Themed collection Geochemistry

Prior to the 1960s, knowledge of biological transformations of highly halogenated aliphatic compounds was limited, except in mammalian organisms where enzymatic transformations occurred to rid the body of ingested harmful chemicals.

Fluorescence spectroscopy is very useful for the characterisation of organic matter in natural water samples. The importance of protein-like fluorescence might be enhanced by several events induced by warming in natural waters such as lake water.

A review that highlights the utility of multi-element compound-specific isotope analysis (CSIA) in halogenated hydrocarbon remediation.

Light-induced reduction of Fe(III) delivers Fe(II) as nutrient or substrate for growth of planktonic or sedimentary organisms. Biological uptake, as well as chemical or microbial oxidation of Fe(II) close this photochemically driven iron cycle.

The review presents a way of comparing environmental geochemistry between thioantimony and thioarsenic, summarizing the latest knowledge about their formation, structure and transformation.

Photophysical models for dissolved organic matter optical properties and photochemistry are critically reviewed.

Environmental change is continuing to affect the flow of nutrients, material and organisms across ecosystem boundaries. In this review, we synthesize current knowledge of cross-ecosystem nutrient subsidies between Arctic and alpine lakes and their surrounding terrain, cryosphere, and atmosphere.

A bibliometric analysis of published papers with the key words “positive matrix factorization” and “source apportionment” in ‘Web of Science’, reveals that more than 1000 papers are associated with this research and that approximately 50% of these were produced in Asia.

Dimethyl sulfide (DMS) production in the northern Arctic Ocean has been considered to be minimal because of high sea ice concentration and extremely low productivity.

The inorganic components in Bio-CaCO₃ catalyze the deoxygenation of biochar and increase the degree of aromatization of the carbon matrix. The stable pyridinic-N structures are doped into the carbon skeleton, which further improves the stability of biochar.

The origin of groundwater salinity and major hydrogeochemical processes in the LKB aquifer were investigated using hydrogeochemical and HCA methods. The results indicate that evaporitic lacustrine deposits are the major source of salinity in the aquifer.

CH₄ and CO₂ fluxes from Toolik Lake obtained for the first time with eddy covariance during ice-free periods 2010–2015.

Microbial genetic potential for the biotransformation of xenobiotics and antibiotic resistance increases with depth during biofiltration.

Divergent soil biogeochemical conditions will determine the fate and pathways of labile carbon released during permafrost thaw, thereby influencing the production of greenhouse gas mixtures and radiative forcing of tundra soils.

Under anoxic conditions, clay minerals sorb dissolved Mn(II) predominantly by forming surface precipitates, which increase Cd sorption.

Phosphorus cycling in the environment.

Yedoma permafrost soils are especially susceptible to abrupt thaw due to their exceptional thickness and high ice content.

Iron accumulation in shallow tundra soils promotes adsorption of phosphate from soil solution, sequestering high concentrations of potentially bioavailable phosphorus.

Under anoxic conditions, clay minerals sorb dissolved Fe(II) predominantly by forming surface precipitates, which transform into Fe(III)-phases upon aeration.

Isotope tracer experiments reveal that rates of dissolved organic matter partial photochemical oxidation are considerably underestimated in arctic surface waters.

Inositol phosphates, particularly myo-inositol hexakisphosphate (myo-IP₆), are an important pool of soil organic phosphorus (P) in terrestrial ecosystems.

Optical measurements reveal the presence of pyrogenic organic matter in laboratory heated soil leachates, indicating their potential for application in field measurements.

Naturally formed halogenated organic compounds are common in terrestrial and marine environments and play an important role in the halogen cycle.

Chloromethane (CH₃Cl) is the most abundant long-lived chlorinated organic compound in the atmosphere and contributes significantly to natural stratospheric ozone depletion.

The response of bacteria communities to the urbanization level.

We investigated the release of mercury from soil to soil solution and the formation of methylmercury in polluted agricultural floodplain fields during a flooding incubation experiment.

The coupling effect of plant, soil, and microbes in bioretention provides conditions conductive for nitrogen (N) removal via nitrification, accretion, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA).

Anthropogenic nutrient enrichment caused macroalgal blooms and further resulted in coral reef degradation in coastal and some remote reef areas of the SCS.

The sensitivity of SQRT model-estimated parameters varied over a temperature gradient whereas no variation in MMRT model-estimated parameters, in simulating temperature responses of soil nitrification over the temperature range, was observed.