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研究生:阮坤杉
研究生(外文):Roan, Kuen-Shan
論文名稱:快速起動厭氧流體化床模型槽促進苯環類化合物分解效率之研究
論文名稱(外文):Rapid Strat-up Strategy of Anaerobic Fluidized Bed Process to Promote Biodegradation of Aromatic Compounds.
指導教授:鄭幸雄鄭幸雄引用關係
指導教授(外文):Sheng-Shung Cheng
學位類別:碩士
校院名稱:國立成功大學
系所名稱:環境工程學系
學門:工程學門
學類:環境工程學類
論文種類:學術論文
論文出版年:1998
畢業學年度:86
語文別:中文
論文頁數:224
中文關鍵詞:厭氧流體化床純對苯二甲酸活性碳最大比產氣速率遲滯期生物膜
外文關鍵詞:Anaerobic Fluidized BedPurified Terephthalic AcidGranular Activated CarbonMaximum Biogas Production RateLag TimeBiofilm
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提要 本研究係以厭氧流體化床模型槽(AnFB pilot)處理富含苯環類
有機污染物之純對苯二甲酸(Purified Terephthalic acid,PTA)綜合廢
水。由於苯環類工業廢水成份複雜且變異性大,因而導致厭氧生物處理程
序之起動甚為困難緩慢,不符放大工程化或快速商業化之原則。緣此,本
研究即擬以快速起動厭氧流體化床模型槽的方式來促進苯環類化合物的分
解效率,以建立厭氧流體化床處理PTA廢水最適化之起動操作策略。
PTA綜合廢水主要有機污染物為醋酸(HAc)、苯甲酸(BA)、對苯二甲酸(TA)
及對甲基苯甲酸(p-Tol)等。經活性碳恆溫吸附實驗結果得知,PTA廢水
COD之吸附模式符合Freundlich model,其中主要苯環類化合物之吸附容
量依序為BA>p-Tol>TA,此三種化合物除了BA的吸附容量隨著溫度的下
降有逐漸上升的趨勢外,其餘並無明顯的改變,而活性碳對於苯環類化合
物的高吸附量將有利於緩衝反應槽所受之突增負荷。 反應槽之植種污
泥來源為豬糞尿消化污泥,污泥在植種前先經活化培養提高生物活性後方
植入反應槽中。對於厭氧流體化床快速起動技術方面,本研究提出的策略
為「物理性固定化快速附著技術」。研究結果顯示,於數日內可完成活
性碳生物膜的固定化,約60%植種污泥被截留於反應槽中,有26%植種污泥
附著於活性碳上。反應槽之起動策略為低負荷廢水進流,污泥有機負荷控
制在0.2~0.3 kgCOD/kgVSS-day,體積負荷控制在0.5~1.0 kgCOD/m3-day
。操作第49天,HAc與BA已可完全去除,TA去除率為41%,CODs去除率則
為46%。操作後期(六個月後),以縮短水力停留時間的方式遞增反應槽體
積負荷至4.0~4.5 kgCOD/m3-day,反應槽內附著性生物質量由76.3 g遞增
至227.7g,CODs去除率達60~70%,HAc及BA可完全去除,TA去除率達
80~90%,p-Tol的去除率則不佳,僅10~20%,顯示難被厭氧生物分解。
經反應槽長期的馴養,厭氧菌在適當食微比下,分解HAc、BA及TA的初始
比產氣速率(由初始產氣速率求得)對初始基質濃度及最大比產氣速率(由
最大產氣速率求得)對初始基質濃度的生化反應動力模式皆符合Monod
model。比較不同基質分解速率得知,苯環類化合物的厭氧生物代謝速率
限制步驟為裂環酸化反應,而非乙酸甲烷化反應。另外,由基質抑制性實
驗結果得知, HAc及BA均對TA有抑制性存在,此兩者均會延長TA分解之遲
滯期。在最大比產氣速率方面,TA受HAc的影響則較BA顯著。由掃描式電
子顯微鏡觀察結果顯示,活性碳凹洞或裂縫處很容易被膠羽所填滿。膠羽
內部滋生的Methanothrix向活性碳裸露的表面蔓延生長而形成交錯的網狀
結構,此交錯網狀結構則網羅了苯環化合物的分解菌,進而在活性碳表面
延展開來而形成一完整的生物膜。

ABSTRACT A pilot-scale anaerobic fluidized bed (AnFB)
reactor was operated to treat the purified terephthalic acid
(PTA) manufacturing wastewater. Due to high complexity of
aromatic constituents in the wastewater, it took a long time to
start up the anaerobic reactor with acclimating microbes.
Anaerobic process engineering and commercialization will be
dependent on the critical biotechnology. Therefore, the purpose
of this study was try to start-up the AnFB pilot rapidly, and to
promote the degradation of aromatic wastewater with process
control. By this way, we also tried to work out the optimum
strategy during the start-up duration. The major organic
components in the PTA wastewater were terephthalic acid (TA),
benzoic acid (BA), p-toluic acid (p-Tol) and acetic acid (HAc).
The results of batch isotherm tests showed that the adsorptive
characteristic of PTA wastewater in terms of COD was fitted with
Freundlich model. There was favorable adsorption of activated
carbon for removing the aromatic compounds in PTA wastewater.
The adsorptive capacity of major aromatic compounds was BA, p-
Tol, TA, in order. Only BA had the property of larger adsorptive
capacity at lower temperature. After the anaerobic bacteria
were cultivated in the batch system, the manure digested sludge
was seeded into a GAC fluidized bed reactor. An innovative
technology of rapid start-up was established in the AnFB pilot.
A large amount of the digested sludge was physically attached
onto the GAC media within several days of batch recirculation.
The strategy of the start-up was conducted to operate the
fluidized bed at lower organic loading (0.2~0.3 kgCOD/kgVSS-
day), the volumetric loading rate was controlled at 0.5~1.0
kgCOD/m3-day. After 49 days operation, HAc and BA removal were
achieved up to 100%, the TA removal was achieved with 41%, while
the CODs removal was achieved at 46%.With 6 months' operation of
continuous flow, the volumetric loading rate could be increased
up to 4.0~4.5 kgCOD/kgm3-day with 60~70% of COD removal
efficiency. HAc and BA removal were still complete, the TA
removal was promoted to 80~90%, while p-Tol removal still
maintained from 10% to 20%. It showed that p-Tol was difficult
to be biodegraded anaerobically. With biokinetic of
biochemical methane potential (BMP) test, two methods were
employed to describe the biokinetic models of the existed
anaerobic biofilm. The initial biogas production rate and the
maximum biogas production rate were represented the bioactivity
of the existed microbes degrading the individual component. Both
parameters showed that the anaerobic biofilm degrading HAc, BA
and TA were fitted with Monod model in BMP test. The result of
BMP test also showed that the rate-limiting step in anaerobic
conversion from aromatic compounds to methane was acidogensis
instead of methanogensis. Anaerobic toxicity assessment (ATA)
test on biodegradation showed that both HAc and BA had substrate
inhibition with TA degradation. The lag time of TA degradation
would be influenced by the high concentration of HAc or BA. As
to the maximum biogas production rate (mL.biogas/gVSS-day), TA
degradation would be influenced by HAc and BA, too, while HAc
was more serious than BA.According to microbial morphology of
electronic microscopy of the existed biofilm, anaerobic floc was
easily attached onto the GAC surface by the hydraulic control of
the granule fluidization. Biofilm was found out to grew
initially in the surface hole and cave of the GAC. With gradual
load increasing, microbial growth was observed in the fluidized
bed. The outer layer of the granular bioparticle was grown with
the predominant Methanothrix species, while the biofilm
interior was filled with syntrophic ecosystem of anaerobic
bacteria.Appropriate inoculation and loading increment provided
good biofilm attachment and microbial growth onto the fluidized
GAC particles. Meantime, process control with decreasing HAc and
BA inhibition could enhance the biodegradation of aromatic
constituents in the PTA manufacturing wastewater. The GAC
anaerobic fluidized process could achieve excellent performance.


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