Sulfate reduction and alterability of sulfur species in sediments of an estuary with irregular hydrological regime

Mirlean, Nicolai; Bem, André Luiz de; Quintana, Guilherme Castro da Rosa; Costa, Larissa Pinheiro; Ferraz, Alexandre Henrique

doi:10.1590/s2675-28242020068321

Acessibilidade / Reportar erro

Brasil

Ocean and Coastal Research

Español English

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Original Article • Ocean Coast. Res. 68 • 2020 • https://doi.org/10.1590/s2675-28242020068321 copy

Sulfate reduction and alterability of sulfur species in sediments of an estuary with irregular hydrological regime

Authorship SCIMAGO INSTITUTIONS RANKINGS

Abstract

The irregular hydrological regime in Patos Lagoon estuary has been suggested as having a distinctive influence on sulfur speciation in sediments. We performed an investigation for different prolonged hydrological conditions focusing on the distribution of sulfides (acid volatile sulfide (AVS), chromium reducible sulfide (CRS), and Free-S^2-) in sediment cores from salt marsh and non-vegetated shallow zone. Significant differences in sulfides content and distribution between the different hydrological periods were found. The predominance of more reducing conditions was observed during the freshwater period. It reflects a higher total reducible inorganic sulfur (TRIS) content in this period, with a great accumulation of AVS in sediments (> 100 mg kg^-1). In the maximum salinity period, more oxidizing conditions prevailed, which significantly decreased the concentrations of metastable sulfides. The intense bioirrigation process exerts control over sulfide formation and distribution, which is as important as that exerted by the variations of the hydrological regime.

Descriptors:
Sulfides formation; Saltmarsh sediment; Hydrological regime; River dominated estuary

Parameter	SM	NV
Fine Grain (%)	$\frac{20.84 - 61.17}{(38.70 \pm 12.54)}$	$\frac{12.42 - 36.80}{(21.12 \pm 9.93)}$
OC (%)	$\frac{0.33 - 5.13}{(1.63 \pm 1.70)}$	$\frac{0.26 - 0.61}{(0.36 \pm 0.10)}$

Parameter	Freshwater period	Maximum salinity period
^* * 0-40 cm depth; Free-S^2- (µmol L^-1)	$\frac{4.87 - 35.18}{(14.10 \pm 9.43)}$	$\frac{4.46 - 18.09}{(9.94 \pm 3.97)}$
^* * 0-40 cm depth; AVS (mg kg^-1)	$\frac{38.20 - 145.18}{(75.45 \pm 35.32)}$	$\frac{12.24 - 206.16}{(81.25 \pm 81.87)}$
^* * 0-40 cm depth; CRS (mg kg^-1)	$\frac{534.35 - 3858.53}{(1948.77 \pm 1428.99)}$	$\frac{421.47 - 1126.06}{(715.26 \pm 210.31)}$
^* * 0-40 cm depth; Eh (mV)	$\frac{- 252.0 - - 69.0}{(- 118.8 \pm 64.0)}$	$\frac{- 181.0 - 82.0}{(- 61.1 \pm 84.4)}$
^ 0-20 cm pH	$\frac{7 - 7.75}{(7.41 \pm 0.25)}$	$\frac{6.1 - 7}{(6.58 \pm 0.35)}$
^ 0-20 cm Conductivity (mS cm^-1)	$\frac{8.63 - 13.11}{(10.76 \pm 1.46)}$	$\frac{25.9 - 28.6}{(27.32 \pm 1)}$

Parameter	Freshwater period	Maximum salinity period
^* * 0-40 cm depth; Free-S^2- (µmol L^-1)	$\frac{9.98 - 387.87}{(95.49 \pm 116.17)}$	$\frac{3.73 - 187.81}{(65.50 \pm 42.99)}$
^* * 0-40 cm depth; AVS (mg kg^-1)	$\frac{3.60 - 299.65}{(62.27 \pm 99.95)}$	$\frac{1.61 - 24.90}{(11.52 \pm 7.54)}$
^* * 0-40 cm depth; CRS (mg kg^-1)	$\frac{95.90 - 4554.79}{(1235.89 \pm 1641.70)}$	$\frac{12.46 - 3290.38}{(809.48 \pm 1103.38)}$
^* * 0-40 cm depth; Eh (mV)	$\frac{- 301.0 - 45.0}{(- 134.7 \pm 91.3)}$	$\frac{- 280.0 - 21.0}{(- 139.9 \pm 71.52)}$
^ 0-20 cm pH	$\frac{6.8 - 7.6}{(7.2 \pm 0.3)}$	$\frac{7.4 - 7.6}{(7.48 \pm 0.05)}$
^ 0-20 cm Conductivity (mS cm^-1)	$\frac{10.31 - 14}{(12.1 \pm 1.47)}$	$\frac{33.43 - 51.9}{(41.1 \pm 6.7)}$

Instituto Oceanográfico da Universidade de São Paulo Praça do Oceanográfico 191, CEP: 05508-120, São Paulo, SP - Brasil, Tel.: (11) 3091-6501 - São Paulo - SP - Brazil
E-mail: diretoria.io@usp.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] *Corresponding author: aleferraz.h@gmail.com

Freshwater Period
	TOC	<63 µm	Eh	Free-S^2-	CRS	AVS
	n=11	n=10	n=20	n=20	n=8	n=10
TOC	1	0,835	-0,816	0,927	0,794	0,105
<63 µm		1	-0,946	0,903	0,975	-0,383
Eh			1	-0,940	-0,985	0,407
Free-S^2-				1	0,918	-0,206
CRS					1	-0,363
AVS						1
Maximum salinity Period
	TOC	<63 µm	Eh	Free-S^2-	CRS	AVS
	n=11	n=10	n=20	n=20	n=8	n=12
TOC	1	0,835	-0,567	0,680	0,823	-0,593
<63 µm		1	-0,608	0,827	0,930	-0,389
Eh			1	-0,901	-0,877	0,143
Free-S^2-				1	0,984	-0,238
CRS					1	-0,248
AVS						1

Freshwater Period
	TOC	<63 µm	Eh	Free-S^2-	CRS	AVS
	(n=11)	n=10	n=20	n=20	n=10	n=11
TOC	1	-0,632	-0,922	0,840	-0,443	0,803
<63 µm		1	0,473	-0,578	0,647	-0,512
Eh			1	-0,718	0,254	-0,642
Free-S^2-				1	-0,703	0,857
CRS					1	-0,513
AVS						1
Maximum salinity Period
	TOC	<63 µm	Eh	Free-S^2-	CRS	AVS
	n=11	n=10	n=20	n=20	n=9	n=11
TOC	1	-0,632	0,216	-0,522	0,404	-0,619
<63 µm		1	-0,202	0,562	0,067	0,282
Eh			1	-0,583	0,596	-0,608
Free-S^2-				1	-0,312	0,731
CRS					1	-0,537
AVS						1

AVS	FWP = MSP
CRS	FWP > MSP
Free-S^2-	FWP = MSP
Eh	FWP = MSP

AVS	FWP = MSP
CRS	FWP = MSP
Free-S^2-	FWP = MSP
Eh	FWP = MSP