活性炭吸附用于城市污水地下回灌技术的研究

通过静态吸附试验比较与Ｃｒｉｔｔｅｎｄｅｎ计算模型分析,选择ＧＨ－１６型粒状活性炭对北京高碑店污水处理厂二级出水进行深度处理试验。结果表明：ＧＨ－１６型活性炭的净化效果存在阈值,约２５％的ＤＯＣ不能被吸附,不被吸附的主要是分子量〉３０００ｕ的有机物。对以ＵＶ２５４表征的有机物去除效果最好,分子量〈１０００ｕ的弱极性有机物易被微孔吸附且吸附容量,对以ＡＯＸ表征的极性有机物去除效果较差。二级出水经活性     

粉末活性炭应用研究

在烧杯试验和小试基础上考察了粉末活性炭处理污染原水的工艺方法和技术关键，试验结果表明：木屑炭由于中孔发动，较适合应用于给水处理。粉末活性炭是最佳投加点是絮凝中端。该工艺可有效避免吸附与混凝之间的竞争，并保证充足的吸附时间。建议粉末活性炭的投加量１０－１５ｍｇ／Ｌ，该条件下ＣＯＤＭｎ可达２０％左右的较稳定去除效果，ＴＴＨＭ和ＡＢＳ可去除５０％以上，酚可去除掉３０％以上。     

珠江水中有机物分子量分布及其去除研究

采用超滤膜分级方法考察了常规混凝、高锰酸钾和粉末活性炭预处理等工艺对珠江水中各级分子量有机物的去除效果。结果表明,珠江水中有机物以分子量小于1kDa的小分子有机物为主,各级分子量有机物TOC和UV254具有良好的相关性。常规混凝工艺主要去除大分子有机物,且去除率随分子量的减小而降低。高锰酸钾预处理能够全面提高各级分子量有机物的去除效果;粉末活性炭主要吸附中小分子有机物,对各级分子量有机物的去除效果与常规混凝成互补。     

基于南水北调中线原水的土臭素去除技术研究

为了初步建立南水北调中线水源发生土臭素污染时的应对机制,通过向南水北调中线引江水中配入土臭素标准品,研究了臭氧氧化、粉末活性炭吸附以及二者联用对水中土臭素的去除效果。结果表明,对于500 ng/L左右的土臭素,臭氧氧化和粉末活性炭吸附均具有很好的去除效果。臭氧氧化去除水中土臭素的反应非常迅速,基本可在3 min左右完成,去除效果随着臭氧投加量的增大显著增强;粉末活性炭吸附去除水中土臭素的效果与其自身特性有关,且随着投加量的增大和吸附时间的延长逐渐增强;采用臭氧氧化与粉末活性炭吸附联用可以有效发挥二者的协同作用,在保证土臭素去除效果的同时减少臭氧或粉末活性炭投加量,提高产水水质的安全性。     

高锰酸钾-粉末活性炭联用去除原水中的嗅味

针对常规处理工艺难以解决东江原水发臭的问题,考察了高锰酸钾-粉末活性炭联用技术对水中嗅味的去除效果。结果表明,高锰酸钾一粉末活性炭联用对水中嗅味具有较好的去除效果,当氧化吸附时间为30min,高锰酸钾投加量为1．5mg/L,粉末活性炭投加量为40mg／L时,经混凝沉淀后水中的嗅味可由5级降至0级。此外,高锰酸钾和粉末活性炭联用对水中的有机物、浊度及锰也有明显的去除效果。     

粉末活性炭对微囊藻毒素的吸附效能研究

利用小试试验研究了粉末活性炭对黄浦江原水中不同浓度的微囊藻毒素的吸附去除效果。研究结果表明,粉末活性炭对水中微囊藻毒素具有较好的去除效果,10mg/L的粉末活性炭在40min内对MC-RR、MC-LR的去除率分别达到55%和45%,而且在一定初始浓度范围下,对于给定的吸附时间、活性炭投加量,在天然有机物存在的条件下,两种微囊藻毒素的去除效果与其初始浓度无关;粉末活性炭对疏水性较弱的MC-RR的吸附效果要略高于疏水性较强MC-LR的吸附效果,原因为两种微囊藻毒素分子在吸附条件下所显带的电荷之间的差异有关,在中性条件下,MC-RR、MC-LR显带的电荷分别为0和-1,从而造成微囊藻毒素与活性炭颗粒之间静电引力有一定的差别。     

粉末活性炭去除水中氯丁二烯的研究

试验研究了粉末活性炭对氯丁二烯的去除效果以及吸附时间、投加量和水质对粉末活性炭吸附性能的影响。结果表明,粉末活性炭对氯丁二烯的去除率在90%以上,吸附规律符合Langmuir吸附等温线和Freunlich吸附等温线;最佳吸附时间为120min;随着投炭量的增加,氯丁二烯的去除率提高,粉末活性炭的吸附容量降低;在不同水质条件下,粉末活性炭的吸附等温线不同,因此在应急处理中,首先应确定原水水质下的吸附等温线,然后计算出投炭量。     

粉末活性炭吸附去除松花江原水中有机物的研究

以松花江水为原水,通过小试和生产性试验研究了粉末活性炭吸附、混凝沉淀、过滤工艺对硝基苯及有机污染物的去除情况。结果表明：投加粉末活性炭很好地控制了有机物的总含量,混凝沉淀、过滤工艺主要使有机物的种类明显减少;投加粉末活性炭是去除环境优先控制有机物的关键措施;松花江水中的硝基苯投加量与检出量虽然存在一定的差异,但两者仍具有良好的线性关系;采用助凝措施强化粉末活性炭吸附去除水中硝基苯的效果不明显,说明硝基苯的去除主要是依靠粉末活性炭的吸附作用。     

探讨粉末活性炭对东江原水的处理效果

针对排涝时期常规处理工艺难以应对东江原水水质突发情况,探讨了粉末活性炭(PAC)吸附去除水中臭和味、UV254消光度、浊度、色度、CODMn等的去除效果。实验结果表明,粉末活性炭对氨氮几乎没有任何吸附效果,而对臭和味、UV254消光度、浊度、色度、CODMn具有一定的去除效果,尤其对臭和味的去除效果更为明显。氧化吸附时间为30min,粉末活性炭的投加量为40mg/L时,去除效果最为理想。     

粉末活性炭吸附水中四氯化碳试验研究

采用粉末活性炭吸附去除水中四氯化碳,考察了活性炭投加量、吸附时间、温度等因素对去除效果的影响.结果表明,该吸附过程符合Freundlich吸附等温线模式,以物理吸附为主,并且在纯水中的吸附容量大于原水;在15-25℃內,温度对吸附效果的影响不大,但去除率随吸附时间的延长而升高;投加80 mg/L粉末活性炭吸附120 m...     

从分子质量的变化分析臭氧活性炭工艺

为了解臭氧活性炭工艺的机理并优化运行条件,采用臭氧活性炭处理黄浦江原水,分析了原水及经不同工艺单元处理后溶解性有机物 (DOM)分子质量 (MW)的变化。结果表明:黄浦江原水中的DOM主要为小分子有机物;臭氧对大分子有机物的氧化分解作用明显强于对小分子有机物的氧化作用;MW<1ku的有机物经臭氧氧化后则表现出不同程度的增加;混凝、沉淀、过滤对MW>3ku的大分子有机物去除效果较好,而对MW<3ku的小分子有机物去除效果较差;生物活性炭单元能有效去除MW为 3~1ku和MW<1ku的小分子有机物;臭氧氧化与活性炭吸附在去除不同MW有机物的过程中有很好的互补性,从而使该工艺能有效去除原水中的DOM。     

Enhanced coagulation in a typical North-China water treatment plant

The characteristics of typical source waters in northern China and their enhanced coagulation features were studied in this paper. Through bench scale tests, a composite coagulant (HPAC) was selected for this kind of high alkalinity and pH water. It can be 30% more efficient in organic matter (OM) removal than the traditional coagulants (AlCl(3), FeCl(3)), and polyaluminum chloride (PACl), especially more efficient in removing high SUVA, hydrophobic and high molecular weight dissolved organic matter (DOM). It is found that some DOM with low SUVA has precedence over that with high SUVA to be removed at conventional dosages in some seasons, and that the priority of DOM removal is in the same sequence for all the coagulants. DOM with high SUVA is not always more easily removed. When applying HPAC as coagulant, flotation process can remove hydrophobic OM more efficiently than sedimentation process in pilot scale tests.     

粉末活性炭/污泥回流工艺强化膜前预处理的研究

采用粉末活性炭(PAC)吸附/混凝沉淀/浸没式超滤膜组合工艺处理苏州市某河水,考察了PAC/污泥回流工艺对膜前预处理的强化效果及对膜污染的影响,并与常规混凝沉淀、污泥回流强化混凝沉淀、PAC吸附/混凝沉淀等3种预处理工艺进行了对比。结果表明,PAC/污泥回流强化预处理工艺对浊度、DOC、UV254和THMFP的去除率分别为80.2%、47.5%、42.3%和52.3%,均比其他预处理工艺的高,对MW30 ku和MW1 ku有机物的去除效果明显。PAC/污泥回流强化预处理和超滤膜组合工艺对浊度、DOC、UV254和THMFP的去除率分别可达到99.2%、54.1%、47.2%和60.2%;经过15 d的运行,超滤膜的跨膜压差基本保持稳定,而其他预处理工艺虽能在一定程度上减轻膜污染,但无法避免不可逆膜污染的发生。     

Dissolved organic matter (DOM) in recycled leachate of bioreactor landfill

Landfill leachate needs sufficient treatment before safe disposal. Bioreactor landfill technology could effectively degrade the organic matters in recirculated leachate, hence leaving a leachate stream of low biodegradability. This study characterized the dissolved organic matter (DOM) in the leachate from simulated bioreactor landfill columns with or without presence of trace oxygen. The removal efficiencies of this DOM using coagulation-sedimentation or electrolysis processes were demonstrated. Recirculated leachates were sampled from the simulated landfill columns applying conventional mode, intermittent-aeration mode, and natural aeration mode, whose DOM was fractionated into humic acids (HA), fulvic acids (FA) and hydrophilic fractions (HyI) by the XAD-8 resin combined with the cation exchange resin method. The recirculated leachate had low BOD/COD ratio, high humic substances contents, and high aromatic content. Their HA fraction comprised mainly large molecules (>10 k Da), while the FA and HyI were composed of smaller molecules (<50 k and <4 k Da, respectively). With the presence of oxygen, the TOC contents and the contents of HA, FA and HyI in leachate reduced, with FA and HyI fractions of molecular weight (MW) lower than 4 k Da more readily degraded. The organic matters left in leachates from intermittent-aeration mode and natural aeration mode were of low biodegradability. It was tested in the following sections the effects of coagulation-sedimentation process and of electrolysis process on the removal of residual DOM in recirculated leachate. Coagulation-sedimentation tests revealed that poly ferric sulphate (PFS) could remove more COD (58.1%) from leachate than polyaluminum chloride (PACl) (22.9%), particularly on the HA fraction with MW>10 k Da. Coagulation-sedimentation could not remove most of HyI in leachate. Furthermore, the corresponding BOD/COD ratio was not improved through coagulation. Electrolysis test could also effectively removed HA of MW>10 k Da. However, the biodegradability of treated effluent considerably was improved. The electrolysis could decompose high MW substances and increase biodegradability of recirculated leachate from bioreactor landfill.     

浸入式膜系统回收膜反洗水的试验研究及工程应用

为提高超滤膜系统的产水率,采用混凝/粉末活性炭/浸入式膜组合工艺,对中试超滤膜反洗水进行了回收处理。结果表明,膜反洗水中的有机物浓度较高,以DOC表征的有机物主要分布在MW30 ku和MW1 ku区间内;回收系统的平均出水浊度为0.07 NTU;当FeCl3和PAC的投量均为15 mg/L时,出水CODMn平均为2.81 mg/L,平均去除率达到了50.7%;回收系统出水的pH和微生物指标均满足《生活饮用水卫生标准》(GB 5749—2006)的要求。将该反洗水回收工艺应用于杨柳青水厂的膜处理示范工程,可使系统的产水率从79.85%提高到98.03%,可减少废水排放量达33×104m3/a。     

混凝-超滤去除腐殖酸的试验研究

进行了直接超滤和混凝－超滤组合工艺对腐殖酸的去除效果和膜污染状况的试验。结果表明，超滤前另混凝土预处理对腐殖酸的DOC和UV254的去除率分别从28％、40％提高到53％、78％。同时高效液相色普（HPLC）分析表明，混凝－超滤组合工艺对分子质量＜6000u的有机物的去除率提高幅度更为显著。混凝－超滤组合工艺的最佳pH值条件pH=7,通过卷扫混凝使小分子有机物结合成微絮体，降低了膜孔污染，使超滤保持了较同的渗透通量。     

受典型除草剂污染原水的应急处理工艺研究

以水中阿特拉津和莠灭净浓度突增为背景,研究了混凝、PAC吸附和PAC吸附＋混凝等工艺对它们的去除效率,同时根据原水水质的变化和水厂的常用工艺,分别考察了混凝剂投加量、pH值、预氧化对混凝去除阿特拉津和莠灭净的影响,以及目标物初始浓度、天然有机物浓度和预氧化对PAC吸附的影响。结果表明,调节pH值及采取预氧化措施均能改善混凝对阿特拉津和莠灭净的去除效果,但其出水浓度仍不能达标;天然有机物浓度对PAC吸附的影响并非是简单的线性关系,同时投加氧化剂和PAC会相互削弱其作用,PAC吸附＋混凝才是去除阿特拉津和莠灭净最简单、有效的方法。     

Effect of moderate pre-oxidation on the removal of Microcystis aeruginosa by KMnO4-Fe(II) process: significance of the in-situ formed Fe(III)

This study developed a novel KMnO₄-Fe(II) process to remove the cells of Microcystis aeruginosa, and the mechanisms involved in have been investigated. At KMnO₄ doses of 0-10.0 μM, the KMnO₄-Fe(II) process showed 23.4-53.3% higher efficiency than the KMnO₄-Fe(III) process did. This was first attributed to the moderate pre-oxidation of M. aeruginosa by KMnO₄, achieved by dosing Fe(II) after a period of pre-oxidation, to cease the further release of intracellular organic matter (IOM) and the degradation of dissolved organic matter (DOM). The extensive exposure of M. aeruginosa to KMnO₄ in KMnO₄-Fe(III) process led to high levels and insufficient molecular weight of DOM, inhibiting the subsequent Fe(III) coagulation. Additionally, Fe(II) contributed to lower levels of the in-situ formed MnO₂, the reduction product of KMnO₄ which adversely affected algae removal by Fe(III) coagulation. However, the in-situ formed Fe(III), which was derived from the oxidation of Fe(II) by KMnO₄, in-situ MnO₂, and dissolved oxygen, dominated the remarkably high efficiency of KMnO₄-Fe(II) process with respect to the removal of M. aeruginosa. On one hand, in-situ formed Fe(III) had more reactive surface area than pre-formed Fe(III). On the other hand, the continuous introduction of fresh Fe(III) coagulant showed higher efficiency than one-off dosage of coagulant to destabilize M. aeruginosa cells and to increase the flocs size. Moreover, the MnO₂ precipitated on algae cell surfaces and contributed to the formation of in-situ formed Fe(III), which may act as bridges to enhance the removal of M. aeruginosa.