Biological oxidation of choline‐based ionic liquids in sequencing batch reactors

Abstract

BACKGROUND Ionic liquids (ILs) are salts consisting of an organic cation and an organic or inorganic anion that are potential use for organic synthesis, biomass conversion, gas absorption, polymerization, metal extraction and lubrication. We examined the biodegradability of choline chloride (CholineCl), choline acetate (CholineAc) and choline bis(trifluoromethylsulfonyl)imide (CholineNTf2) in a sequencing batch reactor (SBR) to assess the influence of the IL anion. RESULTS Following acclimation, activated sludge exhibited good activity, and high COD (80–90%) and TOC removal (75–85%) with initial concentrations of CholineCl and CholineAc over the range 0.25–15 mmol L–1. However, increased concentrations of CholineNTf2 in the reactor feed had an inhibitory effect on the sludge. An analysis of the reaction effluent revealed the presence of the main intermediates of choline degradation: ethanol, and methyl‐, dimethyl‐ and trimethylamine. The initial and final microbial communities of the sludge were characterized by pyrosequencing analysis, and the latter was found to consist mainly of Alfa‐, Beta‐ and Gamma‐proteobacteria. CONCLUSION Choline‐based ionic liquids can be efficiently removed in SBRs. Complete choline degradation (0.25–15 mmol L–1) was accomplished at a variable depletion rate depending on the particular IL anion (chloride, acetate or NTf2). © 2019 Society of Chemical Industry

Catalytic Conversion of Biomass to Furanic Derivatives with Deep Eutectic Solvents

“…For instance, ChCl is forbidden for use in the cosmetic industry, as it may be easily decomposed back to NMe 3 , HCl, and ethylene oxide. [50] Some research has shown that the H-bonds could be formed between the highly electronegative Cl À of ChCl and hydroxy groups of the target product (e. g., HMF), which increased the stability of the target product and prevented further side reactions. [51] To further understand the effects of the structure of HBAs on the behavior of DESs, four quaternary ammonium salts including ChCl, [ ]Cl/EG (pH = 3.97), which was consistent with the DESs catalytic performance.…”

“…The safety issues of ChCl also raise questions. For instance, ChCl is forbidden for use in the cosmetic industry, as it may be easily decomposed back to NMe 3 , HCl, and ethylene oxide [50] …”

Toxicity and inhibition assessment of ionic liquids by activated sludge

“…was regarded as the less toxic IL due to the biodegradable character of the cation (Petkovic et al 2011;Mena et al, 2019). Despite Choline cation belongs to quaternaryammonium IL family, the incorporation of an alcohol group in the side-chain, reduced the toxic effect (Deng et al 2011).…”

In Focus: 7th European Bioremediation Conference (EBCVII)

“…Other pollutants that are highlighted in this issue are the choline‐based ionic liquids, which can easily reach aquifers, due to their high solubility in water, constituting important environmental problems. According to Mena et al ., those substances can be easily degraded in sequencing batch reactors under aerobic conditions using glucose as carbon source …”

“…According to Mena et al, those substances can be easily degraded in sequencing batch reactors under aerobic conditions using glucose as carbon source. 4 The second cluster of studies explored the potential of phytoremediation as an alternative method for the removal and the stabilization of heavy metals. In particular, Shilev et al aimed to design and develop a strategy in order to alleviate the stress conditions induced by heavy metals.…”