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Title: Atmospheric So2 Emissions Since the Late 1800s Change Organic Sulfur Forms in Humic Substance Extracts of Soils

Atmospheric SO2 emissions in the UK and globally increased 6- and 20-fold, respectively, from the mid-1800s to the 1960s resulting in increased S deposition, acid rain, and concurrent acidification of terrestrial and aquatic ecosystems. Structural analyses using synchrotron-based X-ray near-edge spectroscopy (XANES) on humic substance extracts of archived samples from the Rothamsted Park Grass Experiment reveal a significant (R2 = -0.58; P < 0.05; N = 7) shift in soil organic sulfur (S) forms, from reduced to more oxidized organic S between 1876 and 1981, even though soil total S contents remained relatively constant. Over the last 30 years, a decrease in emissions and consequent S deposition has again corresponded with a change of organic S structures of humic extractsreverting in the direction of their early industrial composition. However, the observed reversal lagged behind reductions in emissions by 19 years, which was computed using cross correlations between time series data (R2 = 0.66; P = 0.0024; N = 11). Presently, the ratio of oxidized-to-reduced organic S in humic substance extracts is nearly double that of early industrial times at identical SO2 emission loads. The significant and persistent structural changes of organic S in humic substances as a response to SO2more » emissions and S deposition may have effects on recuperation of soils and surface waters from acidification.« less
Authors:
; ; ;
Publication Date:
OSTI Identifier:
959791
Report Number(s):
BNL-82777-2009-JA
Journal ID: ISSN 0013-936X; ESTHAG; TRN: US201016%%935
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environmental Science and Technology; Journal Volume: 42
Research Org:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org:
Doe - Office Of Science
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ACID RAIN; ACIDIFICATION; AQUATIC ECOSYSTEMS; DEPOSITION; GRAMINEAE; SOILS; SPECTROSCOPY; SULFUR; SURFACE WATERS