Molecular characterization of the composition and transformation of dissolved organic matter during the semi-permeable membrane covered hyperthermophilic composting
TL;DR: In this article, the authors provided molecular insights into the composition and transformations of dissolved organic matter (DOM) in semi-permeable membrane-covered thermophilic compost (smHTC) using multiple spectroscopic methods and ultra-high resolution mass spectrometry.
About: This article is published in Journal of Hazardous Materials.The article was published on 2021-10-14. It has received 11 citations till now. The article focuses on the topics: Humus & Chemistry.
Citations
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01 Apr 2018
TL;DR: In this paper, the authors used ultra-high resolution mass spectrometry to trace differences in the composition of solid-phase extractable (PPL resin) pore water DOM (SPE-DOM) isolated from surface sediments of three boreal lakes before and after 40 days of anoxic incubation, with concomitant determination of CH4 and CO2 evolution.
Abstract: Dissolved organic matter (DOM) contained in lake sediments is a carbon source for many microbial degradation processes, including aerobic and anaerobic mineralization. During anaerobic degradation, DOM is partially consumed and transformed into new molecules while the greenhouse gases methane (CH4) and carbon dioxide (CO2) are produced. In this study, we used ultrahigh resolution mass spectrometry to trace differences in the composition of solid-phase extractable (PPL resin) pore water DOM (SPE-DOM) isolated from surface sediments of three boreal lakes before and after 40 days of anoxic incubation, with concomitant determination of CH4 and CO2 evolution. CH4 and CO2 production detected by gas chromatography varied considerably among replicates and accounted for fractions of ∼2–4 × 10−4 of sedimentary organic carbon for CO2 and ∼0.8–2.4 × 10−5 for CH4. In contrast, the relative changes of key bulk parameters during incubation, such as relative proportions of molecular series, elemental ratios, average mass and unsaturation, were regularly in the percent range (1–3% for compounds decreasing and 4–10% for compounds increasing), i.e. several orders of magnitude higher than mineralization alone. Computation of the average carbon oxidation state in CHO molecules of lake pore water DOM revealed rather non-selective large scale transformations of organic matter during incubation, with depletion of highly oxidized and highly reduced CHO molecules, and formation of rather non-labile fulvic acid type molecules. In general, proportions of CHO compounds slightly decreased. Nearly saturated CHO and CHOS lipid-like substances declined during incubation: these rather commonplace molecules were less specific indicators of lake sediment alteration than the particular compounds, such as certain oxygenated aromatics and carboxyl-rich alicyclic acids (CRAM) found more abundant after incubation. There was a remarkable general increase in many CHNO compounds during incubation across all lakes. Differences in DOM transformation between lakes corresponded with lake size and water residence time. While in the small lake Svarttjarn, CRAM increased during incubation, lignin-and tannin-like compounds were enriched in the large lake Bisen, suggesting selective preservation of these rather non-labile aromatic compounds rather than recent synthesis. SPE-DOM after incubation may represent freshly synthesized compounds, leftover bulk DOM which is primarily composed of intrinsically refractory molecules and/or microbial metabolites which were not consumed in our experiments. In spite of a low fraction of the total DOM being mineralized to CO2 and CH4, the more pronounced change in molecular DOM composition during the incubation indicates that diagenetic modification of organic matter can be substantial compared to complete mineralization.
39 citations
TL;DR: In this article , the authors investigated how different concentrations of penicillin G alter the bacterial community to affect humification during aerobic composting of chicken manure and found that the bacterial communities cooperated to regulate humus and humic acid synthesis.
10 citations
TL;DR: In this paper , the effect of intermittent aeration on oxygen dynamics, organic matter degradation and main gas emissions was investigated in a lab-scale pig manure composting experiment with 30min on and 30min off (I_A) and continuous aeration (C_A).
8 citations
TL;DR: In this paper , a semi-permeable membrane covered hyperthermophilic composting (smHTC) was proposed to reduce CH4 and N2O emissions.
7 citations
TL;DR: In this article , the effects of micro-aerobic conditions on fungal community succession and dissolved organic matter transformation during dairy manure membrane-covered composting were investigated, and the results showed that lignocellulose degradation in the microaerobic composting group (AC: oxygen concentration < 5 %) was slower than that in the static composting Group (SC:oxy concentration < 1 %), but the dissolved organic carbon in AC was greatly increased.
4 citations
References
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TL;DR: Aromatic carbon and the presence of specific aromatic compounds resulted in EEMs that aided in differentiating wastewater effluent DOM from drinking water DOM, and the highest cumulative EEM volume was observed for hydrophobic neutral DOM fractions.
Abstract: Excitation−emission matrix (EEM) fluorescence spectroscopy has been widely used to characterize dissolved organic matter (DOM) in water and soil. However, interpreting the >10,000 wavelength-dependent fluorescence intensity data points represented in EEMs has posed a significant challenge. Fluorescence regional integration, a quantitative technique that integrates the volume beneath an EEM, was developed to analyze EEMs. EEMs were delineated into five excitation−emission regions based on fluorescence of model compounds, DOM fractions, and marine waters or freshwaters. Volumetric integration under the EEM within each region, normalized to the projected excitation−emission area within that region and dissolved organic carbon concentration, resulted in a normalized region-specific EEM volume (Φi,n). Solid-state carbon nuclear magnetic resonance (13C NMR), Fourier transform infrared (FTIR) analysis, ultraviolet−visible absorption spectra, and EEMs were obtained for standard Suwannee River fulvic acid and 15 h...
4,407 citations
TL;DR: In an effort to reduce future occurrences of similar problems, algorithms for correcting and calibrating EEMs are described in detail, and MATLAB scripts for implementing the study's protocol are provided, and this approach will serve to increase the intercomparability of DOM fluorescence studies.
Abstract: The fluorescent properties of dissolved organic matter (DOM) are often studied in order to infer DOM characteristics in aquatic environments, including source, quantity, composition, and behavior. While a potentially powerful technique, a single widely implemented standard method for correcting and presenting fluorescence measurements is lacking, leading to difficulties when comparing data collected by different research groups. This paper reports on a large-scale interlaboratory comparison in which natural samples and well-characterized fluorophores were analyzed in 20 laboratories in the U.S., Europe, and Australia. Shortcomings were evident in several areas, including data quality-assurance, the accuracy of spectral correction factors used to correct EEMs, and the treatment of optically dense samples. Data corrected by participants according to individual laboratory procedures were more variable than when corrected under a standard protocol. Wavelength dependency in measurement precision and accuracy were observed within and between instruments, even in corrected data. In an effort to reduce future occurrences of similar problems, algorithms for correcting and calibrating EEMs are described in detail, and MATLAB scripts for implementing the study's protocol are provided. Combined with the recent expansion of spectral fluorescence standards, this approach will serve to increase the intercomparability of DOM fluorescence studies.
567 citations
TL;DR: It is shown, using ultrahigh-resolution mass spectrometry to unambiguously identify 4,032 molecular formulae in 120 lakes across Sweden, that the molecular composition of DOM is shaped by precipitation, water residence time and temperature.
Abstract: Despite the small continental coverage of lakes, they are hotspots of carbon cycling, largely due to the processing of terrestrially derived dissolved organic matter (DOM). As DOM is an amalgam of heterogeneous compounds comprising gradients of microbial and physicochemical reactivity, the factors influencing DOM processing at the molecular level and the resulting patterns in DOM composition are not well understood. Here we show, using ultrahigh-resolution mass spectrometry to unambiguously identify 4,032 molecular formulae in 120 lakes across Sweden, that the molecular composition of DOM is shaped by precipitation, water residence time and temperature. Terrestrially derived DOM is selectively lost as residence time increases, with warmer temperatures enhancing the production of nitrogen-containing compounds. Using biodiversity concepts, we show that the molecular diversity of DOM, or chemodiversity, increases with DOM and nutrient concentrations. The observed molecular-level patterns indicate that terrestrially derived DOM will become more prevalent in lakes as climate gets wetter.
472 citations
TL;DR: S synchronous spectral peak intensity and its red shift in the region of about 450-480 nm may be used to indicate the presence or absence of high molecular weight and polycondensed humic organic components, or the multicomponent nature of NOM or NOM subcomponents.
411 citations
TL;DR: It is confirmed that the double bond equivalence and the number of oxygen atoms are valuable parameters indicating the selective fractionation of DOM at mineral and water interfaces.
Abstract: Adsorption by minerals is a common geochemical process of dissolved organic matter (DOM) which may induce fractionation of DOM at the mineral-water interface. Here, we examine the molecular fractionation of DOM induced by adsorption onto three common iron oxyhydroxides using electrospray ionization coupled with Fourier-transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). Ferrihydrite exhibited higher affinity to DOM and induced more pronounced molecular fractionation of DOM than did goethite or lepidocrocite. High molecular weight (>500 Da) compounds and compounds high in unsaturation or rich in oxygen including polycyclic aromatics, polyphenols and carboxylic compounds had higher affinity to iron oxyhydroxides and especially to ferrihydrite. Low molecular weight compounds and compounds low in unsaturation or containing few oxygenated groups (mainly alcohols and ethers) were preferentially maintained in solution. This study confirms that the double bond equivalence and the number of oxygen...
294 citations