Contents lists available at ScienceDirect Transportation Research Part D journal homepage: www.elsevier.com/locate/trd Removal effect on stormwater runoff pollution of porous concrete treated with nanometer titanium dioxide Xiao Liang a , Suhua Cui b , Hui Li a,c, ⁎ , Ahmed Abdelhady a,d , Hanbing Wang a , Haonan Zhou a a The Key Laboratory of Road and Traffic Engineering, Ministry of Education, Tongji University, Shanghai 201804, China b School of Mechanical Engineering, Hebei University of Science and Technology, China c University of California Pavement Research Center, Department of Civil and Environmental Engineering, University of California, Davis, CA 95616, United States d Civil Engineering Depart., Faculty of Engineering, Assiut University, 71516, Egypt ARTICLE INFO Keywords: Porous concrete Nanometer titanium dioxide Zebrafish aquatic toxicity Stormwater purification ABSTRACT Development of the cities is facing many problems; one of them is runoff water pollution. On the other hand, some technologies have been applied to remove water pollution such as the pho- tocatalytic effect method using nano-titanium dioxide (nTiO 2 ). That technology exhibited a significant effect to remove various pollutants from runoff water. The use of nTiO 2 on porous concrete (TPC) considers a new technology, which is effective and clean technology to deal with the non-point source pollution. In this paper, the permeability, mechanical properties and water purification capacity of using that technology have been investigated to analyze the environ- mental effect of TPC. In addition, this study tested the environmental impact using zebrafish aquatic toxicity and alkali dissolution experimentally. Moreover, the photocatalytic oxidation reaction of TPC is exploited to detect the purification effects of three typical pollutants, i.e., methylene blue, total phosphorus, and ammonia nitrogen. At the same time, three different application methods with three different concentrations of nTiO 2 have been utilized in the porous concrete to obtain the optimum value. The removal effectiveness in pollutants is also measured, moreover the purification durability effectiveness is tested. After culturing the zebrafish embryos in the leachate of porous concrete with nTiO 2 , the hatching rate was 91.7%, which proved that this technology has little aquatic toxicity to organism and environment. The capacity of pollu- tants removing was effective and reached up to 60%-90%. Besides, porous concrete treated by nTiO 2 that was placed in actual weather for a month showed a half reduction in water pur- ification effect. 1. Introduction 1.1. Background The runoff pollution is one of the major concerns raised with the growth of cities accompanied by several problems attributed to the traditional impervious pavement (Wang et al., 2016). First and foremost, the absorption of the rainfall water through the soil beneath of pavement structure is hindered, which leads to insufficient groundwater replenishment and affects the natural water cycle. https://doi.org/10.1016/j.trd.2019.06.001 ⁎ Corresponding author at: 4800 Caoan Rd, Shanghai 201804, China. E-mail address: hli@tongji.edu.cn (H. Li). Transportation Research Part D 73 (2019) 34–45 1361-9209/ © 2019 Elsevier Ltd. All rights reserved. T