環(huán)境工程畢業(yè)設(shè)計(jì)外文翻譯

1、<p>　　Catalytic strategies for industrial water re-use</p><p>　　F.E. Hancock</p><p>　　Synetix, Billingham, Cleveland, TS23 1LB, UK</p><p><b>　　Abstract</b></p>

2、;<p>　　The use of catalytic processes in pollution abatement and resource recovery is widespread and of significant economic importance [R.J. Farrauto, C.H. Bartholomew, Fundamentals of Industrial Catalytic Proces

3、ses, Blackie Academic and Professional,1997.]. For water recovery and re-use chemo-catalysis is only just starting to make an impact although bio-catalysis is well established [J.N. Horan, BiologicalWastewater Treatment

4、Systems; Theory and Operation, Chichester, Wiley, 1990.]. This paper will </p><p>　　Keywords: COD removal; Catalytic oxidation; Industrial water treatment</p><p>　　1.Introduction</p><

5、p>　　Industrial water re-use in Europe has not yet started on the large scale. However, with potential long term changes in European weather and the need for more water abstraction from boreholes and rivers, the availa

6、bility of water at low prices will become increasingly rare. As water prices rise there will come a point when technologies that exist now (or are being developed) will make water recycle and re-use a viable commercial o

7、peration. As that future approaches, it is worth stating the most i</p><p>　　Hence the general rules for wastewater improvement are: </p><p>　　1. Avoid if possible, consider all possible ways to

8、 minimise. </p><p>　　2. Keep contaminated streams separate. </p><p>　　3. Treat each stream at source for maximum concentration and minimum flow. </p><p>　　4. Measure and identify co

9、ntaminants over complete process cycle. Look for peaks, which will prove costly to manage and attempt to run the process as close to typical values as possible. This paper will consider the industries that are affected b

10、y wastewater issues and the technologies that are available to dispose of the retentate which will contain the pollutants from the wastewater effluent. The paper will describe some of the problems to be overcome and how

11、the technologies solve these probl</p><p>　　2. The industries </p><p>　　The process industries that have a significant wastewater effluent are shown in Fig. 1. These process industries can be in

12、volved in wastewater treatment in many areas and some illustrations of this are outlined below. </p><p>　　Fig. 1. Process industries with wastewater issues. </p><p>　　2.1. Refineries </p>

13、<p>　　The process of bringing oil to the refinery will often produce contaminated water. Oil pipelines from offshore rigs are cleaned with water; oil ships ballast with water and the result can be significant water

14、 improvement issues. </p><p>　　2.2. Chemicals </p><p>　　The synthesis of intermediate and speciality chemicals often involve the use of a water wash step to remove impurities or wash out residua

15、l flammable solvents before drying. </p><p>　　2.3. Petrochemicals </p><p>　　Ethylene plants need to remove acid gases (CO2, H2S) formed in the manufacture process. This situation can be exacerba

16、ted by the need to add sulphur compounds before the pyrolysis stage to improve the process selectivity. Caustic scrubbing is the usual method and this produces a significant water effluent disposal problem. </p>&

17、lt;p>　　2.4. Pharmaceuticals and agrochemicals </p><p>　　These industries can have water wash steps in synthesis but in addition they are often formulated with water-based surfactants or wetting agents. &l

18、t;/p><p>　　2.5. Foods and beverages </p><p>　　Clearly use water in processing and COD and BOD issues will be the end result. </p><p>　　2.6. Pulp and paper </p><p>　　This i

19、ndustry uses very large quantities of water for processing – aqueous peroxide and enzymes for bleaching in addition to the standard Kraft type processing of the pulp. It is important to realise how much human society con

20、tributes to contaminated water and an investigation of the flow rates through municipal treatment plants soon shows the significance of non-process industry derived wastewater. </p><p>　　3. The technologies

21、</p><p>　　The technologies for recalcitrant COD and toxic pollutants in aqueous effluent are shown in Fig. 2. These examples of technologies [2,6,8] available or in development can be categorised according t

22、o the general principle underlying the mechanism of action. If in addition the adsorption (absorption) processes are ignored for this catalysis discussion then the categories are: </p><p>　　1. Biocatalysis &

23、lt;/p><p>　　2. Air/oxygen based catalytic (or non-catalytic). </p><p>　　3. Chemical oxidation </p><p>　　1. Without catalysis using chemical oxidants </p><p>　　2. With cata

24、lysis using either the generation of _OH or active oxygen transfer. Biocatalysis is an excellent technology for Municipal wastewater treatment providing a very cost-effective route for the removal of organics from water.

25、 It is capable of much development via the use of different types of bacteria to increase the overall flexibility of the technology. One issue remains – what to do with all the activated sludge even after mass reduction

26、by de-watering. The quantities involved mean tha</p><p>　　3.1. Redox catalysis and active oxygen transfer</p><p>　　The mechanism of catalytically promoted oxidation with hydrogen peroxide or sod

27、ium hypochlorite cannot be encompassed within one concept, however there are general similarities between the two oxidants that allows one to write a series of reactions for both (Fig. 3) [5]. This type of mechanism coul

28、d be used to describe a broad range of reactions for either oxidant from catalytic epoxidation to COD oxidation. The inherent usefulness of the reactions is that;</p><p>　　1. The reactions take place in a tw

29、o-phase system.</p><p>　　2. High pressure and temperature are not required.</p><p>　　3. The catalytic surface can act as an adsorbent of the COD to be oxidised effectively increasing the concent

30、ration and hence the rate of oxidation.</p><p>　　The simple mechanism shows the selectivity issue with this type of processes. The oxidant can simply be decomposed by the catalyst to oxygen gas – this reacti

31、on must be avoided because dioxygen will play no role in COD removal. Its formation is an expensive waste of reagent with oxygen gas ($20/Te) compared to the oxidant ($400–600/Te). To be cost competitive with alternative

32、 processes redox catalysis needs excellent selectivity.</p><p>　　3.2. Technology mapping</p><p>　　The technologies so far described can be mapped [12] for their applicability with effluent COD c

33、oncentration (measured as TOC) and effluent flow rate (m3 h-1). The map is shown in Fig. 4. The map outlines the areas where technologies are most effective. The boundaries, although drawn, are in fact fuzzier and should

34、 be only used as a guide. Only well into each shape will a technology start to dominate. The underlying cost model behind the map is based on simple assertions – at high COD mass flows</p><p>　　4. Conclusion

35、s </p><p>　　Wastewater treatment processes are in the early stages of development. The key parameters at present are effectiveness and long term reliability. Many processes operating are in this stage, inclu

36、ding the redox Accent TM is a trademark of the ICI Group of Companies. catalysis systems. However,once proven, redox catalysis offers many advantages for COD removal from wastewater: </p><p>　　1. The low ca

37、pital cost of installation. </p><p>　　2. Simple operation that can be automated. </p><p>　　3. Flexible nature of the process – can be easily modified to meet changing demands of legislation. <

38、;/p><p>　　Hence it will be expected to develop into an important technology in wastewater improvement. </p><p>　　Acknowledgements </p><p>　　The author is grateful to Jane Butcher and K

39、eith Kelly of Synetix for discussions on this paper. References </p><p>　　[1] R.J. Farrauto, C.H. Bartholomew, Fundamentals of Industrial Catalytic Processes, Blackie Academic and Professional, 1997. F.E. Ha

40、ncock / Catalysis Today 53 (1999) 3–9 9 </p><p>　　[2] J.N. Horan, Biological Wastewater Treatment Systems; Theory and Operation, Chichester, Wiley, 1990. </p><p>　　[3] F.E. Hancock et al., Catal

41、ysis Today 40 (1998) 289. </p><p>　　[4] F. King, F.E. Hancock, Catal. Today 27 (1996) 203. </p><p>　　[5] J. Hollingworth et al., J. Electron Spectrosc., in press. </p><p>　　[6] F. L

42、uck, Environmental Catalysis, in: G. Centi et al. (Eds.), EFCE Publishers, Series 112, p. 125. </p><p>　　[7] D. Mantzavinos et al., in: Vogelpohl and Geissen (Eds.), in: Proceedings of the Conference on Wate

43、r Science and Technology, Clausthal-Zellerfeld, Germany, May 1996, J. Int. Assoc. Water Quality, Pergamon, 1997. </p><p>　　[8] R. Venkatadri, R.W. Peters, Hazardous Waste Hazardous Mater. 10 (1993) 107. <

44、/p><p>　　[9] A.M. Braun, E. Oliveros, Water Sci. Tech. 35 (1997) 17. </p><p>　　[10] D. Bahnemann et al., Aquatic and surface photochemistry, Am. Chem. Soc. Symp. Ser. (1994) 261. </p><p&

45、gt;　　[11] J. Prousek, Chem. Lisy 89 (1995) 11. </p><p>　　工業(yè)廢水回用的接觸反應(yīng)策略</p><p><b>　　摘要：</b></p><p>　　無論從控制污染還是資源恢復(fù)的角度，接觸反應(yīng)都是被廣泛應(yīng)用并極具經(jīng)濟(jì)效益的。在生物接觸反應(yīng)理論以近于完善的今天，基于水資源恢復(fù)和回用的化學(xué)接

46、觸反應(yīng)技術(shù)正在逐漸興起。本論文將要探討化學(xué)接觸反應(yīng)在水資源回用中的原理。文章中闡述了氧化接觸反應(yīng)化學(xué)在對新技術(shù)的鞏固和利用方面的用途是相當(dāng)多的。明確來講，氧化還原催化作用和活性氧轉(zhuǎn)移氧化劑具有很多優(yōu)點(diǎn)。本文將涉及上述技術(shù)的設(shè)計(jì)。</p><p>　　關(guān)鍵詞：COD去除率 接觸反應(yīng) 工業(yè)廢水回用</p><p><b>　　1．緒論</b></p>&

47、lt;p>　　在歐洲，工業(yè)水回用尚未形成規(guī)模。然而，從歐洲氣候的長遠(yuǎn)變化和越來越多的地上鑿洞及河流取水現(xiàn)象來預(yù)測，低價水將愈加稀少。由于水價的提高，研究水資源恢復(fù)及再利用的技術(shù)將成為可行的貿(mào)易運(yùn)作方式。因此，改善污水水質(zhì)的研究將是未來關(guān)注的熱點(diǎn)。水不在是自然界的廉價溶劑，而是易于污染難于凈化的材料,一旦擴(kuò)散到環(huán)境中將會侵入生物圈的各個部分。</p><p>　　污染物僅僅是被置于錯誤地方的一種物質(zhì),因而,科

48、研的目的就是將它們保存在安全無害的。避免和最小化是是污染物去處的前期步驟。當(dāng)然,避免在這樣一個任何變化都會導(dǎo)致嚴(yán)重結(jié)果的星球上是不可能具有選擇性的。另外，所謂避免也指簡單的液相與氣相之間的轉(zhuǎn)化。液相與氣相污染物的消除都分別存在其利害關(guān)系。但值得注意的是，氣體污染物的去除的發(fā)展遠(yuǎn)先進(jìn)于水中COD的去除。因此，液相中污染物的去除是值得關(guān)注的。</p><p>　　由于研究不能面面俱到，第三步可以從前兩步驟中得到借鑒。

49、徹底清潔是昂貴的，即使你有一個成本高效的途徑，它仍然會降低資產(chǎn)回報和降低經(jīng)濟(jì)合理性 </p><p>　　目前，水資源循環(huán)利用的最優(yōu)技術(shù)便是膜技術(shù)。它是唯一能夠利用化學(xué)工藝產(chǎn)生充分清潔滲透作用的技術(shù)。但是膜技術(shù)難以單獨(dú)運(yùn)行，大都依賴于上向流過濾和處理向下流中含污染物的滯留物的技術(shù)。由此，要在水質(zhì)提高工藝中做到面面俱到就要求多種工藝綜合運(yùn)用。 </p><p>　　因此，廢水水質(zhì)提高的大體規(guī)

50、則如下： </p><p>　　1. 盡可能避免污染，考慮所有使污染最小化的措施。</p><p>　　2. 隔離受污染水體。</p><p>　　3. 源頭處理河水，高濃度低流量。</p><p>　　4. 在完整的處理周期中測量和鑒定污染物。找到運(yùn)行管理費(fèi)用的最高值，盡量使其與常規(guī)費(fèi)用相接近。</p><p>　　

51、本篇論文將要考慮到受污水影響的工業(yè)以及處理滯留物的技術(shù)，滯留物包括由污水管道排出的污染物。本文將要闡述需要克服的問題及解決問題過程中應(yīng)用技術(shù)多樣化的程度。另外解釋了價格控制員如何影響未來技術(shù)的發(fā)展方向。 </p><p><b>　　2．工業(yè)</b></p><p>　　處理工業(yè)龐大的污水出流量。這些處理工業(yè)涉及污水處理的諸多領(lǐng)域，列舉一些示例如下： </p&g

52、t;<p><b>　　2.1 精練廠</b></p><p>　　將原油送往煉油廠的過程中會對水體造成污染。無論是由海面鉆探平臺引出的輸油管道被水沖刷干凈；還是儲油船的壓艙水都會帶來一系列水質(zhì)改良問題。 </p><p><b>　　2.2 化學(xué)藥品</b></p><p>　　合成媒介或特殊化學(xué)藥品在烘干

53、前常需大量清水沖掉雜質(zhì)或殘余可燃性溶媒。 </p><p>　　2.3 石油化工產(chǎn)品</p><p>　　乙烯車間需要去除生產(chǎn)過程中形成的酸性氣體。在通過高溫分解來提高加工選擇性之前添加硫化物更加劇了這一情形。慣常采用腐蝕性擦洗的辦法引發(fā)了大量廢水處理的問題。 </p><p>　　2.4 藥物和農(nóng)用化學(xué)品</p><p>　　這些工業(yè)在合成

54、時需要沖洗步驟，包括以水為基礎(chǔ)的表面活性劑和濕介質(zhì)。 </p><p><b>　　2.5 食品和飲料</b></p><p>　　清潔工藝需水，產(chǎn)生BOD,COD。 </p><p><b>　　2.6 紙漿和造紙</b></p><p>　　生產(chǎn)過程中大量用水---除了標(biāo)準(zhǔn)牛皮紙?zhí)幚砑垵{，漂白階

55、段需要水合過氧化物和酶。</p><p>　　所以充分了解人類社會活動怎樣對水質(zhì)造成的污染是至關(guān)重要的，一份市政處理廠流速的調(diào)查顯示了未經(jīng)處理工業(yè)廢水的重要影響。 </p><p><b>　　3.處理技術(shù)</b></p><p>　　去除出流水體COD和污染物的處理技術(shù)如圖2所示。這些可行的或處于發(fā)展中的工藝示例[2,6,8]依據(jù)大體的反映機(jī)

56、理規(guī)則可被劃分為幾類。如果催化工藝中的吸附過程被忽略的話，則分類如下：</p><p><b>　　1. 生物催話作用</b></p><p>　　2. 以空氣/氧為基礎(chǔ)的接觸反應(yīng)</p><p><b>　　3. 化學(xué)氧化</b></p><p>　　4. 無催化作用的化學(xué)藥劑氧化</p&g

57、t;<p>　　5. 利用_OH或活性氧轉(zhuǎn)移的催化作用</p><p>　　生物催化作用在市政污水處理中發(fā)揮了極佳的作用，為去除水中有機(jī)物提供了經(jīng)濟(jì)高效的途徑。在使用不同種類的細(xì)菌來增加技術(shù)的靈活性方面取得了很大進(jìn)展。一個遺留問題---怎樣處置脫水后的活性污泥。污泥量意味著這是一個棘手的問題，作為肥料這一應(yīng)用途徑是有限的。吸收了重金屬的污泥是有毒性的，反抗的有毒的 COD。這種情況下，焚燒和使用填埋

58、來安全處理灰燼是必要的。</p><p>　　以空氣為基礎(chǔ)的氧化是十分吸引人的，因?yàn)槿绻恍柩趸瘎┚鸵馕吨恍杓兗壍难鯕?。不幸的是，它僅是微溶于水，低溫化學(xué)惰性強(qiáng)，需要一定溫度和壓力來加快反應(yīng)速度。壓力作用下，這類工廠資本緊張。因此，即使運(yùn)行費(fèi)用低廉，最初的建廠資本對后期工藝運(yùn)行費(fèi)用有著極大的影響。催化作用雖然加快了反應(yīng)速度，降低了運(yùn)行溫度和壓力但卻步能完全避免或提供一套完整的解決辦法。使用的催化劑大多為第8族金

59、屬元素，例如鈷和銅。濾去此類金屬進(jìn)入液相是困難的，因?yàn)樗柚沽水愵惖拇呋瘎?lt;/p><p>　　應(yīng)用廉價氧化劑的化學(xué)氧化已經(jīng)在綜合的化學(xué)制品廠良好運(yùn)行。通常的例子就是產(chǎn)生在堿性氯單元的次氯酸鈉廢物，這種堿性氯單元可以在和其它工廠的聯(lián)合體中被用于氧化COD徑流。過氧化氫、二氧化氯、高錳酸鉀在本工藝中都可作為氧化劑使用。選擇的首要因素是廉價，其次是氧化的有效性。</p><p>　　在接觸反

60、應(yīng)領(lǐng)域研究最深入的就是_OH作為一個活性氧化劑的產(chǎn)生和利用。方式隨多，但最有效的就是利用光子和光催化劑。光催化劑通常是TiO2，但具有適當(dāng)譜帶的其它材料也可使用。工藝可以非?；钴S，但工程上的困難是如何得到光，一種催化劑，其高效接觸的出流是不易得到的。實(shí)際上，催化劑對光的低效利用使這種工藝只適用于于日光光源。化石燃料產(chǎn)生的電力釋放出的光子是不能接受的，因?yàn)槎趸嫉尼尫乓馕吨睾虲OD的消除。水力電氣能也是一種可用能源，但其低效性是不可

61、忽視的。</p><p>　　過氧化氫和臭氧已經(jīng)應(yīng)用于光催化，但它們可以獨(dú)立的或與催化劑共同使用來實(shí)現(xiàn)COD的氧化。對于臭氧，問題在于制造途徑，光環(huán)放出作為一個重大的強(qiáng)烈過程通常限制了其應(yīng)用和臭氧的有效性。值得注意的是，這點(diǎn)討論基于氧化劑再沒有激發(fā)的條件下不會因充分的內(nèi)在反應(yīng)而被使用。因此催化劑在有效利用簡單有機(jī)物和復(fù)雜反抗COD方面有著重要的作用。所以使用過氧化氫作為催化劑。</p><p&

62、gt;　　在催化作用方面，氧化劑和次氯酸鹽共同作用形成了一系列在適當(dāng)?shù)拇呋瘎┳饔孟驴勺鳛锳OT氧化劑的材料。如果AOT氧化劑是次氯酸鹽或過氧化氫那么就可以避免三階段反應(yīng)從而極大簡化了流程。廉價而有效的促進(jìn)了不需復(fù)雜化學(xué)工藝并且能夠被環(huán)境所接受的氧化劑，這種氧化劑的產(chǎn)生將成為當(dāng)前困難的最佳解決方案。</p><p>　　3.1 氧化還原催話作用和AOT</p><p>　　通過過氧化氫或次氯

63、酸鈉的接觸反應(yīng)促進(jìn)機(jī)理不能被單一概念所含概。然而兩種氧化劑有許多大體類似反應(yīng)，這種機(jī)理可以被用來形容大范圍的接觸反應(yīng)，從環(huán)氧化劑到COD氧化。固有的反應(yīng)作用如下：</p><p>　　1. 反應(yīng)發(fā)生在兩相系統(tǒng)當(dāng)中。</p><p>　　2. 不需高溫高壓。</p><p>　　3. 接觸反應(yīng)表面可起到COD吸收劑作用，有效提高濃度和氧化速率。</p>

64、<p>　　在本工藝中，簡單的機(jī)理表現(xiàn)為選擇性。氧化劑可以輕易的被降解為氧氣。此類反應(yīng)應(yīng)盡量避免，以為分子氧對COD去除不起作用。相對于氧化劑來講，它的形成將造成反應(yīng)劑及氧氣的嚴(yán)重浪費(fèi)。為了在成本上具有競爭力，氧化還原催化應(yīng)具有高度選擇性。</p><p><b>　　3.2 技術(shù)圖</b></p><p>　　至此，所描述的技術(shù)勾畫出了其對出流COD濃度和

65、出流流速的適應(yīng)性。技術(shù)圖如圖所示。概述了技術(shù)的有效應(yīng)用領(lǐng)域，其邊界是模糊的，只能作為指導(dǎo)。只有在理論系統(tǒng)成型之后，技術(shù)才能居于主導(dǎo)地位。圖示后面劃線的成本模型基于一種簡單的主張，即只有空氣/氧氣才能控制COD的處理成本，因?yàn)檠趸瘎┑牟环€(wěn)定成本相對較低。在水源水質(zhì)恢復(fù)具有選擇性的條件下，對于COD濃度高流量大的污水，只有生物處理設(shè)備是可行的。低流量低COD值時，氧化還原AOT催化是一種重要的技術(shù)。圖5所示的SA過程就屬于這一范疇。<

66、/p><p>　　催化劑在PH<9的嚴(yán)密系統(tǒng)控制下運(yùn)行，所以金屬濾去可被避免。列于表3的催化劑活動性和選擇性的方面的進(jìn)一步研究可以參照可能的表面樣式。這種簡單的觀點(diǎn)可以通過對[3,4,5]的大量研究加以延伸?，F(xiàn)在這種催化劑的機(jī)理以圖6表示。關(guān)鍵步驟就是避免NiO孔洞之間的再結(jié)合。而空間和電子的因素都回促使這種再結(jié)合。</p><p>　　這種工藝的應(yīng)用范圍如下所列，一些化學(xué)藥品的主要類型

67、已經(jīng)被實(shí)驗(yàn)數(shù)據(jù)證明是適宜的，如硫化物、胺、酒精、酮、乙醛、苯酚、氨基酸、石蠟、和芳香烴。</p><p>　　通過工業(yè)校驗(yàn)，反抗COD和硫化物已經(jīng)被成功論證，一種氧化硫磺類物質(zhì)的設(shè)備已經(jīng)安裝并投入運(yùn)行。</p><p><b>　　4. 結(jié)論</b></p><p>　　污水處理工藝尚處于發(fā)展的初級階段。目前的重要參數(shù)是有效性和長期可靠性。許多

68、工藝運(yùn)作的發(fā)展到氧化還原催化體系階段。然而，一旦得到證明，氧化還原催化將為污水COD的去除帶來諸多好處：</p><p>　　1. 安裝價格低廉。</p><p>　　2. 運(yùn)行簡單，自動；化程度高。</p><p>　　3. 工藝性質(zhì)靈活，對不同需求易于改進(jìn)。</p><p>　　因此，它將對污水處理的發(fā)展起到至關(guān)重要的作用。 </p