī)物降解以及碳源/堿度自平衡控制,工況I為最佳補(bǔ)碳模式,系統(tǒng)出水COD,NH4+-N和TP濃度分別為360,10.6和7.9mg/L,相應(yīng)的去除率分別為74.9%,98.6%和84.4%.研究表明,采用A1/A2段原液添加比為1:1的補(bǔ)碳模式(即工況I)能在碳源/堿度自平衡的基礎(chǔ)上實(shí)現(xiàn)豬場(chǎng)糞尿厭氧消化液的高效脫氮除磷.

分步進(jìn)水序批式反應(yīng)器；豬場(chǎng)糞尿液；厭氧消化；原液補(bǔ)碳模式；脫氮除磷

隨著我國(guó)畜禽養(yǎng)殖業(yè)的迅猛發(fā)展,畜禽養(yǎng)殖廢水及糞便排放所導(dǎo)致的環(huán)境污染問(wèn)題日趨嚴(yán)重.厭氧+好氧生物處理組合技術(shù)是目前畜禽養(yǎng)殖廢水處理的主流工藝,然而在厭氧消化過(guò)程中,存在BOD5與COD,BOD5與NH4+-N生物降解及轉(zhuǎn)化不同步的問(wèn)題[1],使厭氧消化出水碳氮比嚴(yán)重失調(diào),導(dǎo)致后續(xù)處理系統(tǒng)電子供體缺乏,堿度失衡,進(jìn)而嚴(yán)重影響后續(xù)工藝的處理效果.針對(duì)這一問(wèn)題,雖然通過(guò)補(bǔ)充堿度[2],投加碳源等方法能夠取得較好的處理效果,但處理成本顯著上升,并且需要根據(jù)進(jìn)水水質(zhì)的波動(dòng)不斷進(jìn)行瞬時(shí)調(diào)節(jié),工藝過(guò)程控制的復(fù)雜程度增加,運(yùn)行費(fèi)用也大幅上升.

分步進(jìn)水序批式反應(yīng)器(SFSBR)是一種依靠缺氧段多步進(jìn)水補(bǔ)充反硝化碳源的生物強(qiáng)化脫氮工藝,該工藝提高了反硝化碳源補(bǔ)給率,脫氮的同時(shí)系統(tǒng)堿度得到回補(bǔ),實(shí)現(xiàn)脫氮過(guò)程碳源堿度自平衡[3-4].目前在利用SFSBR處理豬場(chǎng)養(yǎng)殖廢水方面的研究主要集中在SFSBR直接處理豬場(chǎng)原水[5-6],而關(guān)于SFSBR處理豬場(chǎng)廢水厭氧消化液的研究鮮有報(bào)道.本文研究了豬場(chǎng)廢水原液添加對(duì)豬場(chǎng)糞尿厭氧消化液SFSBR處理特性的影響,以期為SFSBR工藝的優(yōu)化調(diào)控提供實(shí)驗(yàn)依據(jù).

1 材料與方法

1.1 實(shí)驗(yàn)裝置

圖1 實(shí)驗(yàn)裝置示意

采用序批式氣升環(huán)流生物反應(yīng)器,結(jié)構(gòu)如圖1所示.反應(yīng)器高0.45m,內(nèi)徑0.14m,有效容積5.7L,由升流區(qū)(底部供氧,混合液呈上向流),降流區(qū)(混合液呈下向流,并由底部回流至升流區(qū))和三相分離區(qū)3部分組成.空氣由氣泵經(jīng)底部曝氣頭泵入反應(yīng)器中,并通過(guò)轉(zhuǎn)子流量計(jì)調(diào)節(jié)流量,以控制反應(yīng)器中DO濃度;當(dāng)反應(yīng)器處于缺氧階段時(shí),采用充入N2氣的方式確保反應(yīng)器內(nèi)泥水均勻混合.氣泵,進(jìn)水計(jì)量泵和出水口電磁閥由PLC系統(tǒng)控制.反應(yīng)器內(nèi)設(shè)有溫控裝置,維持在25~30℃.

1.2 進(jìn)水水質(zhì)及接種污泥

豬場(chǎng)糞尿廢液原液取自廣東省河源市某規(guī)?；B(yǎng)豬場(chǎng),厭氧消化液取自該豬場(chǎng)黑膜厭氧池出水,水質(zhì)特征見(jiàn)表1.原液和厭氧消化液均未檢出NO2--N及NO3--N.接種污泥取自廣州瀝滘污水廠二沉池,接種量為反應(yīng)器體積的20%,反應(yīng)器運(yùn)行過(guò)程中SRT約為20~25d,MLSS控制在4000~ 5000mg/L.

表1 豬場(chǎng)廢水與厭氧消化液的水質(zhì)特征

注:除pH值外,其余指標(biāo)單位均為mg/L.

1.3 實(shí)驗(yàn)方法

反應(yīng)器的啟動(dòng)馴化主要經(jīng)歷2個(gè)階段:第一個(gè)階段(0~30d),采用豬場(chǎng)廢水厭氧消化液分別稀釋10,5,3,1,0倍后進(jìn)入反應(yīng)器,進(jìn)行污泥的馴化.此階段未添加豬場(chǎng)廢水原液;第二階段(31~90d),采用未經(jīng)稀釋的厭氧消化液進(jìn)水,并按圖2的方式在A1/A2段按不同比例添加豬場(chǎng)廢水原液進(jìn)行馴化.SFSBR系統(tǒng)運(yùn)行一個(gè)周期為28h,其中進(jìn)水2min,缺氧攪拌(A1)4h,曝氣(O1)12h,缺氧攪拌(A2)8h,曝氣(O2)3.5h,靜置25min,出水3min.每周期運(yùn)行開(kāi)始時(shí)向反應(yīng)器內(nèi)泵入800mL厭氧消化液;原液補(bǔ)碳模式采用總量800mL豬場(chǎng)糞尿原液,分別以1:1,1:3和3:1的體積比在A1,A2 2個(gè)缺氧攪拌階段啟動(dòng)時(shí)加至反應(yīng)器中,分別簡(jiǎn)稱(chēng)工況I,II,III,3種工況下SFSBR的運(yùn)行策略見(jiàn)圖2.每周期結(jié)束時(shí)反應(yīng)器排水1.6L,水力停留時(shí)間4.2d.每個(gè)工況曝氣階段的DO濃度均維持在0.5~1.0mg/L.在經(jīng)過(guò)90d的馴化及穩(wěn)定運(yùn)行后,SFSBR系統(tǒng)在每種工況下連續(xù)運(yùn)行10d.

圖2 3種工況下SFSBR的運(yùn)行策略

1.4 分析方法

在一個(gè)運(yùn)行周期內(nèi)每隔2h自反應(yīng)器取樣.水樣4000r/min離心20min,上清液用0.45μm濾膜過(guò)濾.pH值采用PHS-3C精密pH計(jì)測(cè)定;DO采用YSI-550A溶氧儀測(cè)定;NH4+-N采用納氏試劑光度法;NO2--N采用N-(1-萘基)-乙二胺光度法;NO3--N采用紫外分光光度法;TP采用過(guò)硫酸鉀氧化-紫外分光光度法;COD按標(biāo)準(zhǔn)方法測(cè)定[8].

NAR(%),即亞硝酸鹽積累率,通過(guò)公式(1)計(jì)算[7].

式中:NO2--N和NO3--N指反應(yīng)器在曝氣階段積累的亞硝酸鹽氮和硝酸鹽氮的濃度,mg/L.

FA(mg/L),即游離氨濃度,通過(guò)公式(2)計(jì)算[8].

式中:NH4+-N為廢水中氨氮質(zhì)量濃度,mg/L;為反應(yīng)溫度,℃.

實(shí)驗(yàn)數(shù)據(jù)采用Microsoft Excel 2010和Origin8進(jìn)行處理和分析.

2 結(jié)果與討論

2.1 3種工況下SFSBR的運(yùn)行效果

3種工況下SFSBR的運(yùn)行效果如圖3所示.整體來(lái)看,3種工況下SFSBR對(duì)NH4+-N均表現(xiàn)出良好的去除能力,工況I,II,III中NH4+-N的平均去除率分別為98.2%,95.3%,97.8%.工況III中出水NO--N濃度顯著高于工況I和II.

3種工況下出水COD均穩(wěn)定在300~450mg/L,該部分COD被普遍認(rèn)為是難降解有機(jī)物.Prado等[9]采用離心分離等預(yù)處理技術(shù)結(jié)合缺氧-好氧-膜生物反應(yīng)器(A-O-MBR)處理豬場(chǎng)廢水,經(jīng)過(guò)9個(gè)月的穩(wěn)定運(yùn)行,結(jié)果表明該組合處理工藝對(duì)豬場(chǎng)廢水中COD的去除率維持在90%以上,但出水COD仍達(dá)到300~400mg/L.Kim等[10]認(rèn)為各種生物處理及不同的運(yùn)行工況均不能有效去除豬場(chǎng)廢水中的難降解有機(jī)物.

SFSBR在工況II條件下對(duì)TP的去除效果相較于在工況I,III條件下更差,SFSBR在工況I和III條件下每個(gè)運(yùn)行周期的出水TP均小于8mg/L.

2.2 原液補(bǔ)碳對(duì)SFSBR脫氮特性的影響

3種工況下SFSBR系統(tǒng)中氮素在一個(gè)運(yùn)行周期內(nèi)的變化如圖4所示,工況I,II,III進(jìn)水后初始NH4+-N濃度分別為143.8,118.2和167.4mg/L,當(dāng)反應(yīng)器處于A1階段時(shí),工況I和II中NH4+-N濃度無(wú)明顯變化;而工況III中NH4+-N出現(xiàn)明顯的下降,在A1段結(jié)束時(shí)降至131.4mg/L,這可能是工況III在A1階段發(fā)生了厭氧氨氧化作用.在上一周期結(jié)束時(shí)反應(yīng)器內(nèi)滯留的NO2--N在A1階段能得到有效去除,且工況I和III在A1段的反硝化作用優(yōu)于工況II,幾乎能將殘留的NO2--N完全轉(zhuǎn)化,直接原因是工況I和III在A1段易生物利用的碳源補(bǔ)充較工況II充足.

進(jìn)入O1段后,3種工況下NH4+-N均呈現(xiàn)與時(shí)間成線性關(guān)系的下降,同時(shí)出現(xiàn)大量NO2--N的積累,可知反應(yīng)器內(nèi)氨氧化菌(AOB)活性顯著高于亞硝酸鹽氧化菌(NOB),AOB成為優(yōu)勢(shì)菌群.工況I,II,III在O1段的亞硝酸鹽積累率NAR均高于90%,分別為92.6%,91.4%和90.1%.NOB的活性受到抑制是由于初始SFSBR反應(yīng)器內(nèi)較高濃度的FA[11-12].Chung等[13]認(rèn)為,當(dāng)進(jìn)水FA濃度大于5mg/L時(shí),即可顯著抑制NOB活性.本實(shí)驗(yàn)中,工況I,II,III在進(jìn)水后反應(yīng)器中的初始FA濃度分別為17.8,14.6和20.7mg/L,足以抑制NOB活性,促使反應(yīng)器長(zhǎng)期維持短程硝化反硝化狀態(tài).傳統(tǒng)的生物脫氮反應(yīng)動(dòng)力學(xué)理論認(rèn)為[14]:考慮細(xì)胞合成,還原1gNO3--N需要2.47g甲醇(相當(dāng)于3.71gCOD),而還原1gNO2--N需要1.53g甲醇(相當(dāng)于2.30gCOD),還原相同量的NO2--N和NO3--N,前者需求的COD量為后者需求的62%,即短程硝化反硝化過(guò)程相比于完全硝化反硝化過(guò)程節(jié)省了38%反硝化所需消耗的碳源.因此,短程硝化反硝化更有利于脫氮過(guò)程中的電子計(jì)量平衡控制.O1段結(jié)束時(shí),3種工況下反應(yīng)器內(nèi)NO3--N濃度均低于15mg/L,并在A2段開(kāi)始后被迅速完全去除.

一般認(rèn)為,硝化與反硝化的水力停留時(shí)間比以3:1為宜,可達(dá)到70%~80%的脫氮率[15],而在本實(shí)驗(yàn)中,O1段硝化與A2段反硝化的水力停留時(shí)間比達(dá)到1.5:1,如此設(shè)置的原因是A2段反硝化碳源補(bǔ)給來(lái)源于豬場(chǎng)原水中的易生物降解COD,相比于甲醇,乙酸鈉等[16-17]外加速效碳源而言,反硝化速率較慢,相應(yīng)所需水力停留時(shí)間較長(zhǎng).工況I,II,III在A2段補(bǔ)碳結(jié)束后系統(tǒng)的BOD5/NO--N分別為2.45,3.42和1.01,工況III在A2段的反硝化碳源補(bǔ)給明顯低于工況I和II,工況III在A2段的NO2--N去除率與反硝化速率分別為50.1%和1.29mg/(g·h).工況I和II在A2段的NO2--N去除率相差無(wú)幾,分別為93.5%和95.6%,均為工況III的1.8倍.工況I和II在A2段的反硝化速率分別為2.19和2.15mg/(g·h),均約為工況III的1.6倍.鄧良偉[18]等在研究原水添加比例對(duì)豬場(chǎng)廢水厭氧消化液后處理的影響時(shí)發(fā)現(xiàn),當(dāng)原水與厭氧消化液的混合液進(jìn)水BOD5/NO--N由0.70逐漸升高至2.62時(shí),反硝化速率由0.75mg/(g·h)逐漸升至1.50mg/(g·h),反硝化速率與BOD5/NO--N成正相關(guān),由于工況I,II在A2段的BOD5/NO--N高于工況III,所以工況I,II在A2段的反硝化速率比工況III高.由此可見(jiàn),A2段反硝化碳源補(bǔ)給匱乏是工況III在A2段NO2--N去除率低且反硝化速率慢的直接原因.

表2 SFSBR系統(tǒng)進(jìn)出水水質(zhì)及污染物去除率

注:“—”表示未檢測(cè)到數(shù)據(jù),“-”表示無(wú)法計(jì)算.

如表2所示,在工況I,II,III的條件下,SFSBR系統(tǒng)對(duì)NH4+-N的去除率分別為98.6%,95.1%和98.2%, 3種工況下SFSBR系統(tǒng)對(duì)厭氧消化液中的NH4+-N都具有較好的處理效果.工況II出水NH4+-N濃度高于工況I和III,這是由于作為反硝化碳源補(bǔ)給的豬場(chǎng)原水也含有高濃度的NH4+-N,工況II在A2段原水添加過(guò)量造成SFSBR出水NH4+-N濃度過(guò)高.工況III在A2段反硝化因碳源不足而反應(yīng)不完全,反應(yīng)器內(nèi)NO2--N積累導(dǎo)致工況III出水NO2--N濃度顯著高于工況I和II.盡管如此,滯留在反應(yīng)器中的NO2--N在下一個(gè)運(yùn)行周期的A1段幾乎能被完全去除,這也是反應(yīng)器在工況III下還能維持系統(tǒng)長(zhǎng)期穩(wěn)定運(yùn)行的原因.工況I,II,III在A2段啟動(dòng)時(shí)反應(yīng)器內(nèi)NO--N濃度分別為93.6,93.0和113.6mg/L,完全反硝化所需COD濃度從理論上計(jì)算分別為215.3, 218.4和276.4mg/L,而在實(shí)際運(yùn)行過(guò)程中,工況I,II,III在A2段通過(guò)添加原液補(bǔ)充的COD濃度分別為266,400和134mg/L,工況III在A2段的補(bǔ)碳量無(wú)法滿足實(shí)現(xiàn)完全反硝化的理論需求量.因此就一個(gè)運(yùn)行周期內(nèi)的脫氮過(guò)程而言,在控制A2段碳源的補(bǔ)充量與O1段硝化作用產(chǎn)生的NO2--N量相匹配上,工況III要劣于工況I和II,盡管其對(duì)NH4+-N的去除效果還優(yōu)于工況II.

2.3 原液補(bǔ)碳對(duì)SFSBR除磷特性的影響

由表2可知,在工況I,II,III條件下,SFSBR系統(tǒng)對(duì)TP的去除率分別為84.4%,74.9%和87.3%.工況II條件下SFSBR系統(tǒng)的除磷性能較工況I和III有顯著差異.3種工況下SFSBR系統(tǒng)中TP在一個(gè)運(yùn)行周期內(nèi)的變化如圖5所示,工況I和III反應(yīng)器內(nèi)TP的變化情況相似,聚磷菌(PAOs)通過(guò)在A1和O1段分別進(jìn)行釋磷和吸磷作用去除了反應(yīng)器內(nèi)大部分的TP,而工況II中反應(yīng)器在O1段結(jié)束時(shí)對(duì)廢水中的TP幾乎無(wú)去除效果,除磷過(guò)程主要發(fā)生在A2和O2階段.

實(shí)驗(yàn)過(guò)程中,反應(yīng)器內(nèi)TP的變化差異可由反應(yīng)器內(nèi)脫氮與除磷兩過(guò)程相互作用解釋.當(dāng)厭氧段存在NO2--N時(shí),反硝化菌會(huì)與PAOs競(jìng)爭(zhēng)利用生物易降解碳源,導(dǎo)致PAOs可利用的VFA量減少,釋磷量和PHB合成量減少[19].工況I和III在A1段補(bǔ)充了足夠的易降解碳源,能夠同時(shí)滿足完全反硝化和厭氧釋磷的需求,PAOs在釋磷過(guò)程中合成大量PHB,在隨后的O1段通過(guò)利用PHB為內(nèi)碳源進(jìn)行過(guò)量吸磷;而工況II在A1段碳源補(bǔ)充匱乏,反硝化菌優(yōu)先利用碳源使PAOs可利用的VFA量減少,釋磷量和PHB合成量也減少,直接影響O1段PAOs對(duì)磷酸鹽的吸收.相反地,工況III在A2段由于碳源不足,釋磷過(guò)程受到嚴(yán)重抑制;工況I在A2段補(bǔ)充的碳源大部分被反硝化菌利用,A2段PAOs的釋磷量相比于A1段明顯減少;工況II在A2段得到大量碳源補(bǔ)充,但由于前一階段的硝化作用積累了大量NO2--N,使得A2段反硝化菌進(jìn)行反硝化作用所消耗的碳源增多,PAOs可利用的碳源和釋磷量相對(duì)就會(huì)減少.另一方面,PAOs磷吸收量與磷釋放量成正比關(guān)系[20],工況I,III在一個(gè)運(yùn)行周期內(nèi)的釋磷總量均高于工況II,分別為108.6,112.8和79.60mg,因此工況I,III在整個(gè)運(yùn)行周期內(nèi)的吸磷總量也高于工況II,除磷效果更顯著.從除磷效果來(lái)看,A1段補(bǔ)碳量宜大于或等于A2.

圖5 3種工況下SFSBR系統(tǒng)中TP的周期變化

2.4 原液補(bǔ)碳對(duì)反應(yīng)器內(nèi)COD變化的影響

圖6 3種工況下SFSBR系統(tǒng)中COD的周期變化

3種工況下COD在一個(gè)運(yùn)行周期內(nèi)的變化如圖6所示,原水添加模式對(duì)進(jìn)水后反應(yīng)器的初始COD濃度影響較大.SFSBR進(jìn)水中易降解有機(jī)物主要在非曝氣階段被去除,難生物降解有機(jī)物在曝氣階段被去除[21].在A1和A2段添加原水后,其中的易降解碳源被反硝化菌和PAOs利用,COD迅速下降;而在O1和O2階段COD下降幅度較小,難生物降解有機(jī)物的去除主要發(fā)生在O1段,需要長(zhǎng)時(shí)間的曝氣且去除效率較低,若O1段曝氣時(shí)間過(guò)長(zhǎng)則會(huì)導(dǎo)致能耗過(guò)高.3種工況下A2段結(jié)束時(shí)反應(yīng)器內(nèi)的COD濃度均高于O1段結(jié)束時(shí)反應(yīng)器內(nèi)的COD濃度,說(shuō)明原水中部分可生化COD無(wú)法被反硝化菌和PAOs作為碳源利用,當(dāng)A2段原水添加量高于A1段時(shí),部分有機(jī)物無(wú)法被反硝化菌和PAOs利用而殘存在反應(yīng)器中,導(dǎo)致出水COD濃度較高.由表2可知,在工況I,II,III的條件下,SFSBR系統(tǒng)對(duì)COD的去除率分別為74.9%,70.3%和75.1%.SFSBR對(duì)COD的去除效果基本不受原液補(bǔ)碳模式的影響.

2.5 原液補(bǔ)碳對(duì)反應(yīng)器內(nèi)pH值變化的影響

如圖7所示,3種補(bǔ)碳工況下,反應(yīng)器中pH值無(wú)顯著性差異,均穩(wěn)定在8.5左右,表明反應(yīng)器在3種工況下均能長(zhǎng)期穩(wěn)定運(yùn)行.反硝化率是計(jì)算反硝化產(chǎn)生堿度的重要指標(biāo),反硝化率越高,意味著可產(chǎn)生堿度也越多.工況I,II,III在A1段的反硝化率分別為100%,51.7%和85.2%,在A2段的反硝化率分別為93.5%,95.8%和54.8%.工況I在A1,A2段的反硝化率均高于90%,因此,從系統(tǒng)堿度自平衡控制的角度考慮,工況I為最優(yōu)工況.

圖7 典型運(yùn)行周期內(nèi)pH值的變化曲線

3 結(jié)論

3.1 通過(guò)添加原水能夠解決SFSBR處理豬場(chǎng)糞尿厭氧消化液過(guò)程中碳源,堿度嚴(yán)重失衡的問(wèn)題.在三種原液補(bǔ)碳模式下,反應(yīng)器內(nèi)pH值均穩(wěn)定在8.5左右,同時(shí)對(duì)氮,磷及有機(jī)物具有良好的去除效果.

3.2 在3種原液補(bǔ)碳模式下,SFSBR均發(fā)生了短程硝化反硝化,NAR均高于90%,NH4+-N的去除率均達(dá)到95%以上.原液補(bǔ)碳直接影響A1和A2段的反硝化過(guò)程,工況I條件下反應(yīng)器在A1和A2段發(fā)生完全反硝化,而工況II,III反應(yīng)器分別在A1,A2段出現(xiàn)反硝化不完全的現(xiàn)象.工況I,II條件下反應(yīng)器在A2段的反硝化速率分別為2.19和2.15mg/(g·h),均約為工況III條件下的1.6倍.

3.3 不同工況下原液補(bǔ)碳對(duì)A段釋磷和O段吸磷有顯著差異.工況I和III除磷過(guò)程主要發(fā)生在A1-O1階段,而工況II除磷過(guò)程主要發(fā)生在A2-O2階段.工況I和III條件下SFSBR除磷效果更佳,出水TP濃度分別為7.9和6.4mg/L,去除率分別達(dá)到84.4%和87.3%,相較于工況II分別提高了9.5%和12.4%.從除磷效果來(lái)看,A1段補(bǔ)碳量應(yīng)大于或等于A2段.

3.4 綜合考慮脫氮除磷,有機(jī)物降解以及碳源,堿度的自平衡控制,3種原液補(bǔ)碳模式中,工況I為最佳補(bǔ)碳模式,出水COD,NH4+-N和TP濃度分別為360, 10.6和7.9mg/L,相應(yīng)的去除率分別為74.9%,98.6%和84.4%.在此模式下,無(wú)需添加外源有機(jī)碳及堿度,可實(shí)現(xiàn)豬場(chǎng)糞尿厭氧消化液的高效脫氮除磷.

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Effects of carbon supplementation modes of raw wastewater on the performance of SFSBR for anaerobically digested swine manure treatment.

FENG Tao1,2, LI Ping1,2*, WU Jing1,2, MA Jin-zhen1,2, HUANG Yu-sheng1,2, XU Meng3, WU Jin-hua1,2

(1.Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters < Ministry of Education>, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China；2.Key Laboratory of Pollution Control and Ecological Restoration of Guangdong Higher Education Institutes, South China University of Technology, Guangzhou 510006, China；3.Poten Environment Group Co., Ltd., Beijing 100082, China)., 2019,39(9)：3840~3847

In order to solve the problem of serious imbalance of carbon source and alkalinity in the subsequent biological treatment process, anaerobically digestate swine manure was treated by step-fed sequencing batch reactor running the program for "anoxic (A1) + aeration (O1) + anoxic (A2) + aeration (O2)", to achieve self-balance utilization of carbon source and alkalinity in the system. By changing the supplemental amount of carbon in A1and A2stage (the quantitative raw swine manure was used for carbon supplementation in the volume ratio of 1:1, 1:3 and 3:1 at the start of A1 and A2 stages of each cycle of the reactor, respectively, referred to as condition I, II, III), the effect of carbon supplementation mode of raw swine manure on the nitrogen and phosphorus removal characteristics of the treatment process was studied. The results showed that short-cut nitrification and denitrification was achieved in all three carbon supplementation modes, the pH value in the reactor was stable at about 8.5 and the removal rates of NH4+-N were above 95%. The carbon supplementation of raw manure directly affected the denitrification process. The denitrification rates of the reactor in A2 stage under the condition I and II reached 2.19 and 2.15mg/(g·h), respectively, which were about 1.6 times as high as that under the condition III. The carbon supplementation of raw manure had significant differences between A-stage phosphorus release and O-stage phosphorus uptake under the three conditions. The SFSBR phosphorus removal effect was better under the condition I and III, the effluent concentrations of TP were 7.9 and 6.4mg/L respectively, the efficiencies of TP removal were 84.4% and 87.3% respectively, which were 9.5 and 12.4percents higher than those of condition II, respectively. With a comprehensive consideration of nitrogen and phosphorus removal, organic matter degradation and carbon source/alkalinity self-balance control, the condition I was the best carbon supplementation mode, the effluent concentrations of COD, NH4+-N and TP were 360, 10.6and 7.9mg/L respectively, and the removal rates were 74.9%, 98.6% and 84.4% respectively. The results also indicated that the carbon supplementation mode which the A1/A2 raw wastewater addition ratio was 1:1 (condition I) can realize the high-efficiency nitrogen and phosphorus removal of anaerobically digested swine manure on the basis of carbon source/alkalinity self-balance.

SFSBR；swine manure；anaerobic digestion；carbon supplementation mode of raw swine manure；nitrogen and phosphorus removal

X703

A

1000-6923(2019)09-3840-08

馮 濤(1994-),男,浙江杭州人,華南理工大學(xué)環(huán)境與能源學(xué)院碩士研究生,主要從事廢水生物處理研究.發(fā)表論文3篇.

2019-02-04

廣東省科技發(fā)展專(zhuān)項(xiàng)資金資助項(xiàng)目(2017B020247025)

* 責(zé)任作者, 教授, pli@scut.edu.cn