Characteristics of PAHs adsorbed on street dust and the correlation with specific surface area and TOC

Abstract

Street dust was collected from five roads with different traffic volumes in the metropolitan area of Beijing and separated into five size fractions. Concentrations of polycyclic aromatic hydrocarbons (PAHs) adsorbed on street dust in different size ranges and their correlation with specific surface area and total organic carbon (TOC) were investigated. Results show that the concentration of 16-PAHs of sieved samples ranges from 0.27 to 1.30 mg/kg for all the sampling sites. Particles smaller than 40 mum in diameter have the highest 16-PAHs concentration among all of the size ranges for street dust from the four sampling sites with vehicles running on. PAHs with three or four rings account for 68% of the overall 16-PAHs on average. Remarkable positive correlation exists between 16-PAHs concentration and specific surface area with R(2) values from 0.7 to 0.96 for the four sampling sites with vehicles running on. The relationship between the concentration of 16-PAHs and TOC is less clear.

Sources and distribution of polycyclic aromatic hydrocarbons in street dust from the Chang-Zhu-Tan Region, Hunan, China

“…These substances can be absorbed or taken in by the body through the respiratory tract and skin, and digested, absorbed, and accumulated in the human body. These harmful substances can also be washed out by precipitated water into the soil and rivers, leading to direct pollution of the urban environment (Walker et al 1999;Kim and Weber 2005;Brown and Peake 2006;Wang et al 2010). The distribution and concentration of polycyclic aromatic hydrocarbons (PAHs) coated to the dust have been paid special attention to because of their carcinogenicity, mutagenicity, and toxicity, and consequently have been put into the list of priority monitoring pollutants by the United States Environment Protection Agency (Su et al 1998;Bouzige et al 1999;Ren et al 2006;Sun et al 2008).…”

Characterization and Reuse of Residuals Collected from Street Sweeping Operations

“…The authors broke down their samples into five different size fractions including: <40 µm, 40-74 µm, 74-125 µm, 125-300 µm, and 300-500 µm. While on average the 125-300 µm size fraction made up the majority of the sample mass at 31%, they found that the particles smaller than 40 µm had the highest concentration of ∑16PAHs (Wang et al, 2010).…”

“…A number of studies looking at PAHs in both RDS as well as the soil adjacent to the road have found that some of the lowest concentrations were in the highest ADT categories considered. For instance, Wang et al (2010), took samples of RDS from roads across five different ADT classifications including 110,000 cars/day, 45,000 cars/day, 17,000 cars/day, 3,000 cars/day, and finally a walking street with zero cars/day. The authors found that the walking street with no exposure to vehicle traffic had the second highest ∑16PAH concentration of 3.4 mg/kg with the highest ∑16PAH concentration of 3.52 mg/kg being found in the 3,000 cars/day classification (Wang et al, 2010).…”

“…This greater specific surface area typically correlates with increased sorption of contaminants, like PAHs and heavy metals, to attach to (Azah, Kim, & Townsend, 2015;Gunawardana, Egodawatta, & Goonetilleke, 2014;Lau & Stenstrom, 2005;Wang et al, 2010). A number of studies have found that the majority of pollutants in RDS can be found in the smaller size fractions from the 0-300 µm range.…”

“…For instance, in a study by Wang et al (2010), the distribution of PAHs across a range of particle sizes from street dust was investigated. The authors broke down their samples into five different size fractions including: <40 µm, 40-74 µm, 74-125 µm, 125-300 µm, and 300-500 µm.…”