潘 敏,黃曉鳴
(廈門(mén)理工學(xué)院環(huán)境科學(xué)與工程學(xué)院,福建廈門(mén)361024)
間歇曝氣和連續(xù)曝氣對(duì)生物脫氮除磷效果的比較
潘 敏,黃曉鳴
(廈門(mén)理工學(xué)院環(huán)境科學(xué)與工程學(xué)院,福建廈門(mén)361024)
采用序批式生物反應(yīng)器SBR系統(tǒng),考察反應(yīng)階段的間歇曝氣和連續(xù)曝氣對(duì)模擬生活廢水中氮和磷的去除效果.研究表明:IASBR和SBR對(duì)NH-N的去除率分別為99.30%和98.73%;對(duì)PO-P的去除率分別為97.02%和67.47%.間歇曝氣SBR對(duì)氨氮和磷酸根的去除率比連續(xù)曝氣SBR高,有利于實(shí)現(xiàn)強(qiáng)化生物脫磷過(guò)程.間歇曝氣SBR出水中氮、磷和COD濃度均達(dá)到了我國(guó)城鎮(zhèn)污水處理廠污染物排放標(biāo)準(zhǔn) (GB 18918—2002)一級(jí)標(biāo)準(zhǔn).
間歇曝氣;連續(xù)曝氣;氨氮;磷
近年來(lái),水體的富營(yíng)養(yǎng)化問(wèn)題已經(jīng)成為我國(guó)乃至全球面臨的嚴(yán)峻的水污染問(wèn)題之一.水體富營(yíng)養(yǎng)化主要表現(xiàn)為水體中氮和磷尤其是磷的濃度過(guò)高造成的水體污染[1].目前,氮磷的污染控制是熱點(diǎn)更是難點(diǎn)問(wèn)題.為了經(jīng)濟(jì)有效地去除污染水體中的氮和磷,序批式生物反應(yīng)器 (SBR)工藝因操作靈活、對(duì)氮和磷的去除效果好等原因得到了廣泛的應(yīng)用[2-3].SBR法的運(yùn)行工況是以間歇操作為主要特征,一個(gè)運(yùn)行周期可按運(yùn)行次序分為5個(gè)階段,即進(jìn)水、反應(yīng)、沉淀、排水和閑置階段.傳統(tǒng)的SBR系統(tǒng),反應(yīng)階段的曝氣過(guò)程為連續(xù)曝氣過(guò)程.近年來(lái),間歇曝氣因節(jié)省能源且出水水質(zhì)更好等原因,將傳統(tǒng)的連續(xù)曝氣變成間歇曝氣日益引起研究者的關(guān)注[4-7].然而,國(guó)內(nèi)外對(duì)比較連續(xù)曝氣和間隙曝氣對(duì)脫氮除磷的影響的研究甚少.本文以模擬生活廢水為處理對(duì)象,利用SBR比較反應(yīng)階段的連續(xù)曝氣和間歇曝氣對(duì)污水處理過(guò)程中脫氮除磷的影響,為水體富營(yíng)養(yǎng)化防治提供一種新的思路和方法.
1.1 試驗(yàn)裝置
試驗(yàn)中采用2個(gè)完全相同的聚乙烯玻璃柱作為SBR反應(yīng)器,所示2個(gè)反應(yīng)器的內(nèi)徑均為120 mm,高0.3 m,有效容積為2.5 L.一個(gè)作為間歇曝氣式SBR反應(yīng)器 (IASBR),一個(gè)作為傳統(tǒng)的連續(xù)曝氣式SBR反應(yīng)器.試驗(yàn)采用2個(gè)蠕動(dòng)泵(分別帶2個(gè)泵頭)分別用于2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)裝置運(yùn)行如圖1所示.
圖1 試驗(yàn)裝置運(yùn)行圖Fig.1 Schematic diagram of the laboratory-scale SBR systems
1.2 試驗(yàn)用水
人工模擬生活污水作為試驗(yàn)用水.水質(zhì)質(zhì)量濃度為500 mg·L-1COD(醋酸鈉),18 mg·L-1酵母提取物,31.4 mg NH-N/L(NH4Cl),17.8 mg PO-P/L(K2HPO4),130 mg·L-1MgSO4·7H2O,18 mg·L-1CaCl2.6H2O;微量元素溶液包括:CuSO4·6H2O(0.06 mg·L-1),FeCl3·6H2O (3.00 mg·L-1),ZnSO4.7H2O(0.24 mg·L-1),KI(0.06 mg·L-1),H3BO4(0.3 mg·L-1), MnCl2·4H2O(0.24 mg·L-1),Na2MoO4·2H2O(0.12 mg·L-1)和CoCl2·6H2O(0.30 mg·L-1).每升的人工配置模擬生活廢水中加入1 mL微量元素溶液.實(shí)驗(yàn)所需其他試劑均為分析純,購(gòu)于國(guó)藥集團(tuán)化學(xué)試劑有限公司 (上海).
1.3 反應(yīng)器運(yùn)行
活性污泥取自廈門(mén)市杏林污水處理廠. 2個(gè)反應(yīng)器均加入2 L的活性污泥,污泥的懸浮顆粒物質(zhì)量濃度SS為2.8 g·L-1. 2個(gè)反應(yīng)器的運(yùn)行周期均為6 h.其中IASBR的運(yùn)行時(shí)間分布:進(jìn)水 15 min, 3個(gè)不曝氣 (35 min)/曝氣 (60 min)循環(huán),沉淀 40 min,出水 15 min,閑置5 min;連續(xù)曝氣SBR運(yùn)行時(shí)間分布:進(jìn)水15min,不曝氣 105min,曝氣180 min,出水15 min,閑置5 min.間歇曝氣SBR和連續(xù)曝氣SBR在不爆氣階段和曝氣階段的時(shí)間總和相等,試驗(yàn)周期時(shí)間結(jié)構(gòu)如圖2所示.2個(gè)反應(yīng)器曝氣階段的曝氣率均控制在200 ml·min-1.兩個(gè)反應(yīng)器均在每一個(gè)循環(huán)的開(kāi)始進(jìn)水750 ml,水力停留時(shí)間HRT為16 h.每天在沉淀階段開(kāi)始前排出275 ml的混合液,污泥停留時(shí)間為7.2 d.
圖2 試驗(yàn)周期時(shí)間結(jié)構(gòu)圖Fig.2 Operation cycle of IASBR and SBR
1.4 水質(zhì)分析方法
2.1 IASBR和SBR系統(tǒng)在脫氮過(guò)程中的比較
2.2 IASBR和SBR系統(tǒng)在除磷過(guò)程中的比較
圖3 IASBR和SBR出水中NH-N質(zhì)量濃度Fig.3 Profile of effluent NH-N concentrations in IASBR and SBR
圖4 IASBR和SBR出水中NO-N質(zhì)量濃度Fig.4 Profile of effluent NO-N concentrations in IASBR and SBR
圖5 IASBR和SBR出水中NO?-N質(zhì)量濃度Fig.5 Profile of effluent NO-N concentrations in IASBR and SBR
圖6 IASBR和SBR出水中PO-P質(zhì)量濃度Fig.6 Profile of effluent PO-P concentrations in IASBR and SBR
1)與連續(xù)曝氣SBR相比,間歇曝氣SBR系統(tǒng)縮短了系統(tǒng)運(yùn)行穩(wěn)定的時(shí)間;間歇曝氣SBR對(duì)氨氮和磷酸根的去除率更高.
2)間歇曝氣有利于聚磷菌PAOs的生長(zhǎng),可以很好的實(shí)現(xiàn)強(qiáng)化生物脫磷過(guò)程.
3)間歇曝氣SBR出水中氮、磷和COD濃度均達(dá)到了中國(guó)城鎮(zhèn)污水處理廠污染物排放標(biāo)準(zhǔn)(GB18918-2002)一級(jí)標(biāo)準(zhǔn).
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Biological Nitrogen and Phosphorus Removal Efficiency by Intermittent Aeration and Continues Aeration Compared
PAN Min,HUANG Xiao-ming
(School of Environmental Science and Technology,Xiamen University of Technology,Xiamen 361024,China)
Biological nitrogen and phosphorus removal was investigated by an intermittently aerated sequencing batch reactor(IASBR)and a sequencing batch reactor(SBR).The removal efficiencies of ammonium-nitrogen(NH-N)were 99.30% and 98.73%,respectively in IASBR and SBR in steady operation,while phosphorus(PO-P)removal efficiencies were 97.02%and 67.47%in IASBR and SBR respectively.The intermittent aeration pattern has better effect for biological phosphorus removal.Effluent NH-N,PO-P and COD concentrations in the IASBR meets ChinaⅠEmission Standards.
intermittent aeration;continuous aeration;ammonium;phosphorus
X703
A
1673-4432(2015)05-0101-04
(責(zé)任編輯 李 寧)
2015-05-26
2015-09-29
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(mén)理工學(xué)院高層次人才項(xiàng)目(YKJ14037R);廈門(mén)理工學(xué)院對(duì)外科技合作交流專(zhuān)項(xiàng) (E201401200)
潘敏(1982-),女,講師,博士,研究方向?yàn)閺U水生物處理.E-mail:panmin@xmut.edu.cn