Enhanced Removal of Hydrophobic Short-Chain n-Alkanes from Gas Streams in Biotrickling Filters in Presence of Surfactant

Abstract

Emissions of n-alkanes are facing increasingly stringent management challenges. Biotrickling filtration in the presence of surfactants is a competitive alternative for the enhanced removal of n-alkanes. Herein, sodium dodecyl benzene sulfonate (SDBS) was added into the liquid phase feeding a biotrickling filter (BTF) to enhance the removal of various short-chain n-alkanes from n-hexane (C6) to methane (C1). The removal performance of C6–C1 and microbial response mechanisms were explored. The results showed that the removal efficiency (RE) of n-alkanes decreased from 77 ± 1.3 to 35 ± 5.6% as the carbon chain number of n-alkanes decreased from C6 to C1, under the conditions of an n-alkane inlet load of 58 ± 3.0 g/m3·h and EBCT of 30 s. The removal performance of n-alkanes was enhanced significantly by the introduction of 15 mg/L SDBS, as the RE of C6 reached 99 ± 0.7% and the RE of C1 reached 74 ± 3.3%. The strengthening mechanisms were that the apparent Henry’s law coefficient of n-alkanes decreased by 11 ± 1.4–30 ± 0.3%, and the cell surface hydrophobicity of microorganisms improved from 71 ± 5.6 to 87 ± 4.0% with the existence of SDBS. Moreover, the presence of SDBS promoted the succession and activity of the microbial community. The activities of alkane hydroxylase and alcohol dehydrogenase were 5.8 and 5.9 times higher than those without SDBS, and the concentration of the cytochrome P450 gene was improved 2.2 times. Therefore, the addition of SDBS is an effective strategy that makes BTF suitable for the removal of various n-alkanes from waste gas streams.

Significantly Accelerated Photochemical Perfluorooctanoic Acid Decomposition at the Air–Water Interface of Microdroplets

“…The e aq – , I – , and Cl – tend to accumulate at the gas–liquid interface as well, ,, thus the PFASs photochemical treatment induced by other photochemical processes (e.g., UV/I – , UV/Cl – , and even semiconductor photocatalysis) probably can also be accelerated by using microdroplet reactors. Besides, owing to the significantly abundant AWI, microdroplets would be of great promise for eliminating other hydrophobic micropollutants like phenolic compounds and alkanes. , In natural environments, the microlayer of lakes and oceans, as well as the atmospheric aerosols and water droplets generated from bubble burst at water surfaces, provide a prevalent air–water interface for concentration enrichment of PFASs and may display different reaction environment from the bulk interior. The fate and transport of PFASs in natural water bodies and atmosphere will be influenced by air–water interface chemistry and should be re-evaluated based on the current study, as well as the redox cycle of Fe­(II)/Fe­(III).…”

Roles of Biofilm Structure and Functional Genes in Overcoming Limited Dimethyl Sulfide Degradation and Energy Recovery

“…3,5 To meet the demand of waste gas odor control, biodegradation technologies, including biofilters, biotrickling filters, and bioscrubbers, have been widely recognized for their environmental friendliness and high cost-effectiveness. 6,7 Among different biodegradation processes, the microbial fuel cells (MFCs) are known to eliminate organic pollutants and generate electrical energy simultaneously, taking advantage of biocatalysts in the bioanode. 8,9 For VOSCs degradation, several dual-chamber MFCs had been developed.…”

“…Volatile organic sulfur compounds (VOSCs), such as dimethyl sulfide (DMS), methanethiol (MT), and dimethyl disulfide (DMDS), significantly contributed to the generation of malodors in bodies of water due to their low olfactory threshold and high odor intensity. − In fact, VOSCs existed in all the stages of wastewater treatment, which may give rise to localized water issues. , To meet the demand of waste gas odor control, biodegradation technologies, including biofilters, biotrickling filters, and bioscrubbers, have been widely recognized for their environmental friendliness and high cost-effectiveness. , Among different biodegradation processes, the microbial fuel cells (MFCs) are known to eliminate organic pollutants and generate electrical energy simultaneously, taking advantage of biocatalysts in the bioanode. , For VOSCs degradation, several dual-chamber MFCs had been developed. Nonetheless, due to the toxicity of VOSCs to microorganisms, the power density was found to be rather limited. , The challenges on refractory VOSCs removal and fast energy generation in MFCs remain to be addressed. , …”

Recyclable dynamic imine‐based nonionic surfactants and potential use in postprocessing of eluted emulsions

“…Surfactant‐enhanced washing (Befkadu & Chen, 2018; Karthick et al, 2019; Lim et al, 2016; Liu et al, 2021; Munoz‐Morales et al, 2017; Tran et al, 2022; Wu et al, 2022) is one of the most versatile remediation techniques for virtually all target hydrophobic organic contaminants including petroleum‐based oil. Both the interfacial tension (IFT, mN m −1 ) at the oil–water interfaces and the attraction between the oil and soil particles could be remarkably decreased by surfactants.…”