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431.
Jonathan W. Peterson Theresa A. O'Meara Wei Wang 《Environmental pollution (Barking, Essex : 1987)》2009,157(6):1849-1856
Raman spectroscopy was used to investigate sorption mechanisms of cephapirin (CHP), a veterinary antibiotic, onto quartz (SiO2) and feldspar (KAlSi3O8) at different pH. Sorption occurs by electrostatic attraction, monodentate and bidentate complexation. The zwitterion (CHPo) adsorbs to a quartz(+) surface by electrostatic attraction of the carboxylate anion group (-COO−) at low pH, but adsorbs to a quartz(−) surface through electrostatic attraction of the pyridinium cation, and possibly COO− bridge complexes, at higher pH. CHP− bonds to quartz(−) surfaces by bidentate complexation between one oxygen of -COO− and oxygen from carbonyl of an acetoxymethyl group. On a feldspar(+/−) surface, CHPo forms monodentate complexes between CO, and possible -COO− bridges and/or electrostatic attachments to localized edge (hydr)oxy-Al surfaces. CHP− adsorbs to feldspar(−) through monodentate CO complexation. Similar mechanisms may operate for other cephalosporins. Results demonstrate, for the first time, that Raman techniques can be effective for evaluating sorption mechanisms of antibiotics. 相似文献
432.
以改进后的双循环多级水幕塔对烟气进行除尘脱硫性能的研究,利用双循环不同pH值控制的优点和多级水幕的效果,增加气液接触面积和传质动力,提高SO2吸收效果。在正交实验的最佳运行工况基础上,实验从烟气流量、上下两段pH、L/G和SO2进气浓度等方面进行单因素研究。结果表明,除尘效率维持在98%以上,进气SO2浓度在5 000 mg/m3以下时,脱硫率在93%以上。上段pH值为6、下段pH值为5、L/G在15左右的脱硫效率和运行工况最佳,无结垢现象发生。改进后的吸收塔具有良好的应用前景,实验结果对于现场脱硫设备的调试和运行有很好的参考价值。 相似文献
433.
R.A. Ligero J. VidalM.J. Meléndez M. HamaniM. Casas-Ruiz 《Journal of environmental radioactivity》2009
A previous study on seabed sediments of the Bay of Cadiz (SW of Spain) enabled us to identify several relations between sedimentological variables and activity concentrations of environmental radionuclides such as 137Cs, 226Ra, 232Th and 40K. In this paper the study has been extended to a large neighbouring inter-tidal area in order to establish if the above mentioned models can be generalized. As a result we have determined that the measured activity concentrations are closely to the values predicted by the theoretical models (correlation coefficient range = 0.85–0.93). 相似文献
434.
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436.
探讨了用石墨炉原子吸收法测定无铅汽油中的铅。系统地研究了测定波长、测定浓度对测定方法的影响。提出了高浓度石墨炉原子吸收法测定无铅汽油中铅的方法。铅的检出限为 0 .0 0 5 mg/L,相对标准偏差 ( RSD,n=1 1 )在 1 .9%~2 .0 %之间 ,加标回收率在 95 .5 %~ 99.5 %之间 相似文献
437.
介绍了石 灰乳吸收法治理含氯废气的原理、工艺流程、工艺参数以及工艺设备。通过治理工程实际运行,结果表明:该工艺回收了废气中的有机氯化物,治理效果明显,且工艺设备 投资少,运转费用低,经济效益显著,因此,推广前景广阔。 相似文献
438.
439.
Mohammad Khan Jamali Tasneem Gul Kazi Mohammad Bilal Arain Hassan Imran Afridi Nusrat Jalbani Jameel A. Baig Abdul Niaz 《The Environmentalist》2008,28(4):366-375
The recycling of sewage sludge on agriculture land represents an alternative, advantageous, disposal of this waste material.
The aim of the present study was to evaluate the feasibility of using industrial sewage sludge, produced in Pakistan, as a
fertiliser. Agricultural soil amended with 25% (w/w) sewage sludge with or without lime treatment was used for growing a variety
of sorghum (PARC-SS-1). The mobility of the heavy metals (HMs) (Cd, Cu, Cr, Ni, Pb and Zn) and metalloid (As) in the untreated
industrial waste water sewage sludge (UIWS) samples were assessed by applying a modified BCR (Community Bureau of Reference)
sequential extraction procedure. The single extraction procedure comprised of the application of mild extractant (CaCl2) and water for the estimation of the proportion of easily soluble metal fractions. The precision and accuracy of BCR was
evaluated by using a certified reference material of soil amended with sewage sludge BCR 483. The plant available metal contents,
as extracted by the deionised water and 0.01 M CaCl2 solution and exchangeable fraction of BCR sequential, decreased with lime application in the range of 10–44% for As, Cr,
Ni, Pb and Zn, except in the cases of Cd and Cu, where their mobility was increased by 10% and 24%, respectively. Sludge amendment
enhanced the dry weight yield of sorghum and the increase was more obvious after liming up to 25%. The uptake of HMs were
lower in test samples (3.2–21.8%), except for Cu and Cd, which was higher (4%), while they were below the permissible limit
of these metals. The present experiment demonstrates that liming was important in factors facilitating the growth of sorghum
in sludge-amended soil. 相似文献
440.
Kazuhiro Okabe Hiroshi Mano Yuichi Fujioka 《International Journal of Greenhouse Gas Control》2008,2(4):485
A novel process for carbon dioxide (CO2) separation, which was named a membrane flash process, was developed to realize an energy-saving technology and to substitute it for a conventional regenerator. The electric energy for CO2 recovery in a membrane flash process using aluminum oxide and diethanolamine was lower than the thermal energy of the conventional chemical absorption process. Flashing at elevated temperature by the low temperature energy significantly reduced the electric energy and required much less membrane area. This process has potentiality of low cost capture of CO2 when the low temperature energy, which is not available for other purposes, can be utilized to elevate flashing temperature. 相似文献