For decades, heavy metals have been deposited into marine sediments as a result of anthropogenic activities. Depending on their bioavailability, these metals may represent a risk to benthic organisms. Dissolved interstitial water metal concentrations have been shown to be better predictors of bioavailability than sediment metal concentrations. In order to improve our understanding of metals bio...

This study investigates for the first time the relative importance of dissolved organic carbon (DOC) and particulate organic carbon (POC) in the fluvial carbon flux from an actively eroding peatland catchment in the southern Pennines, UK. Event scale variability in DOC and POC was examined and the annual flux of fluvial organic carbon was estimated for the catchment. At the event scale, both DO...

The cycles of carbon and oxygen at the Earth surface are intimately linked, where the burial of organic carbon into sediments represents a source of oxygen to the surface environment. This coupling is typically quantified through the isotope records of organic and inorganic carbon. Yet, the late Neoproterozoic Eon, the time when animals first evolved, experienced wild isotope fluctuations which...

Black carbon (BC) is a pyrolyzed product derived from incomplete combustion. A major fraction of BC produced by landscape fires initially deposited onto onsite soils. Atmospheric deposition soot known to be an important source soil BC, especially in watersheds that are not affected fires. The transport the dissolved oxidized soil, defined as black (DBC), streams considered one loss pathways but...

Assays were carried out to evaluate the dissolved oxygen uptake resulting from mineralization of humic substances (fulvic acid (FA) and humic acid (HA)) from different sources: sediment, dissolved organic matter (DOM) of 120-day decomposed aquatic macrophyte (Scirpus cubensis and Cabomba piauhyensis), and lagoon DOM. The experiments were also aimed at estimating the oxygen uptake coefficient of...

Volatile fatty acids (VFAs) represent the major organic constituent of landfill leachate and provide the greatest potential for leachate induced organic contamination of groundwater (e.g. as represented by an increase in the concentration of dissolved organic carbon and chemical oxygen demand). Long-term diffusion tests were performed for laboratory-compacted clayey soil plugs exposed to contin...

............................................................................. 1 Humic acids....................................................................... 3 Introduction.................................................................... 1 Field studies....................................................................... 4 Analytical developments..........................................

The origin of dissolved arsenic in the Ganges Delta has puzzled researchers ever since the report of widespread arsenic poisoning two decades ago. Today, microbially mediated oxidation of organic carbon is thought to drive the geochemical transformations that release arsenic from sediments, but the source of the organic carbon that fuels these processes remains controversial. At a typical site ...

Highly accurate and precise measurements of marine carbon components are required in the study of the marine carbon cycle, particularly when investigating the causes for its variability from seasonal to interannual timescales. This is especially true in the investigation of the consequences of anthropogenic influences. The analysis of any marine carbon component requires elaborate instrumentati...