常 城,明磊強(qiáng),牟云飛,華志良,李先國,張大海*

廚余垃圾與污泥厭氧發(fā)酵產(chǎn)甲烷的協(xié)同作用

常 城1,明磊強(qiáng)2,牟云飛1,華志良2,李先國1,張大海1*

(1.中國海洋大學(xué)化學(xué)化工學(xué)院,山東 青島 266000；2.液化空氣(中國)研發(fā)有限公司,上海 200030)

以剩余污泥和廚余垃圾混合進(jìn)行共發(fā)酵,評估其厭氧發(fā)酵協(xié)同效果,基于揮發(fā)性固體懸浮物(VSS)設(shè)置剩余污泥和廚余垃圾比例為1:0,4:1,2:1,1:1,1:2,1:4,0:1的生化甲烷潛勢(BMP)實(shí)驗(yàn),通過厭氧發(fā)酵前后pH值、COD、總氮、氨氮、硝酸鹽氮等參數(shù)的變化,甲烷產(chǎn)量,碳的遷移、轉(zhuǎn)化和微生物群落結(jié)構(gòu)變化評價(jià)協(xié)同產(chǎn)甲烷效果.結(jié)果表明,剩余污泥厭氧發(fā)酵過程中,廚余垃圾的加入能顯著提升微生物的污泥降解能力,增大甲烷產(chǎn)量,配比為1:4時(shí)產(chǎn)甲烷量最大,為274.37mL/g-VSS,協(xié)同增長率達(dá)27.41%.廚余垃圾的加入,增加了產(chǎn)甲烷延滯期,能夠促進(jìn)碳元素由固相-液相-氣相的轉(zhuǎn)移,有利于產(chǎn)甲烷菌()及其輔助菌種(等)的生長繁殖.

剩余污泥；廚余垃圾；厭氧發(fā)酵；碳平衡；微生物分析

厭氧發(fā)酵不僅能降解污泥,殺死病原體,還能產(chǎn)生生物能源甲烷,是眾多污水處理廠的污泥處置方法[1-3].污泥厭氧發(fā)酵過程中,經(jīng)常出現(xiàn)碳源不足和氨氮的積累導(dǎo)致的限制問題,難以進(jìn)一步降解[4-5],導(dǎo)致污泥處理不徹底、處置費(fèi)用高.如何在厭氧發(fā)酵過程中綠色補(bǔ)充碳源,促進(jìn)污泥進(jìn)一步降解,是實(shí)現(xiàn)其無害化、減量化、資源化的發(fā)展方向[6].

廚余垃圾富含淀粉類、蛋白質(zhì)等易生物降解組分,含有大量碳源,厭氧發(fā)酵過程降解速率快,容易導(dǎo)致?lián)]發(fā)性脂肪酸積累,影響反應(yīng)進(jìn)行[7-9].廚余垃圾和污泥在厭氧發(fā)酵過程中能夠有效互補(bǔ)碳與氮,兩者共發(fā)酵可減少單一底物帶來的限制.關(guān)于廚余垃圾與污泥混合厭氧發(fā)酵的研究目前主要集中在甲烷產(chǎn)率和效率[10-12],而相關(guān)的碳平衡、微生物分析等鮮有報(bào)道.

本文以剩余污泥和廚余垃圾為研究對象,將其按照不同比例混合進(jìn)行厭氧發(fā)酵,分析了厭氧發(fā)酵前后pH值、COD、總氮、氨氮、硝酸鹽氮等參數(shù)變化,產(chǎn)氣情況,碳的遷移轉(zhuǎn)化、微生物變化,探討厭氧發(fā)酵過程中剩余污泥與廚余垃圾的協(xié)同作用效果及機(jī)理,旨在為廚余垃圾和剩余污泥的無害化、減量化、資源化、低成本處置提供參考.

1 材料與方法

1.1 實(shí)驗(yàn)材料

實(shí)驗(yàn)所用出口泥(厭氧發(fā)酵池出口)、剩余污泥(二次沉淀池)均取自青島某污水處理廠.廚余垃圾原料取自中國海洋大學(xué)北區(qū)第一食堂,以淀粉類(米飯和饅頭)、纖維素類(菜花和油菜)和蛋白質(zhì)類(雞肉和魚肉)質(zhì)量比2:1:1混合,粉碎機(jī)粉碎后,過18目不銹鋼篩(￡1mm)篩分.

表1 實(shí)驗(yàn)材料及相關(guān)參數(shù)

注:TSS為總固體懸浮物,VSS為揮發(fā)性固體懸浮物.

1.2 儀器與試劑

主要儀器:CS-700型粉碎機(jī)(永康市天祺盛世工貿(mào)有限公司);DR200型消解儀配備DR2800型分光光度計(jì)(哈希中國);DHG-9070A型電熱鼓風(fēng)干燥機(jī)(上海一恒科技有限公司);DRZ-12D型馬弗爐(龍口市電爐制造廠); GC-2014C型氣相色譜儀器(日本島津)配備熱導(dǎo)池檢測器.TOC-L CPH SSM-5000A型總有機(jī)碳分析儀(日本島津).

主要試劑: 200～15000mg/LCOD試劑,0～50mg/L氨氮試劑,0～150mg/L總氮試劑均購自哈希中國.

1.3 批式實(shí)驗(yàn)

實(shí)驗(yàn)于有效容積為400mL上下端配置直通閥的發(fā)酵瓶中進(jìn)行發(fā)酵,上直通閥連接集氣袋.反應(yīng)前高純氮驅(qū)氧,創(chuàng)造厭氧環(huán)境.實(shí)驗(yàn)過程中運(yùn)用磁力攪拌器持續(xù)進(jìn)行攪拌.

剩余污泥(S)與廚余垃圾(K)按照VSS質(zhì)量比1:0,4:1,2:1,1:1,1:2,1:4,0:1的比例為飼料泥,設(shè)置7組生化甲烷潛勢(BMP)實(shí)驗(yàn).飼料泥與接種泥(出口泥)以體積比1:1混合,總體積為400mL,35℃,500r/min下持續(xù)攪拌,反應(yīng)時(shí)間為30d.

1.4 分析方法

TSS、VSS采用重量法,測定污泥經(jīng)6000r/min離心取上清液,經(jīng)0.45μm濾膜過濾,采用分光光度法測量溶解性化學(xué)需氧量(SCOD)、總氮(TN)、氨氮(NH4+-N)、硝酸鹽氮(NO3--N)[13].碳含量用燃燒氧化-非分散紅外吸收法測定.排水法測氣體體積.

運(yùn)用16S rDNA擴(kuò)增子測序技術(shù)對樣本中微生物多樣性組成進(jìn)行分析[14].采用CTAB或SDS方法對樣本的基因組DNA進(jìn)行提取,利用瓊脂糖凝膠電泳檢測DNA的純度和濃度,16S V4區(qū)引物(515F和806R)進(jìn)行細(xì)菌PCR擴(kuò)增,PCR產(chǎn)物使用2%濃度的瓊脂糖凝膠進(jìn)行電泳檢測及純化,使用TruSeq? DNA PCR-Free Sample Preparation Kit建庫試劑盒進(jìn)行文庫構(gòu)建,使用NovaSeq6000進(jìn)行上機(jī)測序.

氣體成分應(yīng)用氣相色譜,外標(biāo)法測定氣體中CO2、N2和CH4含量[15].氣相色譜條件:載氣為高純氬氣(99.999 %,0.6MPa),氬氣流量為40mL/min,空氣流量為400mL/min,色譜柱為TDX-01型填充柱(30m×0.32mm×0.25nm),進(jìn)樣口溫度、色譜柱溫度和TCD檢測器溫度分別為60,50和60℃,進(jìn)樣量5mL.

1.5 數(shù)據(jù)處理及分析

比氣體產(chǎn)量表示系統(tǒng)添加單位有機(jī)質(zhì)(以1gVSS計(jì))所產(chǎn)氣量(mL/g-VSS)[16].

1.5.1 相對污泥減量化評價(jià) 考察污泥減量化及廚余垃圾的加入是否增加了污泥的量,以TSS為參考指標(biāo),S:K為1:0體系為基準(zhǔn)得污泥相對減量率(相對),公式如下:

式中:TSSRR()為各比例體系(S:K為1:0,4:1,2:1,1:1, 1:2,1:4,0:1)TSS去除率,%;TSS(S)為S:K為1:0體系厭氧發(fā)酵前的總固體懸浮物,g/L;為反應(yīng)液體積,L;TSSK為廚余垃圾總固體懸浮物,g/L;V為該比例體系廚余垃圾投入量,L.

1.5.2 共發(fā)酵產(chǎn)甲烷評價(jià) 為了評估協(xié)同作用,基于單發(fā)酵體系得模擬產(chǎn)甲烷量[17],公式如下:

式中:模擬為d模擬累計(jì)產(chǎn)甲烷量,mL/g-VSS;B(t)和B(t)分別為d S:K為1:0,0:1的累計(jì)產(chǎn)甲烷量,mL/g-VSS;1和2分別為剩余污泥和廚余垃圾所占的比例.

共發(fā)酵甲烷產(chǎn)量增加率作為協(xié)同評價(jià)指標(biāo).計(jì)算方式如下:

式中:增為增加率,%;實(shí)測和模擬分別為實(shí)測和模擬總產(chǎn)甲烷量,mL/g-VSS.

1.5.3 碳平衡分析 氣相中含碳元素以CH4和CO2計(jì),液相中的含碳元素包括總有機(jī)碳(TOC)和無機(jī)碳(IC),固相中的含碳元素包括TOC和IC.各種含碳元素均以碳(質(zhì)量)計(jì).

氣相中的各種碳含量為:

式中:氣為氣體中碳含量,mg;氣為累計(jì)氣體體積(CH4或CO2),mL;m為氣體物質(zhì)的量體積, 24.54L/ mol (25℃,101kPa);(C)為碳物質(zhì)的量質(zhì)量,12.01g/ mol.

液相中的各種碳含量為:

式中:液為液體中碳含量,mg;液為濃度(TOC或IC), mg/L;為反應(yīng)液體積,L.

固相中的各種碳含量為:

式中:固為固體中碳含量,mg;TSS為總固體懸浮物, g/L;為反應(yīng)液體積,L;為固體中碳(TOC或IC)含量占比,%.

2 結(jié)果與討論

2.1 厭氧發(fā)酵前后參數(shù)變化

表2 不同比例剩余污泥和廚余垃圾厭氧發(fā)酵前后基礎(chǔ)參數(shù)變化

注:initial為厭氧發(fā)酵前,finish為厭氧發(fā)酵后,RR為去除率.

由表2可知,厭氧發(fā)酵后pH值范圍有一定幅度的升高(由7.06～7.20升至7.62～7.81),TN、NH4+-N升高較為顯著,與Li等[18]的研究相似.郭燕峰等[19]得出的在厭氧發(fā)酵過程中pH值先降低后增加,總體為增加;NH4+-N是先增加后降低,總體為增加. NO3--N有下降趨勢,廚余垃圾占比高的體系NO3--N下降較多.厭氧發(fā)酵過程中,液相中TN主要以有機(jī)氮和無機(jī)氮(NH4+-N、NO3--N等)形式存在.隨著反應(yīng)的進(jìn)行,固相中部分氮元素會轉(zhuǎn)移到液相中,有機(jī)氮如蛋白質(zhì)等會水解,并降解為NH4+-N,導(dǎo)致液相中TN和NH4+-N的顯著增加,NH4+-N的積累能夠提供堿度,導(dǎo)致pH值升高[20],NO3--N則會發(fā)生反硝化反應(yīng)轉(zhuǎn)化為氮?dú)馀懦鯷21-22],這也是氣相中N2的主要轉(zhuǎn)化途徑和來源.測試結(jié)果表明廚余垃圾的初始SCOD高于剩余污泥(表1),因此廚余垃圾的占比越高,混合體系的初始SCOD就越高.隨著廚余垃圾占比增加,TCOD、TSS、VSS去除率都隨之增加,這與Pan 等[23]的研究結(jié)果一致,除了協(xié)同作用外,原因還可能是剩余污泥中含有復(fù)雜的結(jié)構(gòu)如胞外聚合物和剛性細(xì)胞壁等,難溶物質(zhì)如金屬離子、重金屬等,導(dǎo)致降解效率低下[24],廚余垃圾主要是由淀粉、蛋白質(zhì)等組成,容易被降解利用.通過相對的分析,廚余垃圾的加入沒有增加污水處理廠污泥的處理負(fù)荷,而且實(shí)現(xiàn)了污泥的減量化,其中S:K為4:1和1:2體系相對減量效果較好,分別為50.10%和28.08%.綜合各種剩余污泥和廚余垃圾比例體系,TN、NH4+-N、NO3--N沒有顯著差異,廚余垃圾的加入提高了系統(tǒng)的降解能力,為產(chǎn)甲烷資源化提供了良好的基礎(chǔ).

2.2 厭氧發(fā)酵產(chǎn)氣

BMP實(shí)驗(yàn)累計(jì)產(chǎn)氣量統(tǒng)計(jì)結(jié)果表明,廚余垃圾占比的增加,有助于厭氧發(fā)酵產(chǎn)氣(圖1a),其中S:K為1:0,4:1,2:1的厭氧發(fā)酵體系到達(dá)產(chǎn)氣平臺期時(shí)間為4d,S:K為1:1,1:2,1:4的厭氧發(fā)酵體系則分別為6d,8d,12d.S:K為0:1體系的產(chǎn)氣速率較不穩(wěn)定,存在突躍性和滯后性,第24d產(chǎn)氣量才能反超S:K為1:4體系,最終產(chǎn)氣量為520.74mL/g-VSS.廚余垃圾的占比增加雖然增大了產(chǎn)氣總量,但同時(shí)增大了產(chǎn)氣滯后期,這是由于廚余垃圾富含碳水化合物,發(fā)酵早期積累的乳酸造成了pH值下降,抑制了產(chǎn)氣作用,造成了滯后期的增加[25].初始SCOD越高的體系第1d產(chǎn)氣越高(圖1b),這與Ma等[26]研究結(jié)果一致,即SCOD更容易被利用產(chǎn)氣.

圖1 不同比例剩余污泥和廚余垃圾厭氧發(fā)酵產(chǎn)氣量

2.3 厭氧發(fā)酵產(chǎn)甲烷

BMP實(shí)驗(yàn)累計(jì)產(chǎn)甲烷量統(tǒng)計(jì)結(jié)果表明,剩余污泥和廚余垃圾共發(fā)酵增大了甲烷產(chǎn)量,S:K為1:4體系獲得了最大累積產(chǎn)甲烷量274.37mL/g-VSS,超過了S:K為0:1體系.除S:K為0:1體系外,依然是隨著廚余垃圾占比的增加,累計(jì)產(chǎn)甲烷量越高,且產(chǎn)甲烷的滯后期有所增加.Mater等[12]的研究得出,污泥:食物垃圾為1:3時(shí)取得了最大產(chǎn)甲烷量,高于食物垃圾單發(fā)酵,與本文研究結(jié)果相似.魯斌等[27]的研究也得出相似結(jié)果,有機(jī)負(fù)荷量過高時(shí),甲烷產(chǎn)率略微下降.添加易降解的廚余垃圾可以提高降解效率并加速剩余污泥的水解,因?yàn)閰捬跷⑸锏纳L速度更快,微生物更快的生長速度導(dǎo)致更高的水解速度,從而導(dǎo)致更高的酸化和產(chǎn)甲烷潛力[28].而酸化是導(dǎo)致滯后期的原因,累計(jì)產(chǎn)甲烷平臺期滯后現(xiàn)象(圖2a)同累計(jì)產(chǎn)氣平臺期(圖1a),廚余垃圾占比的增加,也延長了最大產(chǎn)甲烷率出現(xiàn)時(shí)間,S:K為4:1,2:1, 1:1,1:2,1:4體系最大產(chǎn)甲烷率分別在第2,2,4,8,11d (圖2b).剩余污泥和廚余垃圾共厭氧發(fā)酵有著更高的產(chǎn)甲烷潛力,最大產(chǎn)甲烷率是S:K為1:2體系,為32.40mL/(g-VSS·d),其次是S:K為1:4和1:1體系,分別為27.58,26.20mL/(g-VSS·d),明顯高于單發(fā)酵的S:K為1:0體系的4.08mL/(g-VSS·d)和S:K為0:1體系的17.47mL/(g-VSS·d).

模擬產(chǎn)甲烷量表示剩余污泥和廚余垃圾在厭氧發(fā)酵過程中不存在協(xié)同作用的產(chǎn)甲烷量,通過比較模擬和實(shí)測產(chǎn)甲烷量評估協(xié)同效果.由圖3可見,實(shí)測產(chǎn)甲烷量均大于模擬產(chǎn)甲烷量,表現(xiàn)了共厭氧發(fā)酵的積極作用,廚余垃圾和剩余污泥的共發(fā)酵產(chǎn)甲烷具有正協(xié)同作用,可增加產(chǎn)甲烷量.這種協(xié)同作用是由于共基質(zhì)的存在,提供了更高的緩沖能力,降低了抑制作用[29].S:K為1:4體系的協(xié)同效果最好,產(chǎn)甲烷增加率最高,為27.41%,與Pan等[23]得出的在污泥和食物垃圾配比1:1時(shí)取得最大產(chǎn)甲烷增加量不同.剩余污泥和廚余垃圾共厭氧發(fā)酵能夠有效提高甲烷轉(zhuǎn)化效率,具有協(xié)同產(chǎn)甲烷能源的優(yōu)勢.

圖2 不同比例剩余污泥和廚余垃圾厭氧發(fā)酵產(chǎn)甲烷量

圖3 不同比例剩余污泥和廚余垃圾厭氧發(fā)酵模擬、實(shí)測甲烷產(chǎn)量及增加率對比

2.4 碳平衡分析

厭氧發(fā)酵過程中碳元素發(fā)生遷移轉(zhuǎn)化,主要有兩個(gè)方面:其一由固相向液相中遷移,其二轉(zhuǎn)化為CH4和CO2.因測量、計(jì)算誤差和可能的碳損失原因,各體系厭氧發(fā)酵前后總含碳量稍有差異.厭氧發(fā)酵前,各體系固相IC,液相IC,固相TOC沒有明顯差異.廚余垃圾具有較高的SCOD,表明液相中具有較高的碳,所以隨著廚余垃圾占比增加,液相中TOC升高(圖4a).因厭氧發(fā)酵前各體系只有液相TOC具有明顯差距,結(jié)合厭氧發(fā)酵第1d產(chǎn)氣情況(圖1b),得出液相中TOC較高的體系第1d產(chǎn)氣量越多,碳元素主要是從液相轉(zhuǎn)化到氣相.厭氧發(fā)酵后,各體系固相和液相IC稍有增加,原因可能是CO2的溶解,增加了液相中的碳酸根離子,造成了液相中IC的增加,而這些碳酸根離子與污泥中的重金屬等形成難溶性碳酸鹽,增加了固相中的IC含量;隨著廚余垃圾占比增加,產(chǎn)CH4量和產(chǎn)CO2量都隨之增加(圖4a),厭氧發(fā)酵前后各體系固相和液相TOC占比變化顯著(圖4b),結(jié)合固相和液相IC的變化,可以得出氣相中的CH4和CO2是由TOC提供的.其中S:K為1:4體系固相TOC變化最大(72.06%～45.44%),說明該體系能利用更多的固相中的碳產(chǎn)CH4,同時(shí)該體系也獲得了最大的協(xié)同增長率(圖3f).剩余污泥和廚余垃圾共厭氧發(fā)酵的優(yōu)勢,提升了降解能力,促進(jìn)碳元素由固相-液相-氣相之間的轉(zhuǎn)移.

圖4 不同比例剩余污泥和廚余垃圾厭氧發(fā)酵前后碳平衡分析

R表示厭氧發(fā)酵后,下同

2.5 微生物多樣性分析

剩余污泥加入廚余垃圾進(jìn)行共厭氧發(fā)酵,可增加厭氧發(fā)酵過程的細(xì)菌多樣性,增加產(chǎn)甲烷菌的相對豐度及活性.厭氧發(fā)酵前7組不同S:K發(fā)酵體系中(圖5a)共有的操作分類單元(OTUs)為1352,S:K為1:0,4:1,2:1,1:1,1:2,1:4,0:1獨(dú)有的OTUs分別為158,154,116,194,156,117,145.厭氧發(fā)酵過程中長期處于厭氧環(huán)境,好氧細(xì)菌的死亡導(dǎo)致厭氧發(fā)酵后體系中細(xì)菌物種多樣性減少.厭氧發(fā)酵后7組(圖5b)共有的OTUs為840,S:K為1:0,4:1,2:1,1:1,1:2,1:4,0:1獨(dú)有的OTUs分別為183,184,202,245,178, 157,64; shannon指數(shù)分別為8.179,7.635,7.939,8.064,7.551, 7.231,7.236; simpson指數(shù)分別為0.989,0.980,0.984, 0.986,0.980,0.968,0.976.厭氧發(fā)酵后隨著廚余垃圾所占發(fā)酵體系比例的增加,物種多樣性先增加后降低,說明適宜配比的共發(fā)酵可以增加厭氧發(fā)酵過程中細(xì)菌多樣性.

基于樣品OTUs的注釋結(jié)果,最大豐度排名前10的物種在門和屬水平上以物種相對豐度堆疊圖展示(圖6).在門水平上(圖6a),主要優(yōu)勢菌門為擬桿菌門(Bacteroidota)、變形菌門(Proteobacteria)、Halobacterota、綠彎菌門(Chloroflexi)、熱袍菌門(Thermotogae).厭氧發(fā)酵前各體系間細(xì)菌差異較小.厭氧發(fā)酵后,Chloroflexi、Halobacterota隨著廚余垃圾占比的增加而增加,一些隸屬于Chloroflexi的細(xì)菌在硝化和反硝化過程中發(fā)揮重要作用[30],對應(yīng)了厭氧發(fā)酵后NO3--N變化(表2);Halobacterota中含有一些產(chǎn)甲烷菌[31],對應(yīng)了累計(jì)產(chǎn)甲烷量(圖2a);Bacteroidota、Proteobacteria隨廚余垃圾比例的增加而減小,Thermotogae除S:K為1:0體系外,也隨廚余垃圾比例的增加而減小,Bacteroidota和Proteobacteria具有相似的功能,包括降解一些有機(jī)化合物及利用葡萄糖和一些揮發(fā)性脂肪酸[32], Thermotogae可以降解不同類型的碳水化合物,如木糖和纖維素[33],與產(chǎn)氣延滯期相對應(yīng)(圖1).

在屬水平上(圖6b),主要優(yōu)勢菌屬有甲烷絲狀菌屬(),DMER64,SC103,長繩菌屬(),互營熱菌屬().的功能是產(chǎn)甲烷,是生態(tài)環(huán)境中甲烷的主要生產(chǎn)者[34],的功能是代謝多種碳水化合物,與甲烷菌共培養(yǎng)時(shí)促進(jìn)其生長[35];厭氧發(fā)酵后(S:K為1:0,4:1,2:1,1:1,1:2,1:4,0:1體系分別為4%,4%,5%,5%,8%,7%,11%)和(S:K為1:0,4:1,2:1,1:1,1:2,1:4,0:1體系分別為5%,4%,5%, 5%,7%,8%,10%)相對豐度有所提高,整體上隨著廚余垃圾占比的增加而增加,說明廚余垃圾的加入為產(chǎn)甲烷菌及其輔助菌種提供了良好的生存環(huán)境,促進(jìn)了生長,產(chǎn)甲烷菌及其輔助菌種的相對豐度的增加,提高了體系產(chǎn)甲烷能力,使得累計(jì)產(chǎn)甲烷量增加(圖2a);DMER64參與直接種間電子傳遞,促進(jìn)電子從產(chǎn)酸菌轉(zhuǎn)移到產(chǎn)甲烷菌,從而提升產(chǎn)甲烷速率[36],隨著廚余垃圾占比的增加,DMER64減小,表明產(chǎn)甲烷反應(yīng)速率減小,這是產(chǎn)氣滯后期的原因;厭氧發(fā)酵后SC103隨廚余比例的增高,有著先增高后下降的趨勢;的功能是降解蛋白質(zhì)[37],該細(xì)菌在各體系間沒有明顯差異,厭氧發(fā)酵后整體減少,原因應(yīng)該是厭氧發(fā)酵后蛋白質(zhì)通過降解含量減少,使得其養(yǎng)料不足,相對豐度下降.

圖5 OTUs比較花瓣圖

3 結(jié)論

3.1 剩余污泥與廚余垃圾共厭氧發(fā)酵,系統(tǒng)在S:K為1:4的條件下,運(yùn)行性最優(yōu),甲烷產(chǎn)量和協(xié)同增長率分別達(dá)到了274.37mL/g- VSS和27.41%

3.2 廚余垃圾的加入促進(jìn)了系統(tǒng)內(nèi)碳元素的遷移轉(zhuǎn)化,S:K為1:4時(shí)固相TOC占比下降了26.62%.

3.3 廚余垃圾占比的增加,為系統(tǒng)提供了良好的厭氧微生物環(huán)境,產(chǎn)甲烷菌()由4%提高到11%,長繩菌屬()由5%提高到10%.

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Synergistic effect of kitchen waste and sludge anaerobic fermentation for methane production.

CHANG Cheng1, MING Lei-qiang2, MU Yun-fei1, HUA Zhi-liang2, LI Xian-guo1, ZHANG Da-hai1*

(1.School of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266000, China；2.Air Liquide (China) R&D Co., Ltd., Shanghai 200030, China)., 2022,42(3)：1259～1266

Excess sludge and kitchen waste were co-fermented to evaluate the synergistic effect of anaerobic fermentation. Based on the volatile solid suspension, excess sludge and kitchen waste ratios of 1:0, 4:1, 2:1, 1:1, 1:2, 1:4, 0:1 were employed to conduct the biochemical methane potential experiments. The synergistic methanogenic effect was evaluated by combining the changes of pH, COD, TN, NH4+-N, NO3--N, gas production, carbon migration and transformation, and microbial community structure before and after anaerobic fermentation. During anaerobic fermentation of excess sludge, the addition of kitchen waste could significantly improve the sludge degradation ability of microorganisms and increase methane production. The maximum methane production at the ratio of 1:4was 274.37mL/g-VSS, with a synergistic growth rate of 27.41%. The addition of kitchen waste delayed the methanogenic time, promoted the transfer of carbon elements from solid phase to liquid phase to gas phase, and increased the growth and reproduction of methanogenic bacteria () and their auxiliary bacteria (, etc.).

excess sludge；kitchen waste；anaerobic fermentation；carbon balance；microbial analysis

X705

A

1000-6923(2022)03-1259-08

常 城(1995-),男,山東菏澤人,中國海洋大學(xué)碩士研究生,主要從事污泥資源化研究.

2021-07-28

液化空氣(中國)研發(fā)有限公司生物制氣項(xiàng)目(20200216)

*責(zé)任作者, 副教授, dahaizhang@ouc.edu.cn