Soluble hydrocarbons uptake by porous carbonaceous adsorbents at different water ionic strength and temperature: something to consider in oil spills

Abstract

Nowadays, petrochemical operations involve risks to the environment and one of the biggest is oil spills. Low molecular aromatics like benzene, toluene, and naphthalene dissolve in water, and because of their toxicological characteristics, these produce severe consequences to the environment. The oil spill cleanup strategies are mainly designed to deal with the heavy fractions accumulated on the water surface. Unfortunately, very limited information is available regarding the treatment of dissolved fractions.A commercial (Filtrasorb 400) and modified activated carbons were evaluated to remove benzene, toluene, and naphthalene from water, which are the most soluble aromatic hydrocarbons, at different ionic strengths (I) and temperatures (0-0.76 M and 4-25 °C, respectively). This allowed simulating the conditions of fresh and saline waters when assessing the performance of these adsorbents. It was found that the hydrocarbons adsorption affinity increased 12 % at a I of 0.5 M, due to the less negative charge of the adsorbent, while at a high I (≃0.76 M) in a synthetic seawater, the adsorption capacity decreased 21 % that was attributed to the adsorbent's pores occlusion by water clusters. Approximately, 40 h were needed to reach equilibrium; however, the maximum adsorption rate occurred within the first hour in all the cases. Moreover, the hydrocarbons adsorption and desorption capacities increased when the temperature augmented from 4 to 25 °C. On the other hand, thermally and chemically modified materials showed that the interactions between adsorbent-contaminant increased with the basification degree of the adsorbent surface.

Effect of the Water Type, the Inoculum and the Concentration on the Phenanthrene Degradation in a Fluidized Bed Reactor Using Activated Charcoal as a Bacterial Support

“…The support materials used in bioreactors play an important role. Among the most used are perlite and sepiolite (Arnaiz et al 2006), silica gel (Martínez & García 2012), activated charcoal (Moreno et al 2007, Flores et al 2016, and kaolinite and quartz (Gong et al 2018). However, although support materials are important, many other variables should be considered; metabolic activity, contaminant concentration in the environment, and metabolites that produce degradation (García & Peralta 2008;Rosales 2008), temperature and pH (Liu et al 2018) are important to account for in the design of bioreactors to determine the appropriate conditions for microbial activity.…”