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971.
以污水处理厂剩余污泥为研究对象,污泥经酸/碱预处理(pH=3.0/pH=10.0)后,分别以FeOOH、FeCl3及Fe2O3为外加铁源,进行厌氧发酵,探究铁源对厌氧系统中蓝铁石晶体生成的影响.结果表明:FeCl3和FeOOH可以高效地被还原为Fe2+,其铁还原效率(EFe)最高为56.24%~80.10%,且酸处理效果优于碱处理(3.00%~13.31%),而Fe2O3的EFe相对较低,最高分别为31.94%(pH=3.0)和50.1%(pH=10.0).FeOOH和Fe2O3的投加,可促进胞外聚合物(EPS)中蛋白质含量的提升,增强胞外电子传递能力,但Fe2O3因其结晶度高,阻碍了铁还原微生物对铁源的利用,导致铁还原效率低.上清液PO43-浓度、污泥Fe-P比例与EFe呈负相关,EFe越高则PO 相似文献
972.
973.
研究Fe(Ⅲ ) -邻氯苯基荧光酮络合吸附波发现 ,Fe(Ⅲ )与邻氯苯基荧光酮在pH为 10 .7的氨 -氯化氨缓冲溶液中形成紫色络合物 ,并于 - 0 .70V左右产生灵敏的络合吸附波。研究表明 ,Fe(Ⅲ )与配位体络合比为 1∶2 ,K稳 为 5 .4× 10 12 ,Fe(Ⅲ )浓度在 0 .8- 2 4μg/L和 2 4- 72 μg/L分段呈线性关系。应用电化学分析手段对其机理进行了研究 ,并将此法用于头发中微量铁的测定 相似文献
974.
The effects of nano-scale and micro-scale zerovalent iron (nZVI and mZVI) particles on general (dehydrogenase and hydrolase) and specific (ammonia oxidation potential, AOP) activities mediated by the microbial community in an uncontaminated soil were examined. nZVI (diameter 12.5 nm; 10 mg g−1 soil) apparently inhibited AOP and nZVI and mZVI apparently stimulated dehydrogenase activity but had minimal influence on hydrolase activity. Sterile experiments revealed that the apparent inhibition of AOP could not be interpreted as such due to the confounding action of the particles, whereas, the nZVI-enhanced dehydrogenase activity could represent the genuine response of a stimulated microbial population or an artifact of ZVI reactivity. Overall, there was no evidence for negative effects of nZVI or mZVI on the processes studied. When examining the impact of redox active particles such as ZVI on microbial oxidation-reduction reactions, potential confounding effects of the test particles on assay conditions should be considered. 相似文献
975.
A new technique for the separation and pre-concentration of dissolved Fe(III) from the ligand-rich aqueous system is proposed. A solid phase extraction (SPE) system with an immobilized macrocyclic material, commonly known as molecular recognition technology (MRT) gel and available commercially, was used. Synthetic Fe(III) solution in aqueous matrices spiked with a 100-fold concentration of EDTA was used. Dissolved iron that was ‘captured’ by the MRT gel was eluted using hydrochloric acid and subsequently determined by graphite furnace atomic absorption spectrometry. The effect of different variables, such as pH, reagent concentration, flow rate and interfering ions, on the recovery of analyte was investigated. Quantitative maximum separation (∼100%) of the dissolved Fe(III) from synthetic aqueous solutions at a natural pH range was observed at a flow rate of 0.2 mL min-1. The extraction efficiency of the MRT gel is largely unaltered by the coexisting ions commonly found in natural water. When compared with different SPE materials, the separation performance of MRT gel is also much higher. 相似文献
976.
Nanoscale zero valent iron (NZVI) was immobilized on the organobentonite (CTMA-bent), so as to enhance the reactivity of NZVI and prevent its aggregation. This novel composite (NZVI/CTMA-Bent) was characterized by transmission electron microscope and X-ray diffraction. Good dispersion of NZVI particles on the bentonite was observed. Its performance on removing pentachlorophenol (PCP) was investigated by batch experiments. Results showed NZVI/CTMA-Bent could rapidly and completely dechlorinate PCP to phenol with an efficiency of 96.2%. It was higher than the sum (54.5%) of reduction by NZVI (31.5%) and adsorption by CTMA-Bent (23.0%) separately. The kinetic studies indicated the removal rate of PCP was positively related to the adsorption. We proposed that the adsorption of PCP by CTMA-Bent enhanced the mass transfer of PCP from aqueous to iron surface. Besides, NZVI/CTMA-Bent exhibited good stability and reusability, and CTMA-Bent could also reduce the amount of iron ions released into the solution. 相似文献
977.
978.
采用酸浸法处理高硅铁尾矿,制备工业原料Fe2O3和SiO2微粉.最佳工艺条件为:反应温度100℃,反应时间90 min,铁尾矿中位粒径6.19 μm,盐酸体积分数60%.在上述最佳条件下,制备的SiO2产率(所得产品中SiO2的质量占原铁尾矿中SiO2质量的比例,下同)达98.2%,品质达到YB/T 115-2004《... 相似文献
979.
研究Fe/Cr6+比值和不同浓度的NO3-、Cl-和SO42-对金属铁去除Cr6+效果的影响。结果表明,金属铁对水中Cr6+有很好的还原去除效果;当金属铁的使用量为Cr6+量的1/2 000时,铁对Cr6+的去除效果较差且易失去活性,而当金属铁的使用量为Cr6+量的8 000倍时,铁对Cr6+的去除效果较好且其活性的持续性较强;3种阴离子(NO3-、Cl-和SO42-)均能提高金属铁对重金属Cr6+去除率,但在反应初期,3种阴离子对金属铁去除水中Cr6+影响的差异性不显著,随着反应时间的增加,SO24-对金属铁去除水中Cr6+的促进作用逐渐强于Cl-和NO3-,3种阴离子对金属铁去除Cr6+效率促进作用的大小顺序为SO24-〉Cl-〉NO3-。 相似文献
980.
对某钢厂康斯迪电炉爆炸事故现场进行了调查,分析了引起电炉爆炸的原因,得出该事故是由于废钢铁中混有爆炸性物质的结论,提出钢厂对回炉熔炼用的废钢铁要严格分类、筛选,防止此类事故再次发生. 相似文献