Evaluation of the Engineering Properties of Powdered Activated Carbon Amendments in Porous Asphalt Pavement

Shengyi Huang,Chenju Liang

doi:10.3390/pr9040582

Abstract

Porous asphalt pavement (PAP) with a high drainage capacity was modified with powdered activated carbon (PAC) addition to produce permeable reactive pavement (PRP), which may exhibit the potential to reduce environmental non-point source (NPS) pollution. The experimental design mixtures used to produce and test the PRP incorporated with PAC (named PRP-PACs) were conducted as follows: first, the PACs were initially tested to determine their feasibility as an additive in PAP; second, different amounts of PAC were added during the preparation of PAP to produce PRP-PAC, and the unregulated and regulated physical characteristics for the mechanical performance of PRP-PACs were examined to ensure that they meet the regulatory specifications. Third, the aqueous contaminants, namely benzene, toluene, ethyl-benzene, and xylene (BTEX), column adsorption tests were preliminarily conducted to demonstrate their adsorption capacities compared to traditional PAP. The compositions of 0.8% and 1.5% PAC (by wt.) (PRP-PAC08 and PRP-PAC15) met all the regulated specifications. As compared to PAP, PRP-PAC08 exhibited higher BTEX adsorption capacities than PAP, which were 47%, 49%, 29% and 2%. PRP-PAC08 showed both superior physical properties and adsorption performance than PAP and may be recommended as an engineering application that reduces the potential for NPS contamination of air, soil, groundwater, and surface water.

Highlights

Non-point source (NPS) pollution from traffic or industry, such as volatile organic compounds (e.g., benzene, toluene, ethyl-benzene, and xylenes (BTEX)), are frequently detected in ambient air and rain (the tabulated literature-reported data pertaining to BTEX concentrations in ambient air and rain are shown in Tables S1 and S2, Supplementary Materials (SM))
Their model highlighted the trend of volatile organic compound transfer in the air, which may require a control of these emissions
Since pollution originating from vehicle exhaust is one of the major NPS sources, if pollutant emissions produced while cars moving on the road could be retained by the asphalt pavement, migration of these hazardous materials could thereby be controlled

Summary

Introduction

Non-point source (NPS) pollution from traffic or industry, such as volatile organic compounds (e.g., benzene, toluene, ethyl-benzene, and xylenes (BTEX)), are frequently detected in ambient air and rain (the tabulated literature-reported data pertaining to BTEX concentrations in ambient air and rain are shown in Tables S1 and S2, Supplementary Materials (SM)). A fugacitybased model developed by Iordache et al [1] indicated the potential of BTEX transfer from point sources such as wastewater discharges into the environment. Their model highlighted the trend of volatile organic compound transfer in the air, which may require a control of these emissions. Given the growing numbers of vehicles, and increasing area of pavement, it may be beneficial to capture the pollution from vehicle exhaust on pavement, and thereby reduce the potential for these contaminants to be transported to air, soil, surface water, and groundwater. Successful control of vehicle exhaust chemicals on pavement will reduce human exposure to these compounds

Methods

Results

Conclusion