吸附--催化氧化技術處理廢水中苯酚的研究.pdf

1、楊洋：吸附催化氧化技術處理廢水中苯酚的研究摘要含酚廢水是一類毒性高且難以生物降解的有機廢水，含酚廢水的處理方法一直是人們研究的重點。隨著環(huán)境保護要求的提高，廢水的達標排放要求也越來越嚴格。因此，單一的處理方法往往難以滿足企業(yè)的需求，多種水處理技術的組合成為研究的熱點方向之一。本文采用吸附催化氧化組合技術對模擬廢水與石化廢水中的苯酚進行深度處理，即先通過吸附的方法對預處理后廢水中的苯酚進行富集，再將吸附的苯酚脫附下來進行集中催化氧化處理，

2、從而大大降低生化處理的時間，提高廢水的處理效率。活性炭纖維(ACF)作為一種新型的吸附材料，具有比表面積大、孔徑分布窄、微孔含量豐富、吸脫附速度快、再生條件溫和等優(yōu)點，可以作為一種有效的處理廢水的吸附劑。實驗首先采用ACF為吸附劑，以苯酚水溶液作為模擬廢水，考察了不同條件對ACF吸附苯酚性能的影響，并且考察了NaOH溶液對苯酚的脫附效果。結果表明，ACF對苯酚的吸附速率較快，一般情況下吸附30min且N可接近平衡；溫度對ACF吸附的影響

3、較小，升高溫度不利于ACF吸附苯酚；增jJHACF投加量可提高苯酚的去除率，但平衡吸附量下降，ACF禾IJ用率降低；酸、中性介質條件有利于ACF吸附苯酚。吸附飽和后的ACF選用質量濃度3％的NaOH溶液在60。C下即可脫附再生，ACF經(jīng)10次吸附與脫附重復實驗后，吸附性能穩(wěn)定。采用ACF為吸附劑，對比研究TACF對模擬廢水與石化廢水中苯酚的吸附過程，主要從吸附等溫線、吸附動力學以及動態(tài)吸附脫附等方面作了比較。采用LangmuirNFre

4、undlich兩種吸附模型對實驗數(shù)據(jù)進行擬合，結果表明ACF對模擬廢水中苯酚的吸附更符合Langmuir吸附模型，ACF對石化廢水中苯酚的吸附更符合Freundlich吸附模型，主要因為石化廢水中油類等物質的存在，影Ⅱ向至I]ACF表面對苯酚的吸附，不再是單純的單分子層吸附。動力學實驗表明，ACF吸附模擬廢水和石化廢水中苯酚時，平衡吸附量隨著吸附劑投加量和溫度的增加而減小。不同ACF用量和溫度下，ACF吸附兩種廢水的吸附過程均符合準二級

5、動力學模型；熱力學和活化能參數(shù)表明，ACF吸附苯酚是一個自發(fā)的放熱過程，ACF對廢水中苯酚的吸附以物理吸附過程為主。采用自制的ACF吸附柱對兩種廢水的動態(tài)吸附與脫附性能作了考察。動態(tài)吸附實驗表明，ACF填充量相同時，由于石化廢水中油類等物質的存在，在出水量500mL為之前石化廢水經(jīng)過吸附柱后的出水中苯酚濃度要高于模擬廢水，說明石化廢水中的油類物質與苯酚產(chǎn)生了競爭吸附。動態(tài)脫附實驗表明，模擬廢水中被吸附的苯酚從ACF上脫附的速率高于石化廢

6、水中被吸附的苯酚，兩種水樣在達到脫附平衡后，平衡脫附液中石化廢水中苯酚濃度也要高于模擬廢水。油類等物質占據(jù)了ACF中一些的孔道，阻礙了苯酚分子的脫附。楊洋：吸附催化氧化技術處理廢水中苯酚的研究IllIIIIIM11111111IIIIINilIII—AbstractY2632406Phenolsareaclassofhighlytoxicanddifficulttodegradeorganicmatter，thetreatmentofp

7、henolicwastewateristhefocusofthestudyWastewaterdischargerequirementshavebecomemorestringentduetothedemandforenvironmentalprotectionThus，asingletreatmentmethodisdifficulttomeettheneedsofenterprisesThecombinationofavariety

8、ofwatertreatmenttechnologyhasbecomeoneofthehotresearchdirectionsInthispaper，thetechnologythatcombinedadsorptionwithcatalyticoxidationareappliedindepthtreatmentofphenolinsimulatedwastewaterandpetrochemicalwastewater，thati

9、s，centralizedphenolofpretreatedwastewaterbytheadsorptionmethodfirstly，thentheadsorbedphenolaredesorbedtohandlewithcatalyticoxidationThereby，greatlythebiochemicaltreatmenttimecanbereducedandtheefficiencyofwastewatertreatm

10、entcanbeimproved。Activatedcarbonfiber(ACF)asanovelfunctionalmaterialcanserveasaneffectiveadsorbentfortreatingwastewater,ithasremarkableadvantages：alargesurfacearea，narrowporesizedistribution，abundantmicropores，fastadsorp

11、tionanddesorption，mildregenerationconditions，etcInthispaper，ACFusedasadsorbent，phenolsolutionusedassimulatedwastewater，theinfluenceoftheACFadsorptionpropertiesofphenolwereinvestigatedindifferentconditions，andtheeffectofp

12、henoldesorptioninNaOHsolutionisalsoinvestigatedTheresultsshowthattheadsorptionrateofphenolinitialrapidonACF，generally30mintoclosetoequilibriumThetemperaturehasalittleeffectontheACFadsorptionproperties，raisingthetemperatu

13、reisnotconducivetotheadsorptionofphen01IncreasingtheACFdosagecanpromotephenolremovalrate，buttheequilibriumadsorptioncapacitydecreasedtocauseACFlowerutilizationInacidandneutralmedium，theadsorptionpropertybeRerthanalkaline

14、mediumSaturatedACFCallberegeneratedbymassconcentrationof3％sodiumhydroxideat60“C，ACFadsorptionperformancearestableandmaintainhighlevelafter10timesrepeatedadsorptionanddesorptionexperimentsUsingACFasadsorbent，thecomparativ

15、estudyintheadsorptionprocessofphenolofpetrochemicalwastewaterandsimulatedwastewateronACFhasbeeninvestigated，mainlyfromtheadsorptionisotherms，adsorptionkineticsanddynamicadsorptionanddesorption，etcAdsorptionisothermswered

16、eterminedandmodeledwithLangmuirandFreundlichadsorptionmodelTheresultsshowedthattheadsorptionprocessofphenolfromsimulatedwastewateronACFfitstheLangmuirmonolayeradsorption，buttheadsorptionprocessofphenolfrompetrochemicalwa

17、stewaterfitsFreundlichisothermmodelberetItismainlyduetotheoilandothersubstancesinpetrochemicalwastewateraffecttheadsorptionofphenolonACFsurface，adsorptionprocessisnolongerasimplemonolayeradsorptionKineticexperimentsshowt