Fe3O4纳米磁性微粒对全氟辛烷磺酸盐的吸附

采用共沉淀法合成Fe3O4纳米磁性颗粒,用透射电子显微镜(TEM)、X射线衍射仪(XRD)以及振动样品磁强计(VSM)对Fe3O4纳米磁性颗粒的粒径、形貌和磁性进行表征并研究Fe3O4纳米磁性微粒对全氟辛磺酸盐的吸附。结果表明:在PFOS初始浓度4 mg/L,pH为3,反应时间24 h,Fe3O4纳米磁性微粒投加量1.25 g/L,对全氟辛磺酸盐去除率达到90%。Fe3O4纳米磁性微粒对PFOS的吸附符合Freundlich吸附方程。     

农业生态与土壤环境中铁元素的关系

论述了铁元素的地球化学特征及其分布 ,与铁元素有关的主要作物分类、作物与铁元素的关系以及影响铁元素有效态的因素 ,铁肥的种类和施用方法与效果     

Removal of Alachlor from Water by Catalyzed Ozonation in the Presence of Fe2+, Mn2+, and Humic Substances

Abstract

The effects of Fe(II), Mn(II) and humic substances on the catalyzed ozonation of alachlor, an endocrine disruptor were investigated. Results revealed that small amounts of Fe(II), Mn(II), and humic substances could enhance the ozonation of alachlor, but larger amounts of them would retard the oxidation. These results were successfully identified by an electron paramagnetic resonance (EPR) spectroscopy/spin-trapping method that could quantify hydroxyl radicals. The production of hydroxyl radicals was obviously increased with the increasing of Fe(II) concentration, which contributed to enhance ozonation at low concentrations. But the excess Fe(II) consumed some of the radicals when it was added at a higher concentration (1.5 mg/L). However, no obvious radicals were observed when a different amount of Mn(II) was used, and the catalytic ozonation of alachlor by Mn(II) mainly followed the mechanism of “active sites created on the surface of MnO₂.” The radical pathway was followed when alachlor was ozonated with different concentrations of humic substances because of its radical initiating, promoting, and inhibiting effects.     

Dissimilatory reduction of Fe~III (EDTA) with microorganisms in the system of nitric oxide removal from the flue gas by metal chelate absorption

IntroductionThecombustionoffossilfuelsgeneratesSO2 andNOxpollutantswhichcauseairpollutionandacidrain .Existingfluegasdesulfurization(FGD)scrubbersinvolvelimestoneprocesses,whichareefficientforcontrollingSO2 emission ,butareincapableofremovingalmostwater i…     

水厂快滤过程动态模型的建立与识别

作为构建国家饮用水安全风险评估框架的一部分 ,开发了一种用于风险评估的水厂快滤过程动态模型。该模型通过对扩散、生物降解、吸附、脱附和反冲洗等过程的概化 ,建立了可模拟不同污染物的普适性水厂快滤动态模型。本模型以实际水厂的现场监测数据为依托 ,以CODMn、氨氮、浊度和微生物为例对模型进行了率定。结果表明模型较好地吻合了实际快滤过程。该模型将可有效地应用于评估不同过滤过程去除各种污染物的风险 ,以及识别饮用水安全风险关键控制点的工作。     

Synchronous-scan fluorescence spectra of Chlorella vulgaris solution

The characterization of the Chlorella vulgaris solution was carried out using synchronous-scan spectroscopy. The range of concentration of algae and Fe(III) in aqueous solutions were 5 × 10⁸–8 × 10⁹ cells l⁻¹ and 10–60 μM, respectively. Effective characterization method used was synchronous-scan fluorescence spectroscopy. The wavelength difference (Δλ) of 90 nm was maintained between excitation and emission wavelengths; 90 nm was found to be the best Δλ for effective characterization of Chlorella vulgaris solution with or without quencher species (e.g., Fe(III), humic acid (HA)) for the first time. The peak was observed at about EX 236.6 nm/EM 326.6 nm for synchronous-scan fluorescence spectra. The fluorescence quenching of algae in system of algae–Fe(III)–HA was studied using synchronous-scan spectroscopy for the first time. Fe(III) was clearly the effective quencher. The relationship between I₀/I (quenching efficiency) and c (concentration of Fe(III) added) was a linear correlation for the algae solution with Fe(III). Also, Aldrich humic acid was found to be an effective quencher. pH effect on synchronous-scan fluorescence intensity of algal solution with Fe(III) and/or HA was evident.     

Temporal variability of bioavailable Cd,Hg, Zn,Mn and Al in an upwelling regime

Monthly variability of Cd, Hg, Zn, Mn and Al concentrations in mussels (Mytilus californianus) soft tissue and brown seaweed (Macrocystis pyrifera) was studied at a pristine rocky shore off San Quintin Bay, Baja California, México. The results were related to climatic and hydrographic conditions and to the physiological state of the mussels (condition index) by correlation analysis and principal component analysis (PCA). A "normalization" to account for the variability induced by the physiological state of the mussel was performed. The PCA was performed in two ways to relate the environmental variables and the condition index to: (1) the metal concentrations in mussels, and (2) the "normalized" mussel concentrations. The association of the variability of Cd with the upwelling season was revealed in both PCAs. The temporal variability of this metal in mussels was highly correlated to that in seaweed, suggesting that the dissolved phase determined the variability of Cd in mussels. However, for Hg, Zn, Mn and Al the results from both PCAs were different. The first PCA showed the relationship of these metals to pluvial precipitation and to the condition index. The PCA for the normalized mussel concentrations showed that, after eliminating the effect of the condition index, only Al was related to pluvial precipitation. Manganese, and to a less degree Zn, were related to these metals in seaweed. Because zinc is an essential element in mussels, some regulation of their internal concentrations is likely. Mercury was not detected in seaweed, but because of its reactive nature, it is not expected that the dissolved fraction could be a significant pathway; therefore, it can be concluded that its temporal variability was determined by the variability in the condition index only.     

制备条件对Fe/AC脱硫活性的影响

考察了Fe/AC脱硫剂的煅烧温度和载铁量对脱硫活性的影响，并对脱硫剂进行了X－射线衍射（XRD）和EXAFS表征，结果表明：经250℃煅烧的Fe/AC脱硫剂具有最高的脱硫活性，200℃煅烧，前驱体未完全分解，高于250℃煅烧，会使活性组分聚集，二者均导致脱硫活性降低。Fe/AC脱硫剂适宜的载铁量为3．5－14％，大于14％担载量使脱硫剂微孔堵塞严重，致使其脱硫活性下降。     

17O-NMR研究Al(Ⅲ),Fe(Ⅲ)盐对水缔合的影响

测试了AlCl3,Al2(SO4)3,FeCl3,Fe2(SO4)3等对水的^17O-NMR化学位移和半峰宽的影响。并利用水^17O-NMR化学位移和半峰宽的变化与氢键的关系，分析了AlCl3,Al2(SO4)3。FeCl3,Fe2(SO4)3等对水缔合的影响，研究表明，AlCl3,Al2(SO4)3。FeCl3,Fe2(SO4)3等对水缔合有促进作用。且Fe^3 对水缔合的作用大于Al^3 。     

雷州无瓣海桑群落7种元素的生物累积和循环

在雷州市附城镇岚北人工生态恢复的 7a生无瓣海桑群落生物量调查的基础上 ,对所采集的无瓣海桑进行了植物体各组分样品的灰分和元素含量测定与循环分析 ,结果表明 :无瓣海桑植物体不同组分的灰分含量范围为 2 .2 7%～ 2 6 .4 1% ,以细根的含量最高 ,枯枝的含量最低 .植物体各组分中 7种元素质量分数范围分别为K 0 .11%～ 1.5 6 % ,Na0 .11%～ 1.6 6 % ,Ca 0 .2 0 %～ 2 .6 6 % ,Mg 0 .15 %～ 1.5 9% ,Fe 0 .0 4× 10 -3 ～ 9.6 4× 10 -3 ,Zn 0 .0 5× 10 -4～ 1.0 3× 10 -4,Cu0 .16× 10 -5～ 1.5 0× 10 -5.其加权平均的富集系数为 0 .0 5～ 9.70 ,其中Ca >K >Cu >Na >Mg>Zn >Fe .群落现存生物量中的累积储量分别为K 10 9.76gm-2 ,Ca 138.89gm-2 ,Na 86 .5 7gm-2 ,Mg 81.0 7gm-2 ,Fe 13.139gm-2 ,Zn 0 .4 83gm-2 ,Cu 0 .10 8gm-2 .群落 2 0 0 1年的元素存留累积储量分别为Ca4 1.6 8gm-2 ,K 37.2 4gm-2 ,Mg 2 7.33gm-2 ,Na2 5 .5 6gm-2 ,Fe 4 .2 75gm-2 ,Zn 0 .188gm-2 ,Cu 0 .0 39gm-2 .2 0 0 1年归还量分别为Ca 2 8.5 9gm-2 ,K 16 .83gm-2 ,Mg 12 .0 7gm-2 ,Na 11.5 8gm-2 ,Fe 0 .916gm-2 ,Zn 0 .14 1gm-2 ,Cu 0 .0 2 6gm-2 .年吸收量分别为Ca 70 .2 7gm-2 ,K 5 4 .0 7gm-2 ,Mg 39.4 0gm-2 ,Na 37.1