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富含氨氮、磷发酵制药有机废水处理技术研究

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'巾图分类号;X522密级:公开UDC:^码;ML__懂L'ir:,,jggi^該^p':;支"^味、皆HEBEIUNIVE民SITYOFSCIENCEAND下ECHNOLOGY硕:t学位论文富含氨氮、磯发醇制药有机废水处理技术研究'论文作者:杨亚男指导教师:杨景亮教授企业指导教师;陈平高王申请学位类别:工程硕古学科、领域:环境工程t所在单位;环境科学与工程学院答辩日期15年6月:20 巧北科技大学学位论文原创性声明本人郑重声明:所呈交的学位论文,,是本人在导师的指导下独立进行研究工作所取得的成果。对本文的研究做出重要贡献的个人和集体,均已在文中明确方。式标明除文中已经注明引用的内容外,本论文不包含任何其他个人或集体己经发表或撰写过的作品或成果。。本人完全意识到本声明的法律结果由本人承担学位论文作者签名:^誓指导教师签名:;^料办>度年6月曰灰咬年月^曰_^河北科技大学学位论文版权使用授权书本学位论文作者完全了解学校有关保留、使用学位论文的规定,同意学校保留并向国家有关部口或机构送交论文的复印件和电子版,允许论文被查阅和借阅。本人授权河北科技大学可W将本学位论文的全部或部分内容编入有关数据库进行检索,可W宋用影印、缩印或扫描等复制手段保存和汇编本学位论文。?.□保密,在_年解密后适用本授化书。本学位论文属于/保密。""(请在W上方框内打V)学位论文作者签名:襄舅指导教师签名;丢I-精為^?之。作年&如^月月矣曰少年夕曰 ClassifiedIndex:X522SecrecyRate:PublicizedUDC:502UniversityCode:10082HebeiUniversityofScienceandTechnologyDissertationfortheMasterDegreeStudyonTreatmentTechnologyofOrganicPharmaceuticalFermentationWastewaterwithHighAmmoniaNitrogenandPhosphateCandidate:YangYananSupervisor:Prof.YangJingliang.Enterprise-basedCo-supervisor:S.E.ChenPingAcademicDegreeApppliedfor:MasterofEngineeringSpeciality:EnvironmentalEngineeringEmployer:SchoolofEnvironmentalScienceandEngineeringDateofOralExamination:June,2015 摘要本文针对某发酵制药废水COD、氨氮和磷酸盐含量高、可生化性差等特点,采用“磷酸铵镁-混凝沉淀法-SBR”组合工艺进行处理试验研究,考察了各处理单元的效能,优化确定各处理单元的最佳工艺控制参数。采用磷酸铵镁沉淀法(MAP)对废水进行脱氮除磷预处理试验研究。选取预处理的沉淀剂组合为MgCl2·6H2O和NaH2PO4·12H2O,当初始反应条件:pH=9.0、2+3-+n(Mg)/n(PO4)/n(NH4)投配比为1.44:1.2:1和反应时间30min,进水氨氮浓度为1450~1600mg/L时,处理后出水氨氮浓度小于90.0mg/L,氨氮去除率在90.0%以上;当进水磷酸盐含量在70~100mg/L时,处理后出水磷浓度小于15.0mg/L,采用MAP处理废水,COD也有所降低,平均去除率在20%左右。采用混凝法对MAP法处理后的出水进行处理实验,通过对聚合氯化铝(PAC)、聚合硫酸铁(PFS)、聚合氯化铝铁(PAFC)3种混凝剂的筛选实验,以聚合氯化铝(PAC)效果最佳;其最适混凝条件为:PAC投加量为10mL,pH=8,反应时间25min,当进水COD为3200~3600mg/L、磷酸盐浓度为15~20mg/L时,经混凝处理后出水COD为2000~2200mg/L,去除率大于30%;磷酸盐浓度小于2mg/L,去除率大于85%,出水磷浓度达到排放标准。采用SBR反应器对混凝出水进行处理,反应器接种好氧污泥45d后,顺利实现启动。试验结果表明:采用“进水10min-曝气4h-厌氧搅拌1.5h-沉淀出水0.5h”的运行方式,可取的良好的有机物去除和脱氮效果。当进水COD为2200mg/L、氨氮为80mg/L时,控制反应温度为30℃,溶解氧3.5mg/L,pH值为7,出水COD小于30mg/L,COD去除率可达到95%以上,出水氨氮小于5mg/L,去除率达到95%3以上。经过近一个月的稳定运行,反应器容积负荷达到2.0kgCOD/(m·d),出水水质满足《发酵类制药工业水污染物排放标准》(GB21908-2008)中规定的水污染物排放标准要求。在SBR运行过程中,活性污泥沉降性能良好,硝化与反硝化活性很高。对污泥菌群进行FISH分析检测,确定硝化菌群和反硝化菌群的相对丰度分别从1.94%和1.21%增加到21.94%和18.21%,说明硝化和反硝化菌群逐渐成为优势菌群。关键词发酵制药废水;磷酸铵镁;混凝沉淀;SBR;污泥活性I AbstractThepharmaceuticalfermentationwastewaterwithhighCOD,ammonianitrogenandphosphateandpoorbiodegradabilitywastreatedbyusingthecombinedprocessesof"magnesiumammoniumphosphate-coagulationandsedimentation-SBR"inthisstudy.Theperformaceofeachprocesswasinvestigatedandtheoptimaloperationparametersofweredetermined.Themainachievementsareasfollows:Themagnesiumammoniumphosphateprecipitationmethod(MAP)wasusedforwastewaterpretreatmenttoremovalnitrogenandphosphate.Andthenweconductedateststudyonpretreatmentofnitrogenandphosphorusremoval.MgCl2·6H2OandNaH2PO4·12H2Owereselectedasprecipitationagentsforpretreatment.Theoptimal2+reactionconditionsofMAPweredeterminedastheinitialpHof9.0,theratioofn(Mg)3-+/n(PO4)/n(NH4)of1.44:1.2:1andthereactiontimeof30min.Whentheinfluentammoniaconcentrationwas1450~1600mg/L,thetreatedeffluentammoniaconcentrationwaslessthan90.0mg/L,andtheammoniaremovalratewasabove90%.Whentheinfluentphosphorusconcentrationwas70~100mg/L,thetreatedeffluentphosphoruscontentwaslessthan15.0mg/L.Inaddition,CODwasalsoremovedbyMAPtreatmentwithanaverageremovalrateofabout20%.Thecoagulation-sedimentationprocesswasusedtotreattheeffluentafterMAPtreatment.Thepolymerizationaluminumchloride(PAC),polyferricsulfate(PFS)andpolyaluminumferricchloride(PAFC)werecomparedascoagulationagentsandPACwasdeterminedtobebetter.Theoptimalcoagulationconditionsweredeterminedas:PACdosageof10mL,pH=8,andreactiontimeof25min.WhentheinfluentCODwas3200~3600mg/L,theeffluentCODwas2000~2200mg/Laftercoagulation-sedimentationtreatmentandtheremovalratewasmorethan30%.Whentheinfluentphosphorusconcentrationwas15~20mg/L,theeffluentphosphateconcentrationwaslessthan2mg/LIII andtheremovalratewasmorethan85%,whichreachedthedischargestandard.ASBRreactorwasusedtotreattheeffluentofcoagulation-sedimentationprocess.Thesuccessfulstart-upofthereactorwasachivedafter45dsinceseedingaerobicsludge.Theoperationmodewas"influentfor10min-aerationfor4h-anaerobicfor1.5h–sedimentationandeffluentfor0.5h".Theefficientorganicsandnitrogenremovalwereobtainedwiththisoperationmode.UndertheoperationconditionsoftheinfluentCODof2200mg/L,theammonianitrogenof80mg/L,reactiontemperatureof30C,DOof3.5mg/LandpHof7,theeffluentCODwaslessthan30mg/LandtheremovalrateofCODreachedabove95%,whiletheeffluentammonianitrogenwaslessthan5mg/Landitsremovalratereachedmorethan95%.Afterstableoperationfornearlyonemonth,the3volumetricloadreached2.0kgCOD/(m·d),andtheeffluentqualitycouldmeetthe"fermentationpharmaceuticalindustrialwaterpollutantdischargestandards"(GB21908-2008).DuringoperationprocessofSBR,thesludgesettlingabilitywasacceptable,andthesludgeactivityofnitrificationanddenitrificationwasstrong.TheFISHanalysiswasusedtodetectthenitrifyingbacteriaanddenitrifyingbacteriainthesludge,andtheirrelativeabundancesreachedto18.21%and21.94%finally,indicatingthatnitrifyinganddenitrifyingbacteriabecamedominantinactivatedsludge.KeywordsFermentationpharmaceuticalwastewater;Magnesiumammoniumphosphate;Coagulationandsedimentation;SBR;SludgeactivityIV 目录摘要·································································································································IAbstract····························································································································III第1章绪论················································································································11.1发酵制药废水的来源及特征·················································································11.2废水处理现状及进展····························································································21.2.1预处理技术····································································································21.2.2生物处理技术································································································41.2.3组合处理技术进展·························································································61.3研究的对象、目的意义与内容·············································································71.3.1研究的对象····································································································71.3.2目的与意义····································································································71.3.3研究内容········································································································8第2章实验材料和方法································································································92.1实验工艺················································································································92.1.1实验工艺流程································································································92.2装置与设备············································································································92.2.1MAP和混凝实验装置···················································································92.2.2SBR实验装置································································································92.2.3实验设备······································································································102.3实验用水··············································································································102.4实验污泥菌种······································································································112.5实验药品··············································································································112.6分析项目及方法··································································································122.6.1常规监测项目与方法···················································································122.6.2污泥硝化与反硝化活性测定·······································································122.6.3悬浮性固体(SS)和悬浮性挥发性固体(VSS)····································132.6.4功能菌群FISH检测····················································································132.6.5磷酸铵镁沉淀的SEM观察·········································································15第3章磷酸铵镁沉淀法脱氮除磷实验研究·······························································173.1MAP反应原理·····································································································173.2条件与方法··········································································································17V 3.2.1实验用水······································································································173.2.2实验方法······································································································173.3实验结果与讨论··································································································183.3.1初始反应pH值对去除效果的影响····························································182++3.3.2n(Mg)/n(NH4)投配比对去除效果的影响················································193-+3.3.3n(PO4)/n(NH4)投配比对去除效果的影响················································202+3-+3.3.4n(Mg)/n(PO4)/n(NH4)投配比对去除效果的影响··································223.3.5反应时间对去除效果的影响·······································································233.3.6平行实验······································································································243.4本章小结··············································································································25第4章混凝法控制条件的优化与确定·······································································274.1混凝沉淀基本原理······························································································274.2实验条件与方法··································································································274.2.1实验用水······································································································274.2.2实验方法······································································································274.3实验结果与讨论··································································································284.3.1混凝剂的筛选······························································································284.3.2反应pH值对混凝效果的影响····································································304.3.3混凝剂的投加量对处理效果的影响···························································304.3.4反应时间对去除效果的影响·······································································314.3.5平行实验······································································································324.4本章小结··············································································································32第5章SBR启动及运行控制······················································································345.1条件与方法··········································································································345.1.1实验用水······································································································345.1.2实验方法······································································································345.2实验结果与讨论··································································································365.2.1SBR反应器的启动······················································································365.2.2运行工况的确定···························································································375.2.3运行参数的优化···························································································395.2.4SBR反应器稳定运行阶段··········································································435.3本章小结··············································································································44第6章活性污泥的特性表征·······················································································476.1接种污泥的培养训化··························································································47VI 6.1.1接种污泥的活性···························································································476.1.2接种污泥硝化与反硝化性能·······································································476.1.3接种污泥功能菌群的变化···········································································486.2SBR反应器启动后污泥活性变化······································································496.2.1启动后污泥活性···························································································496.2.2启动后污泥硝化与反硝化性能···································································506.2.3启动后污泥功能菌群的变化·······································································516.3SBR反应器稳定运行污泥活性变化··································································526.3.1稳定运行阶段污泥活性···············································································526.3.2稳定运行阶段污泥硝化与反硝化性能·······················································536.3.3稳定运行阶段功能菌群的变化···································································546.4本章小结··············································································································54结论······························································································································57参考文献··························································································································59攻读硕士学位期间所发表的论文···················································································65致谢······························································································································67VII 第1章绪论制药行业是人类工业发展中的一个较大行业体系,欧、美、日等发达国家在较早的时期就对西药胶囊和抗生素进行研制和生产。随着经济的发展这些国家的制药行业从生产到原料利用率和后续的环境问题已经衔接的相当成熟,废水的治理也相[1-5]对更彻底和先进。截止目前我国的大大小小制药企业共计3600多家,总产量位居世界第二,但是由于技术引进不彻底和发展的不规范,使得制药行业废水的处理问[6,7]题日益严重。在制药废水处理中,由于我国大比例的药厂是作为发达国家的原料药生产地,[8,9]发酵制药废水的治理一直制约着行业发展并影响着环境。由于我国发酵制药工艺技术发展的局限,在整个生产过程中存在着方方面面的问题如原料利用率低、提炼纯度低、废水处理率低等。以上情况造成排放的废水中含有大量高浓度有机物和悬浮固体,在建国初期这些废水在毫无处理情况下就被排放到我国的江、河、海中,破坏了天然水体的自净能力,引起水质变黑变臭、水体富营养化、传播病菌危害人[10,11]类健康和自然环境,对我国水资源造成了严重的污染和危害。随着我国对环境问题的认识越来越清晰,重视程度越来越高对制药行业废水排放标准也在不断的提高。据有关研究资料显示,制药行业废水是对水污染较重的七大行业之一,制药废[12-14]水一般废水颜色深、气味重、毒性强、可生化性差;废水中氨氮、磷酸盐含量较高。随着我国对发酵制药及其它5项大的制药行业方向的水污染物排放标准的制定与实施,制药废水的处理防治问题已成为了行业发展的瓶颈问题。1.1发酵制药废水的来源及特征发酵类制药的一般生产过程为:首先在种子罐中经过种子培养,然后进行生产发酵,完成发酵过程后,依次进行发酵液和菌丝体的分离和有效成分的提取;然后[15]对提取的有效成分进行精制纯化而制得到产品。工艺流程见图1-1。1 原材料原材料种子发酵发酵分离提取精制纯化产品废水废水废液废水图1-1工艺流程图由图1-1可以看出,在发酵类制药的生产工艺中,各工序均有废水产生,例如,发酵工序产生的废水主要包括设备冲洗水、提取有机废液;精制纯化过程中产生的废水为含酸碱废水及冷却排污水,每个生产过程中所产生的废水汇聚在一起排放对[16-18]环境造成巨大污染。发酵制药废水的主要特点包括:①高COD,高悬浮物。废水中含有菌丝体、营养物质、代谢产物和有机溶剂等加上药品的发酵工艺中原料反应不彻底,造成大量有机废物残留在水中,这些物质随废水排放使得废水中COD含量可高达2000~10000mg/L。②氨氮浓度高,发酵制药工艺使用的无机和有机含氮化合物的利用效率相对较低,废水在排放时便会残留较多的氨氮和有机氮物质,出水氨氮浓度一般在1000-5000mg/L以上。③有些发酵制药废水因为含有磷及无机盐常常偏酸性,而且浓度高、色度高、毒性高。④制药产品一般是间歇性生产,废水排放也就不定时,因而排放废水的水质、水量波动变化大。1.2废水处理现状及进展1.2.1预处理技术发酵制药废水的处理一直是水处理研究领域的热点,在众多处理工艺中好多研究者采用一些物化处理方法对废水进行预处理,来降低发酵制药废水的毒性和提高[19]其可生化性。1.2.1.1催化氧化处理技术制药废水的色度较深还含有相当高浓度的COD和大量难降解有毒有害物质,可[20]采用催化氧化技术进行预处理。常用的催化氧化法主要有光催化氧化、电解法和湿式氧化等技术。2 光催化氧化技术主要是针对不饱和烃进行降解而去除有害物质,此技术高效、[21]无害,具有很大的应用前景。李耀中等制备了一种二氧化钛光催化剂,是以30~40目的耐火砖颗粒为载体的负载型催化剂,利用流化床反应器采用这种负载型催化剂对制药废水进行光催化氧化,结果表明:在最优的实验条件下进水COD在596~861范围时,废水经过处理后出水COD为113~124mg/L,COD去除率在80%以上,且废水的可生化性也发生了变化,BOD5/COD值由0.2提高至0.5。电解技术已经被广泛应用于工业废水的处理过程中。利用电解法可以将废水中[22]的高浓度COD去除,使得废水的可生化提高。张月峰等利用NaCl作为电解质加入到甲红霉素制药废水中,当进水COD浓度很高为30万以上时,处理后COD去除[23]率为40%以上。童晓庆采用铁炭做电极进行电解反应,废水COD去除率达到25~30%,废水BOD5/COD值提高,可以顺利进行下一步的生化处理反应。1.2.1.2高磷酸盐废水处理技术磷是生物体不可缺少的、维持生命活动的基本元素之一,在生物圈物质循环中[24]大部分是单向流动,自然界的物质循环难以将沉积在江河湖海的磷回到生物体中。因此,我们认为磷是不可再生资源。但是随着国民经济发展和人民生活水平的提高,过量含磷化合物被使用和排放,对环境造成了严重的污染和损害,引起了社会的广[25]泛关注。所以在对污水进行除磷的同时又能将磷回收利用便既解决了污染问题又解决了磷资源的可持续利用问题。因此,研究去除并回收废水中的磷的方法技术是当前资源环境领域的研究热点。现在的高磷酸盐废水处理技术主要有化学混凝、吸[26-28]附、化学沉淀等方法。混凝法是通过向水中投加混凝剂,使得污水中大分子物质和胶体颗粒失去稳定性凝聚成大颗粒而下沉。一般情况下采用混凝处理后,能够有效地降低废水中污染[29,30]物的浓度,提高废水的可生化降解性。混凝沉淀法一般用来去除磷酸盐含量较高的生物制药废水,采用的药剂一般是铝盐、铁盐(包括亚铁盐)和及其聚合物等,和[31,32]废水中的磷酸盐生成沉淀被去除。随着环境污染的加重对排放污水的氮、磷有了更高更严格的出水水质要求,因此对废水进行脱氮除磷是现在物化水处理技术的[33]一个研究热点。化学沉淀法除磷是将金属盐离子投加到含磷废水中,在一定合适比例下相互反应形成不溶性磷酸盐沉淀,然后通过分离装置将沉淀从污水中除去。化学沉淀法除[34]磷工艺设备具有占地面积小、投资省、处理效率高的优点。化学沉淀法近年来研究最多,成果最丰硕的便是磷酸铵镁沉淀法,通过磷酸铵镁沉淀法不仅可以去除废[35]水中的大部分氨氮还可以同时去除部分磷酸盐。李再兴等采用磷酸铵镁沉淀法对2+3-+高氨氮7-ACA综合废水进行预处理,在pH值=9,n(Mg)/n(PO4)/n(NH4)投配比为1:1:1时,反应时间20min的最佳反应条件下,进水氨氮浓度为2185~2340mg/L时,3 处理后出水氨氮浓度为小于140.0mg/L,去除率在80%以上,利于进行下一步生化处理。吸附法是指利用多孔性固体的吸附性来吸附废水中的污染物,从而将这些污染物质从废水中去除使废水得到净化。通常会用煤灰或活性炭作为吸附剂对一些中成药的生产废水进行预处理。经过吸附法预处理后,出水的COD得到大幅度削减,同[36]时废水的色度和臭味也有一定程度的去除。1.2.1.3高氨氮废水处理技术近年来,我国水污染环境最突出的问题便是相当高含量的氨氮,氨氮成为了污[37]水处理的首要任务。国内的研究者们对氨氮污染治理的重视程度也不断升高,使得脱氮研究成为水处理研究的热点领域之一,主要研究成果有吹脱法、膜分离、折[38-40]点加氯法、离子交换、化学沉淀等方法。+3-2+其中磷酸铵镁沉淀法是基于水体系中同时存在的NH4,PO4及Mg三种离子[41]发生化学反应生成MgNH4PO4·6H2O沉淀,从而去除水体系中的氨氮,而反应之后生成的磷酸铵镁沉淀可以用来生产饲料或者作为肥料的添加剂。磷酸铵镁沉淀也是一种农业上常用的长效复合肥,是可溶性较高的一种缓释肥料,养分高、肥效[42]利用率较高,达到回收利用的经济效益。+吹脱技术主要将空气与废水充分接触,在一个碱性条件下废水中溶解的NH4-N+便会向气体中转移,并随着气体逸出从而去除废水中的NH4-N,达到降低其浓度的效果。该技术反应中气体流速、气液比、氨氮、pH、温度等因素是影响吹脱技术处+理效果的主要因素。该方法操作简便,宜处理高浓度NH4-N废水。但吹脱法能耗较大,并且会对环境产生二次污染,吹脱塔容易结垢后续清理繁琐。膜分离法有反渗透和电渗析是利用天然的或者人工合成的选择性薄膜,利用外界能量或化学电位差来推动各种组分不同程度的透过薄膜,并实现它们的相互分离。膜分离法具有流程简单、投资成本低的优点,但是其运行稳定性差,对废水组分要求严格浓度不适宜过高。离子交换技术的原理是利用交换树脂对非离子态的氨和对离子铵选择性吸附,对它们进行离子交换作用的过程来去除废水中的氨氮。离子交换工艺具有操作方便,[43]流程短的优点但是离子交换树脂再生繁琐,容易对环境产生二次污染。对于物理化学法脱氮,化学沉淀法操作简便、实现资源回收的优点是近年来研究学者们较为青睐的工业废水脱氮预处理方法。但是沉淀剂高额的药剂成本,限制了其在废水处理实际应用中的发展。1.2.2生物处理技术目前国内外主要采用单独厌氧、单独好氧或厌氧加好氧结合的方式对废水进行4 处理工艺研究。1.2.2.1厌氧生物处理技术随着研究者们对厌氧工艺的日益了解,发展了多种多样形式的反应器如UASB[44]反应器、厌氧颗粒污泥膨胀床(EGSB)、UTC、厌氧流化床(AFB)等。[45]李宇庆等以江苏某制药厂的废水为研究对象采用UASB厌氧反应器进行试验研究,当反应器进水COD在1240~5062mg/L范围时,COD去除率稳定在65%~80%,[46]同时发现如果废水中含盐量过高时会降低反应器对有机物的去除率。王路光等采用厌氧颗粒污泥床反应器对生产青霉素的制药废水进行了试验研究,结果表明:提高进水COD为6000mg/L时,处理后COD去除率在80%以上,取到了较好的处理[47]效果。夏怡等对某制药厂的抗生素废水处理工艺采用IC反应器进行了工程调试研3究,逐步提高COD的进水负荷当反应器容积负荷为4kgCOD/(m·d),进水COD为8000mg/L,COD的去除率为70%以上,为下一步的生化处理提供有利条件。1.2.2.2好氧生物处理技术近年来好氧生物处理技术也出现了好多工艺与方法主要包括序列式间歇曝气活性污泥法(SBR)、循环曝气活性污泥工艺(CASS)、及活性炭曝气生物滤池(BAC)、[48]氧化沟以及生物膜法等。[49]吴汝林等对制药有机废水采用活性污泥法进行有机物降解实验研究,在最佳工艺运行参数下,当进水BOD浓度为2000~4000mg/L制药有机污水,总BOD去除[50]率均在90%以上,出水BOD达到排放标准的要求50~100mg/L。孙伟等以某制药3厂的制药废水为研究对象采用A/O工艺处理,当进水为2.27(kgCOD/m·d)时,COD[51]去除率为90%以上,废水出水实现了达标排放。杨波等采用膜法A/O工艺处理高有机物浓度范围的发酵制药废水,当进水COD为2000~14000mg/L变化时,氨氮浓度为100mg/L及以上时,COD和氨氮去除率均达到90%以上。SBR工艺是间歇序批式反应器(SequencingBatchReactor)的简称,它是通过在不同时间段对反应器进行不同的反应环境,使得活性污泥中的微生物在不同时间段发挥自己的作用。它去除污染物的机理与传统活性污泥工艺基本一致。传统的活性污泥工艺采用连续运行方式,污水连续进入系统并连续排出而SBR可以实现反应器间[52]歇反应运行。通过合理控制进水、曝气时间、反应器内溶解氧浓度、厌氧搅拌时间、闲置时间等运行参数,在同一空间不同时间序列上实现反应器内厌氧/缺氧/好氧的组合。与其他污水处理工艺相比,SBR工艺的整体反应结构较少,处理过程相对简单。最重要的是SBR工艺对废水的水质、水量变化具有一定的缓冲适应性,不宜产生污泥膨胀现象。SBR工艺作为一种较理想的除磷脱氮工艺近年来被广为研究、[52-56]改进和应用。5 1.2.2.3好氧-厌氧组合处理技术经过大量研究表明:单纯的好氧技术进行污水处理存在动力消耗大,处理污染物能力有限;单纯厌氧工艺,废水中的有毒有害物质往往会毒害厌氧微生物,进而影响微生物活性使得废水处理效果受到影响。以上这些弊端促进了研究者们在进行发酵制药废水处理时开展了厌氧和好氧的组合处理工艺研究。从20世纪80年代到现在经过研究者们的大量理论和实验研究,厌氧-好氧组合处理工日益成熟,由于其诸多优点便被并迅速的应用于各类废水的处理。其主要特点为首先通过厌氧处理段较大幅度地去除废水中的有机污染物质降低COD浓度,再通过好氧处理段进一步处理厌氧出水的COD以及氨氮等污染物,使废水得到深度净化,实现废水各项指标的[57-59]达标排放。[60]潘碌亭等对某制药厂工业区排放的废水进行实验研究时采用水解酸化-改良SBR-强化絮凝的组合工艺进行试验研究,结果显示,当系统进水COD和氨氮分别为500mg/L和60mg/L时,在最佳运行条件下COD和氨氮去除率分别能达到80%和[61]82%,出水达标排放。胡大锵等进行的中试实验研究组合工艺混凝沉淀-UASB-水解酸化-接触氧化对制药废水的处理情况。当系统进水的COD和氨氮分别为9650mg/L、和160mg/L时,系统出水的COD小于100mg/L并且氨氮小于15mg/L,满足了出水要求,使得出水达标排放。1.2.3组合处理技术进展随着我国水环境污染日益严重,为了保护环境实现人类与自然环境和谐共处、发展,我国对制药废水排放标准也日益严格,治理制药废水是一项任务艰巨的系统工程关系着我国制药行业的健康发展和我国经济的发展。如何将各种处理技术优化组合(物化处理、生物处理)来提高制药废水的处理效率和经济性具有重要作用,因此,我国研究工作者对如何高效处理制药废水进行了大量的理论研究和实验工作,以下[62-64]列举了几种处理效果相对较好组合处理工艺。1.2.3.1混凝-水解酸化-CASS工艺首先采用混凝(投加PAM)对发酵类制药废水进行预处理,通过预处理降低废水生物毒性和大分子有机物质后,在对废水进行生化处理。用水解酸化CASS工艺,CASS工艺是近几年我们从国外学习引进的新型污水生物处理工艺也被称循环活性污泥法。在CASS工艺的处理池中设置有半软性弹性填料并均匀布置了许多曝气头,该系统合理的构造形式和运行模式能有效地预防污泥的膨胀。该系统对进水COD的去除可以达到90%以上。该工艺具有控制灵活、抗冲击能力强、工艺流程相对简单的优点。6 1.2.3.2微电解-水解-好氧接触氧化工艺某些制药厂的发酵类制药废水含高浓度有机物质,并呈现强酸性。根据这种废水的特点诞生了采用微电解-水解-生物接触氧化处理工艺。首先对废水进行微电解处理,即去除了部分COD又中和了废水的酸性,提高了废水的可生化性,最后通过好氧接触氧化进一步处理废水,在最佳的运行条件下最后使得废水各项指标均达到行业标准排放。1.2.3.3絮凝-厌氧-好氧处理工艺由于发酵类制药废水中残留的大量未充分反应的原料以及有机溶剂残留物可以对微生物产生毒害抑制作用,使废水处理效果受到影响,所以这类废水单纯依靠生物处理,出水难以达到排放标准。对抗菌素废水先进行絮凝预处理后,降低了废水的毒性,并去除了废水大部分COD。预处理后的废水经过厌氧污泥床进行处理厌氧反应,系统稳定后COD去除率达到厌氧进水的60%。厌氧处理后的出水,再通过两级好氧装置进行好氧处理去除残留的有机物和氨氮等污染物质。经过絮凝-厌氧-好氧组合工艺的处理废水出水的最终COD可降至排放标准以下。采用组合法处理发酵类制药废水将成为主流方法,比如物化和物化、物化和生化、生化和生化等新型组合方式的探索和开发将成为这类废水的研究热点之一。发酵类制药废水的成分非常复杂,含有多种难降解的无机、有机物质,单单一种处理方法很难进行有效去除和达标排放。因此,许多国内外学者已把多种处理方法组合起来处理发酵类制药废水,也取得了较好的效果。1.3研究的对象、目的意义与内容1.3.1研究的对象本研究以石家庄某企业生物制药废水为对象,开展该废水处理技术研究。该废+水水质特点为:有机物浓度高,COD为3500~4200mg/L;氨氮浓度高,NH4-N为3-1450~1600mg/L;并含高磷酸盐,PO4为70~100mg/L。目前针对此类废水处理的研究,所见报道较少。1.3.2目的与意义本研究针对废水的高氨氮、高COD、含磷高的特点,采用现代化学技术:生化技术对废水开展处理研究,探索出有效的处理工艺技术路线,对各处理单元工艺条件和影响因素进行实验研究和优化,在最佳运行条件下对所研究的富含氨氮、磷的高有机废水实现氮、有机物和磷的最终去除,出水能够达到《发酵类制药工业水污染物排放标准(GB21908-2008)》中表2的规定达标排放。本课题预期成果首先能为发酵制药废水的处理提供理论和技术支持,然后对含7 有高氨氮高COD并含有磷的发酵类制药废水处理提供技术参考,最后对促进我国制药行业的持续、健康发展具有重要的理论现实意义。1.3.3研究内容针对此公司排放的发酵制药废水高氨氮、高COD、含磷高的特点,拟采用“磷酸铵镁-混凝沉淀-SBR”的结合工艺进行试验研究,探究各项废水处理构成单元的运行效能,优化运行条件。使出水达到《发酵类制药工业水污染物排放标准》(GB21908-2008)中规定的COD<100mg/L;氨氮<20mg/L;总氮<30mg/L和磷酸盐<3.0mg/L的要求。本课题主要内容如下:1)磷酸铵镁沉淀法脱氮除磷最佳工艺条件的确定。2)混凝沉淀运行条件的优化研究。3)SBR启动及运行控制技术研究。8 第2章实验材料和方法2.1实验工艺2.1.1实验工艺流程确定的实验工艺流程见下图2-1。Mg2+混凝剂空气MAP混凝沉淀SBR反应出水废水3-PO4图2-1实验工艺流程如图2-1所示,实验处理废水的工艺流程为,首先在废水中依次加入镁盐和磷酸盐后调节pH为一定值时进行磷酸铵镁沉淀法初步脱氮除磷反应,之后再加入适量效果较好的混凝剂,调节反应pH值后反应一定时间,弃去混凝沉淀进一步去除废水中的磷,出水作为SBR反应器的进水。SBR反应器在启动运行前,首先要接种活性较好的活性污泥,然后优化运行条件后逐步提高污染物负荷启动运行SBR反应器,最后在最优运行条件下连续进水、出水运行,实现SBR反应器稳定运行,出水指标符合国家要求的排放标准。2.2装置与设备2.2.1MAP和混凝实验装置在进行磷酸铵镁沉淀(MAP法)和混凝沉淀实验时采用六联搅拌器,对废水和化合物实行搅拌反应,可以根据实验要求调节搅拌的转速和搅拌时间。六联搅拌器可以自由调节反应的转速和设定反应时间,适于磷酸铵镁及混凝沉淀法进行小型烧杯污水处理实验。2.2.2SBR实验装置试验所用反应容器为SBR反应器,SBR反应器由PVC塑料板制成,反应器高50cm,反应器内径12cm,有效容积为4.5L。实验装置见下图2-29 搅拌排水阀贮水箱进水泵排水排泥阀曝气图2-2SBR反应器结构说明如图2-2所示,SBR反应器顶部开放,在一侧设有不同高度的出水口,反应器从底部进水,反应器设有曝气装置提供好氧反应所需的溶解氧,同时设有定时搅拌装置满足厌氧或者缺氧所需反应条件。2.2.3实验设备实验中所使用的实验设备见下表2-1。表2-1实验所用主要设备仪器名称型号分析方法电子天平AB204-N称量药品微波消解COD速测仪WMX微波消解溶解氧测定仪OXI330I测定溶解氧TOC-V总有机碳分析仪TOC-VCPN测定总氮浓度紫外可见分光光度计UV2600吸光度可见分光光度722E吸光度台式高速离心机D37520离心光学显微镜OLYMPUSBX41显微镜检测电动搅拌器JJ1搅拌污泥pH计PHS-25pH值测定2.3实验用水实验用水取自石家庄某制药有限责任公司的发酵制药产生的废水。废水水质见下表2-2。10 表2-2实验用水水质水质指标COD(mg/L)氨氮(mg/L)磷酸盐(mg/L)pH浓度范围3500~42001450~160070~1006.8~7.4如表2-2所示,以此废水作为磷酸铵镁沉淀法实验用水,后续的混凝沉淀和SBR实验用水分别为上一级的出水指标是下一级的进水。2.4实验污泥菌种本试验所用污泥均取自石家庄桥西污水处理厂好氧曝气池,经过短期培养,活性提高之后投入使用。并对污泥菌种进行了检测,其pH值和SS、VSS和SVI。如下表2-3所示。表2-3污泥菌种活性SS(g/L)VSS(g/L)VSS/SSSVI(ml/g)pH6.073.8763.7662.217.12如上表2-3可知污泥的VSS/SS>30,5010时,NH4-N去除率降低至75.38%,推断可2+能是因为在碱性条件下Mg更倾向于形成氢氧化镁沉淀造成了沉淀剂的浪费,造成氨氮去除率下降的情况发生;另外可以看出随着pH值的变化残磷量的变化发生了很大变化,说明pH值对MAP反应的影响较大,无论在酸性或者碱性条件下一旦金属盐比例不当,投加的磷酸盐就会残留在废水中。当pH值>8.0时残磷量可降至60.0mg/L左右,在pH值为9时残磷量最低。随着初始反应pH值的变化,COD去除率维持在20%左右,MAP法对COD有所去除可能是因为对废水迅速调节pH值时造成部分胶体物质失稳而沉淀,还有磷酸铵镁沉淀絮体捕捉的少量有机物的原因。18 分别选取反应pH为7.0和9.0时的结晶物进行了SEM扫描,SEM照片见图3-3。pH=7.0pH=9.0图3-3不同初始反应pH值时结晶物SEM照片(×500)从图3-3可以看出,当初始反应pH值为7.0时,生成的结晶物质颗粒松散,成型不好分布不均。初始反应pH值为9.0时,生成结晶物颗粒相对集中,粒径相对较大(80μm~95μm)、分布较密、表面光滑。+由以上分析得出,NH4-N去除率在pH=9时达到最高为80.60%、残磷量相对较低和结晶物的SEM分析,可以确定最佳初始反应pH值为9.0。2++3.3.2n(Mg)/n(NH4)投配比对去除效果的影响3-+在最佳初始反应pH值9.0条件下,控制n(PO4)/n(NH4)投配比为1.0:1,调整2++n(Mg)/n(NH4)投配比分别为0.8:1、1.0:1、1.2:1和1.4:1、1.6:1,反应时间30min,+考察废水NH4-N和磷酸盐的去除效果,实验结果如图3-4所示。15010012080残磷量9060氨氮去除率COD去除率6040去除率(%)3020出水总磷浓度(mg/L)000.8:11:11.2:11.4:11.6:12++n(Mg)/n(NH4)投配比2++图3-4n(Mg)/n(NH4)投配比对去除效果的影响2++2+由图3-4可以看出,当n(Mg)/n(NH4)投配比<1.0:1时,随着Mg投加量的增+2++加,NH4-N去除率从75.11%提高至82.57%;当n(Mg)/n(NH4)投配比>1.0:1时,19 +NH4-N去除率无明显变化,维持在80%左右,说明加入过量的MgCl2·6H2O对MAP2++沉淀效果的提高基本没有影响。当n(Mg)/n(NH4)投配比>1.0:1时,残磷量逐渐下2++降至11.77mg/L。当n(Mg)/n(NH4)投配比为1.2:1时残磷量依旧相对较低,可能是由于在此条件下产生了Mg3(PO3)2沉淀,致使废水中的残磷量降低。但是当2++n(Mg)/n(NH4)投配比>1.2:1时残磷量迅速上升,可能是由于过量的镁离子抑制了反应进行,造成添加的磷酸盐残留在废水中。COD去除率随反应环境变化不大在20%左右。2++选取n(Mg)/n(NH4)投配比分别为1.0:1和1.2:1条件下的磷酸铵镁结晶物进行了SEM观察,SEM照片见图3-5。2++2++n(Mg)/n(NH4)=1.0:1n(Mg)/n(NH4)=1.2:12++图3-5不同n(Mg)/n(NH4)投配比时结晶物SEM照片(×500)2++从图3-5可以看出,当n(Mg)/n(NH4)投配比=1.2:1时,生成的结晶物粒径较大2++(65μm~95μm)较整齐,形状一致,晶形完整。而当n(Mg)/n(NH4)投配比=1.0:1时,结晶物表面粗糙,晶形残缺,片状居多。+结合以上NH4-N去除效果、残磷量的多少和磷酸铵镁结晶物SEM分析,确定2++MAP沉淀法预处理发酵制药废水的最佳n(Mg)/n(NH4)投配比为1.2:1。3-+3.3.3n(PO4)/n(NH4)投配比对去除效果的影响2+4+在最佳初始反应pH值为9.0、n(Mg)/n(NH)投配比=1.0:1的条件下,调整3-+n(PO4)∶n(NH4)投配比分别为0.6:1、0.8:1、1.0:1、1.2:1和1.4:1,反应时间30min,+考察废水NH4-N和磷酸盐的去除效果,实验结果见图3-6。20 20010016080残磷量12060氨氮去除率80COD去除率40去除率(%)4020出水总磷浓度(mg/L)000.6:10.8:11:11.2:11.4:13-+n(PO4)/n(NH4)投配比3-+图3-6n(PO4)/n(NH4)投配比对氨氮去除效果的影响3-++从图3-6可以看出,随着n(PO4)/n(NH4)投配比的增加,NH4-N去除率变化明显升高由68.58%升至94.96,COD去除率维持在80.0%左右,COD去除率维持在20%3-+左右。当n(PO4)/n(NH4)投配比<1.0:1时,残磷量由80.63mg/L降低至7.78mg/L,3-+2+4+而当n(PO4)/n(NH4)投配比>1.0:1时,残磷量上升,可见在n(Mg)/n(NH)投配比3-=1.0:1加入过量Na2HPO4不能使沉淀反应更加完全,反而会使PO4残留在废水中致使残磷量上升。3-+选取n(PO4)/n(NH4)投配比分别为1.0:1和1.4:1条件下的结晶物进行SEM扫描,SEM照片见图3-7。3-+3-+n(PO4)/n(NH4)=1.0∶1n(PO4)/n(NH4)=1.4∶13-图3-7不同PO4投加量时结晶物SEM照片(×600)3-+从图3-7中可以看出,当n(PO4)∶n(NH4)投配比=1.0:1时,生成的结晶物粒径3-+较均匀(65μm~95μm),晶体致密,晶形较好。而当n(PO4)∶n(NH4)投配比=1.4:1时结晶物大小不一,晶体残缺。21 +针对以上NH4-N去除效果、残磷量和结晶物扫描电镜分析,确定了MAP沉淀法3-+预处理废水的最佳n(PO4)/n(NH4)投配比为1.0:1。2+3-+3.3.4n(Mg)/n(PO4)/n(NH4)投配比对去除效果的影响2++3-+在以上pH值、n(Mg)/n(NH4)投配比、n(PO4)/n(NH4)投配比影响因素研究中3-++发现当n(PO4)/n(NH4)>1:1即磷酸盐过量时NH4-N去除率相对较高,所以考虑保2+3-3-+持n(Mg)/n(PO4)=1.2:1不变,逐步提高n(PO4)/n(NH4)投配比做了三组实验研究2+3-+n(Mg)/n(PO4)/n(NH4)=1.2:1:1、1.44:1.2:1、1.68:1.4:1。2+3-+控制初始反应pH值9.0和反应时间30min,调整n(Mg)/n(PO4)/n(NH4)投配+比为1.2:1:1、1.44:1.2:1、1.68:1.4:1,考察废水NH4-N和磷的去除效果,实验结果如图3-87510060残磷量80氨氮去除率45COD去除率603040去除率(%)1520出水总磷浓度(mg/L)001.2:1:11.44:1.2:11.68:1.4:12+3-+n(Mg)/n(PO4)/n(NH4)投配比2+3-+图3-8n(Mg)/n(PO4)/n(NH4)投配比对去除效果的影响2+3-从图3-8看出当保证镁盐相对磷酸盐过量保持比例n(Mg)/n(PO4)=1.2:1时+NH4-N去除率提高到90%以上,可能是由于镁盐和磷酸盐相对过量时可以促进磷酸铵镁的形成,同时填补了在体系反应时其他反应消耗的镁盐和磷酸盐量。但是当3-+n(PO4)/n(NH4)>1.2:1时,废水出水的残磷量剧烈增加。可能是由于体系反应不能消+耗特别过量的磷酸盐而导致的。综合考虑NH4-N去除率和残磷量两个指标,调高磷2+3-+酸盐投配比,最佳比例n(Mg)/n(PO4)/n(NH4)=1.44:1.2:1。2+3-+选取n(Mg)/n(PO4)/n(NH4)投配比分别为1.44:1.2:1和1.68:1.4:1条件下的结晶物进行SEM扫描,SEM照片见图3-922 2+3-+2+3-+n(Mg)/n(PO4)/n(NH4)=1.44:1.2:1n(Mg)/n(PO4)/n(NH4)=1.68:1.4:12+3-+图3-9n(Mg)/n(PO4)/n(NH4)不同投配比对去除效果的影响2+3-+从图3-9中可以看出,当n(Mg)/n(PO4)/n(NH4)=1.44:1.2:1时,生成的结晶物2+3-+呈细条状粒径均匀,晶体整齐,晶形较好。当n(Mg)/n(PO4)/n(NH4)=1.68:1.2:1时结晶物粗细不一,晶体呈扁平状,晶形不整齐。由以上对氨氮去除率和残磷量多少的分析再加上扫描电镜图片的比对,确定反2+3-+应最佳的n(Mg)/n(PO4)/n(NH4)投配比为1.44:1.2:1。3.3.5反应时间对去除效果的影响2+3-+控制已经确定的最佳条件,初始反应pH值为9.0和调节n(Mg)/n(PO4)/n(NH4)+投配比为1.44:1.2:1,考察反应时间废水NH4-N和磷酸盐去除效果,实验结果见图3-10。501004080残磷量3060氨氮去除率COD去除率2040去除率(%)出水总磷浓度(mg/L)1020001020304050反应时间/min图3-10反应时间对去除效果的影响+从图3-10可以看出,反应时间08时,COD去除率有所上升但是变化不大,而残磷量迅速上升可能是由于混凝反应偏向于在中性或弱碱性下发生反应,当碱性条件下时利于产生Al(OH)3或者Fe(OH)3等沉淀影响混凝反应体系,造成去除效率的降低。4.3.3混凝剂的投加量对处理效果的影响在最佳初始反应pH值8.0条件下,反应时间25min,考察混凝剂PAC投加量对废水去除效果的影响,实验结果如图4-4所示。30 15残磷量50COD去除率%1240930620去除率(%)310出水总磷浓度(mg/L)00910111213PAC投加量/ml图4-4PAC为混凝剂投加量对去除效果的影响由图4-4可知,当投加10%PAC的量为10~11ml,COD去除率从19.8%上升为32.2%,之后加大投药量去除率变化不大,残磷量降为2mg/L达到污水排放标准。当PAC投加量大于11ml时残磷量迅速增加,说明继续投加过量的PAC不仅没有增加去除效果,反而使得残磷量迅猛增加,为了经济节约,所以对废水处理投加PAC最佳的剂量为10ml。4.3.4反应时间对去除效果的影响控制初始反应pH值8.0和投加10%PAC的量为10ml,考察不同反应时间对废水去除效果的影响,实验结果见图4-5。1550残磷量12COD去除率%40930620去除率(%)310出水总磷浓度(mg/L)00515253545反应时间/min图4-5反应时间对去除效果的影响31 从图4-5可以看出,反应时间01.5h发现出水氨氮浓度略有上升可能是因为厌氧搅拌时间过长导致部分好氧菌的菌体自溶。当曝气6h时,氨氮和COD去除效率和曝气4h的反应器出水水质基本一致,所以为了节省时间经济采用曝气4h厌氧搅拌1.5h运行工况。SBR反应器在最适条件下稳定运行一个工况的数据见表5-2。38 表5-2最适运行工况下一个周期实验结果出水水质去除率时间(min)PHCOD氨氮亚硝酸盐氮硝酸盐氮COD氨氮(mg/L)(mg/L)(mg/L)(mg/L)(%)(%)07.72087.476.40.82.400605.7386.547.84.426.981.437.41205.761.024.43.534.597.068.01806.244.010.91.746.797.885.62406.513.51.50.853.399.397.92856.930.62.11.330.998.097.23306.131.72.20.715.996.597.03606.127.61.90.41.097.297.23757.2928.141.50.30.755.445.6由表5-2可知,SBR反应器曝气阶段4个小时内氨氮基本被全部通过硝化作用氧化为硝酸盐氮,经过1.5h的厌氧搅拌反硝化反应,硝酸盐氮被转化为氮气总氮得到去除,COD在初期的曝气1h内可以被大部分的去除,最终出水COD<50mg/L,氨氮<5mg/L达到国家一级A出水标准。5.2.3运行参数的优化5.2.3.1pH值的影响硝化细菌对低pH颇为敏感,因为氨氮的氧化会影响碱度,从而影响pH,因此在本实验中我们对整个运行周期的pH值进行了检测,一个运行周期内pH值的变化见图5-11。39 87654pH值3PH2100120240330375时间/min图5-5一个运行周期内pH值变化由图5-5所示,在曝气阶段随着COD的去除和氨氮的氧化pH值下降,但是随着厌氧搅拌及静置阶段反硝化反应的进行pH值又略有回升,适当补充碱度后使得出水pH为7左右。符合排放出水一级A标准。5.2.3.2溶解氧的影响为了研究溶解氧对SBR反应器的运行影响,分别控制溶解氧为2.5、3.5、4.5,好氧曝气4h之后厌氧搅拌1.5h的运行工况,进水COD、氨氮浓度约为2200mg/L和75mg/L,控制一个运行工况内进水量为2.5L,在反应器反应完毕后,静置30min取出水测试其各项水质指标。实验结果见图5-6到5-11。2500100200080出水COD150060COD去除率(%)100040COD去除率(%)50020出水COD浓度(mg/L)001060120180240300360时间/min图5-6SBR反应器COD去除率(DO=2.5)由图5-6可以得出,在反应器运行过程中,10120min后COD去除率稳定在95%以上,去除效果良好。100100出水氨氮8080氨氮去除率(%)60604040去除率(%)出水浓度(mg/L)2020001060120180240300360时间/min图5-7反应器氨氮去除情况(DO=2.5)图5-7表明,当溶解氧为2.5左右时,由于反应体系首先进行有机物的去除,在t>120min时有机物基本去除完毕,而由于溶解氧较低,在有限的曝气时间内无法将废水中的氨氮转化为硝酸盐氮,造成反应器出水总氮去除率相对较低,出水总氮为20mg/L左右。2500100200080出水COD1500COD去除率(%)60100040COD去除率(%)50020出水COD浓度(mg/L)001060120180240300360时间/min图5-8反应器COD去除情况(DO=3.5)由图5-8可以得出,在反应器运行过程中,1060min后COD去除率稳定在95%以上,去除效果41 良好。100100出水氨氮8080氨氮去除率(%)60604040去除率(%)出水浓度(mg/L)2020001060120180240300360时间/min图5-9反应器氨氮去除情况(DO=3.5)图5-9表明,当溶解氧为3.5左右时,反应体系进行有机物去除的时间缩短,在t>60min时有机物基本去除完毕,而由于溶解氧浓度相对适宜进行硝化反应,而且在厌氧搅拌阶段溶解氧可以降低到一定浓度,有利于反硝化的进行,实现硝化和反硝化的良好衔接。从而反应器出水总氮去除率相对较高,出水总氮为在5mg/L以内。2500100200080出水COD1500COD去除率(%)60100040CDO去除率(%)50020出水COD浓度(mg/L)001060120180240300360时间/min图5-10反应器COD去除情况(DO=4.5)由图5-10可以得出,在反应器运行过程中,1060min后COD去除率稳定在95%以上,去除效果良好。42 10010080出水氨氮8060氨氮去除率(%)604040去除率(%)出水浓度(mg/L)2020001060120180240300360时间/min图5-11反应器氨氮去除情况(DO=4.5)图5-11表明,当溶解氧为4.5左右时,反应体系很快进行完有机物的去除,在t>60min时有机物基本去除完毕,而由于溶解氧较高,在有限的厌氧搅拌时间内溶解氧无法降低到适宜反硝化的浓度,无法将废水中的硝酸盐氮转化为氮气,造成反应器出水残留一些硝酸盐氮,总氮去除率相对较低,出水总氮为15mg/L左右。5.2.3.3温度的影响大部分细菌的适宜生长温度为20~30℃,因为本实验是在冬季进行,所以将反应器放置在保温柜中,保温柜中放置有电暖气采用温控系统控制保温柜温度为25℃左右。5.2.4SBR反应器稳定运行阶段启动SBR反应器时,保持溶解氧为3左右,一个运行周期内保持COD有机物浓度不变大概在2000-2200mg/L,在最佳运行条件下保持SBR反应器运行3周,运行情况见图5-1243 2500100200080150060进水COD100040出水CODCOD去除率(%)COD浓度(mg/L)500COD去除率(%)200013579111315171921时间/d图5-12稳定运行阶段COD去除情况从5-12可见,由于在反应器稳定运行阶段COD去除率已经提高至90%以上,在提高进水量阶段COD去除率稳定在90%以上。10010080806060进水氨氮4040去除率(%)浓度(mg/L)出水氨氮+4+4NH去除率(%)NH20200013579111315171921时间/d图5-13稳定运行阶段氨氮去除情况由图5-13可以看出在进水氨氮浓度在70-85mg/L时,反应器稳定运行,SBR反应器的出水氨氮浓度在8mg/L以下,去除率最高达到99.4%。说明反应器在好氧和厌氧各个阶段反应过程良好,去除效果稳定,反应器性能良好,可以稳定去除COD、氨氮的浓度为2000mg/L和80mg/L。废水出水实现达标排放。5.3本章小结通过SBR反应器处理混凝出水的实验研究,得出以下结论。44 1)采用SBR反应器对混凝出水进行处理,研究表明反应器接种好氧絮状污泥45d后,采用模拟废水逐步提高污染物负荷,反应器容积负荷达到2.0kgCOD/(m³·d)时,平均去除负荷在90%以上,顺利实现成功启动。2)针对废水水质特点,实验进行不同模式及工况对比研究,灵活调整,确定了SBR处理混凝出水的最佳工况为进水10分钟+曝气4小时+厌氧搅拌1.5小时十沉淀出水0.5小时,一个周期总共为6小时。3)通过调整工况及运行参数,SBR反应器的运行稳定处理效果较好。当进水COD为2100mg/L左右时,出水COD为30mg/L以内,去除率达到95%以上。当氨氮进水为80mg/L时,出水氨氮约为3mg/L,去除率高达90%以上。综合上述,混凝出水经过SBR反应器的处理可以实现达标排放。45 46 第6章活性污泥的特性表征6.1接种污泥的培养训化在SBR生化实验中所使用的活性污泥取自石家庄市桥西污水处理厂好氧曝气O段的污泥,取出2.5L的污泥放入3L体积的烧杯中,用小型气泵间歇曝气即曝气6h后停止,开启自动搅拌器搅拌2h,之后静置1h,最后从烧杯上倒出250mL上清夜在重新补充250mL的实验室模拟废水,废水成分见表6-1。对污泥进行上述培养训化10个周期后,对活性污泥各项指标进行了检测并做了硝化和反硝化性能的研究。表6-1模拟废水水质情况基质种类浓度(mg/L)微量元素组成浓度(mg/L)COD1500FeSO40.1NH4Cl60CuSO40.03Na2CO360MnSO40.03KH2PO410CaCL20.16.1.1接种污泥的活性针对从污水处理厂取来的活性污泥进行了上述培养驯化后,检测了污泥的pH值和SS、VSS和SVI。如下表6-2所示。表6-2污泥活性SS(g/L)VSS(g/L)VSS/SSSVI(mL/g)pH6.073.8763.7662.217.12由表6-2可知污泥的VSS/SS>30,5030,5030,5030,50