1.1背景和目的

? Man's influence on the environment is receiving increasing public and scientific attention.The quality of some of the nation's water bodies has been subjected to continuingdegradation as a result of man's activities. While there has been considerable success inreversing this trend, one roadblock to greater progress often has been the lack of thenecessary technology to reliably and economically remove the pollutants which are thecause of degradation of receiving waters. While conventional technology is well developedfor removing organics from wastewater, the processes for the control of nitrogen inwastewater effluents have been developed only recently.
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? 人類(lèi)對(duì)環(huán)境的影響正受到越來(lái)越多的公眾和科學(xué)關(guān)注。由于人類(lèi)活動(dòng)的影響，一些國(guó)家水體的質(zhì)量已經(jīng)持續(xù)惡化。雖然在扭轉(zhuǎn)這一趨勢(shì)方面已經(jīng)取得了相當(dāng)?shù)某晒?，但更大進(jìn)展的一個(gè)障礙常常是缺乏必要的技術(shù)，可以可靠且經(jīng)濟(jì)地去除導(dǎo)致水體退化的污染物。雖然傳統(tǒng)技術(shù)已經(jīng)很好地發(fā)展出用于從廢水中去除有機(jī)物，但用于控制廢水出水口中的氮的處理過(guò)程最近才得到開(kāi)發(fā)。

The beginnings of the implementation of nitrification on a significant scale occurred in theU.S. as late as the 1960's. The practice of nitrification was widespread in England muchearlier. The first implementation of full nitrogen removal was as late as 1969 at South LakeTahoe in California and even this installation encountered many problems. A flurry ofresearch and development activity on the various nitrogen control methods occurred veryrecently beginning in the late 1960's and continues to date. Recent legislation and stateregulatory activities have spurred many localities into nitrogen control projects.
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? 尿素化工法的大規(guī)模推廣在美國(guó)直至20世紀(jì)60年代才開(kāi)始，而在英國(guó)尿素化工法的應(yīng)用則更早期普及。首個(gè)全氮去除工程至遲于1969年在加利福尼亞的南太浩湖展開(kāi)，甚至該工程亦曾遭遇多種問(wèn)題。自20世紀(jì)60年代后期始，各種氮控制方法的研究與開(kāi)發(fā)活動(dòng)便快步展開(kāi)，并持續(xù)至今。隨著最近立法以及州級(jí)監(jiān)管活動(dòng)的推動(dòng)，許多地方也陸續(xù)啟動(dòng)了氮控制工程。

Nitrogen control techniques are divided into two broad categories. The first group ofnitrogen control processes is involved with the conversion of organic and ammonia nitrogento nitrate nitrogen, a less objectionable form. These processes are termed nitrificationprocesses. The second category involves processes which result in the removal of nitrogenfrom the wastewater, not just merely the conversion of nitrogen from one form to anotherform in the wastewater. This latter group includes biological nitrification-denitrification, ionexchange, ammonia stripping and breakpoint chlorination.
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? 氮控制技術(shù)可分為兩個(gè)廣泛類(lèi)別。第一組氮控制過(guò)程涉及將有機(jī)和氨氮轉(zhuǎn)化為硝態(tài)氮，這是一種較少引起反感的形式。這些過(guò)程被稱(chēng)為硝化過(guò)程。第二類(lèi)過(guò)程涉及從廢水中除氮，而不僅僅是將氮從一種形式轉(zhuǎn)化為另一種形式。這后一類(lèi)包括生物硝化反硝化、離子交換、氨吸附和斷點(diǎn)氯化過(guò)程。

? The purpose of this manual is the dissemination of the available data on the nitrogen controltechniques developed to date. Further, this manual is not simply an assembly of data.rather, data from a variety of sources has been scrutinized and reasonable design criteriadrawn on the basis of all available sources. Where design procedures come directly from asingle investigator, appropriate reference is made to the work.
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本手冊(cè)的目的是傳播迄今為止開(kāi)發(fā)的氮控制技術(shù)的可用數(shù)據(jù)。此外，該手冊(cè)不只是數(shù)據(jù)的組裝。相反，數(shù)據(jù)來(lái)自各種來(lái)源已經(jīng)被仔細(xì)審查，并且所有可用資源的基礎(chǔ)上得出了合理的設(shè)計(jì)標(biāo)準(zhǔn)。在設(shè)計(jì)過(guò)程直接來(lái)源于單個(gè)研究者的情況下，將對(duì)該工作進(jìn)行適當(dāng)引用。

This manual could not have been prepared five years ago because of the state of nitrogencontrol technology at that time. It may well be that continuing research will require anupdate of this manualin the future. Nonetheless, the body of knowledge on nitrogen controltechniques is now well developed and municipalities and local agencies have a firm basis uponwhich to plan those wastewater treatment facilities which require nitrogen controltechniques.
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此手冊(cè)在五年前由于當(dāng)時(shí)的氮控技術(shù)狀態(tài)而無(wú)法準(zhǔn)備。未來(lái)的持續(xù)研究可能需要更新本手冊(cè)。然而，氮控技術(shù)的知識(shí)體系現(xiàn)已完善，市政和地方機(jī)構(gòu)在規(guī)劃需要氮控技術(shù)的廢水處理設(shè)施時(shí)有了堅(jiān)實(shí)的基礎(chǔ)。