Halide and Thiocyanate Metal Acid Complexes Extraction in the Water – Ethoxylated Nonylphenol – Ammonium Sulfate System

Nonionic ethoxylated surfactants, including ethoxylated nonylphenols, can be considered as neutral oxygen-containing extraction reagents, the formation of delamination systems with which is possible when salting-out with inorganic salts. In this work, the distribution of halide and thiocyanate acid complexes of thallium (III), iron (III), indium and gallium in the water – ethoxylated nonylphenol (neonol AF 9-12) – ammonium sulfate system at 25°C was investigated. It is established that thallium (III) is quantitatively extracted in the form of tetrahalidetallate-ion with an acidity of more than 0.1 mol/l, extraction of other metals is not quantitative. Among the thiocyanate acid complexes, zinc, cobalt and copper (II) are quantitatively concentrated, which can be used for group concentration of these metals or their extraction-spectrophotometric determination methods

Use of Ethoxylated Surfactants to Improve Digestate Stability

Thermal or thermocatalytic treatment of sludge resulting from anaerobic digestion in continuous flow installations involves conditioning it in order to homogenise it and stabilize of these suspensions. In this study the digestate resulting in the processing of the algal biomass was conditioned in the presence of potato processing waste. The conditioning was done in several stages. In the first stage, the water content was reduced by controlled evaporation. The partially dried digestate was then ground, and the particle size distribution was determined bydynamic light scattering (DLS) using Nano ZS (Red badge). The digestate suspension was stabilized by adding ethoxylated surfactants and a lipid fraction. The stability of the digestate suspension was determined using a Turbiscan Lab. The stability of the digestate slurry was improved by the addition of lipid fraction and by addition of ethoxylated castor oil.

Transposon Mutagenesis Identifies Genes Critical for Growth of Pseudomonas nitroreducens TX1 on Octylphenol Polyethoxylates

ABSTRACTPseudomonas nitroreducensTX1 is of special interest because of its ability to utilize 0.05% to 20% octylphenol polyethoxylates (OPEOn) as a sole source of carbon. In this study, a library containing 30,000 Tn5-insertion mutants of the wild-type strain TX1 was constructed and screened for OPEOnutilization, and 93 mutants were found to be unable to grow on OPEOn. In total, 42 separate disrupted genes were identified, and the proteins encoded by the genes were then classified into various categories, namely, information storage and processing (14.3%), cellular processes and signaling (28.6%), metabolism (35.7%), and unknown proteins (21.4%). The individual deletion of genes encoding isocitrate lyase (aceA), malate synthase (aceB), and glycolate dehydrogenase (glcE) was carried out, and the requirement foraceAandaceBbut notglcEconfirmed the role of the glyoxylate cycle in OPEOndegradation. Furthermore, acetaldehyde dehydrogenase and acetyl-coenzyme A (acetyl-CoA) synthetase activity levels were 13.2- and 2.1-fold higher in TX1 cells grown on OPEOnthan in TX1 cells grown on succinate, respectively. Growth of the various mutants on different carbon sources was tested, and based on these findings, a mechanism involving exoscission to liberate acetaldehyde from the end of the OPEOnchain during degradation is proposed for the breakdown of OPEOn.IMPORTANCEOctylphenol polyethoxylates belong to the alkylphenol polyethoxylate (APEOn) nonionic surfactant family. Evidence based on the analysis of intermediate metabolites suggested that the primary biodegradation of APEOncan be achieved by two possible pathways for the stepwise removal of the C2ethoxylate units from the end of the chain. However, direct evidence for these hypotheses is still lacking. In this study, we described the use of transposon mutagenesis to identify genes critical to the catabolism of OPEOnbyP. nitroreducensTX1. The exoscission of the ethoxylate chain leading to the liberation of acetaldehyde is proposed. Isocitrate lyase and malate synthase in glyoxylate cycle are required in the catabolism of ethoxylated surfactants. Our findings also provide many gene candidates that may help elucidate the mechanisms in stress responses to ethoxylated surfactants by bacteria.