Anaerobic degradation of a mixture of MtBE, EtBE, TBA, and benzene under different redox conditions

Abstract

The increasing use of biobased fuels and fuel additives can potentially change the typical fuel-related contamination in soil and groundwater. Anaerobic biotransformation of the biofuel additive ethyl tert-butyl ether (EtBE), as well as of methyl tert-butyl ether (MtBE), benzene, and tert-butyl alcohol (TBA, a possible oxygenate metabolite), was studied at an industrially contaminated site and in the laboratory. Analysis of groundwater samples indicated that in the field MtBE was degraded, yielding TBA as major product. In batch microcosms, MtBE was degraded under different conditions: unamended control, with medium without added electron acceptors, or with ferrihydrite or sulfate (with or without medium) as electron acceptor, respectively. Degradation of EtBE was not observed under any of these conditions tested. TBA was partially depleted in parallel with MtBE. Results of microcosm experiments with MtBE substrate analogues, i.e., syringate, vanillate, or ferulate, were in line with the hypothesis that the observed TBA degradation is a cometabolic process. Microcosms with ferulate, syringate, isopropanol, or diethyl ether showed EtBE depletion up to 86.5% of the initial concentration after 83 days. Benzene was degraded in the unamended controls, with medium without added electron acceptors and with ferrihydrite, sulfate, or chlorate as electron acceptor, respectively. In the presence of nitrate, benzene was only degraded after addition of an anaerobic benzene-degrading community. Nitrate and chlorate hindered MtBE, EtBE, and TBA degradation.Electronic supplementary materialThe online version of this article (10.1007/s00253-018-8853-4) contains supplementary material, which is available to authorized users.

Distribution of ETBE-degrading microorganisms and functional capability in groundwater, and implications for characterising aquifer ETBE biodegradation potential

“…* bdl indicates that the ethB gene was below detection limit and a ratio was therefore not determined. Results are the mean +/-SD of technical replicates Fayolle-Guichard et al 2012;Stupp et al 2012;Bombach et al 2015;van der Waals et al 2018;Nicholls et al 2020;Thornton et al 2020). The detection of the ethB gene in aquifer samples can provide additional microbiological-based evidence to support the hydrochemical assessment, complementing other molecular tools which may be deployed to evaluate GEO biodegradation (e.g.…”

“…Accidental releases of ETBE into the subsurface environment, either as a pure chemical, or in a mixture (as found in gasoline formulations), can result in contamination of groundwater (Stupp et al 2012 ; van der Waals et al 2018 ). The potential for ETBE biodegradation in groundwater is determined largely by the presence and activity of organisms within the aquifer microbial community able to mineralise the parent compound.…”

Leaky Gut and Autoimmunity: An Intricate Balance in Individuals Health and the Diseased State

“…Thus, things that were initially barred from passing through (e.g., proteins, gluten, microbes, and food antigens) can now breach through the tissue as well as systemic circulation, resulting in intestinal inflammation that may trigger an array of autoimmune diseases such as inflammatory bowel disease, celiac diseases, autoimmune hepatitis, multiple sclerosis, etc. [ 4 , 40 , 41 , 42 , 43 , 44 ]. We have accumulating evidence in support of the presence of overexpressed zonulin in subjects with autoimmune diseases [ 41 ].…”

Natural Purification Through Soils: Risks and Opportunities of Sewage Effluent Reuse in Sub-surface Irrigation

“…In addition, SSI provides a soil barrier surpassing drip and sprinkler irrigation where the STP effluent comes in direct contact with the crops (Ghattas et al 2017;Hamann et al 2016;Nham et al 2015;van der Waals et al 2018). Furthermore, using SSI as a method of supply can decrease CoECs owing to filtration and buffer functions of soil.…”

“…SSI systems can supply STP effluent to crops while the soil is used as a filter and buffer zone. Two major advantages that SSI via a controlled drainage system may have compared to sprinkling irrigation are that (1) there is no direct contact between fieldworkers and STP effluent lowering human health risks and (2) SSI could make optimal use of soil processes that minimize environmental occurrence and dispersion of CoECs (Hamann et al 2016;Nham et al 2015;van der Waals et al 2018). Nevertheless, there are uncertainties concerning the environmental and public health implications which are associated with the reuse of STP effluent for SSI in agriculture.…”