Enhanced containment of polycyclic aromatic hydrocarbons through organic modification of soils

Abstract

A methodology to enhance the containment of polycyclic aromatic hydrocarbons (PAHs) in pervious pavement systems was developed through the chemical modification of a typical Rhode Island glacial outwash soil. In addition, the PAH‐retaining capacity of different structural components of pervious pavements was evaluated using column experiments in terms of PAH retention. Two methods were used for soil amendments. The first method was a direct modification of the porous matrix using quaternary ammonium cations through an ion exchange process. The second method involved blending the soil with a commercial organoclay (PM‐199; CETCO Oil Field Services). These amendments successfully increased the soil's fraction of organic carbon (foc) by at least 70%. To quantify the efficiency of these amended soils to sorb PAHs, a series of batch isotherms and column experiments were conducted on unmodified and modified soils. These studies demonstrated that, through the synthetic modification, the sorption of PAH was increased by up to 20‐fold. The Langmuir (α, β) and Freundlich (KF, n) isotherm coefficients calculated from batch studies were higher when compared with column experiments. Overall, the organoclay‐glacial outwash blend exhibited the greatest KF value of 114.2. Breakthrough curves obtained using HYDRUS 1D were compared with measured data. The column experiments conducted on porous concrete and aggregate demonstrated that these materials have a minimal contribution to the overall containment of PAH in pervious pavement systems. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 47–54, 2014

Enhancement of Surface Runoff Quality Using Modified Sorbents

“…The PAH solutions were prepared as described elsewhere. 21 PAH standards and deuterated PAH standards were obtained from Ultra Scientific, U.S.A. Metal reference standards containing 1000 mg/L ± 1% certified cadmium, copper, lead, nickel, and zinc were obtained from Fisher Chemical. Sodium sulfate (Na 2 SO 4 ), disodium phosphate (Na 2 HPO 4 ), and sodium nitrate (NaNO 3 ) were obtained from Sigma-Aldrich.…”

“…Two common stormwater PAH compounds, acenaphthene and fluorene (purity grade of 98% or higher) were obtained from Sigma-Aldrich. The PAH solutions were prepared as described elsewhere . PAH standards and deuterated PAH standards were obtained from Ultra Scientific, U.S.A. Metal reference standards containing 1000 mg/L ± 1% certified cadmium, copper, lead, nickel, and zinc were obtained from Fisher Chemical.…”

“…Exposure to pathogens can lead to serious illness, such as gastroenteritis or cholera. , Ideally, structural BMPs should simultaneously attenuate organic, inorganic, and microbiological contaminants. However, most stormwater BMPs are only effective in treating heavy metals and petroleum hydrocarbons − through filtration and sorption. ,, They are largely ineffective in treating pathogens. − Previous studies showed that materials such as organoclays amended with quaternary ammonium compounds exhibit higher sorption for PAHs and metals. − The quaternary ammonium polymer 3-(trihydroxysilyl)­propyldimethyloctadecyl ammonium chloride (TPA) is used as a disinfectant material in environmental and medical applications such as in ceramic filters and prosthetic devices . Silver nanoparticles (AgNPs) are another well-known antimicrobial agent.…”

Recent Developments and Applications of the HYDRUS Computer Software Packages

“…The types of applications are very broad, ranging between agricultural problems evaluating different irrigation schemes, the effects of plants on the soil water balance and groundwater recharge (see Agricultural Applications section below), to many environmental applications simulating the transport of different solutes and particle‐like substances (see Transport of Particle‐Like Substances section) as well as evaluating the effects of land use and environmental changes. While many early applications focused mostly on subsurface flow processes, the relatively general formulation of the transport and reaction terms in the HYDRUS models makes it possible to simulate the fate and transport of many different solutes including nonadsorbing tracers, radionuclides (e.g., Pontedeiro et al, 2010; Matisoff et al, 2011; Merk, 2012; Xie et al, 2013), mineral N species (e.g., Li et al, 2015), pesticides (Pot et al, 2005; Dousset et al, 2007; Köhne et al, 2009b), chlorinated aliphatic hydrocarbons (e.g., Kasaraneni et al, 2014; Ngo et al, 2014), hormones (e.g., Casey et al, 2005; Arnon et al, 2008; Chen et al, 2013), antibiotics (e.g., Wehrhan et al, 2007; Unold et al, 2009; Chu et al, 2013; Engelhardt et al, 2015), explosives and propellants (e.g., Dontsova et al, 2006, 2009; Alavi et al, 2011), as well as many particle‐like substances such as viruses, colloids, bacteria, nanoparticles, and carbon nanotubes (see Transport of Particle‐Like Substances section).…”

New Antimicrobially Amended Media for Improved Nonpoint Source Bacterial Pollution Treatment

“…Therefore, introducing these materials into BMPs should not lead to an export of antimicrobials into the environment and affect microbial communities in soils. If leaching should occur, quaternary ammonium compounds have been shown to sorb to clay and other soil particles, 45,46 further minimizing the possible impact on the environment. Even though both antimicrobials are strongly sorbed to the RC, there are benefits to using TPA over AgNP.…”