腐植酸研究历史Word文档下载推荐.docx

腐植酸研究历史Word文档下载推荐.docx

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BYMICHAELSUSIC

RESEARCHSCIENTIST

2FEBRUARY2001

（Revised10June2008）

ABSTRACT

Eventhoughhumuswasnamedin1761andtheextractionof 

humicacidswasreportedin1786,humicacidstructureand 

originhasonlyrecentlybeendetermined.Suchatimespanfromthediscoveryofasubstancetotheelucidation 

ofitsoriginandstructureisindeedrare,perhapsunique. 

Yethumicacidsareextremelycommon,andalsoareprecursorstosuchimportantnaturalresourcesascoaland 

petroleum.Thepressuretoimproveagricultureinthe18thand19thcenturieswastheimpetusbehindtheeffort 

tounderstandhumicacidchemistry,andthegrowingimportanceofcoalandpetroleuminthe20thcentury 

furtherincreasedthispressure.Therehasbeennoshortage 

ofresearcheffort,withabout10,000reportsinthescientificliterature.Despitethis,theworkhasbeen 

conflictingandconfused.Therearetwoprincipalreasons 

whyprogresshasbeensoslow.First,humicacidchemistrywasdifficulttounravelwiththetechnologythatwasavailablebeforeWWII.Second,asaconsequenceofthis,researchersbecamestubbornlypolarizedintheirinterpretationofdataandrefusedtoacknowledgevalidresultsthatweredifferenttotheirown.WhenadequatetechnologyforthestudyofhumicacidsbecameavailableafterWWII,thepreviousunhealthyattitudeswerecontinuedandmajorerrorswentunchallengedforlongperiodsoftime.Itishopedthatwiththelatesthumic 

aciddiscoveriesamoresensibleapproachwillprevail, 

andthatfutureprogresswillbemuchmorerapid.

Introduction

Withinthepast150yearsorso,thestructuresof 

naturally-occurringorganiccompoundshavegenerallybeen 

elucidatedwithindecadesoftheirdiscovery.Aclassic 

exampleisthestructureelucidationofDNA.Evenifthe 

exactsequenceofaminoacidsandsugarsinforexample,a 

glycoprotein,hasnotbeendetermined,thenumberandtypes 

ofaminoacidsandsugarsiswell-known.Incontrast,the 

situationforhumicacidshasbeenverydifferent.Humicacids*arebrown-blackpolymericacidsofplantoriginthatareubiquitousattheEarth’ssurface.Theycontributetosoilfertility,afactthathasbeenrecognizedsinceancient 

times.Asthestudyofhumicacidsprogressedfrom1786when 

theywerefirstextractedfrompeatbogsinGermany,their 

importancehasbecomeclearer.Notonlyaretheyimportant 

forsoilfertility,buttheyarealsoprecursorsofkerogens,peat,asphalt,bitumen,petroleum,andcoal.Buttheyalso 

havedeleteriouseffects,andinmorerecenttimesithasbeendiscoveredthathumicacidsaffecttheenvironmentby 

complexingwithmetalsandorganics,whichcanmodifythe 

toxicityofheavymetals,pesticides,andherbicides.They 

canalsointerferewiththeefficiencyofindustrial 

processessuchasaluminaextractionfrombauxite,adversely 

affectwaterpurification,andformcarcinogensduringraw 

waterdisinfection.

Alongwithagoodclimate,fertilesoilsareanecessityforhumanexistence,survival,andenjoymentoflife.Theculturesofmanyancientpeoplewerebasedonan 

agriculturalexistence.Tothemfertilesoilswerethe 

responsibilityofthegods,whomtheyfrequentlyimplored 

forgoodcrops.AsknowledgeofMan’senvironmentslowly 

grew,especiallyintheMiddleAges,humansturnedtheir 

mindstomoreconcretereasonsforgoodcropyields,rather 

thanthemerewhimsofmythicalgods.Differencesinplant 

litterwereafairlyobviouscandidateforstudy,apartfromthenon-descriptentitiessuchas 

wind,earth, 

and 

fire 

whichwereinvogueatthetime.Hence,thelinkingofsoil 

fertilitywithplantlitterwasnosurprise.Butthe 

complexnatureofthiscouldnothavebeenforeseen.After 

all,itisnowknownthatplantsarecomposedofaplethora 

ofchemicalcompounds,andevenmoreareproducedinthe 

soilduetomicrobialalterationofthem.Knowledgeabout 

thisinaneraof 

thinkinghadtocomeslowlybyobservation,experiment,andrecordingofresults.Man’sobviousneedforandconcernaboutfood,orthescarcityofit,broughthumus,andlater,humicacids,intosharpfocus.

Thepressuretoimproveagricultureinthe18thand19thcenturieswastheimpetusbehindtheefforttounderstandhumicacidchemistry.Then,thegrowingimportanceofcoalandpetroleuminthe20thcenturyfurtherincreasedthepressure.However,fromthelate1700stothemid1800s 

researcherswereonlyjustdiscoveringsuchsimplethings 

asoxygen,hydrogen,carbondioxide,andthenoblegases, 

yetthequestionwasbeingasked:

Whatarehumicacids?

Thequestioncamefartooearly,andwiththeinadequateknowledgeandtechnologyofthetime,incorrectviewpoints 

becamestubbornlyentrenched.Thisattitudethenpersisted 

evenwhenadequatetechnologybecameavailableafter 

WWII.

*