中国科学院生态环境研究中心机构知识库
Advanced  
RCEES OpenIR  > 环境水质学国家重点实验室  > 学位论文
题名: 污泥臭氧原位减量工艺中典型抗生素的去除研究
作者: 汪鲁
学位类别: 博士
答辩日期: 2016-11
授予单位: 中国科学院研究生院
授予地点: 北京
导师: 强志民
关键词: 活性污泥工艺 ; 污泥臭氧处理 ; 污泥原位减量 ; 磷回收 ; 抗生素
其他题名: Removal of typical antibiotics during in-situ sludge ozone- reduction process
学位专业: 环境工程
中文摘要:     产量庞大的剩余污泥不仅是抗生素进入自然环境的重要途径,还成为活性污泥法面临的严峻挑战。可以同步实现污泥减量及污泥中抗生素去除的工艺对于控制剩余污泥带来的二次污染具有重要意义。由于传统污泥处理处置能力有限而且成本较高,污泥原位减量已经引起了国内外研究者的广泛兴趣。因此,污泥原位减量工艺中抗生素的去除值得关注,但是目前相关研究还比较有限。臭氧是一种强氧化剂,可以氧化去除水体中多种有机污染物。此外,臭氧处理还是一种有效的污泥溶胞手段,可以与活性污泥系统联合构成基于溶解 -隐性生长机制的污泥原位减量工艺。因此,本文选取 3种四环素类抗生素(TCs:四环素(TCN)、土霉素(OTC)、强力霉素(DOX))、5种氟喹诺酮类抗生素(FQs:诺氟沙星(NOR)、氧氟沙星(OFL)、环丙沙星(CIP)、洛美沙星(LOM)、恩诺沙星(ENR))以及 1种大环内酯类抗生素(阿奇霉素(AZN))作为目标抗生素(TAs),并对它们在污泥臭氧原位减量工艺中的去除规律进行了研究。
     首先,通过批次实验及模拟处理系统的连续运行考察了 SBR和  A/A/O污泥臭氧原位减量工艺的污泥减量效果和污水处理性能。其次,通过批次实验研究了TAs在活性污泥工艺中的去除机制、吸附及生物降解特征,深化了对  TAs在活性污泥工艺中迁移转化行为的认识,为  TAs在污泥臭氧原位减量工艺中去除规律的研究奠定了基础。再次,通过批次实验研究了活性污泥中 TAs在臭氧处理过程
中的去除效果、降解过程及影响因素。最后,通过模拟处理系统的连续运行考察了 TAs在  SBR及  A/A/O污泥臭氧原位减量工艺中的去除规律。本文得到的主要结论为:
    (1)臭氧处理具有良好的污泥溶胞效果,会导致污泥液相中的溶解性COD(SCOD)、总氮(TN)和总磷(TP)浓度大幅上升。污泥初始 pH偏碱性可以促进污泥溶胞,对有机物和氮的溶出有利;但是,过高的初始 pH会对污泥溶胞产生抑制作用;初始 pH偏酸性有利于含磷物质的释放。臭氧处理后污泥回流对SBR系统中的微生物活性、COD、有机氮和氨氮(NH4+-N)的去除未产生明显的不利影响,但导致除磷效率大幅下降。钙磷摩尔比(Ca/P)为 10.0时,臭氧处理后污泥上清液中TP和磷酸盐(PO43- -P)的去除率均超过  80%,滞后于理论Ca/P;经过除磷后,上清液中的 SCOD和  TN浓度有所降低。
    (2)A/A/O污泥臭氧原位减量工艺中臭氧处理单元的最佳臭氧投加量约为100 mg O3 g1 MLSS,此时污泥溶解率约为 35.5%。在此臭氧投加量下,该系统取得的最大污泥减量率约为 85%。臭氧处理后污泥回流对 A/A/O单元的  COD和N的去除、MLVSS/MLSS及污泥活性没有显著影响,系统内污泥的沉降性能得到了明显提高,然而 A/A/O单元的除磷效能显著下降。COD和 N的总体质量衡算表明,臭氧处理后污泥回流可以促进 A/A/O单元内有机物矿化和反硝化反应。P的每日质量衡算表明,磷回收单元可以回收入水中  29%的磷,从而使得污泥臭氧原位减量系统的除磷能力得到部分恢复。
   (3)TAs的存在(每种浓度  100 μg L–1)没有对污泥生物活性表现出明显的抑制。在活性污泥工艺中,TAs的水解和挥发作用可以忽略;吸附是  TAs的主要去除路径;FQs类抗生素观察到了微弱的生物降解,而  TCs类抗生素和  AZN并未观察到生物降解。TAs在污泥上的吸附是一个自发的、放热的、焓变驱动的、由表面反应控制的可逆过程。TAs在活性污泥上的吸附能力由非疏水分配作用决定。TAs不同离子化形态的吸附能力有所差异。TCs、FQs和   AZN吸附能力最强的离子化形态分别为一价阳离子态、两性离子态和二价阳离子态。与缺氧条件相比,好氧条件有利于 TAs在活性污泥上的吸附。FQs在活性污泥工艺中的生物降解符合伪一级动力学模型,半衰期很长(> 100小时)。
    (4)臭氧处理可以有效的去除污泥中的 TAs。臭氧投加量为 102mg O3g–1MLSS,pH = 7.2时,污泥中各种  TAs的总体去除率均在  86%以上。TAs的总体降解及吸附态 TAs的去除均符合伪一级动力学,而溶解态TAs浓度随时间的变化可以用连续反应动力学模型描述。吸附态 TAs脱附及溶解态   TAs的臭氧氧化是污泥臭氧处理过程中 TAs降解的主要途径。初始  pH上升(5.0–9.5)对污泥臭氧处理过程中 TAs的降解具有促进作用。
    (5)进水中 TAs(每种浓度 100 μg L–1)的存在没有对 SBR和  A/A/O系统的 COD、TN、NH4+ -N和  TP的去除性能产生明显的影响。SBR及 A/A/O污泥臭氧原位减量工艺出水中  TAs浓度均在一定范围内波动,表明活性污泥系统在长期运行过程中保持了相对稳定的  TAs去除性能,而且臭氧处理后污泥回流及剩余污泥零排放没有对两系统中活性污泥的  TAs吸附能力造成明显影响。污泥臭氧原位减量工艺不仅可以实现污泥的大幅减排,还可以显著降低污泥中 TAs的含量。每日质量衡算表明  TAs在污泥臭氧原位减量工艺中的变化是一个输入和输出渐趋平衡的过程。
英文摘要:     The large amount of excess sludge not only is an important source of the antibiotic release to the environment, but  also has long been a serious challenge to the  activated sludge process. The process  simultaneously achieving sludge reduction and  antibiotic removal  from sludge  is  of great  significance  to  the control  of  secondary pollution caused by excess sludge. The in-situ sludge reduction has aroused great interest due to the limited capacity and  high operation cost of the  conventional sludge treatment and disposal. Thus, the antibiotic removal  in the in-situ sludge reduction process  deserves great attention.  However, to date,  the relevant studies on  this have been  still limited.Ozone is  a strong  oxidant which  could oxidize multiple  organic pollutants  in water. Moreover, ozonation is also an effective method for sludge solubilization, which could constitute  the  in-situ   sludge  reduction  process   based  on  lysis-cryptic  growth   of microbes along  with the activated  sludge system. This  study selected  3 tetracyclines (TCs:   tetracycline   (TCN),   oxytetracycline   (OTC),  doxytetracycline   (DOX)),5 fluoroquinolones  (FQs:  norfloxacin  (NOR),  ofloxacin  (OFL),  ciprofloxacin  (CIP),lomefloxacin (LOM), enrofloxacin (ENR)), and 1 macrolide  (azithromycin (AZN)) as target antibiotics (TAs),  and clarified the removal  of TAs in the  in-situ sludge ozone-reduction process.
    The sludge reduction  efficiencies and wastewater treatment  performance of SBR and A/A/O in-situ sludge  ozone-reduction processes were first investigated  through a series  of  batch  experiments  and  the  continuous  operation  of  simulated  treatment systems. Then, a series of batch experiments were conducted to clarify the mechanisms of  TAs removal  and  the  characteristics of  TAs  sorption  and  biodegradation in  the activated sludge process, which  not only provides an insight into  the behavior of TAs in the activated sludge procsss, but also lays a foundation for the study on TAs removal during the in-situ sludge ozone-reduction process.  Thereafter, batch experiments were carried out to clarify  the TAs removal efficiencies, degradation processes,  and impact factors during sludge ozonation. Finally, the removal of TAs in the SBR and A/A/O in-situ  sludge   ozone-reduction   processes  was   investigated  through   the  continuous operation of the simulated treatment systems. The main conclusions are as follows:
    (1) Ozonation could exhibit  good sludge-solubilization performance, resulting in a significant  increase  in the  aqueous concentrations  of  soluble COD  (SCOD), total nitrogen (TN),  and  total phosphorus  (TP). Alkaline  initial pH  facilitated  the sludge solubilization and the release of organic matters and N, while the sludge solubilization was inhibited  by highly  alkaline pH.  Acidic initial  pH  favored the  P release during sludge  ozonation.  The ozonated  sludge  recycle  did  not  significantly  influence the microbial activity and the removal of  COD, organic nitrogen, and ammonia (NH4+  -N) in the SBR, but obviously decreased the P removal. The removal efficiencies of TP and phosphate (PO43-  -P)  exceeded 80% at Ca/P molar  ratio 10.0, which was  much higher than the theoretical value. After P recovery, the SCOD and TN concentrations in sludge supernatant were decreased slightly.
    (2) The optimal ozone dose for the sludge ozonation module  in the A/A/O in-situ sludge  ozone-reduction  process  was   about  100  mg  O3  g1   MLSS,  at  which  the solubilization ratio reached 35.5%. The maximum  sludge reduction efficiency of 85% could be achieved  under this ozone dose in  the A/A/O in-situ sludge ozone-reduction
process.  Ozonated  sludge  recycle  caused  little  changes  in   COD  and  N  removal, MLVSS/MLSS  ratio,  and  sludge activity  in  the  A/A/O  module,  but  enhanced the activated sludge settleability. However,the deterioration  of P removal was observed.The overall mass balances of COD and N reveal that the ozonated sludge recycle could enhance the organic mineralization and denitrification in the A/A/O module. The daily mass balance of P indicates that the P recovery module could recover 29% of the input phosphorus, which partially restored the P removal capability.
    (3) The presence of TAs (100 μg L1 each) exhibited little inhibition on the sludge bioactivity. Sorption was the primary  removal pathway of TAs in the activated sludge process, while  hydrolysis and  volatilization could  be negligible.  The biodegradation was observed  for FQs,  but not for  TCs and  AZN. The sorption  of TAs  on activated sludge was a spontaneous, exothermic, enthalpy-driven, and reversible process,  which was governed by surface reactions.  The sorption affinity of TAs with activated sludge was  determined  by the  hydrophobicity-independent  mechanisms.  Different  ionized species of TAs possessed different sorption affinity with activated sludge. For TCs, FQs, and AZN, the ionized species  possessing the strongest sorption affinity with activated sludge  were   monovalent  cations,   zwitterions,  and  divalent   cations,  respectively.Aerobic condition facilitated  the sorption of TAs on  activated sludge comparing with anoxic condition.  The biodegradation  of FQs followed  the pseudo-first-order  kinetic model, with long half-lives (> 100 h).
    (4) TAs in excess  sludge could be effectively removed  by sludge ozonation. The total removal efficiencies of TAs in sludge reached  over 86% at 102 mg O3 g1MLSS and pH 7.2.  Both the total degradation  of TAs and the removal  of sorbed TAs during sludge ozonation followed the pseudo-first-order kinetic model, whilst the consecutive reaction model  could well  express the  changes of  dissolved TA  concentrations with reaction time. The desorption  of sorbed TAs and their  subsequent oxidation by ozone in  the  liquid  phase constituted  the  main  route  for  TAs  degradation during  sludge ozonation. The increasing initial pH (5.0–9.5) facilitated TAs degradation during sludge ozonation.
    (5) The presence of TAs (100  μg L1 each) in the influent  exerted little influence on the  removal of COD,  TN, NH4 +  -N, and  TP in the  SBR and  A/A/O systems. The concentrations of  TAs in the  effluent of the  SBR and A/A/O  systems fluctuated  in a certain range,  suggesting that  the removal  capability of TAs  by the  activated sludge system remained relatively stable in the long-term operation. Furthermore, the sorption affinity of  TAs with activated  sludge was  not significantly  changed by the  ozonated sludge recycle and zero sludge discharge. Significant reduction of sludge discharge and TAs concentrations  in sludge  could be achieved  simultaneously in the  in-situ sludge ozone-reduction process. The daily mass balance indicates that the variations of TAs in the SBR and A/A/O in-situ sludge ozone-reduction processes were  a process in which the balance between TAs input and ouput was achieved gradually.
内容类型: 学位论文
URI标识: http://ir.rcees.ac.cn/handle/311016/36966
Appears in Collections:环境水质学国家重点实验室_学位论文

Files in This Item:
File Name/ File Size Content Type Version Access License
汪鲁--污泥臭氧原位减量工艺中典型抗生素的去除研究.pdf(4826KB)学位论文--限制开放 联系获取全文

Recommended Citation:
汪鲁. 污泥臭氧原位减量工艺中典型抗生素的去除研究[D]. 北京. 中国科学院研究生院. 2016.
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[汪鲁]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[汪鲁]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Copyright © 2007-2017  中国科学院生态环境研究中心 - Feedback
Powered by CSpace