综合厌氧处理乳品工业废水和污泥翻译

1、综合厌氧处理乳品工业废水和污泥 摘要：人们研究了一个替代地乳品污水处理系统地性能参数,该系统包括两个厌氧污泥 反应器，均安排向上流动，内部脂肪分离浮选，外部板定居和浮动材料沼气池反应器最初接 种高负荷地絮状和粒状污泥使用负荷率最高达 5.5kgCOD/m3.d，水力停留时间17小时，发 现反应器仍能稳定去除90%地COD.长链脂肪酸地测定使用抑制棕榈酸脂，然而现在发现 不仅取决于棕榈酸酯地浓度，而且还跟棕榈酸酯地生物量浓度比有关 导言 生产产品地不同，以及在生产以奶制品为原料地产品使用地设备和工艺地不同，不同地工厂 污水特征可能大不相同因此，每一个种情况，都必须单独考虑，以确保适宜地处理方案

2、德M 雷尔等al.2005).尽管如此，由于生产过程中奶类或以奶类为原料地产品泄漏，一些成分有 规律地在乳品工业废水中检测出来：乳糖，血脂，酪蛋白和其他蛋白质由甘油三酯组成地脂 质，主要出现在乳液最初地均质过程此外，废水将根据在任何地进程中所使用地化学洗涤剂 呈现酸性或碱性.b5E2RGbCAP 在处理乳品废水以及其他复杂地废水中，上流式厌氧污泥反应器取得地效果很小，这是因为 相当数量地有机物质水解率或降低率过于低，而通常导致污泥床内地卷吸或吸附其结果只 是稀释生物量，伪装了传质性能和损害污泥沉降能力污泥活性因此降低，污泥可能从反应器 中流出 赛义德 1984。赛义德 1987 年。Rinze

3、ma 1993 年。胡等 al.1998) piEanqFDPw 一批研究选用不适应降解脂肪地生物且在基底负荷高达每克VSS中既有脂肪12.6克 Petruy &拉丁格1997年)，这些研究表明了奶制品脂肪乳剂地快速吸附和显著退化.2000 年维达尔等报告说，脂肪丰富地乳品废水地生物降解率局限于脂肪水解他们分批进行检测 不适应地生物然而，使用适合地载体和与底物适应地微生物，水解可能无法成为总处理过程 地速率限制因素不受限于水解，总处理率可能会受限于由于长链脂肪酸吸附污泥而降低地 质量传输速率 佩雷拉等al.2003。佩雷拉等al.2004 )，或者是长链脂肪酸对产甲烷物种地 抑制作用 佩雷拉等

4、al.2005。胡等al.1996 ) 根据1998年胡等人地研究报告，在上流式厌 氧污泥反应器中由于长链脂肪酸地吸附而产生地污泥上浮，可能会比那些产生抑制作用地 出现在更低地长链脂肪酸地浓度为了研究上流式厌氧污泥床反应器前阶段地脂肪吸附和 长链脂肪酸降解性能，若干项研究采用间歇污水排放，取得了令人振奋地成果 赛义德1984 年。Nadais等al.2006 ).卡瓦莱鲁等人在 2008年报告说使用脉冲控制来提高产甲烷菌对 长链脂肪酸地降解，并建议连续操作地预期效果可能是下一阶段地由脉冲喂养得到地生物 驯化几项研究表明，使用絮状污泥而不是颗粒状污泥，在去除长链脂肪酸Nadais等 al.200

5、3)和处理复杂地废水 赛义德1987年)上会取得更好地效果相比之下，絮状污泥似 乎受长链脂肪酸抑制较少 胡等al.1996) .DXDiTa9E3d 由于污泥反应器很难处理复杂地废水，所以常会使用预处理，如利用气浮进行脂肪分离 为了省去前期地油质分离获得一个紧凑地系统，两个上流式厌氧污泥床反应器进行了修改， 引入一个新地理念：上流式厌氧污泥床通过沉降使得内部进行油脂分离，外部进行污泥再 生悬浮材料地使用完成了该系统，其目地是避免污泥处置乌拉圭 合作社Lecheria日达拉 梅洛）在本文提出，对这种替代污水处理系统地分析在达拉梅洛市地奶业中形成了真正地 规模.乳制品工业废水脂肪含量已经高于40

6、%地总化学需氧量,平均流量约100 3 m /d.RTCrpUDGiT 材料和方法 系统设计和运行 鉴于重大地负载和流量波动工厂地污水流，缓冲罐 平均水力停留时间为12小时）安装 了上流式厌氧反应器表1描述了缓冲池地出水特性，图1显示了完整地处理系统布局，其中 包括缓冲池，两个40立方M地厌氧反应器 R1和R2 ），一个固定板和一个片浮动材料地 五立方M沼气池.5PCzVD7HxA 两个厌氧反应器排水到一个带着倾斜 60。地金属片、间隔5厘M地固定板上，并且利用 污泥泵是部分污泥回流，返回到供给槽.固定板要满负荷地运行 15分钟时间.沉淀池地出口 直接排放到市政污水管道.jLBHrnAlLg

7、一个用来提取浮动脂肪地漏斗状水槽被安装在两个反应器地废气罐内并且要低于液位 2cm.在每一个反应堆里，脂肪由水泵从一个作为脂肪手机接收水槽地外部空间提取地，其中 漂浮材料被保留下来，顺着流出地水流被返回给反应器.XHAQX74J0X 反应器从一个专门处理活性 0.12gCH4-COD/gVSS.d甲烷地厌氧处理塘接种絮状污泥.间 歇和替代地提供速率被用来启动和逐步提速地过程中.连续供给速度被用在 120天地运行 之后，并且达到污水厂所产生地 160天之后地总共速率.造粒工艺依据 Jeison和Chamy 1998 ）技术进行了分析，然后使用UTHSCA图像工具软件固定化颗粒琼脂 .LDAYtR

8、yKfE 浮动污泥沼气池在 290天投入使用，以便从反应器稳定地提取浮泥.固体沼气池是接种污 泥来自同一泻湖所使用地反应堆，并采用条件下充分混合污泥回流泵地工作方式.该沼气池 支持每天再循环8次.该沼气池出口流排入 R1和R2以保持该系统地生物量稳定.Zzz6ZB2Ltk 产生地沼气除了用来保持沼气池内容在温度32 C和38 C以外,还被用来增加3-4 C地 流反应器进水温度.一个不锈钢材料地同心管用于增加进水和沼气池地温度.dvzfvkwMH 通过以监测有机物去除地COD和脂肪和油地基础地数据记录和系统运行分析，对反应器 地性能进行了评价.鉴于废水波动，每周用冷冻24小时采集地样本对 R1和

9、R2进水和污水 流进行分析.COD为联合确定地所有样品.参照该阶段之前使用地分析，以便确定可溶性化学 需氧量COD和胶体化学需氧量，避免造成扭曲测量变量污泥结转.油脂分析每月使用相结合 地样品进水和污水流 标准方法，APHA , AWW A ,世界经济论坛1995年）每日针对进水和 污水流样本点进行温度和 pH测量记录。并且每周三次采用总碱度，重碳酸盐碱度和挥发性 脂肪酸地滴定法测定基础样品点.每天监测数M外连接到地反应堆产生地沼气 .rqyn14ZNXI 固定板执行每日测量 settleable固体30分钟后地进水和出水流样本.利用监测率和挥发性 固体清除率地脂肪和除油，对沼气池地性能进行了

10、评价.交易量测量浮动了污泥提取地反应 堆和美联储地沼气池。和沼气池进，出口样品分析了每周地总固体，挥发性固体和油脂.沼气 池温度测量一天两次，开始和结束时地采暖期.EmxvxOtOco 长链脂肪酸含量反映了长链脂肪酸地抑制效果，一批实验进行了不同关系地长链脂肪酸/ 地VSS .长链脂肪酸抑制测定分批运行使用钠棕榈酸酯，最丰富地牛奶甘油三酯和引物较小 地长链脂肪酸存在于牛奶.上流式厌氧污泥床反应器是用来进行颗粒污泥测试地.三份测量 是在150mL瓶不同浓度地生物量表示地 VSS ）和棕榈酸，而醋酸浓度显示表保持不 变.SixE2yXPq5 结果与讨论 污泥床反应堆 图2显示反应器地 COD去除率

11、 每周平均）.去除效率保持在 90 %左右地COD负荷值 增加地最多，为5.5kg/m3.d。水力停留时间在最大负荷时保持有效时间约17小时.在整个实 验过程中，反应器地温度波动范围为20 C至30 C ,并且对 COD去除率没有产生太大影 响.6ewMyirQFL 运行地反应堆 R1和R2分别开始使用 440和400kgVSS平均浓度值地 11和10 kgVSS/m3 ）.图3显示地VSS演变.初期减少地5克/LVSS浓度是由于结转.两个反应堆之 间又增加了约 290 kgVSS污泥,250天恢复了初始浓度地污泥.R2地和R1分别在于肉芽开 始在350天还是400天。R2地和R1分别还在于被

12、测量地400天地小颗粒地平均粒径为 0.57 毫 M 还是 0.45 毫 M.kavU42VRUs 造粒导致减少污泥结转，也会导致增加 VSS浓度,上述地20克/ L地污泥容积指数从在 inoculums地37mL /克以12mL /克下降完成.尽管在絮状污泥据报告中，有更有效治疗废水高 长链脂肪酸浓度 佩雷拉等人.2002年。Nadais，等al.2003 ），以及复杂地废水 赛义德 1987年），然而颗粒 污泥已自发在较高 地有机负 荷地 阶段，从而提高了污 泥停留能 力.y6v3ALoS89 结果是,微生物生长，反应器运转过程中经过消解和遗留地污泥可以顺利流出，从而避 免了污泥地突然暴增

13、. Integrated anaerobic treatment of dairy industrial wastewater and sludge M2ub6vSTnP ABSTRACT full-scale dairy efflue nee treatme nt system comprising two an aerobic sludge-bla nket Performa nee parameter were studied in an alter native reactors in parallelarran geme ntwith upwardflow,i nternalfat-

14、 separationby flotation,externallamella settler and floated material digester. Reactors were initiallyinoculatedsludge and granulated in a high-load stage. Usi ng load ing rates up to a maximum 5.5kgCOD/m3.d- efficiencywas found to hydraulic reside nee time of 17hours-reactor rema in stable arou nd

15、90% of COD. Average sludge digester efficiency using a loading rate of 3.5kgVS/m 3. d with a lipid content of 47% of COD amoun ted to 78% of VS.Nonetheless, on account ofprocess leakage of milk or milk-based products, a number of con stitue nts are systematically found in dairy in dustrial wastewate

16、r: lactose, lipids,case inand other prote ins. Lipids, composed of triglycerides, are found mainly in emulsionsresultingfrom initial process stage of homoge ni zati on. In additi on, efflue nts will be acidic or basic accordi ngto chemicalclea ning as used at any time of process. eUts8ZQVRd The use

17、of UASB reactors in dairy wastewater treatment-as well as in the treatme nt of other complex efflue nts-has found limited success in view of the fact that a considerable amount of organic material hydrolyzes or degrades at an excessively low rate, while normally building up within the sludge blanket

18、 by entrainment or adsorption. The result is the dilution of biomass, the affectationof mass transfer properties and the impairment of sludge settling capacity. Sludge activity is therefore reduced and sludge washed out from the reactor in the outlet stream could occur(Sayed 1984。Sayed 1987。Rinzema

19、1993。 Hwu et al.1998. sQsAEjkW5T Rapid adsorptionand significantlyslow degradation of dairy fat emulsi ons were reported for batch studies using biomass that was not adapted to degrad ing fats and a substrate load as high as 12.6 grams of fat per gram of VSS(Petruy & Lett in ga 1997.Vidal et al.(200

20、0 reported that fat-rich dairy wastewater biodegradability rate is limited by fats hydrolysis. They performed batch assays with non-adapted biomass. However, using moderate loads and substrate-adapted microorga nisms, hydrolysis may not be the rate limit ing stage of total treatme nt process. Not li

21、mited by hydrolysis, total process rate may be limited by a reduced mass tran sfer rate due to LCFA adsorpti on on to sludge (Pereira et al.2003。Pereira et al.2004, or by the inhibitory effect of LCFA on acetotrophic methanogenic populations (Pereira et al.2005。Hwu et al.1996.According to research r

22、eported by Hwu et al.(1998, sludge flotation in UASB reactors due to LCFA adsorption may occur at lower LCFA concentration than those that produce in hibitory effect. With a view to study ing the in flue nce of the stage of adsorpti on preced ing lipid-andLCFA- degradati onon the performance of UASB

23、 reactors, several studies were made using an in termitte nt efflue nt feed, leadi ng to en couragi ng results (Sayed 1984。Nadais et al.2006.Cavaleiro et al.(2008 reported that use of pulse-feeds results in in creased tolera nce of acetotrophic metha nogens to LCFA, and suggest that satisfactory res

24、ults for continu ous operati on may be obtainedfollowinga stage of biomassacclimatizationby means of pulse-feed.Several studies dem on strated that the use of floccule nt sludge-rather tha n granu lar- results in a higher efficie ncy in removing LCFA(Nadais et al.2003and treatingcomplex effluents (S

25、ayed 1987.ln con trast, floccule nt sludge appears to be less resista nt to LCFA in hibiti on (Hwu et al.1996. GMsIasNXkA As a result of difficulties in treating complexeffluentsin sludge blanket reactors, pre-treatment methods are normally used, such as fat separation by means of flotation by disso

26、lved air. In order to obtain a compact system without the need of previous fats separation, two UASB reactors were modified to introduce a novel concept:Upflow An aerobic Sludge Bia nket with in ternalfat separatorand exter nal sludge recovery by settling.The system is completed by a floated materia

27、l digesterwith the objective of avoid sludge disposal. An an alysis of this alter native wastewater treatme nt system con structed at real scale in a dairy industry in Melo City, Uruguay (Cooperativa de Lecheria de Melo is prese nted in this paper. This dairy in dustrial wastewater has lipid content

28、 higher than 40% of total COD, and the mean flow is about 100 m3/d. TirRGchYzg MATERIALS AND METHODS System design and operation In view of significant load and flow-ratefluctuationsin the plant s efflue nt stream,a buffer tank , a lamella settler and a 5m3 digester of floated material. 7EqzcWLZNx O

29、utlet efflue ntsof both an aerobic reactors discharge to a lamella settler with plates tilted 60 and spaced at 5cm, retainingpart of the sludge carry-over from the reactors, returningit to the feed box by means of pumping equipment. The lamellasettler operates at a reside nee time of 15 mi nu tes at

30、 full-load. The settli ng tank outlet is discharged to mun icipal sewer.lzq7iGfO2E A funn el-shaped si nk for extracti on of float ing fat was in stalled in both reactors, in side of the off-gas header and two cen timeters, below liquid level. At each reactor, fat extract ion was performed by pump i

31、ng from an exter nal chamber-act ing as fat trap-receivi ng the discharge of the sink, whereby float material is retained, returning the outlet stream of this chamber to the reactor. zvpgeqjihk The reactors were inoculatedwith flocculentsludge from an an aerobic treatme nt Iago on of an abattoir wit

32、h Specific Metha nogenic Activity of 0.12gCH4-COD/gVSS.d. I ntermitte nt and alternate feed rates were used at start-up, with rate in creas ing gradually. Con ti nu ous feed rate was used after 120 day operation,reachingthe total rate of wastewater gen erated by the pla nt 160 days after start-up. G

33、ranu lati on process was an alysedfollow ingtheJeis onand Chamy (1998 technique,immobilizinggranules in agar and then using UTHSCA Image Tool software. Nrpojac3v1 The float sludge digester was put in operati on on day 290 in order to stabilize floating sludge extracted from the reactors. Solid diges

34、ter was inoculated with sludge from the same lagoon as used for the reactors,and operated un der full mixing con diti ons with sludge recirculatio n by means of pump ing. The digester hold-upwas recirculated 8 times per day. The digester outlet stream was discharged into R1 and R2 in order to retain

35、 the system s biomass holdup. 1nowfTG4KI Gen erated biogas was used to in crease reactor in flue nt stream temperature by 3-4C , in addition to keeping the digester contents at a temperature between 32 C and 38 C . A concentric tubes exchanger con structed in stai nless steel was used to in crease t

36、he temperature of the in flue nt and of the digester content. fjnFLDa5Zo Data record ing and system operati on an alysis Reactor performa nee was evaluated by mon itori ng the orga nic matter removal on a COD and a fat-and-oil basis. In view of wastewater fluctuati ons, R1 and R2 in flue nt and effl

37、ue nt streams were an alyzed weekly using refrigerated 24-hour samples collected daily. COD was determ ined for all comb ined samples. A sett ing stage was used prior to analysis, so that COD determinations include soluble COD and colloidal COD, avoid ing distorted measureme nt result ing from varia

38、ble sludge carry-over. Fats and oils were analyzed monthlyusing combined samples of in flue nt and efflue nt streams (Sta ndard Methods, APHA, AWWA, WEF 1995. Temperature and PH measureme nts were recorded daily for point samples of the in flue nt and efflue nt streams。 and total alkali nity, bicarb

39、 on atealkali nity and volatile fatty acids were determined by titration for point samples on a three-per-weekbasis. Gen erated biogas was mon itoreddaily by meters conn ected toeither reactor. tfnNhnE6e5 Lamella settler performanee was evaluated by daily measurement of settleable solids in after 30

40、 minu tes, for both in flue nt and efflue nt stream samples. HbmVN777sL Digester performanee was evaluated by monitoringthe rate of volatile solid removal and the rate of fat-and-oil removal. Daily volume measureme nt were made of floated sludge extracted from the reactors and fed to the digester 。

41、and digester inlet and outlet samples were analysed on a weekly basis for Total Solids, Volatile Solids and Fats and Oils. Digester temperature was measured twice a day, at the begi nning and end of the heati ng period. v7l4jRB8Hs Assay ing LCFA in hibiti on To evaluate the effect of LCFA inhibition

42、,batch tests were carried out with differe nt relati on ships of LCFA/VSS. LCFA in hibiti on was assayed in batch runs using sodium palmitate-the largest abundant of milk triglycerides and primer of smaller LCFA present in the milk. Granular adapted sludge from the UASB reactors was used to perform

43、the tests. Triplicate measureme ntswere made in 150mL vials with vary ing concen trati on of biomass (expressed as VSS and palmitate, while the acetate concen trati on was kept con sta nt as show n in Table2.831cpa59W9 RESULTS AND DISCUSSION Sludge blanket reactors Figure 2 shows reactor feed loads and removal efficiency in COD (weekly average. Removal efficie ncy rema ined at a value around 90% of COD for load values increasing up to 5.5kg/m 3.d。 the hydraulic reside nee time rema iningat a value around 17hours duri ngthe maximum load stage. Reactor temperature fluc