零价铁强化厌氧-MFC耦合降解喹啉效果影响探究

通过将微生物燃料电池(MFC)与厌氧零价铁(ZVI)耦合,探究其对喹啉降解效果的影响。选取250 mg/L的喹啉作为单一基质将其分别在纯厌氧条件和添加ZVI的条件下降解12 h,随后取上清液在MFC反应器中降解,分析其降解效果。实验结果表明,添加ZVI对MFC降解喹啉有促进作用,喹啉在MFC中5 d内可降解完毕,降解率达99.0%。     

纳米零价铁对硝基苯厌氧降解效能的影响研究

采用纳米零价铁(NZVI)和厌氧微生物(AD)组合体系降解废水中的硝基苯,研究了该组合体系对硝基苯的降解效果,考察了影响降解效果的主要因素,并对降解机理进行了探讨。结果表明,相比单独NZVI体系、单独AD体系,NZVI-AD体系对硝基苯的降解效果更好。其最佳处理条件:初始pH=4,初始硝基苯质量浓度200 mg/L,NZVI投加量0.6 g/L。在最佳条件下,硝基苯降解率达到72.5%。厌氧微生物和纳米零价铁之间存在明显的协同作用。     

Cu@nZVI制备及降解2,4-DCP研究

众所周知,在液相体系中纳米铁(n ZVI)对有机氯化物具有良好的脱氯能力。本文采用一部液相还原法制备Cu@n ZVI和n ZVI纳米颗粒,并将其应用于2,4-DCP降解的对比研究。对Cu/Fe质量比、2,4-DCP初始浓度及p H的影响进行了探讨。得出最佳降解条件为Cu/Fe质量比=1∶1,2,4-DCP初始浓度=100 mg/L,p H=3.5。同时证明Cu@n ZVI体系的氧化还原效果明显好于n ZVI体系。     

过硫酸盐强化零价铁还原去除硝基苯的实验研究

考察了过硫酸盐(PS)强化零价铁(ZVI)对水中硝基苯去除的性能。结果表明在单纯利用ZVI还原去除硝基苯过程中,初始p H 3.0时初期去除硝基苯速率较快,初始p H 4.0~7.0时随p H的升高反应速率减慢,而ZVI投量的增加对去除速率有较大提升作用。向体系中投加PS能显著促进零价铁去除硝基苯的速率,在达到相同去除效果的情况下,外加PS的成本远远小于提升ZVI投量所引起的成本增加。综合固体产物的XRD表征得知,PS提高ZVI去除硝基苯的效果主要是通过促进ZVI的腐蚀和改变ZVI腐蚀产物的种类来实现。通过FTIR表征可知,外加PS仅对硝基苯去除过程起加速作用,而不改变其还原路径。GC-MS的结果则验证了硝基苯被ZVI/ZVIPS降解的主要产物为苯胺。     

ZVI/Na_2S_2O_8体系处理微污染原水实验研究

采用零价铁(ZVI)催化过硫酸盐处理微污染原水,考察p H值、过硫酸盐和Fe0的投加量、温度等因素对处理效果的影响。结果表明,该方法能有效去除微污染原水中的污染物,在p H=7、ZVI投加量为0. 11 g/L、Na2S2O8投加量为0. 7 g/L的条件下,COD与氨氮的去除率达到92%和40%;温度的升高促进了S2O2-8被分解成SO-4·反应的发生。反应后,ZVI表面不仅存在Fe0,同时有Fe2+、Fe3+价态生成,覆盖了大量的絮状氧化物。     

ZVI/Na_2S_2O_8体系处理微污染原水实验研究

采用零价铁(ZVI)催化过硫酸盐处理微污染原水,考察p H值、过硫酸盐和Fe0的投加量、温度等因素对处理效果的影响。结果表明,该方法能有效去除微污染原水中的污染物,在p H=7、ZVI投加量为0. 11 g/L、Na2S2O8投加量为0. 7 g/L的条件下,COD与氨氮的去除率达到92%和40%;温度的升高促进了S2O2-8被分解成SO-4·反应的发生。反应后,ZVI表面不仅存在Fe0,同时有Fe2+、Fe3+价态生成,覆盖了大量的絮状氧化物。     

微波强化催化湿式H_2O_2氧化降解喹啉的研究

采用微波强化催化湿式H_2O_2氧化法降解喹啉,以负载型Cu-Ce/γ-Al2O3/TiO_2为催化剂,考察了微波功率、反应温度、H_2O_2投加量和溶液初始p H对降解效果的影响。实验结果表明,在喹啉初始质量浓度为100 mg/L、微波功率为500 W、反应温度为60℃、pH=6、H_2O_2投加量为0.094 mol/L的条件下,反应18 min后,喹啉和TOC去除率分别可达100%、82.18%。微波可明显提高反应速率,反应体系中喹啉降解和H_2O_2分解均符合一级动力学。     

菌种FS-1降解季铵盐生产废水及机理研究

采用正交试验法研究了微生物产生菌处理季铵盐生产废水的最佳条件,并根据菌种的过氧化氢酶的性质、过滤后的菌液与过滤得到的黏液层等单独处理废水后的CODCr的去除率讨论了降解机理。采用正交试验,以废水的CODCr去除率为评价指标,优化菌种投加量、废水初始p H值、处理温度、降解时间等处理条件。极差分析显示,影响CODCr去除率的主要因素为菌种投加量,废水初始p H值对处理效果几乎没有影响。在最优化条件下,即菌种投加量30m L、降解时间18h、处理温度24℃、废水初始p H值10时,CODCr的去除率达到75.27%。     

黄钾铁矾类Fenton法处理难降解有机物喹啉

喹啉是典型芳香化合物,毒性大、难降解,传统的生物法对其去除效果差,高级氧化法处理这种难降解有机物效果极佳。用水热法合成了一种类Fenton催化剂,并考察了其对喹啉的处理效果。通过对材料的表征,证实此催化剂是黄钾铁矾且具有较好的稳定性。单因素影响实验结果表明:在初始p H=3.0、催化剂投加质量浓度3.0 g/L,H2O2质量浓度500 mg/L条件下处理50 mg/L喹啉溶液1.5 h,去除率可达100%。     

臭氧氧化法深度处理污泥干化冷凝液实验研究

对燃煤耦合污泥发电系统冷凝液进行了臭氧催化氧化实验研究，分别从催化剂选型、催化剂投加量、体系p H、臭氧投加量及接触时间五个因素入手探究其对难降解有机物去除效果的影响，进一步利用核磁共振技术及质谱技术对体系内蒽醌和萘酚的降解过程进行了监测。实验表明，当选用Fe/γ-Al₂O₃为催化剂且投加量为6 g/L，体系p H为9.2，臭氧投加量为120 mg/L，接触时间为120 min时，臭氧催化氧化对剩余难降解有机物的去除效果最佳，去除率可达83.2%，核磁共振和质谱监测结果也显示芳香类有机物随接触时间延长而迅速发生降解。     

零价铁及其耦合技术强化抗生素废水的处理

抗生素被广泛应用于治疗疾病、畜牧养殖业及病虫害防治等,然而抗生素大规模的生产及使用,对生态系统造成了持久性破坏。同时,未完全降解的抗生素在环境中逐步积累,导致抗生素抗性基因（ARGs）的富集,对环境造成极大的威胁,因此亟待开发经济、高效且可削减ARGs的抗生素处理方法。零价铁（ZVI）因廉价、易操作、不产生二次污染,被广泛用于含难降解污染物的污水处理过程,并在抗生素废水的处理中进行了广泛研究。本文从ZVI及其耦合技术对抗生素的作用机制与ZVI对厌氧消化的影响等方面,综述ZVI及耦合技术在处理抗生素废水中的应用。文章指出,ZVI主要通过产生羟基自由基（·OH）氧化降解抗生素,此外ZVI被腐蚀后形成的氢氧化物、氧化物也可吸附去除大量抗生素。零价铁-光芬顿与零价铁-电芬顿耦合工艺分别通过光能与电能促进·OH的产生,并实现Fe²⁺的循环利用。ZVI耦合厌氧生物处理过程中,ZVI可优化微生物群落,提高酶活性,从而促进厌氧消化降解抗生素,并削减部分ARGs。针对以上工艺特点,合成廉价高效的ZVI材料、探索ZVI对厌氧消化过程中ARGs的削减机制将是ZVI及其耦合技术强化抗生素废水处理的研究重点。     

Performance of a ZVI‐UASB reactor for azo dye wastewater treatment

BACKGROUND: Zero valent iron (ZVI) is expected to be helpful for creating an enhanced anaerobic environment that might improve the performance of the anaerobic process. Based on this idea, a ZVI packed upflow anaerobic sludge blanket reactor (ZVI‐UASB) was developed to enhance azo dye wastewater treatment. RESULTS: The ZVI‐UASB reactor was less influenced by a decrease in the operational temperature from 35 °C to 25 °C than a reference UASB reactor that did not contain ZVI. In addition, chemical oxygen demand (COD) and color removal efficiencies of the ZVI‐UASB reactor at an HRT of 12 h exceeded those of the reference reactor at an HRT of 24 h. The hydraulic circulation in the ZVI bed enhanced the function of ZVI so that it improved the COD and color removal efficiencies. Moreover, fluorescence in situ hybridization experiments revealed that the abundance of Archaea in the sludge of the ZVI bed was significantly higher than that at the reactor bottom, which made the reactor capable of greater COD removal under low temperature and short HRT conditions. CONCLUSION: This ZVI‐UASB reactor could adapt well to changes in the operational conditions during wastewater treatment. Copyright © 2010 Society of Chemical Industry     

Reductive transformation and dechlorination of chloronitrobenzenes in UASB reactor enhanced with zero‐valent iron addition

BACKGROUND: Zero‐valent iron (ZVI) is increasingly being applied in biological wastewater treatment to enhance the conversion of various contaminants. The objective of this present study was to investigate the effect of ZVI on the anaerobic biotransformation and dechlorination of chloronitrobenzenes (3,4‐DClNB and 4‐ClNB). Experiments were conducted in two upflow anaerobic sludge blanket (UASB) reactors, one (R2) with 30 g L^?1 ZVI added, and the other (R1), serving as control reactor. RESULTS: ZVI‐based anaerobic granular sludge (ZVI‐AGS) composed of bacteria associated with precipitated FeCO₃ and FeS was successfully developed within 5 months in reactor R2. ZVI addition obviously enhanced 3,4‐DClNB transformation and dechlorination efficiencies under high 3,4‐DClNB loads, and further promoted dechlorination of 4‐chloroaniline (4‐ClAn) to aniline. Compared with the AGS formed in R1 reactor, iron and its corrosion products were observed and colonized with anaerobes such as methanothrix in ZVI‐AGS, and the specific transformation rates of 3,4‐DClNB and 4‐ClNB using ZVI‐AGS were improved by 34.0% and 64.4%, respectively. Furthermore, ZVI‐AGS provided higher 3,4‐dichloronailine and 4‐ClAn dechlorination efficiency than AGS. Abiotic transformation of ClNBs by ZVI, appropriate concentration of iron corrosion products, lower redox potential and greater hydrogen production were the main factors providing enhanced transformation and dechlorination of ClNBs in the UASB reactor. CONCLUSION: Addition of ZVI to a UASB reactor enhanced the reductive transformation and dechlorination of ClNBs. It provides a feasible proposal for the design and optimization of a high‐rate anaerobic wastewater treatment technique for industrial wastewater. Copyright © 2010 Society of Chemical Industry     

响应曲面法分析零价铁对普施安蓝H-5R脱色的影响因素

该文分别从零价铁（zVI）投加量、粒径、pH值、盐浓度、摇床摇速对偶氮染料普施安蓝H-5R进行脱色速率研究,并通过响应曲面进行试验优化。结果表明在初始染料溶液浓度为200mg／L时,最适投加量为1．5g／L,脱色速率随着粒径和摇床摇速增大而升高,中性和偏酸条件下pH影响不大,高浓度盐可以增加染料的脱色。响应曲面法（RSM）结果还表明不同影响因素之间存在相互作用,从而影响染料脱色。     

湿式过氧化氢催化氧化降解喹啉及其机理

采用浸渍法制备了负载型铜铁氧化物催化剂,并以喹啉为目标污染物,建立了湿式过氧化氢催化氧化(CWPO)体系.研究了反应温度、初始pH、H₂O₂和催化剂投加量对喹啉去除效果的影响,并分析了CWPO体系中 的作用及喹啉的降解路径.结果表明,CWPO对喹啉具有很好的去除效果,反应30 min喹啉的去除率可达到100%,反应60 min矿化率可达到88.34%.确定了最佳反应温度为80℃,初始pH为7,H₂O₂和催化剂投加量分别为29.15 mmol·L^-1和4 g·L^-1. 氧化在CWPO降解喹啉体系中起主导作用,其平均产生速率为1.69×10^-6 mmol·L^-1·min^-1.推测了CWPO降解喹啉的4种可能路径,在中性和酸性条件下,分别生成以吡啶环或苯环为主的中间产物.     

过硫酸盐强化零价铁还原去除硝基苯的实验研究

考察了过硫酸盐（PS）强化零价铁（ZVI）对水中硝基苯去除的性能。结果表明在单纯利用ZVI还原去除硝基苯过程中,初始pH 3.0时初期去除硝基苯速率较快,初始pH 4.0～7.0时随pH的升高反应速率减慢,而ZVI投量的增加对去除速率有较大提升作用。向体系中投加PS能显著促进零价铁去除硝基苯的速率,在达到相同去除效果的情况下,外加PS的成本远远小于提升ZVI投量所引起的成本增加。综合固体产物的XRD表征得知,PS提高ZVI去除硝基苯的效果主要是通过促进ZVI的腐蚀和改变ZVI腐蚀产物的种类来实现。通过FTIR表征可知,外加PS仅对硝基苯去除过程起加速作用,而不改变其还原路径。GC-MS的结果则验证了硝基苯被ZVI/ZVI-PS降解的主要产物为苯胺。     

超声波/零价铁协同降解硝基苯的机理

采用正交试验考察初始pH值、铁屑投加量及超声波功率对超声波协同零价铁降解硝基苯的影响大小及确定最佳反应条件,并探讨了降解过程的动力学规律.结果表明,降解率随铁屑投加量及超声波功率的增加而增大,随初始pH值的增加而变化不大.超声波与零价铁联用降解硝基苯具有明显的协同作用,协同因子为4.96,且降解过程符合拟一级反应动力学...     

钻井废弃泥浆中CMC的协同降解方法研究

提出了一种降解石油废弃泥浆中羧甲基纤维素钠(CMC)的UV/Fenton-TiO2协同降解方法,考察了催化剂用量、pH值以及Fenton试剂用量等因素对反应的影响。结果表明,该方法降解效果显著,在紫外光照射下,30%的H2O2用量为4.00 mL,FeSO4.7H2O用量为0.3794 g,TiO2催化剂0.50 g,pH=5,完全降解浓度为60.0 mg/L,体积为2 L的CMC溶液只需15 min。该方法具有降解效率高、时间短、费用低、实验操作简单易行等特点。     

The improvement of boron-doped diamond anode system in electrochemical degradation of p-nitrophenol by zero-valent iron

Boron-doped diamond (BDD) electrodes are promising anode materials in electrochemical treatment of wastewaters containing bio-refractory organic compounds due to their strong oxidation capability and remarkable corrosion stability. In order to further improve the performance of BDD anode system, electrochemical degradation of p-nitrophenol were initially investigated at the BDD anode in the presence of zero-valent iron (ZVI). The results showed that under acidic condition, the performance of BDD anode system containing zero-valent iron (BDD-ZVI system) could be improved with the joint actions of electrochemical oxidation at the BDD anode (39.1%), Fenton's reaction (28.5%), oxidation–reduction at zero-valent iron (17.8%) and coagulation of iron hydroxides (14.6%). Moreover, it was found that under alkaline condition the performance of BDD-ZVI system was significantly enhanced, mainly due to the accelerated release of Fe(II) ions from ZVI and the enhanced oxidation of Fe(II) ions. The dissolved oxygen concentration was significantly reduced by reduction at the cathode, and consequently zero-valent iron corroded to Fe(II) ions in anaerobic highly alkaline environments. Furthermore, the oxidation of released Fe(II) ions to Fe(III) ions and high-valent iron species (e.g., FeO²⁺, FeO₄²⁻) was enhanced by direct electrochemical oxidation at BDD anode.