【作者】 马聪；

【导师】 于水利；

【作者基本信息】 哈尔滨工业大学 ， 市政工程， 2013， 博士

【摘要】 我国北方地区尤其是东北地区，冬季的低温微污染水处理困难，常规处理工艺对低温微污染水中的有机物、氨氮等的处理效果非常有限。因此，开发一种经济高效、环境友好、易于操作的低温微污染水处理技术具有重要意义。本研究利用粉末活性炭对有机物的吸附作用、生物活性炭对氨氮的良好去除效果，以及膜对微生物、病毒和粉末活性炭的优异分离性能，构建了粉末活性炭/膜组合工艺，以解决低温条件下，微污染水中有机物和氨氮等的处理问题；并通过对膜污染机理的研究，提出了有效减轻膜污染的新方法。本课题研究主要从以下三个方面展开：粉末活性炭/膜组合系统的构建与运行参数的确定；处理效能与影响因素；膜污染的影响因素、控制技术及膜污染机理。通过以上三方面对粉末活性炭/膜组合工艺处理低温微污染水进行了系统和深入的研究，为我国东北地区低温微污染水处理提供了可资借鉴的新思路。通过粉末活性炭静态吸附腐殖酸的实验和微滤膜连续流处理低温微污染水试验，对二者各自处理低温（10oC）微污染水的性能进行研究。结果表明：粉末活性炭非常适合在低温条件下吸附腐殖酸；微滤膜对低温微污染水中的浊度去除率非常好。结合二者处理低温微污染水的优点，构建粉末活性炭/膜组合系统，并对系统的运行参数，包括粉末活性炭投加量、水力停留时间（HRT）和曝气量等进行确定。结果表明：粉末活性炭投加量为50g/L；HRT为2h；以30min为一个过滤周期，前29.5min以16.6L/（m²·h）的膜通量进行过滤，之后30s以115L/（m²·h）的膜通量进行反洗；曝气量为0.25m3/h；运行100天后需要换炭，换炭量为每天2.5%换炭。采用膜组合工艺连续流处理低温微污染水试验，考察其稳定运行后对低温微污染水的处理效能，及原水水质、启动方式和温度对膜组合工艺处理微污染水效能的影响。结果表明：氨氮平均去除率为95%；DOC、UV₂₅₄、TOC和高锰酸盐指数平均去除率分别为70.8%、88.4%，76.3%和58.9%；三卤甲烷生成势（THMFP）平均去除率为81.7%；浊度去除率在99%以上。膜组合工艺处理效能受原水中氨氮、有机物和浊度浓度变化的影响较小。投加200mL生物粉末活性炭混合浆液可以缩短整个低温启动周期至25天，即膜组合工艺已具备良好的消化能力，可是对有机物的去除效能变差，而且不可逆膜污染更严重。虽然低温会降低微生物的活性，但高浓度粉末活性炭可以为微生物提供适宜的生存环境以抵御恶劣的外界条件（低温），此时的氨氮去除率仅比常温时低4%；粉末活性炭吸附有机物为放热反应，因而低温时对有机物去除率略高于常温时。利用红外光谱分析、原子力显微镜和扫描电镜等分析手段对经不同化学溶液清洗后的膜表面进行表征，阐述膜组合工艺处理低温微污染水的膜污染机理。结果表明：在总膜污染中，化学可逆膜污染占83%，其中有机污染物主要为蛋白质、多糖和腐殖酸，无机污染物主要为Ca²⁺和Fe³⁺；依次经NaOH、NaClO、HCl和H₂O₂清洗后，污染膜表面的形态和亲水性基本恢复到新膜程度，膜污染得到有效控制。通过对跨膜压差（TMP）及膜阻力分布和混合浆液的性质的分析，研究膜污染影响因素（包括启动方式、温度和换炭量）并提出膜污染控制技术(包括曝气、去离子水反洗和进水中投加Ca²⁺)。结果表明：当膜组合工艺内高浓度粉末活性炭失效后不换炭或每天1%换炭量时，和投加200mL生物粉末活性炭混合浆液两种情况，会加重不可逆膜污染，因为粉末活性炭混合浆液中溶解性微生物产物（SMP）含量增加。低温使混合浆液平均粒径尺寸有减小的趋势，而且混合浆液中SMP含量也有所增加，从而也会加重不可逆膜污染。去离子水反洗可以恢复有机物与膜表面之间的排斥力，有效减轻在膜污染缓慢增长期的不可逆膜污染；通过调节适当的曝气量与在进水中投加Ca²⁺，可以控制粉末活性炭混合浆液平均粒径尺寸与SMP含量，从而减轻在膜污染快速增长期的不可逆膜污染。更多还原

【Abstract】 In northern China，especially the Northeast，it’s difficult to treat micro-pollutedwater at low temperature in Winter. Remval efficiency of organic matters andammonia nitrogen in micro-polluted water at low temperature is extremely limited,which is treated by traditional water treatments. So，it’s particularly important todevelp a cost-effective，environment-friendly and easy-to-operate technology totreat micro-polluted water at low temperature.A high concentration powdered activated carbon （PAC）/microfiltration （MF）hybrid process was established to treat organic matters and ammonia nitrogen inmicro-polluted water at low temperature，taking advantage of adsorption of organicmatters onto PAC，excellent removal efficiency of ammonia nitrogen by biologicalactivated carbon （BAC），outstanding separation of microbes, virus and PAC. Newmethods of mitigating membrane fouling was brought out by the research onmechanisms of membrane fouling.The research mainly includes three parts: establishment of high concentrationPAC/membrane hybrid process and determination of operational parameters,removal efficiency and influencing factors, and influencing, control techniques andmechanism of membrane fouling. The aim of the research is to provide a newmethod of treating micro-polluted water at low temperature for northest China.Humic acid （HA） adsorbed by PAC and micro-polluted water treated by MF atlow temperature （10oC） were studied to investigate the performance of the separatetechnology. The results showed that: PAC was ideal to adsorb HA at lowtemperature and the removal efficiency of turbidity by MF was excellent at lowtemperature. High concentration PAC/membrane hybrid process was established andthe operational parameters were also determined as: PAC dosage of50g/L，HRT of2h，29.5-min-filtraiton with16.6L/（m²·h） and then0.5-min-backwash with115L/（m²·h），aeration rate of0.25m3/h and everyday2.5%PAC bulk replacementafter100days operation.Performance and influencing factors （characteristics of the feed water, start-upmethods and temperature） of membrane hybrid process were studied. The results showed that: removal efficiency of ammonia nitrogen was95%, removal rate ofdissolved organic carbon （DOC）, ultraviolet adsorption at254nm (UV₂₅₄), totalorganic carbon （TOC） and permanganate index was70.8%,88.4%，76.3and58.9%,respectively, removal efficiency of trihalomethane formation potential （THMFP）was81.7%and removal rate of turbidity was above99%. Characteristics of the feedwater （ammonia nitrogen, organic matters and turbidty） had little effect on theperformance of the hybrid membrane process.The start-up time at low temperaturecould be shortened to25days by inoculating with200mL biological PAC （BPAC）bulk from other reactors, however, removal efficiency reduced and irreversiblemembrane fouling increased. Low temperature reduced the activity of the microbes,however, removal efficiency of ammonia nitrogen at low temperature was4%lowerthan that at room temperature, because high concentration of PAC provide theconvenient environment for microbes to resist the bad conditions （low temperature）.The reaction of organic matters adsorbed by PAC was exothermic, so removal rateat low temperature was higher than that at room temperature.Membrane fouling in hybid membrane process for treating micro-pollutedwater at low temperature was elaborated, using attenuated total reflection fouriertransform infrared spectroscopy （ATR-FTIR）, atomic force microscope （AFM）,scanning electron microsope analysis to observe characteristics of membranesurface after different chemical cleaning. The results showed that: chemicalreversible membrane fouling accounted for83%of total membrane fouling. Themain organic fouling matters were protein, polysaccharide and humic acid, and themain inorganic fouling matters were Ca²⁺and Fe³⁺. The shape and hydrophilicitiy offouled membrane returned to the extent of the new membrane after chemicalcleaning in turn （NaOH, NaClO, HCl and H₂O₂） and membrane fouling obtainedeffective control.Influencing factors （start-up methods, temperature and replacement of PACbulk） were investigated by analysis of trans-membrane pressure （TMP）, distributionof membrane fouling resistance and characteristics of the bulk, and new techniques(aeration, backwash with deionized water and input with Ca²⁺in the feed water) tomitigate membrane fouling was brought up. The results showed that: when highconcentration of PAC in the reactor lost adsorption ability, no PAC bulk replacement or everyday1%PAC bulk replacement and input with200mL BPACbulk, would increase irreversible membrane fouling, because the concentration ofSMP in PAC bulk increased. Average particle size distribution decreased and SMPin PAC bulk increased at low temperature, accelerating irreversible membranefouling. Backwash with deionized water could restore the repulsion betweenorganic matters and membrane surface and then reduce irreversible fouling withinthe slow growth period. Particle size distribution of PAC bulk could be increasedand concentration of SMP could be reduced through input with Ca²⁺in the feedwater, lead to mitigation of irreversible fouling during the rapid growth period.更多还原