進(jìn)水有機(jī)負(fù)荷和曝氣速率對(duì)強(qiáng)化脫氮的影響

潘 敏,黃曉鳴

(廈門理工學(xué)院環(huán)境科學(xué)與工程學(xué)院，福建 廈門 361024)

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進(jìn)水有機(jī)負(fù)荷和曝氣速率對(duì)強(qiáng)化脫氮的影響

潘 敏,黃曉鳴

(廈門理工學(xué)院環(huán)境科學(xué)與工程學(xué)院，福建 廈門 361024)

以模擬含氮廢水為處理對(duì)象，利用間歇曝氣序批式生物反應(yīng)器比較進(jìn)水有機(jī)負(fù)荷和曝氣速率對(duì)短程硝化反硝化強(qiáng)化脫氮的影響.實(shí)驗(yàn)結(jié)果發(fā)現(xiàn)，進(jìn)水有機(jī)負(fù)荷由0.35g/(L·d)增加到1.00g/(L·d)時(shí)，在同一個(gè)曝氣速率0.6L/min條件下，CODCr的去除率由97.67%減小到95.80%，TN的去除率由92.07%減少到85.64%；短程硝化反硝化效率η從38.96%升高到84.59%.在3個(gè)階段中，CODCr的去除率均隨著曝氣速率的增加而增加；總氮TN的去除率變化與曝氣速率的增加沒(méi)有明顯的關(guān)系；η隨著曝氣速率的增加而減少.η值越高，而TN的去除率越低.

曝氣；脫氮；進(jìn)水有機(jī)負(fù)荷；曝氣速率；短程硝化反硝化效率

研究表明，生物脫氮過(guò)程可以不經(jīng)過(guò)硝酸態(tài)氮[1]，而以亞硝酸態(tài)氮為中間產(chǎn)物被反硝化還原成氮?dú)?，這種技術(shù)即是短程硝化技術(shù)[1-2].短程硝化技術(shù)的優(yōu)點(diǎn)是：由于亞硝化菌的世代周期比硝化菌短，可以縮短反應(yīng)周期和水力停留時(shí)間并節(jié)省30%～40%的反應(yīng)器容積[3-5].近年來(lái)，關(guān)于短程硝化技術(shù)的研究大都集中在“短程同步硝化反硝化”“厭氧氨氧化”[6-9].與其相比，短程硝化反硝化(partialnitrificationanddenitrification,PND)有許多優(yōu)點(diǎn)，例如由于好氧和厭氧周期分步交替作用，PND可以減少系統(tǒng)的好氧曝氣時(shí)間，從而抑制硝化菌的生長(zhǎng)，并節(jié)約了由好氧過(guò)程曝氣所產(chǎn)生的能源消耗；另外PND存在厭氧反應(yīng)階段，可以提高厭氧反硝化菌的代謝效率和活性，并可有效抑制污泥膨脹等問(wèn)題的出現(xiàn)[6,10-12].為了保持穩(wěn)定的短程硝化，必須抑制硝化菌的生長(zhǎng)活性或代謝活性.溫度、pH值、溶解氧和污泥齡等因素都是抑制硝化菌活性和影響短程硝化效率的關(guān)鍵[13]，但是有效操控這些參數(shù)的相互作用，既增加了污水脫氮系統(tǒng)的操作難度，也成為了短程硝化實(shí)現(xiàn)的制約因素.根據(jù)研究發(fā)現(xiàn)，快速交替的間歇式曝氣策略可以實(shí)現(xiàn)短程分步硝化[14-15].在此基礎(chǔ)上，根據(jù)序批式生物反應(yīng)器(sequencingbatchreactor，SBR)曝氣易操控，處理效率高的特點(diǎn)，間歇曝氣SBR的研究正逐漸得到重視[16-17].目前對(duì)間歇曝氣SBR強(qiáng)化脫氮的研究多集中在運(yùn)行參數(shù)對(duì)短程硝化的影響，但間歇曝氣SBR工藝運(yùn)行參數(shù)影響短程硝化反硝化效率的報(bào)道極少.

本研究以模擬含氮廢水為處理對(duì)象，利用間歇曝氣SBR比較進(jìn)水負(fù)荷和曝氣速率對(duì)短程硝化反硝化效率的影響，對(duì)短程硝化反硝化效率進(jìn)行量化計(jì)算，為間歇曝氣SBR實(shí)現(xiàn)PND的機(jī)理研究提供理論基礎(chǔ).

1 材料與方法

1.1 實(shí)驗(yàn)裝置

試驗(yàn)中采用3個(gè)完全相同的圓柱體作為間歇曝氣序批式生物反應(yīng)器.兩個(gè)反應(yīng)器內(nèi)徑為19cm，外徑為20cm，高度為40.8cm，底部厚度0.6cm，有效容積為10L.試驗(yàn)采用兩個(gè)蠕動(dòng)泵(分別帶3個(gè)泵頭)分別用于3個(gè)反應(yīng)器的進(jìn)水和出水.小型的鼓風(fēng)機(jī)接砂頭進(jìn)行曝氣，停止曝氣后采用攪拌器進(jìn)行攪拌.曝氣/不曝氣的時(shí)間控制由時(shí)間控制器實(shí)現(xiàn).試驗(yàn)時(shí)間結(jié)構(gòu)圖見(jiàn)圖1和實(shí)驗(yàn)裝置運(yùn)行圖見(jiàn)圖2.

運(yùn)行分3個(gè)階段，3個(gè)階段的運(yùn)行周期都是8h，第Ⅰ階段運(yùn)行時(shí)間為62d，第Ⅱ階段運(yùn)行時(shí)間為63d，第Ⅲ階段，運(yùn)行時(shí)間為60d，間歇曝氣SBR運(yùn)行條件如表1所示.

表1 間歇曝氣SBR的運(yùn)行條件

1.2 實(shí)驗(yàn)用水

1.3 分析方法

pH值和DO含量測(cè)定采用便攜式pH計(jì)和溶解氧檢測(cè)儀測(cè)定.

2 結(jié)果與分析

2.1 曝氣速率對(duì)強(qiáng)化脫氮的影響

表2 3個(gè)運(yùn)行階段出水水質(zhì)

運(yùn)行階段曝氣速率/L·min-1CODCr濃度/mg·L-1去除率/%TN濃度/mg·L-1去除率/%Ⅰ0.230.24±0.8696.986.37±0.2993.230.428.76±0.8597.124.96±0.0894.730.623.28±1.0097.677.47±0.1592.07Ⅱ0.436.05±0.9796.4011.28±0.2688.020.629.84±0.6397.018.31±0.2291.170.827.47±0.5097.259.44±0.1689.97Ⅲ0.641.98±0.4695.8013.53±0.1785.640.838.25±0.6896.1711.64±0.1587.641.036.17±1.08—12.53±0.8686.60

2.2 進(jìn)水負(fù)荷對(duì)強(qiáng)化脫氮的影響

從表2得到，進(jìn)水負(fù)荷由0.35g/(L·d)增加到0.68g/(L·d)時(shí)，在同一個(gè)曝氣速率 0.4L/min條件下，CODCr和TN的去除率均是減??；η從63.31%升高到81.28%.同樣，進(jìn)水負(fù)荷由0.35g/(L·d)增加到1.00g/(L·d)時(shí)，在同一個(gè)曝氣速率0.6L/min條件下，CODCr和TN的去除率均減小，η從38.96%升高到84.59%.進(jìn)水負(fù)荷由0.68g/(L·d)增加到1.00g/(L·d)時(shí)，在同一個(gè)曝氣速率0.8L/min條件下，CODCr和TN的去除率均減小，從34.86%升高到73.69%.

3 結(jié)論

CODCr的去除率隨著曝氣速率的增加而增加；TN的去除率變化與曝氣速率的增加沒(méi)有明顯的關(guān)系.η值隨著曝氣速率的增加而減少.η值越高，TN的去除率越低.在同一個(gè)曝氣速率條件下，進(jìn)水負(fù)荷的增加會(huì)導(dǎo)致CODCr和TN的去除率減少、η值升高.

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(責(zé)任編輯 宋 靜)

Effect of Influent Organic Loading Rates andAeration Rates on Enhanced Nitrogen Removal

PAN Min, HUANG Xiaoming

(SchoolofEnvironmentalScience&Technology,XiamenUniversityofTechnology,Xiamen361024,China)

Inthisstudy,theeffectsofinfluentorganicloadingrates(OLRs)andaerationratesonpartialnitrificationanddenitrification(PND)inIASBRwereinvestigated.ExperimentalresultsshowedthatwhentheOLRswereincreasedfrom0.35g/(L·d)to1.00g/(L·d),attheaerationrateof0.6L/mincondition,theCODCrremovalratesweredecreasedfrom97.67%to95.80%,andtheTNremovalrateswerereducedfrom92.07%to85.64%;partialnitrificationanddenitrificationratesηwereincreasedfrom38.96%to84.59%.Inthethreestages，theCODCrremovalrateswereincreasedwiththeincreaseoftheaerationrates,theTNremovalrateschangeshadnoapparentrelationshipwiththeaerationrates；however,ηdecreasedwiththeincreaseoftheaerationrate.ηValuewashigher，leadingtotheTNremovalratelower.

intermittentaeration;denitrification;influentorganicloadingrate;aerationrate；partialnitrificationanddenitrificationefficiency

2016-07-30 [修回時(shí)間]2016-09-26

福建省自然科學(xué)基金計(jì)劃項(xiàng)目(2016J05140)；教育部留學(xué)回國(guó)人員科研啟動(dòng)基金(教外司留[2015]311號(hào))；廈門理工學(xué)院對(duì)外科技合作交流專項(xiàng)(E201401200)；廈門理工學(xué)院高層次人才項(xiàng)目(YKJ14037R)

潘敏(1982-)，女，講師，博士，研究方向?yàn)閺U水生物處理技術(shù).E-mail：panmin@xmut.edu.cn

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1673-4432(2016)05-0102-07