Kinetic study of the anaerobic biodegradation of alkyl polyglucosides and the influence of their structural parameters

Abstract

This paper reports a study of the anaerobic biodegradation of non-ionic surfactants alkyl polyglucosides applying the method by measurement of the biogas production in digested sludge. Three alkyl polyglucosides with different length alkyl chain and degree of polymerization of the glucose units were tested. The influence of their structural parameters was evaluated, and the characteristics parameters of the anaerobic biodegradation were determined. Results show that alkyl polyglucosides, at the standard initial concentration of 100 mgC L(-1), are not completely biodegradable in anaerobic conditions because they inhibit the biogas production. The alkyl polyglucoside having the shortest alkyl chain showed the fastest biodegradability and reached the higher percentage of final mineralization. The anaerobic process was well adjusted to a pseudo first-order equation using the carbon produced as gas during the test; also, kinetics parameters and a global rate constant for all the involved metabolic process were determined. This modeling is helpful to evaluate the biodegradation or the persistence of alkyl polyglucosides under anaerobic conditions in the environment and in the wastewater treatment.

Synthesis and Properties of Alkoxyethyl β‐d‐Xylopyranoside

“…All HLB numbers are at the range of 10.7–13.9, which illustrates that all of them are hydrophilicity since HLB > 10. By comparison, three alkyl polyglucosides (APG) had HLB numbers of 13 (capryl glucoside, APG‐R 8–10 DP 1.4 ), 11.9 (coco glucoside, APG‐R 8–14 DP 1.3 ), and 11.2 (lauryl glucoside, APG‐R 12‐14 DP 1.5 ), respectively (Ríos et al, ). Therefore, our prepared alkoxyethyl β‐ d‐ xylopyranosides ( 6a – 6f ) also achieved around the APG HLB values by introducing a hydrophilic spacer (─OCH 2 CH 2 ─) instead of increasing DP.…”

“…APG, C 8 APG, C 9 APG, C 10 APG, and C 12 APG have CMC ( γ CMC ) values of 1.71 × 10 −3 (29), 1.23 × 10 −3 (33), 7.81 × 10 −4 (31), and 2.97 × 10 −4 mol L −1 (32 mN m −1 ) (El‐Sukkary et al, ). Two representative commercial APG had CMC values of 1.01 (capryl glucoside, APG‐R 8–10 DP 1.4 , HLB = 13) and 0.15 (coco glucoside, APG‐R 8–14 DP 1.3 , HLB = 11.9), respectively (Ríos et al, ). For the alkyl polyxylosides, the CMC ( γ CMC ) values of octyl α/β‐ d‐ xyloside (DP = 1, HLB = 11.4) and octyl β‐ d‐ oligoxylosides (DP > 2) were 0.953 g·L −1 (i.e., 3.66 × 10 −6 mol L −1 ) (27 mN m −1 ) and 4.23 g L −1 (27.0 mN m −1 ), respectively (Ochs et al, ).…”

“…Alkyl polyglycosides (APGs) are safe and environmentally friendly sugarbased nonionic surfactants. APG is synthesized from carbohydrates and fatty alcohols that are naturally occurring and renewable raw materials (Ríos, Fernández-Arteaga, Lechuga, Jurado, & Fernández-Serrano, 2016). They have been employed in industrial and consumer application fields, such as detergents, food products, pharmaceuticals, agrochemicals, protein science, and personal care products, because they possess the excellent properties including low surface tension, efficient decontamination ability, exquisite and stable foam, low toxicity, and so on (Ardolino, Meloni, Brugali, Corsini, & Galli, 2016;Du, Wang, Tai, Wang, & Liu, 2016;Lukic, Pantelic, & Savic, 2016;Reading et al, 2015).…”

Water Solubility and Surface Activity of Alkoxyethyl β-d-Maltosides

“…Due to their enhanced hydrophilicity, improved water solubility, wellmaintained excellent surface activity, and thermotropic liquid crystalline texture, such β-D-maltosides should have broader potential importance in a diversity of applications. However, further attempts to resolve related issues including the technology, surface activity, 53 self-assembly, 54 rheology, 55 liquid crystal texture, 35,43 structural biological research, 56 biodegradation, 11 environmental risk assessment, 57 reconstruction, 58 and commercial value 59…”

“…9,10 AGs and APGs have many advantages over other surfactants, such as excellent surface activity, decontamination foam, low ecotoxicity, and good biodegradability. 11 As a result of the above advantages, AGs and APGs are widely used in the fields of detergents, cosmetics, food industry, and other fields. 12,13 In addition to this, AGs are found to be applied in biomedicine 14 and organic microporous materials, 15,16 and to modify protein molecules, and so on.…”