Centennial record of anthropogenic impacts in Galveston Bay: Evidence from trace metals (Hg, Pb, Ni, Zn) and lignin oxidation products

The photocatalytic pretreatment of lignocellulosic biomass to oxidize lignin and increase biomass stability has gained attention during the last few years. Conventional pretreatment methods are limited by the fact that they are expensive, non-renewable and contaminate the anaerobic digestate later on. The present study was focused to develop a metal-derived photocatalyst that can work with visible electromagnetic spectra light and oxidize commercial lignin liquor. During this project the advanced photocatalytic oxidation of lignin was achieved by using a quartz cube tungsten T3 Halogen 100 W lamp with a laboratory manufactured TiO2-ZnO nanoparticle (nanocomposite) in a self-designed apparatus. The products of lignin oxidation were confirmed to be vanillic acid (9.71 ± 0.23 mg/L), ferrulic acid (7.34 ± 0.16 mg/L), benzoic acid (6.12 ± 0.17 mg/L) and p-coumaric acid (3.80 ± 0.13 mg/L). These all products corresponded to 85% of the lignin oxidation products that were detectable, which is significantly more than any previously reported lignin pretreatment with even more intensity. Furthermore, all the pretreatment samples were supplemented in the form of feedstock diluent in uniformly operating continuously stirred tank reactors (CSTRs). The results of pretreatment revealed 85% lignin oxidation and later on these products did not hinder the CSTR performance at any stage. Moreover, the synergistic effects of pretreated lignin diluent were seen that resulted in 39% significant increase in the methane yield of the CSTR with constant operation. Finally, the visible light and nanoparticles alone could not pretreat lignin and when used as diluent, halted and reduced the methane yield by 37% during 4th HRT.

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Chronology of anthropogenic impacts reconstructed from sediment records of trace metals and Pb isotopes in Todos os Santos Bay (NE Brazil)

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2017.07.053 ◽

2017 ◽

Vol 125 (1-2) ◽

pp. 459-471 ◽

Cited By ~ 15

Author(s):

R.L.B. Andrade ◽

V. Hatje ◽

P. Masqué ◽

C.M. Zurbrick ◽

E.A. Boyle ◽

...

Keyword(s):

Trace Metals ◽

Anthropogenic Impacts ◽

Pb Isotopes ◽

Sediment Records

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Fate of CuO-derived lignin oxidation products during plant combustion: Application to the evaluation of char input to soil organic matter

Organic Geochemistry ◽

10.1016/j.orggeochem.2008.07.011 ◽

2008 ◽

Vol 39 (11) ◽

pp. 1522-1536 ◽

Cited By ~ 31

Author(s):

Li-Jung Kuo ◽

Patrick Louchouarn ◽

Bruce E. Herbert

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Oxidation Products ◽

Lignin Oxidation

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Comments on "Lignin oxidation products in soil, dripwater and speleothems from four different sites in New Zealand"

10.5194/bg-2020-345-rc2 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

New Zealand ◽

Oxidation Products ◽

Lignin Oxidation

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Lignin oxidation products in soil, dripwater and speleothems from four different sites in New Zealand

10.5194/bg-2020-345 ◽

2020 ◽

Author(s):

Inken Heidke ◽

Adam Hartland ◽

Denis Scholz ◽

Andrew Pearson ◽

John Hellstrom ◽

...

Keyword(s):

New Zealand ◽

High Resolution Mass Spectrometry ◽

Lignin Content ◽

Oxidation Products ◽

Vegetation Changes ◽

Original Source ◽

Cave System ◽

Open Questions ◽

Lignin Oxidation ◽

Ultrahigh Performance Liquid Chromatography

Abstract. Lignin oxidation products (LOPs) are widely used as vegetation proxies in climate archives, such as sediment and peat cores. The total LOP concentration, Σ8, provides information on the abundance of vegetation, while the ratios C / V and S / V of the different LOP groups also provide information on the type of vegetation. Recently, LOP analysis has been successfully applied to speleothem archives. However, there are many open questions concerning the transport and microbial degradation of LOPs on their way from the soil into the cave system. These processes could potentially alter the original source-dependent LOP signals, in particular the C / V and S / V ratios, and thus complicate their interpretation in terms of past vegetation changes. We analyzed LOPs in leaf litter and different soil horizons as well as dripwater and flowstone samples from four different cave sites from different vegetation zones in New Zealand using ultrahigh performance liquid chromatography coupled to high resolution mass spectrometry. We test whether the original source-dependent LOP signal of the overlying vegetation is preserved and can be recovered from flowstone samples and investigate how the signal is altered by the transport from the soil to the cave. The LOP concentrations range from mg/g in the soil to ng/g in the flowstones. Our results demonstrate that, from the soil to the flowstone, the C / V and S / V ratios both increase, while the total lignin content, Σ8, strongly decreases. This shows that the LOP signal is strongly influenced by both transport and degradation processes. Nevertheless, the relative LOP signal from the overlying soil at the different cave sites is preserved in the flowstone. We emphasize that for the interpretation of C / V and S / V ratios in terms of past vegetation changes, it is important to compare only samples of the same type (e.g., speleothem, dripwater or soil) and to evaluate only relative variations.

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Evidence of Natural and Anthropogenic Impacts on Rainwater Trace Metal Geochemistry in Central Mexico: A Statistical Approach

Water ◽

10.3390/w12010192 ◽

2020 ◽

Vol 12 (1) ◽

pp. 192 ◽

Cited By ~ 3

Author(s):

D. M. Rivera-Rivera ◽

D. C. Escobedo-Urías ◽

M. P. Jonathan ◽

S. B. Sujitha ◽

S. Chidambaram

Keyword(s):

Trace Metals ◽

Trace Metal ◽

Statistical Approach ◽

Anthropogenic Impacts ◽

Human Consumption ◽

Monthly Basis ◽

Air Masses ◽

Local Transport ◽

High Concentrations ◽

Toxic Potential

Trace metals Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, and As were determined on a monthly basis in a total of 52 rain samples collected from six different locations in the central region of Mexico during March 2016–April 2017. The average concentrations of trace metals (mg/L) in the rainwater samples showed an order of Zn (0.873) > Fe (0.395) > Mn (0.083) > Cr (0.041) ≥ Cu (0.041) > Pb (0.031) > Ni (0.020) > Co (0.013) > As (0.0003) > Cd (0.002). The differences observed in metal concentrations are related to variations in the influence of continental air masses, local transport, regional advection, and the solubility of trace metals. High concentrations of metals were observed in the months of March to May at all sites, probably due to the less extensive removal of air/air pollutants. The values obtained from the enrichment factor (EF) per metal showed relatively high values for Cd, Zn, Cu, Pb, Co, Ni, and Cr, suggesting anthropogenic origin. Pearson’s correlation matrix validated the distribution of trace metal sources and their relationships with local/regional meteorological characteristics. This paper presents relevant basic information for the evaluation of the toxic potential of rainwater and the possible health risks when using this source of water for human consumption.

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