Influence of Sodium Dodecyl Sulfate Presence on Esterification of Propylene Glycol with Lauric Acid

3D electro-Fenton augmented with iron-biochar particle electrodes derived from waste iron bottle caps and sugarcane bagasse for the remediation of sodium dodecyl sulphate

The present work demonstrates a novel strategy of synthesizing iron-biochar (Fe@BCSB) composite made with the waste iron bottle cap and sugar cane bagasse for implementation in the three-dimensional electro-Fenton (3DEF) process. The catalytic ability of the Fe@BCSB composite was explored to remediate the sodium dodecyl sulphate (SDS) surfactant from wastewater at neutral pH. At the optimum operating condition of Fe@BCSB dose of 1.0 g L-1, current density of 4.66 mA cm-2, and Na2SO4 dose of 50 mM, nearly 92.7 ± 3.1% of 20 mg L-1 of SDS abatement was attained during 120 min of electrolysis time. Moreover, the Fe@BCSB showed significant recyclability up to six cycles. Besides, other organics were successfully treated with more than 85% abatement efficiency in the proposed Fe@BCSB-supported 3DEF process. The total operating cost obtained during SDS treatment was around 0.31 US$ m-3 of wastewater. The phytotoxicity test revealed the positive impact of the 3DEF-treated effluent on the germination of the Vigna radiata. The electron paramagnetic resonance conveyed •OH as the prevailing reactive species for the oxidation of SDS in the 3DEF process. Further, about 81.3 ± 3.8% of SDS and 53.7 ± 4.1% of mineralization efficacy were acquired from the real institutional sewage.

Interesterification of Soybean Oil with Propylene Glycol in Supercritical Carbon Dioxide and Analysis by NMR Spectroscopy

The time course study of high monoester mixtures from soybean oil (HMMS) synthesis, as healthier alternatives to trans food products, in a supercritical CO₂ (SCCO₂) medium with and without enzyme, was investigated. Phosphorous nuclear magnetic resonance (³¹P-NMR) was used to quantify the absolute amount of partially esterified acylglycerols (PEGs). Carbon NMR was utilized to determine the type and position of the fatty acids (FAs) of HMMS. Enzyme and time significantly influenced the synthesis of 1-monoglycerides (1-MGs), 2-MGs, and 1,2-diglycerides (1,2-DGs) in this alcoholysis of soybean oil with 1,2-propanediol, based on high catalytic activity and operational stability of Novozym 435 in SCCO₂ during short reaction time. Results suggest that 4 h is a suitable reaction time for this lipase-catalyzed interesterification (LIE) system for the synthesis of 2-MGs with a yield of 20%. The highest polyunsaturated fatty acid (PUFA) (65%) in the triglyceride (TG) of HMMS was produced after 4 h of reaction. After 6 h of reaction, a high level (20%) of saturated fatty acids (SFAs) was found in the TGs of HMMS, which were distributed between the sn-2 (5%) and sn-1, 3 (15%) positions.

One-Step Synthesis of W/O and O/W Emulsifiers in the Presence of Surface Active Agents

The main goal of this study was to describe the method of the synthesis of the dodecyl-, tetradecyl-, hexadecyl- and octadecyl-propylene glycol emulsifiers in the presence of selected anionic and nonionic surfactants. Acyl propylene glycol emulsifiers were produced by esterification of propane–1,2-diol (propylene glycol, PG) with C_12:0–C_18:0 fatty acids in the presence of anionic sodium dodecyl sulfate (SDS) and nonionic-poly(ethylene glycol) monolaurate (PEGML). The presence of SDS and PEGML in the reaction system caused microemulsion formation. Depending on the structure and amount of the surfactant in the system reactions proceeded at different rates and with different efficiency levels. The esterification of propylene glycol carried out under applied conditions causes products with the desired contents of propylene glycol monoesters (MAPG) to be obtained in a one-step reaction. Knowledge of the reaction kinetics creates the possibility to program the composition and properties of the synthesized emulsifiers. The interaction of nonionic, lipophilic MAPG with anionic, hydrophilic SDS or nonionic, hydrophilic PEGML influences the hydrophile–lipophile balance (HLB) values of the products which may be used to stabilize water-in-oil (W/O) and oil-in-water (O/W) emulsions. Use of the synthesized compounds allows stable emulsions to be prepared which include the following vegetable fats in the oil phase: mango oil, palm oil, shorea butter and hydrogenated soybean oil.