Oil spill cleanup by natural fibers: a review

Purpose In recent years, oil spill pollution has become one of the main problems of environmental pollution. Recovering oil by means of sorbent materials is a very promising approach and has acquired more attention due to its high cleanup efficiency. Compared to synthetic fibrous sorbents, the use of natural fibers in oil spill cleanups offers several advantages including environmental friendliness, degradable features and cost-effectiveness. Therefore, studies on developing sorbents using natural fibers for oil spill cleanup applications have become a research hotspot. Design/methodology/approach This paper reviews the work conducted by several researchers in developing oil sorbents from fibers such as cattail, nettle, cotton, milkweed, kapok, populous seed fiber and Metaplexis japonica fiber. Some featured critical parameters influencing the oil sorption capacity of fibrous substrates are discussed. Oil sorption capacity and reusability performance of various fibers are also discussed. Recent developments in oil spill cleanups and test methods for oil sorbents are briefly covered. Findings The main parameters influencing the oil sorption capacity of sorbents are fiber morphological structure, fiber density (g/cc), wax (%), hollowness (%) and water contact angle. An extensive literature review showed that oil sorption capacity is highest for Metaplexis japonica fiber followed by populous seed fiber, kapok, milkweed, cotton, nettle and cattail fiber. After use, the sorbents can be buried under soil or they can also be burned so that they can be vanished from the surface without causing environmental-related issues. Originality/value This review paper aims to summarize research studies conducted related to various natural fibers for oil spill cleanups, fiber structural characteristics influencing oil sorption and recent developments in oil spill cleanups. This work will inspire future researchers with various knowledge backgrounds, particularly, from a sustainability perspective.

Obtaining effective oil sorbents based on chemical industry waste for water treatment

It was proposed new technologies for producing effective oil sorbents based on chemical industry waste. It was shown the possibility of using PET waste as a binder in the produc- tion of oil sorbents with specific properties (hydrophobicity, oleophilicity, magnetic proper- ties) using thermally expanded and oxidized graphite (TEG and OG) and ferritized iron- containing galvanic sludge (FGS). The presence of iron ions in the galvanic sludge allows one to obtain magnetite and ferrites during ferritization, which leads to the appearance of magnetic properties in FGS, established using a vibration magnetometer, the saturation induction was ~ 0.02 T. Electroplating sludge was carried out at t ≈ 1000 oC and τ = 1.5 hr with preliminary mechanical activation. The physicomechanical, chemical, and sorption properties of the obtained oil sorbents (bulk density, abrasion, grindability, particle size distribution, oil capacity, moisture capacity, wettability, buoyancy, specific surface area, chemical composition, adsorption capacity of materials under static and dynamic conditions) are studied. It was found that sorption ma- terials have 100% buoyancy, are highly active in cleaning water surface from films of oil products with different thicknesses (1–5 mm). It was shown that sorption capacity increases with increasing film thickness and reaches a maximum value at a thickness of 3 mm. The cleaning efficiency is 99.0%. It has been established that the sorption capacity of the sorption material (SM) depends on the nature of oil products, its viscosity, solubility and initial concentration in water. It is proved that the processes of sorption of oil products proceed by the physical mechanism, which can be represented as the oleophilic interaction of particles of the Sorption material and oil products, which is confirmed by the type of sorption isotherms, which are type II and IV according to the BDT theory and type L according to the Hills classification char- acteristic of polymolecular adsorption. The obtained adsorption isotherms were processed in the framework of the Langmuir and Dubinin – Radushkevich models, and the constants of the adsorption equations were calculated.

Organic Contaminant-Triggered Self-Healing Soil Mix Cut-Off Wall Materials Incorporating Oil Sorbents

Soil mix cut-off walls have been increasingly used for containment of organic contaminants in polluted land. However, the mixed soil is susceptible to deterioration due to aggressive environmental and mechanical stresses, leading to crack-originated damage and requiring costly maintenance. This paper proposed a novel approach to achieve self-healing properties of soil mix cut-off wall materials triggered by the ingress of organic contaminants. Oil sorbent polymers with high absorption and swelling capacities were incorporated in a cementitious grout and mixed with soil using a laboratory-scale auger setup. The self-healing performance results showed that 500 µm-wide cracks could be bridged and blocked by the swollen oil sorbents, and that the permeability was reduced by almost an order of magnitude after the permeation of liquid paraffin. It was shown by micro-CT scan tests that the network formed by the swollen oil sorbents acted as attachments and binder, preventing the cracked mixed soil sample from crumbling, and that the oil sorbents swelled three times in volume and therefore occupied the air space and blocked the cracks in the matrix. These promising results exhibit the potential for the oil sorbents to provide soil mix cut-off walls in organically-contaminated land with self-healing properties and enhanced durability.

INVESTIGATION OF QUALITY CHARACTERISTICS OF UNIVERSAL SORBENTS USED AT UFA REFINERIES

Determined the efficiency of use and capacity of oil absorption of natural large-dispersed hydrophilic isotropic-porous universal sorbent “Canadian Sphagnum Peat Moss” and organic finely-dispersed coarse hydrophilic isotropic-porous sorbents: “Profsorb”, “Lessorb”, “STsN-2” in relation to various environments and products of oil refining. The quantitative analysis method was carried out according to GOST 33627-2015. The obtained results showed that the high absorption capacity when bottling gasoline, kerosene and drying oil sorbents “Lessorb” and “STsN-2”, when bottling oil sorbents No. 1, “Lessorb” and “STsN-2”, when bottling benzene, p-xylene and o-xylene – sorbents “Profso”, “STsN-2”.