一般污泥和含油污泥的處理方法外文翻譯

1、<p>　　The ways of regular sludge and oily sludge treating</p><p>　　Generally speaking， there is a procedure for treating sludge after secondary treatment of wastewater if we want to prevent our living e

2、nvironment from second polluting. </p><p>　　Wastewater treatment objectives are accomplished by concentrating impurities into solid form and then separating these solids from the bulk liquid. This concentrat

3、ion of solids， referred to as sludge， contains many objectionable materials and must be disposed of properly. Sludge disposal facilities usually represent 40 to 60 percent of disposed of the construction cost wastewater-

4、treatment plants， account for as much as 50 percent of the operating cost， and are the cause of a disproportionate sh</p><p>　　First of all， the initial sludge is separated from the clean water lying upon it

5、 in the secondary clarifier by pumping it to a tank. Because the initial sludge have a high water content that usually can up to 99.5 percent in volume， sludge thickening is a necessary procedure， and there are several t

6、echniques are available foe volume reduction. Mechanical methods such as vacuum filtration and centrifugation may be used where the sludge is subsequently to be handled in a semisolid state. There met</p><p>

7、;　　Gravity thickeners are very similar in design and operation to the secondary clarifiers used in wastewater treating systems. The thickening function is the major design parameter， and tanks are generally deeper than s

8、econdary clarifiers to provide greater thickening capacity. A well-designed， well-operated gravity thickener should be able to， at least double the solids content of the sludge. In another word， the water content ratio o

9、f sludge can be reduced from 99.5 percent in volume to 98 perce</p><p>　　In dissolved air flotation， a small quantity of water， usually secondary effluent is subjected to aeration under a pressure of about 4

10、00kPa. This supersaturated liquid is then release near the bottom of a tank through which the sludge is passed at atmospheric pressure. The air is release in the form of very small bubbles that attach them selves to， or

11、become entrapped in， the sludge solids， floating the solids to the surface. The thickened sludge is skimmed off at the top of the tank while the l</p><p>　　After volume reducing， sludge represents a consider

12、able hazard to the environment and must be rendered inert prior to disposal. The most common means of stabilizing is by biological degradation. Because this process is intended to convert solids to unicellular end produc

13、ts， the term digestion is commonly applied to this process. Sludge digestion serves both to reduce the volume of the thickened sludge still further and to render the remaining solids inert and relatively pathogen-free. T

14、hese goal</p><p>　　Sludge contains a wide variety of organisms， and thus requires a wide variety of organisms for its decomposition. The literature relating to anaerobic sludge digestion often divides the or

15、ganisms into two kinds， the acid formers and the methane formers. So we can divide the anaerobic sludge digestion into two steps too. On the first step， the acid formers consist of facultative and anaerobic bacteria that

16、 solubilize the organic solids through hydrolysis. The soluble products are then fermented t</p><p>　　Sludge can also be stabilized by aerobic digestion. Generally restricted to biological sludge in the abse

17、nce of primary sludge， this process is essentially a continuation of the aeration process， with the volume being reduced by thickening in the secondary clarifier and sludge thickener. The most common application of aerat

18、ion digestion involves stabilizing sludge wasted from extended aerobic systems. Then， aerobic digestion is not as sensitive to environmental factors as is its anaerobic counte</p><p>　　After sludge digestion

19、， the organics can be removed and the volume of sludge can be reduced by further. Then， the sludge needs disposed. Several potions are available for the ultimate disposal of sludge. These include incineration， placement

20、in a sanitary landfill， and incorporation into as a fertilizer or soil conditioner. Raw sludge can be incinerated， provided the water content is sufficiently reduced. Supplement fuel is necessary to initiate and maintain

21、 combustion and municipal solid waste </p><p>　　We see the treatment of sludge as a regular treating what have been mentioned in the front of this writings. The sludge will contribute to the environment poll

22、uting， so we should be do our best to make the sludge hazardless. Now， some sludge of more different characteristics which leading different kinds of environment polluting are investigated. In this writings， I will talk

23、something about oily sludge which can be saw as a topic sludge produced from our oil production and processing activities</p><p>　　A huge amount of oily sludge is produced， and this sludge usually contains a

24、 considerable quantity of oil， which should be removed before its finally disposal. Generated in a vast amount in petroleum refinery plants oily sludge cannot be safely disposed unless its oil content is reduced below a

25、certain limit. In addition， the vast amounts if oil sludge generated in refineries from water-oil separation systems and accumulation of waste oily materials in crude oil storage tanks poses great problem</p><

26、p>　　Petroleum is a complex mixture of non-aqueous and hydrophobic components like n-alkane， aromatics， resins and asphalt. Many of these components are toxic， mutagenic and carcinogenic. Therefore， their release to th

27、e environment is strictly controlled and they are classified as priority environmental pollutants by the US Environmental Protection Agency due to their adverse impact on human health and environment. </p><p&g

28、t;　　A variety of methods have been suggested to treat oily sludge. There are physical or chemical methods such as incineration， chlorination， ozonation， and combustion， biological treatment such as bioremediation， conven

29、tional composting and so on. Nowadays， with the technology of oily sludge treatment developing， separation of oil from oily sludge by freezing and thawing and the oily sludge bioremediation could be more attractive ways&

30、lt;/p><p>　　Freeze/thaw treatment is generally accepted as a physical sludge conditioning method that can significantly improve certain sludge dewatering characteristics， change the floc structure into a more c

31、ompact form and reduce the sludge bound water content .Once the so-called `‘`gross-migration“ of flocs occurs， freezing front would reject impurities in the solution to the far-ends of the vessel， thereby achieving conce

32、ntration purposes recently discussed the benefit obtainable from freeze/thaw treat</p><p>　　Comparing the result from freeze/thaw treatment to regular treatment， we can find that after thawing， however， an o

33、il layer gradually appeared at the top of the sample. Finally， three layers stood clearly in the tube: at the top was a clear， transparent oil layer; at the bottom， a deep-dark sediment layer， while in between， a water l

34、ayer. Still settling of original sludge for 24 h leads to a clear supernatant and a deep-dark sediment. No oil phase could be visually observed. The above-mentioned </p><p>　　The physico-chemical treatments

35、can be applied for the oily sludge， but these methods are extremely expensive. Composting and bioremediation with an introduction of oil degrading microorganisms (bio-augmentation) or activation of indigenous ones are no

36、w considered as two major economic methods for the decontamination of oil pollutions. Composting has some visible advantages including relatively low capital and maintenance costs， simple design and operation and some (b

37、ut incomplete) removal of oi</p><p>　　For more content of the oil， the oily sludge is much more difficult for the bioremediation. Numerous researches have demonstrated high bioremediation efficiency for oil

38、polluted soils， but these methods have limitations for the oily sludge mainly dealt with extremely high pollution level. Most of the experiments were carried out in the lab， while the field experiments were very few. The

39、 bioremediation treatment of the oily sludge was just beginning. These experiments were meaningful for the adva</p><p>　　There is a study of oily sludge treating in China during 2004.  The bioremed

40、ia- tion by augmentation of biopreparation was compared with a conventional composting. The oily sludge and oil polluted soil were received from an oil production plant. The total hydrocarbon content (THC) varied from 32

41、7.7 to 371.2 g kg-1 of dry sludge and the THC in contaminated soil was 151.0 g kg-1. Before application of preparation， straw， sawdust， top sand and pure soil were added in different proportions to the sl</p><

42、p>　　一般污泥和含油污泥的處理方法</p><p>　　一般來講，為了不造成環(huán)境的二次污染，需要在污水處理的二級處理之后添加一道污泥處理工藝。污水處理的目標(biāo)通過把水中雜質(zhì)濃縮成固體形態(tài)再從流體中分離而實現(xiàn)。這種濃縮質(zhì)變稱為污泥，因包含了大量的有害物質(zhì)，需要妥善處置。污泥處理設(shè)備大約占污水處理廠的40%-60%基建投資，污泥處理則占50%左右的處理費用，同時也造成了和其經(jīng)濟費用不成比例的處理難度。</

43、p><p>　　首先，原污泥通過污泥泵由二沉池打到另一個池子中從而和上清液分離。因為原污泥的含水率通常能達(dá)到99.5%，所以污泥必須濃縮，有多種可行的方法用于減少污泥的體積。例如真空過濾和離心等機械處理的方法通常用于將污泥以半固體形式處置之前。通常這些方法是污泥焚燒處理的準(zhǔn)備工作。</p><p>　　如果計劃采用生物處理，則多數(shù)才用重力沉降或者是氣浮的方法進(jìn)行濃縮。這兩種情況所對應(yīng)的污泥仍然

44、是流態(tài)的。重力濃縮池的設(shè)計和運行類似于污水處理中的二沉池。濃縮功能是主要的設(shè)計參數(shù)，為了滿足更大的濃縮能力，濃縮池基本上比二沉池要深。一個設(shè)計正確，運行良好的重力濃縮池至少能提高兩倍的污泥含泥量。也就是說，污泥的含水率可以有99.5%減少到98%，或者更少。這里值得一提的是，重力濃縮池的的設(shè)計要盡量基于中式結(jié)果的分析，因為合適的污泥負(fù)荷率與污泥的屬性的有很大關(guān)系的。</p><p>　　如果采用溶氣氣浮濃縮，需要

45、有一小部分的水，通常是二沉池出水，在400kPa的壓力下充氣。這種過飽和的液體通入罐底，而污泥在大氣壓下通過。氣體以小氣泡的形式和污泥中的固體顆粒黏附，或則是被包圍，從而帶動固體顆粒上浮到表面。濃縮了的污泥的上部被除去，而液體由底部流回溶氣罐充氣。體積減少后，污泥中含有大量的有害成分，在處置之前需要將之轉(zhuǎn)化為惰性成分。最常用的方法是生物降解穩(wěn)定。因為這個過程目的在于將物質(zhì)轉(zhuǎn)化為最終無菌產(chǎn)物，所以常應(yīng)用消化的方法。污泥消化既能進(jìn)一步的減少

46、污泥體積也能使所含固體轉(zhuǎn)化為惰性物質(zhì)并且大體的上沒有病菌。通過厭氧消化或好養(yǎng)消化都能達(dá)到污泥消化目的。</p><p>　　污泥含有多種有機物，因此需要多種微生物來分解。有關(guān)資料將厭氧消化中的微生物分為兩類：產(chǎn)酸菌和甲烷菌。所以，我們也能把厭氧消化分為兩步。</p><p>　　第一步，由兼性厭氧菌和厭氧菌組成的產(chǎn)酸菌通過水解作用溶解有機固體。接著溶解質(zhì)由發(fā)酵作用轉(zhuǎn)化為酒精和低分子量分子。

47、</p><p>　　第二步，有嚴(yán)格厭氧菌組成的甲烷菌將乙酸、酒精、水和二氧化碳轉(zhuǎn)化為甲烷。因為兩種菌群只能在無氧的環(huán)境下存活，所以厭氧消化的反應(yīng)器必須是密閉的。設(shè)計容器的時候同時也要考慮另外的一些因素，例如：溫度、pH值和混合物攪拌。污泥也可以通過好氧消化穩(wěn)定。這種消化基本上只能用于可生化污泥而不能用于初沉池污泥，伴隨著二沉池和污泥濃縮池中污泥體積的減少，這個工藝需要不斷的鼓氣。好氧消化多應(yīng)用于深度曝氣系統(tǒng)。再

48、者，好氧消化對環(huán)境條件不敏感，也不局限有流行變化。污泥消化以后，污泥中的有機物能被去除并且能進(jìn)一步的減少污泥體積。</p><p>　　接下來，污泥需要處置。多種方法可以用來有效的處置污泥。其中包括焚燒、衛(wèi)生填埋和用作化肥以及土壤改良劑。原污泥可以用來焚燒，可以有效地減少含水率。添加燃料可以用來引起和維持燃燒，城市垃圾也可能用來達(dá)到這個目標(biāo)。原污泥和消化污泥也可以用衛(wèi)生填埋來處置。污泥的土地應(yīng)用實踐了好幾年，而現(xiàn)

49、在只限于處理消化污泥。污泥的營養(yǎng)成分有利于植物成長，而其顆粒特性可用于土地改良。這些應(yīng)用局限有飼料作物和非人類消費，而運用于支持可食用植物的可能性正在研究中。污泥土地應(yīng)用的主要限制因素為植物富集金屬毒性和水體富營養(yǎng)污染。污泥的應(yīng)用可通過在流態(tài)時由噴淋器噴淋、溝渠導(dǎo)流或直接注入土壤。去水污泥可以由傳統(tǒng)農(nóng)用機械鋪設(shè)在土地之上在和培養(yǎng)土壤。</p><p>　　上述文字指的是一般污泥的處理。因為污泥能造成環(huán)境的污染，所

50、以我們需要盡最大的努力使之無害化?，F(xiàn)在，很多導(dǎo)致類型污染的具有不同特性污泥正在研究中。</p><p>　　在本文中，我將敘述一種來自于人類產(chǎn)油和石油工業(yè)的污泥，這個代表性污泥稱之為含油污泥。大量的污泥產(chǎn)生，而這種污泥中含有相當(dāng)大量的油，必須在最終處置之前將之去除。煉油廠產(chǎn)生的污泥不能被安全的處置，除非將其含油量去除到一定程度。此外，在煉油廠的油水分離系統(tǒng)和儲油罐中因為含油原料的累積而產(chǎn)生的污泥的處理費用很高，并

51、且對環(huán)境造成很嚴(yán)重的污染。石油是一種疏水混合物例如：烷烴，芳香烴，樹脂和瀝青。許多化合物是有毒性的，致突變的和致癌的。它們的排放的受到嚴(yán)格控制的，因為它們對人體健康和環(huán)境的負(fù)面影響，它們被美國環(huán)保部門分類并列為環(huán)境污染物優(yōu)先。</p><p>　　有很多種方法可以用來處理含油污泥?；瘜W(xué)和物理的方法例如：焚燒、氯氧化、臭氧氧化和燃燒，生物的處理方法例如：生物修復(fù)、傳統(tǒng)堆肥法等等?，F(xiàn)在，隨著技術(shù)的發(fā)展，含油污泥的低溫

52、冷處理和生物修復(fù)成為了兩條有效的處理途徑。低溫冷處理技術(shù)作為一種物理的處理方法能有效地增加污泥的脫水性質(zhì)，改變絮凝劑的結(jié)構(gòu)形式并減少污泥周圍的水含量。比較那種“初沉降”，冷處理能夠除掉溶液中的雜質(zhì)，因此達(dá)到更好濃縮目的，最近就是在討論冷處理的這種好處。據(jù)我們所知，現(xiàn)在的資料中沒有討論冷處理技術(shù)來分離油泥中的油的可行性。但是，如果在自然條件允許的許多國家里，冷處理技術(shù)提供了一種有效的處理含油污泥的處理和處置的方法。通過比較常規(guī)方法處理和冷

53、處理之后污泥，我們可以發(fā)現(xiàn)，冷處理之后的樣品上面浮了一層油。最后我們可以發(fā)現(xiàn)試管中分三層：最上面的一層是清的浮油，底層是一層深色的沉降物，中間一層是清水。原始的污泥經(jīng)過24小時的沉降，可以看見上浮液和底部沉降物，但是沒有可見的油相。通過上面的敘述的現(xiàn)象揭示了簡單的冷處理能有效分離油泥中的油。物理化學(xué)的方法可以用來處理油泥，但是費用卻是很高的。堆肥和通過接種降解油類菌種或激活原有生物進(jìn)行生物</p><p>　　一

54、個關(guān)于油泥處理的研究于2004年在中國進(jìn)行。添加生物添加劑的生物修復(fù)法和傳統(tǒng)的堆肥進(jìn)行對比。含油污泥和油污染的土壤取之于油田。干污泥的總碳?xì)浠衔锖繛?27.7 到371.2 g kg-1，和油污染的土壤的總碳?xì)浠衔锖繛?51.0 g kg-1。在運用添加劑之前，在污泥和土壤中添加不同比例的秸梗、木屑、沙子和純油并混合均勻。這些污泥和土壤組分用來無控制處理和通過激活原有微生物處理。而在堆肥中，糞肥和木屑添加到污泥中，總碳?xì)浠衔锖?/p>

55、量為101.4 g kg-1。生物添加劑每2周用一次，而實驗環(huán)境溫度下持續(xù)56天。污泥每3天加水?dāng)嚢枰槐?。在添?次生物添加劑以后，含油污泥和土壤中的總碳?xì)浠衔锖拷档?6-53%，在激活原有微生物法處理后，總碳?xì)浠衔锖拷档?3-23%，無控制處理則沒有油的降解。通過堆肥，則含油污泥中總碳?xì)浠衔锖拷档土?1%。</p><p>　　上述現(xiàn)象表明，生物修復(fù)可作為一種有效同樣經(jīng)濟的方法處理含油污泥的方法。&