Reduction of volatile halocarbons in anoxic seawater, results from a study in the Black Sea

Date

1996-09-01

Author

Tanhua, T
Fogelqvist, E
Basturk, O

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

231
views

0
downloads

The Black Sea is characterised by an oxic surface water layer and anoxic deep water rich in both hydrogen sulphide and methane, and in between a suboxic zone with very low concentrations of both oxygen and hydrogen sulphide. This makes the Black Sea a useful site for the study of oxidation-reduction reactions in seawater. In this study, the distributions of tetrachloromethane, trichloromethane, 1,1,1,-trichloroethane, dibromomethane, dibromochloromethane and bromodichloromethane across the oxic-anoxic interlace were related to the oxygen/hydrogen sulphide concentrations and thereby the redox potential gradient. All of the investigated halocarbons decrease rapidly in concentration as the oxygen decreases, most likely due to reduction. The results show that the higher the redox potential of a halocarbon, the higher up in the water column, i.e. at a higher oxygen level, reduction occurs. Most of the tetrachloromethane is transformed to trichloromethane as an intermediate product.

Subject Keywords

General Chemistry, Oceanography, Water Science and Technology, Environmental Chemistry

URI

https://hdl.handle.net/11511/66405

Journal

MARINE CHEMISTRY

DOI

https://doi.org/10.1016/0304-4203(96)00005-9

Collections

Graduate School of Marine Sciences, Article

Suggestions

OpenMETU
Core

Comparison of TOC concentrations by persulphate UV and high temperature catalytic oxidation techniques in the Marmara and Black Seas Tuğrul, Süleyman (Elsevier BV, 1993-01-01) Total organic carbon (TOC) concentrations were determined in the Marmara Sea and both oxic and anoxic waters of the Black Sea, using the Shimadzu high-temperature catalytic oxidation technique and the Technicon persulphate-UV oxidation method. The TOC values in the deep waters of the Marmara Sea ranged between 60 and 73 μ MC by the Shimadzu technique and from 40 to 50 μMC by the Technicon method. The TOC values obtained by both methods in the deep anoxic waters of the Black Sea varied between 105 and 130 μM...
The chemical composition of Black Sea suspended particulate organic matter pyrolysis GC MS as a complementary tool to traditional oceanographic analyses Coban Yıldız, Yesim; Chiavari, D; Fabbri, D; Yılmaz, Ayşen; Tuğrul, Süleyman (Elsevier BV, 2000-03-01) A “traditional” description of the abundance and chemical composition of suspended particulate organic matter (POM) in open and coastal waters of the southern Black Sea in June 1996 has been confirmed and extended by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) analyses. Py-GC/MS provided depth profiles of the relative concentrations of twenty three marker compounds characteristic of chlorophylls (CHL), lipids, carbohydrates (CBH) and proteins produced by thermal degradation of the POM retained...
Trace metal composition of suspended particulate matter in the water column of the Black Sea Yiğiterhan, O; Murray, J W; Tuğrul, Süleyman (Elsevier BV, 2011-09-20) We analyzed the chemical composition of suspended matter from the Black Sea for a complete suite of elements used as tracers for various sources and processes. Samples of suspended matter were collected at four stations from the Bosporus to the center of the western gyre during a R/V Bilim cruise in September 2000. Sample depths were from the oxic surface layer, the suboxic zone and the upper part of the anoxic (sulfidic) layer. All samples were analyzed for Al, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Mo, Ag, Cd, Ba...
Enrichment of metals in the surface sediments of Sapanca Lake Bakan, G; Balkas, TI (Wiley, 1999-01-01) A comprehensive lake sediment study was performed on the Sapanca Lake of Turkey in which certain metal analyses were conducted using inductively coupled plasma atomic emission spectroscopy. The purpose of the study was to find the enrichment of metals in the surface sediments of Sapanca Lake. A method, namely, the index of geoaccumulation, was used to define the degree of anthropogenic pollution in the Sapanca Lake basin. Results of the geoaccumulation index indicate that only enrichments of trace metals, c...
ORGANIC-CARBON DISTRIBUTION IN THE SURFACE SEDIMENTS OF THE SEA-OF-MARMARA AND ITS CONTROL BY THE INFLOWS FROM ADJACENT WATER MASSES ERGIN, M; BODUR, MN; EDIGER, D; EDIGER, V; YILMAZ, A (Elsevier BV, 1993-02-01) The organic carbon contents and textural composition of a total of 166 surficial sediment samples (from 10 to 1226 m water depths) together with data on primary productivity rates and dissolved oxygen concentrations have been studied to investigate the main controls on the distribution of organic carbon buried within the modern sediments across the Sea of Marmara.

Citation Formats

T. Tanhua, E. Fogelqvist, and O. Basturk, “Reduction of volatile halocarbons in anoxic seawater, results from a study in the Black Sea,” MARINE CHEMISTRY, pp. 159–170, 1996, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/66405.