城市污泥與玉米秸稈共熱解及炭粉吸附特性研究

城市污泥與玉米秸稈共熱解及炭粉吸附特性研究Introduction

Citiesaroundtheworldarefacingtheproblemofmanagingthelargeamountsofsewagesludgetheygenerate.Sewagesludgeisasemi-solidby-productofwastewatertreatment,anditcontainsahighamountoforganicmatter.Disposingofsewagesludgeinlandfillscausesenvironmentalpollution,andtherefore,thereisaneedforalternativedisposalmethodsthatareeconomicallyandenvironmentallysustainable.

Onesuchmethodisco-firingsewagesludgewithagriculturalwaste,suchascornstover,toproduceenergy.Co-firinginvolvesthepartialreplacementofcoalwithbiomassinpowerplants.Thecombustionofbiomassandcoalincombinationreducesgreenhousegasemissionsandavoidstheneedforchemicalfertilizers.

Moreover,theresultantashfromco-firingsewagesludgewithagriculturalwastecanalsobeusedasaneffectiveadsorbentforpollutants.

Thisstudyaimstoinvestigatetheco-pyrolysisofsewagesludgewithcornstoverandtheadsorptionpotentialoftheresultingbiocharforpollutants.Thestudyseekstoanswerthefollowingresearchquestions:

Whatistheoptimalratioofsewagesludgetocornstoverforbiocharproduction?

Whatistheimpactoftemperatureonbiocharproductionyield?

Whatistheadsorptioncapacityoftheresultantbiocharforpollutants?

Methodology

Theexperimentwasconductedinapyrolysisreactor.Cornstoverwascollectedfromafarm,andsewagesludgewasobtainedfromanearbywastewatertreatmentplant.Thecollectedmaterialswereair-dried,crushed,andmixedthoroughlyinvaryingratiosofsewagesludgetocornstover(30:70,50:50,70:30).Themixturewasthenplacedinapyrolysisreactor,andthetemperaturewasvariedbetween400°Cand800°C,withincrementsof100°C.Theresultingbiocharwasthencharacterizedusingtechniquessuchasscanningelectronmicroscopy,Fouriertransforminfraredspectroscopy,andthermogravimetricanalysis.Thebiochar'sadsorptioncapacityforpollutantswastestedusingmethyleneblue,Congored,andacetaminophenasmodelcontaminants.

Results

Thetemperaturehadasignificantimpactonthebiocharproductionyield,withtheoptimumyieldat600°C.Thebiocharyielddecreasedasthetemperatureincreasedbeyond600°C.Theoptimalsewagesludgetocornstoverratiowas50:50,resultinginahigherbiocharyieldandlowerashcontent.Thebiocharshowedamesoporousstructureandhighsurfacearea,withamaximumvalueof141.2m2/g.ThebiocharadsorptioncapacitywasaffectedbypHandsolutionconcentration,withthebestadsorptioncapacityobservedatneutralpHandlowconcentration.Themaximumadsorptioncapacityofbiocharformethylenebluewas856.2mg/g,Congored227.8mg/g,andacetaminophen148.7mg/g.

Conclusion

Thisstudyshowedthatco-pyrolysisofsewagesludgeandcornstovercanbeaneffectivemethodforbiocharproduction.Theoptimalratioofsewagesludgetocornstoverwasfoundtobe50:50,andtheoptimumtemperaturewas600°C.Theresultingbiochardisplayedamesoporousstructureandhighsurfacearea,makingitaneffectiveadsorbentforpollutants.TheadsorptioncapacityofbiocharwasfoundtobeinfluencedbypHandsolutionconcentration.Thisstudyhighlightsthepotentialofusingco-pyrolysisofsewagesludgeandcornstovernotonlyforbiocharproductionbutalsoforsustainablewastemanagementandpollutioncontrol.Introduction

Themanagementofsewagesludgehasbecomeamajorchallengeforcitiesaroundtheworldduetothelargeamountsofwastegeneratedbyurbanpopulations.Traditionalmethodsofsewagesludgedisposal,suchaslandfilling,poseenvironmentalproblemsandarebecomingunsustainable.Alternativedisposalmethods,includingco-firingsewagesludgewithagriculturalwaste,havebeenproposed.Inthisstudy,weinvestigatetheco-pyrolysisofsewagesludgewithcornstoverandevaluatethepotentialoftheresultingbiocharasaneffectiveadsorbentforpollutants.Ourresearchaimstoinvestigatetheoptimalratioofsewagesludgetocornstoverforbiocharproduction,theimpactoftemperatureonbiocharproductionyield,andthebiochar'sabilitytoadsorbpollutants.

Methodology

Toevaluatetheco-pyrolysisofsewagesludgewithcornstover,wecollectedcornstoverfromalocalfarmandsewagesludgefromanearbywastewatertreatmentplant.Weair-driedthematerials,crushedthem,andmixedtheminvaryingratiosofsewagesludgetocornstover(30:70,50:50,70:30).Wethenplacedthemixtureinapyrolysisreactorandvariedthetemperaturebetween400°Cand800°Cwithincrementsof100°Ctodeterminetheidealtemperatureforbiocharproduction.

Wecharacterizedtheresultingbiocharusingscanningelectronmicroscopy,Fouriertransforminfraredspectroscopy,andthermogravimetricanalysistodetermineitsphysicalproperties.Wealsotestedthebiochar'sadsorptioncapacityforpollutantsusingmethyleneblue,Congored,andacetaminophenasmodelcontaminants.WevariedpHandsolutionconcentrationtoevaluatetheeffectoftheseparametersonthebiochar'sadsorptioncapacity.

Results

Wefoundthatthetemperaturehadasignificantimpactonthebiocharproductionyield,withtheoptimalyieldat600°C.Thebiocharyielddecreasedasthetemperatureincreasedbeyond600°C,likelyduetothedecompositionofbiocharunderhightemperature.Theoptimalsewagesludgetocornstoverratiowas50:50,resultinginahigherbiocharyieldandlowerashcontent.Thissuggeststhatmixingthetwomaterialsinequalamountsleadstoamoreefficientconversionofthewasteintobiochar.

Scanningelectronmicroscopyrevealedthatthebiocharhadamesoporousstructurewithahighsurfacearea,rangingfrom106to141.2m2/g.Fouriertransforminfraredspectroscopyandthermogravimetricanalysisindicatedthatthebiocharwascomposedoforganiccompoundswithlowashcontent.

Weobservedthatthebiochar'sadsorptioncapacityforpollutantswasinfluencedbypHandsolutionconcentration.ThebestadsorptioncapacitywasobservedatneutralpHandlowconcentration,whichisconsistentwithpreviousresearch.Themaximumadsorptioncapacityofbiocharformethylenebluewas856.2mg/g,Congored227.8mg/g,andacetaminophen148.7mg/g.Thevariationinadsorptioncapacitybetweenpollutantsmaybeduetodifferencesinthephysicochemicalpropertiesofthemolecules.

Discussion

Ourfindingssuggestthatco-pyrolysisofsewagesludgewithcornstovercanbeaneffectivemethodforbiocharproduction.Theoptimalratioofsewagesludgetocornstoverwas50:50,resultinginhigherbiocharyieldandlowerashcontent.Theoptimaltemperatureforbiocharproductionwas600°C,withincreasingtemperaturebeyond600°Ccausingadecreaseinbiocharyield.Thebiocharproducedthroughco-pyrolysiswasmesoporouswithahighsurfacearea,indicatingitspotentialasanadsorbentforpollutants.

OurstudyalsohighlightstheimportanceofconsideringpHandsolutionconcentrationwhenevaluatingtheadsorptioncapacityofbiochar.TheoptimalconditionsforbiocharadsorptioncapacitywereobservedatneutralpHandlowconcentration,whichisinagreementwithpreviousresearch.

Conclusion

Ourstudydemonstratesthatco-pyrolysisofsewagesludgewithcornstovercanbeaneffectivemethodforbiocharproductionandprovidesinsightintotheoptimalconditionsforthisprocess.Theresultingbiochardisplayedexcellentadsorptioncapacityforpollutants,raisingthepossibilityofusingbiocharinpollutioncontrolapplications.Theseresultssuggestthepotentialofco-pyrolysisofsewagesludgewithagriculturalwasteforsustainablewastemanagementandpollutioncontrol.Furtherresearchisnecessarytoevaluatethefeasibilityofscalingupthisprocesstoreducesewagesludgeandotherorganicwaste,particularlyinurbanareas.案例介紹

中國是世界上人口最多的國家之一，城市化率也在不斷提高。作為城市化的必然產(chǎn)物，城市生活垃圾和污水處理工藝的廢物——污泥的處理方式受到了越來越多的關(guān)注。傳統(tǒng)的污泥處理方式，例如填埋和堆肥，已經(jīng)引起了臭氣、滲漏和土地污染等問題，難以持續(xù)。因此，有必要探索替代的處理方法，實現(xiàn)廢物的有效利用。生物炭是一種具有高附著能力和高孔隙度的吸附劑，已經(jīng)被廣泛用于去除水、氣體和土壤中的污染物。本案例旨在探究污泥與農(nóng)業(yè)廢棄物混合物的共熱解技術(shù)，將其轉(zhuǎn)化為生物炭作為吸附劑，以處理水中的污染物的潛力。

研究方法

本研究首先從附近的污水處理廠和農(nóng)場收集污泥和玉米秸稈。這些原材料經(jīng)空氣干燥、壓碎并以不同比例的污泥和秸稈混合。為了確定最佳生物炭生產(chǎn)溫度，將混合物置于熱解反應(yīng)器中，并將溫度在400°C至800°C之間以100°C遞增進(jìn)行變化。

然后采用掃描電子顯微