污泥的處理與處置

1、Zero valent iron simultaneously enhancesmethane production and sulfate reduction inanaerobic granular sludge reactorauthor：Yiwen Liu,AWMC, The University of Queensland, AustraliaYaobin Zhang,Dalian University of Technology, ChinaBing-Jie Ni,AWMC, The University of Queensland, Australia 注：AWMC:Advanc

2、ed Water Management Centre(先進(jìn)水資源管理中心）在厭氧顆粒污泥反應(yīng)器中零化合價鐵能促進(jìn)甲烷的生產(chǎn)同時增強(qiáng)反硫化作用作者：劉一文,先進(jìn)水資源管理中心,昆士蘭大學(xué)張耀斌,工業(yè)生態(tài)與環(huán)境工程重點(diǎn)實驗室,環(huán)境學(xué)院,大連理工大學(xué)倪丙杰,先進(jìn)水資源管理中心,昆士蘭大學(xué) ARTICLE INFOArticle history Received 30 September 2014 Revised 19 February 2015 Accepted 25 February 2015 Available online 6 March 2015key words Zero valent i

3、ron Methane production Sulfate reduction Mathematical modeling Anaerobic granular sludgeHighlightsA model is developed for ZVI-anaerobic granular sludge treating sulfate wastewater.The model is successfully calibrated and validated using three independent data sets.Model results confirm that ZVI pro

4、motes propionate degradation and methanogenesis.ZVI also alleviates the inhibition of un-dissociated H2S on acetogens(產(chǎn)乙酸菌), MA(產(chǎn)甲烷古菌)and SRB(硫酸鹽還原菌).擴(kuò)充：擴(kuò)充：acetogens的影響因子MA的影響因子 SRB的影響因子 (1) PH值SRB生長最適PH值一般在中性范圍內(nèi)。當(dāng)pH值在6.8-7.2之間時，硫酸鹽還原效果最好（2）溫度(最佳溫度35）（3）ORP（須低于100mV)（4）硫化物（H2S) (5) 乙酸(HAc ) （6) 可見光

5、（7）有毒物質(zhì)（8）與非SRB菌種的競爭可能會與SRB構(gòu)成競爭關(guān)系的菌種主要有反硝化細(xì)菌、產(chǎn)乙酸細(xì)菌，產(chǎn)甲烷細(xì)菌等 硫酸鹽還原又稱為硫酸鹽呼吸或反硫化作用，是指在厭氧條件下，化能異養(yǎng)型硫酸鹽還原細(xì)菌（SRB）利用廢水中的有機(jī)物作為電子供體，將氧化態(tài)硫化物（硫酸鹽、亞硫酸鹽、硫代硫酸鹽）還原為硫化物（包括HS-、H2S和S2-）的過程。(1) PH值對環(huán)境PH變化適應(yīng)差，一般來說，最適pH值在6.5-7.5之間（2）溫度（3039/5060)（3）ORP最適ORP范圍-300-500mV（4）有機(jī)負(fù)荷率 (5) 污泥濃度（6) 堿度（7）接觸和攪拌（8）營養(yǎng)COD/N/P=500：5:1左右為宜

6、 (9) 抑制劑和激活劑未離解的H2S存在抑制作用，丙酸的積累對厭氧微生物具有抑制作用(1) PH值產(chǎn)酸細(xì)菌生存的PH范圍很寬，在PH為3.5-8范圍均可生存（最適PH 6-7)（2）溫度(最佳溫度35）（3）ORP最適ORP范圍-200-300mV（4) 堿度（5）水力停留時間（HRT）和有機(jī)負(fù)荷（OLR)ABSTRACT零價鐵（ZVI）填充顆粒污泥的反應(yīng)器已經(jīng)被開發(fā)用于改進(jìn)厭氧廢水的處理；用一個數(shù)學(xué)模型來描述通過在厭氧顆粒污泥反應(yīng)器中加入ZVI，提高甲烷產(chǎn)量和 增強(qiáng)反硫化作用；該模型通過兩個獨(dú)立的零價鐵強(qiáng)化厭氧顆粒污泥反應(yīng)器在不同的運(yùn)行條件下長期收集的數(shù)據(jù)得到成功的校核和驗證；該模型從這兩

7、個系統(tǒng)中，成功描述了化學(xué)需氧量（COD）的去除，反硫化作用和甲烷產(chǎn)量的數(shù)據(jù)，實驗結(jié)果表明： 1、ZVI直接推動丙酸降解和甲烷的生成，提高沼氣產(chǎn)量； 2、ZVI通過緩沖pH值（Fe0 + 2H+ =Fe2+ + H 2）和硫化鐵沉淀，減輕了未離解的H2S對產(chǎn)乙酸菌，產(chǎn)甲烷菌和硫酸鹽還原菌（SRB）的抑制作用，提高了硫酸鹽的還原能力(尤其是在惡化的條件下)； 3、與沒有加入ZVI反應(yīng)器相比，ZVI對甲烷產(chǎn)量和反硫化作用的增強(qiáng)主要發(fā)生在相對低的COD/ SO42-比率，而不是高的COD/ SO42-比率。希望在這項工作中所提出的模型，能為形成一個更有效的以零價鐵為基礎(chǔ)的厭氧顆粒系統(tǒng)提供進(jìn)一步的發(fā)展支

8、持。 Introduction Contents1 Materials and methods 2 Results 3 Discussion 4 Conclusions 51、Introdunction厭氧技術(shù)已被廣泛地用作有機(jī)工業(yè)廢水的處理由于低運(yùn)行成本和高去除率;a.硫酸鹽還原菌（SRB）和產(chǎn)甲烷古菌（MA）會競爭從水解和發(fā)酵過程中產(chǎn)生的有機(jī)碳； b.SRB在豐富的硫酸鹽底物條件下可以戰(zhàn)勝M(fèi)A; c.硫酸鹽還原過程中產(chǎn)生的H2S會抑制MA;零價鐵（ZVI）是一種還原劑，將有助于創(chuàng)造厭氧處理的性能增強(qiáng)的厭氧環(huán)境, a.當(dāng)在厭氧生物處理反應(yīng)器利用時，ZVI可以降低氧化還原電位（ORP），并作為

9、一種酸緩沖液，為MA保持穩(wěn)定和有利的條件； b.ZVI可以作為反硫化作用和產(chǎn)甲烷的電子供體； c.微米大小的磁鐵礦（Fe3O4）粒子通過改善電子轉(zhuǎn)移，以提高甲烷產(chǎn)量；作者開發(fā)了一種基于ADM1（The Anaerobic Digestion Model No. 1）一個數(shù)學(xué)模型來描述零價鐵-顆粒污泥的反應(yīng)器中甲烷產(chǎn)量的提高和反硫化作用的增強(qiáng)。 將預(yù)測結(jié)果與兩個獨(dú)立的零價鐵-厭氧顆粒污泥UASB反應(yīng)器在不同的操作條件下測得的數(shù)據(jù)進(jìn)行比較，來測試模型的有效性和適用性。 2、Meterial and methodsModel development Experimental data for mod

10、el evaluation Model calibration and validationa.Biological and physicochemical reaction modelb.Anaerobic granular sludge reactor modela.Anaerobic granular sludge reactor with ZVI (R1) and without ZVI (R2)b.ZVI-anaerobic granular sludge reactor treating high strength sulfate wastewater (R3)2、Meterial

11、 and methods（1）反應(yīng)器）反應(yīng)器ZVI-UASB反應(yīng)器（R1）： 一個圓柱形ZVI床（ 90 mm 300 mm）被安裝在2/3深度的圓筒狀的工作體積為9.4L的由丙烯酸制成的UASB反應(yīng)器（ 100 mm 1200 mm） 在由不銹鋼網(wǎng)的構(gòu)造的圓柱形ZVI床（ 90 mm 300 mm）用300克鐵屑（約8 mm 4 mm 2 mm）進(jìn)行填充基于UASB反應(yīng)器(R2) ： 沒有ZVI床，其他設(shè)置同R 1（2）接種污泥）接種污泥 接種的污泥從中國大連春柳河污水處理廠收集。揮發(fā)性懸浮物質(zhì)與總懸浮物的比例（VSS/ TSS）為0.69。每個反應(yīng)器接種 4L污泥，初始的TSS為13.5g

12、/L。（3）操作過程）操作過程初始啟動：兩個反應(yīng)器以間歇方式進(jìn)行操作；每天一次換反應(yīng)器中的廢水， HRT:24h，進(jìn)水COD逐漸增加至5000mg/L（無硫酸鹽）兩周后： 兩個反應(yīng)器在連續(xù)模式下操作；HRT:24h；操作溫度：351約30d后: 兩個反應(yīng)堆的COD去除率和甲烷生產(chǎn)的達(dá)到穩(wěn)定狀態(tài)， 進(jìn)水為COD濃度為固定值5000mg/L，硫酸鹽濃度為300mg/L(第一階段30d）， 和1100mg/L（第二階段30d）。用蔗糖合成的廢水，NH4Cl 和KH2PO4 作為碳源， 氮源和 磷源，Na2SO4作為硫酸鹽使用。流入的廢水的pH用NaHCO3溶液調(diào)節(jié)到8。（4）測定）測定 定期監(jiān)測出水

13、COD，硫酸鹽濃度，pH值，未離解的H2S和CH4的量來評估每個反應(yīng)器的性能。2.2. Experimental data for model evaluation2.2.1. Anaerobic granular sludge reactor with ZVI (R1) and without ZVI (R2)2、Meterial and methods（1）反應(yīng)器）反應(yīng)器ZVI-UASB反應(yīng)器（R3）處理高濃度的含硫廢水： 40g廢鐵加入成圓筒狀的工作體積為2L由丙烯酸制成的UASB反應(yīng)器中（( 100 mm 280 mm），形成ZVI-UASB反應(yīng)器（R3）。（2）接種污泥）接種污泥 從

14、實驗室UASB反應(yīng)器得到的污泥用作種子污泥。揮發(fā)性懸浮物質(zhì)與總懸浮物的比例（VSS/ TSS）為0.71。R3初始的TSS為14.2g/L。（3）操作過程）操作過程初始啟動：R3反應(yīng)器在連續(xù)模式下操作；HRT:24h；操作溫度：20 進(jìn)水的COD濃度為固定值3000mg/L; 第一個月：進(jìn)水硫酸鹽濃度逐步提高從100mg/L至200mg/L，400mg/L，800mg/L，最后至1500mg / L，致使COD / SO42-=2：1的比例 第二個月：R 3在這一條件操作一個月（4）測定）測定 定期監(jiān)測出水COD，硫酸鹽濃度 2.2. Experimental data for model e

15、valuation 2.2.2. ZVI-anaerobic granular sludge reactor treating high strength sulfate wastewater (R3)3、Results1、Enhanced methane production and sulfate reduction in ZVI-anaerobic granular sludge reactorsFig. 1 - Modeling; results with the experimental data from R1 (with ZVI) and R2 (without ZVI) dur

16、ing Phase I: (a) Effluent sulfate and removal, (b) Effluent un-dissociated H2S, (c) Effluent COD and removal, and (d) Methane production.Fig. 2-Model validation results using the experimental data from R1 (with ZVI) and R2 (without ZVI) during Phase II: (a)Effluent sulfate and removal, (b) Effluent

17、un-dissociated H2S, (c) Effluent COD and removal, and (d) Methane production.Fig. 3 - Model predictions and experimental results for R3 under a low COD/SO4 2- ratio of 2 at an influent COD of 3000 mg/L:(a) Effluent sulfate and removal, and un-dissociated H2S, (b) Effluent COD and removal, and methan

18、e production.These results clearly indicated the enhanced methane production and sulfate reduction by ZVI addition in anaerobic granular sludge reactors under relatively low COD/SO42 ratio.3、Results2、 Model calibration(模型校準(zhǔn))A two-step procedure was applied to calibrate the model：在第一步驟中，通過在控制反應(yīng)器（未加ZV

19、I）中測得的COD，甲烷，硫酸鹽和硫化物數(shù)據(jù)來測試動力學(xué)因子（水解，產(chǎn)酸發(fā)酵，產(chǎn)乙酸，產(chǎn)甲烷和反硫化作用）在第二步驟中，通過在控制反應(yīng)器（加ZVI）中測得的實驗數(shù)據(jù)來進(jìn)一步校準(zhǔn)與ZVI相關(guān)的參數(shù)和相關(guān)過程中ZVI的增強(qiáng)作用。注：在這項工作中，文獻(xiàn)報道動力學(xué)可以描述未加ZVI的R2（Fig.1）的COD，硫酸鹽，硫化物和甲烷。The good agreement between these simulated and measured data supported that the developed model properly captures the interactions betwee

20、n ZVI and relevant microorganisms.3、Model validation and further evaluation（模型驗證及進(jìn)一步評價）4、DiscussionIn this model, ZVI releases into bulk liquid through a corrosion reaction and serve as a pH buffer, which promotes propionate degradation and methanogenesis for enhanced methane production, and relieve

21、s the toxicity from un-dissociated H2S for improved sulfate reduction capacity.The successful application of the model in this work indicates it is applicable to describe the ZVI enhanced methane production and sulfate reduction in anaerobic granular sludge reactors.Direct ZVI promotion on sulfate r

22、eduction processes was not considered in this model.The improved COD removal would be attributed to direct enhancement of either acidogenesis, acetogenesis or methanogenesis by ZVI.Direct promotion on propionate(丙酸) degradation by ZVI was included in the model. Direct promotion on both methanogenesi

23、s pathways( (乙酸乙酸/H/H2 2+CO+CO2 2) ) by ZVI was incorporated in the developed model. 4、DiscussionThe fact that the synthetic wastewater containing sucrose(蔗糖) as carbon source was used in this work.the inhibition of long-chain fatty acids(長鏈脂肪酸)(Batstone et al., 2002) on microorganisms was not inclu

24、ded in the developed model due to the extremely low long-chain fatty acids level observed during the reactor operation.Propionate degradation and methanogenesis activity were assumed to be promoted by ZVI addition.The simulated pH data in R1 with ZVI were stable and well maintained in a neutral rang

25、e (Fig. S1). This in turn led to less un-dissociated H2S accumulation. Additionally, FeS precipitate could further relieve the inhibition (Haaning Nielsen et al., 2005). All of these contributed to the better performance of R1 in terms of COD removal, methane production and sulfate reduction.Further

26、 model simulations show that SRB inhabit near the granule surface due to the better penetration of sulfate. In comparison, MA tend to live in the deeper layer due to better protection from unfavorable conditions.the impurities in the ZVI (e.g., scrap iron used in this work) might also benefit the re

27、actor performance as the micronutrients such as Ni, Mn and Mo might increase biomethane production due to the fact that methanogens require these micronutrients (微量元素）for growth (Speece, 1988). Fig. 4 - Model simulation results of sulfate reduction and methane production efficiencies of R1 with ZVI

28、under varying COD/SO4 2- ratio conditions at a fixed influent COD of 5000 mg/L.Therefore,ZVI could effectively stabilize the performance of anaerobic granular sludge reactor for the treatment of sulfate-containing wastewater under suitable COD/SO42 ratio conditions (e.g., 8.3) In general, the durati

29、on of ZVI function time in anaerobic reactors with participation reactions was between 0.5 and 1 year (Zhang et al., 2012). Hence, ZVI replacement or extra addition should be taken into consideration properly if long-term operation of the system would be required in future applications.5、ConclusionA mathematical model with consideration of the physiochemical and