Department of Civil, Water and Environmental Engineering, Shahid Beheshti University, Abbaspour Blvd., Tehran Pars, P.O. Box 16765-1719, Tehran, Iran.
Faculty of Civil Engineering, College of Engineering, University of Tehran, P.O. Box 4563-11155, Enghelab Square, Tehran, Iran.
Environ Sci Pollut Res Int. 2018 Oct;25(29):29481-29492. doi: 10.1007/s11356-018-3008-9. Epub 2018 Aug 22.
In this research, the effectiveness of using pervious concrete as a reactive barrier to decrease the concentration of nitrates in polluted water was investigated. Parameters of concrete mix design including water to cement ratio (W/C), aggregate to cement ratio (A/C), the amount of nano-silica (NS), and fine aggregates (FA) were studied based on Taguchi method. Properties of concrete such as compressive strength, density, permeability, and porosity, as well as pH measurement and the column method were carried out to assess the nitrate removal capacity of pervious concrete. Also, SEM-EDX, XRD, and FTIR were used to analyze the results. It was found that the optimum mix design in terms of nitrate removal corresponded to the mix with W/C = 0.26, A/C = 5, NS = 6%, and FA = 20%. Based on the results, it can be said that adding NS (up to 6%) and FA (up to 20%) to pervious concrete had the best influence on nitrate removal and compressive strength. Addition of NS increased the nitrate removal capacity due to increase in surface positive charges and provision of new surface functional groups.
在这项研究中，研究了使用透水混凝土作为反应性屏障来降低受污染水中硝酸盐浓度的效果。基于田口法研究了混凝土配合比设计的参数，包括水灰比（W/C）、骨料与水泥比（A/C）、纳米二氧化硅（NS）的用量和细骨料（FA）。通过抗压强度、密度、渗透性和孔隙率的测试以及柱法来评估透水混凝土的硝酸盐去除能力，并采用 SEM-EDX、XRD 和 FTIR 进行了分析。结果表明，从去除硝酸盐的角度来看，最佳的配合比设计为 W/C=0.26、A/C=5、NS=6%和 FA=20%。根据结果可以说，向透水混凝土中添加 NS（高达 6%）和 FA（高达 20%）对硝酸盐去除和抗压强度的影响最好。添加 NS 增加了表面正电荷并提供了新的表面官能团，从而提高了硝酸盐的去除能力。
