Effective exploitation of anionic, nonionic, and nanoparticle-stabilized surfactant foams for petroleum hydrocarbon contaminated soil remediation

Contaminated environments posed serious threats to the ecosystems and their living beings. Suitable preventive approaches should be adopted for effective remediation of contaminated environments to remove or lower their health and environmentally-related hazardous aspects. Petroleum or traces of petroleum contamination from oil fields and refineries to exposed soil in the form of gasoline, petrol, diesel, and used motor oil are a rich source of potential damage to the environment. Conventional ways of treatment and management of hydrocarbon are complicated, insufficient, and expensive. Herein, we reviewed a smart approach for the removal of petroleum source contamination from exposed soil using environment-friendly chemical surfactants and nanoscale surfactant system. The host/guest complexes formation of surfactants with the hydrocarbons (hydrophobic contaminants) of soil and water by the encapsulation mechanism of hydrophobes into the (micelles) a self-assembly aggregation of surfactants. Recently, surfactants stabilized by nanoparticles (NPs) acquired more importance and popularity over surfactant alone. The persistence of diverse hydrocarbon-based contaminants and the mechanisms of removal using pristine surfactants or NP-stabilized surfactant foams are discussed with suitable examples. In summary, herein, an effort has been made to present the notable potentialities of pristine surfactants and NP-stabilized surfactant foams to remediate the petroleum hydrocarbon contaminated soil for a greener and sustainable ecosystem.

Properties and Vesicle Formation in Mixed Systems of a Branched Anionic Carboxylate Surfactant and a Cationic Surfactant

Mixtu res of the anionic surfactant AEC7-Na (branched alcohol ether carboxylate) and the cationic surfactant didecylmethylhydroxyethylammonium chloride (DEQ) were systematically investigated. The results showed that the mixtures possess synergisms. The DEQ-AEC7-Na mixture with a mass ratio of 1:1 showed the best result in terms of surface activity, wettability and emulsifying performance. However, when the mass ratio m(DEQ):m(AEC7-Na) = 8:2, the foaming ability and foam stability of the individual surfactants are better. Vesicles smaller than 100 nm coexist with worm-like micelles as soon as a small amount of AEC7- Na is added to DEQ (m(DEQ):m(AEC7-Na) = 8:2). At m(DEQ):m(AEC7-Na) = 4:6 and 2:8, vesicles of approximate ly 80 nm were observed.

Preparation and Application of Modified Imidazole with MPEG (Polyethylene Glycol Monomethyl Ether) as Carbon Steel Inhibitor

The inhibition effect of three inhibitors with different chain lengths of their ether groups on Q235 steel in 0.5 M HCl solution at 318 K was determined by means of weight loss measureme nt, electrochemical methods (Tafel and EIS) and surface analysis (SEM). Moreover, the further study of corrosion inhibition mechanism was also conducted by computational methods (Quantum chemical calculations and Molecular dynamics simulations). Results reveal that the three inhibitors exhibit an excellent inhibition performance for carbon steel, and the corrosion inhibition efficiency of the three inhibitors increases with the increase of the chain length, which favors the formation of a protection film adsorbed on the surface. Analysis of polarization data informs that the adsorption type of three inhibitors basically obeys the Langmuir monolaye r adsorption, which is mainly of chemisorptive nature. Computational methods also tell that the three inhibitors possess a high reactivity and strong interaction with the iron surface, furthermore, the interaction is increased with the increase of the chain length of three inhibitors. The conclusion is in good agreement with the experimental results.

Schiff' Bases as Corrosion Inhibitor for Aluminum Alloy in Hydrochloric Acid Medium

Three Schiff' bases (SB) were synthesized, characterized and evaluated as corrosion inhibitor for aluminum in 1.0 M HCl using chemical (weight loss) and electrochemical (open circuit potential, potentiodynamic polarization, and electrochemical impedance) techniques. The influence of temperature and concentration was investigated. It has been shown that the efficiency of corrosion inhibition increases with the inhibitor concentration and decreases with increasing temperature. The addition of the inhibitor molecules to the corrosive medium shifts the corrosion potential (Ecorr) to the nobler direction. It has been found that the adsorption of the used compounds obeys the Langmuir adsorption isotherm.

Synthesis, Characterizations and Multifunctional Activities of New Thiourea-Based Non-Ionic Surfactants

Six new thiourea-based non-ionic surfactants were prepared from easily existing raw resources in good yield name 1-sec-butyl-3-dodecanoylthiourea, 1-dodecanoyl-3-phenylthiourea, 1,1-dibutyl-3-dodecanoylthiourea, 3-dodecanoyl-1, 1-diphenylthiourea, 1-cyclohexyl-3-dodecanoylthiourea and 1-butyl-3-dodecanoylthiourea. The structural chemistry of these compounds was studied by multinuclear magnetic resonance (1H, 13C), Infrared spectroscopy and UV-Visible spectrophotometry techniques. Their solubility varies according to temperature. They show a low solubility, which increases with the temperature of the water. However, they are not stable. The are soluble in organic solvent like ethanol. These molecules possess a low critical micelle concentration and due to this it shows that they are moderately hydrophobic. These molecules were studied regarding their antimicrobial activities and their antifungal and antibacterial efficiency was tested against five microoganism strains. In all cases, the new compounds show a significant inhibition growth against the tested five bacterial and fungal strains. Due to these behaviors they can be used as future candidates in cleaning as well as in agriculture features. The corrosion inhibition behavior was also studied using chromium and aluminum metals.

Micelles as Soil and Water Decontamination Agents

Contaminated soil and water pose a serious threat to human health and ecosystem. For the treatment of industrial effluents or minimizing their detrimental effects, preventive and remedial approaches must be adopted prior to the occurrence of any severe environmental, health, or safety hazard. Conventional treatment methods of wastewater are insufficient, complicated, and expensive. Therefore, a method that could use environmentally friendly surfactants for the simultaneous removal of both organic and inorganic contaminants from wastewater is deemed a smart approach. Surfactants containing potential donor ligands can coordinate with metal ions, and thus such compounds can be used for the removal of toxic metals and organometallic compounds from aqueous systems. Surfactants form host-guest complexes with the hydrophobic contaminants of water and soil by a mechanism involving the encapsulation of hydrophobes into the self-assembled aggregates (micelles) of surfactants. However, because undefined amounts of surfactants may be released into the aqueous systems, attention must be paid to their own environmental risks as well. Moreover, surfactant remediation methods must be carefully analyzed in the laboratory before field implementation. The use of biosurfactants is the best choice for the removal of water toxins as such surfactants are associated with the characteristics of biodegradability, versatility, recovery, and reuse. This Review is focused on the currently employed surfactant-based soil and wastewater treatment technologies owing to their critical role in the implementation of certain solutions for controlling pollution level, which is necessary to protect human health and ensure the quality standard of the aquatic environment.

Synthesis and Spectrophotometric Study of Toxic Metals Extraction by Novel Thio-Based Non-Ionic Surfactant

A new thio-based non-ionic surfactant 1-(3-chlorophenyl)-3-te-tradecanoylthiourea has been synthesized from potassium thiocyanate, tetradecanoyl chloride and 3-chloroanaline. The purity of the compound was characterized by techniques like 1H NMR, 13C NMR, and FT-IR. The compound was used to detect the toxic metals like copper, mercury and manganese by using UV-Visible spectrophotometric technique. The compound is able to act as a ligand as well to form micelles. Due to this the compound extracts these toxic metals in form of solubilization and complexation. The extracted metals settle down to the bottom in a water tank. The visible change in color with time proves the interaction of the compound with the metals. The compound having carbonyl as well as sulfur groups have soft corner to metal for complexation. This will be used to remove toxic metals from polluted soil and soft drinking surface and underground water. The surfactant is easily synthesized, very economical and environmentally acceptable. The CMC of the surfactant is also determined.