Theoretical and experimental investigation on the removal of oil spill by selective sorbents

Application of Sorbents for Oil Spill Cleanup Focusing on Natural-Based Modified Materials: A Review

Conventional synthetic sorbents for oil spill removal are the most widely applied materials, although they are not the optimal choices from an economic and environmental point of view. The use of inexpensive, abundant, non-toxic, biodegradable, and reusable lignocellulosic materials might be an alternative to conventional sorbents, with obvious positive impact on sustainability and circular economy. The objective of this paper was to review reports on the use of natural-based adsorbing materials for the restoration of water bodies threatened by oil spills. The use of raw and modified natural sorbents as a restoration tool, their sorption capacity, along with the individual results in conditions that have been implemented, were examined in detail. Modification methods for improving the hydrophobicity of natural sorbents were also extensively highlighted. Furthermore, an attempt was made to assess the advantages and limitations of each natural sorbent since one material is unlikely to encompass all potential oil spill scenarios. Finally, an evaluation was conducted in order to outline an integrated approach based on the terms of material–environment–economy.

Absorption Behavior of Graphene Nanoplates toward Oils and Organic Solvents in Contaminated Water

In this work, graphene nanoplates (GNPs) were successfully prepared via direct chemical exfoliation from natural graphite. The properties of prepared GNPs were investigated using scanning electron microscopy and X-ray diffraction. The resultant GNPs had a low bulk density of 0.015 g mL−1, C content of 99.6%, a lateral diameter of 5–15 µm, and thickness of <15 nm, respectively. The absorption capacity of the GNPs for a range of oils and organic solvents including pump oil, polydimethylsiloxane oil (PDMS), dioctyl phthalates (DOP) oil, olive oil, bean oil, mazut oil, xylene, ethanol, and ethylene glycol (EG) was evaluated. The effects of the sorption conditions such as the absorption time (sorption kinetics), temperature, and aging manner (static, stirring, and ultrasonic) on the absorption capability of the GNPs were also investigated. It could be seen that the GNPs revealed extremely high absorption capacities for oil and organic solvents, reaching 21–42 times their own weight only after 2 min of absorption at room temperature, which were found to be much higher than those shown by various commercially available absorbents.

Sorption and removal of crude oil spills from seawater using peat-derived biochar: An optimization study

Bio-based sorbents are preferred over chemical-based methods for the clean-up of crude oil spills in marine environments because bio-based sorbents are more environmentally friendly. This study evaluates the use of peat-derived biochar (PB) as a bio-sorbent for the sorption and removal of crude oil spills from synthetic seawater. Experiments were designed to determine the effect of four operating factors (PB/crude oil contact time, PB dosage, oil dosage, and temperature) on two performance indicators (crude oil sorption capacity of PB, S, and oil removal efficiency, R%). Regression models containing linear, quadratic, and two-way interaction terms were developed to predict S and R% from the four factors. Response surface methodology (RSM) was employed to identify the optimum conditions for the sorption and removal of crude oil from seawater. The performance indicators were predicted with a high degree of accuracy, i.e. with coefficient of determination (R²) values exceeding 90%. The optimum values of S and R% were estimated to be 32.5 g of crude oil/g of sorbent and 91.2% respectively. These optimum values were attained after 70 min of PB/crude oil contact time and at a temperature of 45 °C. The spent sorbent maintained its performance after three cycles of regeneration and reuse, suggesting that the material is reusable.