The science of the total environment

Water quality issues are a major challenge that humanity is facing in the twenty-first century. Here, we review the main groups of aquatic contaminants, their effects on human health, and approaches to mitigate pollution of freshwater resources. Emphasis is placed on chemical pollution, particularly on inorganic and organic micropollutants including toxic metals and metalloids as well as a large variety of synthetic organic chemicals. Some aspects of waterborne diseases and the urgent need for improved sanitation in developing countries are also discussed. The review addresses current scientific advances to cope with the great diversity of pollutants. It is organized along the different temporal and spatial scales of global water pollution. Persistent organic pollutants (POPs) have affected water systems on a global scale for more than five decades; during that time geogenic pollutants, mining operations, and hazardous waste sites have been the most relevant sources of long-term regional and local water pollution. Agricultural chemicals and wastewater sources exert shorter-term effects on regional to local scales.

https://www.annualreviews.org/doi/pdf/10.1146/annurev-environ-100809-125342

Global Water Pollution and Human Health

Microbial communities are at the heart of all ecosystems, and yet microbial community behavior in disturbed environments remains difficult to measure and predict. Understanding the drivers of microbial community stability, including resistance (insensitivity to disturbance) and resilience (the rate of recovery after disturbance) is important for predicting community response to disturbance. Here, we provide an overview of the concepts of stability that are relevant for microbial communities. First, we highlight insights from ecology that are useful for defining and measuring stability. To determine whether general disturbance responses exist for microbial communities, we next examine representative studies from the literature that investigated community responses to press (long-term) and pulse (short-term) disturbances in a variety of habitats. Then we discuss the biological features of individual microorganisms, of microbial populations, and of microbial communities that may govern overall community stability. We conclude with thoughts about the unique insights that systems perspectives - informed by meta-omics data - may provide about microbial community stability.

/pdf/fundamentals-of-microbial-community-resistance-and-56eaa2ns72.pdf

Fundamentals of microbial community resistance and resilience

Earth's climate is warming as a result of anthropogenic emissions of greenhouse gases, particularly carbon dioxide (CO(2)) from fossil fuel combustion. Anthropogenic emissions of non-CO(2) greenhouse gases, such as methane, nitrous oxide and ozone-depleting substances (largely from sources other than fossil fuels), also contribute significantly to warming. Some non-CO(2) greenhouse gases have much shorter lifetimes than CO(2), so reducing their emissions offers an additional opportunity to lessen future climate change. Although it is clear that sustainably reducing the warming influence of greenhouse gases will be possible only with substantial cuts in emissions of CO(2), reducing non-CO(2) greenhouse gas emissions would be a relatively quick way of contributing to this goal.

Non-CO2 greenhouse gases and climate change.

Although peatlands cover only 3% of the Earth's land surface, boreal and subarctic peatlands store about 15?30% of the world's soil carbon as peat. Despite their potential for large positive feedbacks to the climate system through sequestration and emission of greenhouse gases, peatlands are not explicitly included in global climate models and therefore in predictions of future climate change. In April 2007 a symposium was held in Wageningen, the Netherlands, to advance our understanding of peatland C cycling through integration across disciplines and research approaches and to develop a more synthetic picture of the present and future role of peatlands in the global C cycle and their interactions with the climate system. This paper aims to synthesize the main findings of the symposium, focusing on (i) small-scale processes, (ii) C fluxes at the landscape scale, and (iii) peatlands and climate. The paper concludes with a summary of the main drivers of the C balance of peatlands, and proposes directions for new research to reduce key uncertainties in our knowledge of C cycling in peatlands in order to facilitate the explicit inclusion of these ecosystems in a new generation of earth system models.

/pdf/peatlands-and-the-carbon-cycle-from-local-processes-to-e7avqndx2e.pdf

Peatlands and the carbon cycle: from local processes to global implications - a synthesis

https://www.uni-muenster.de/imperia/md/content/landschaftsoekologie/hydrologiebodenkunde/profblodauliteratur/_18__bauer___blodau2006.pdf

Mobilization of arsenic by dissolved organic matter from iron oxides, soils and sediments.

Covering only 3% of the land area, northern peatlands store about 30% of the global soil carbon and account for 5 to 10% of the global methane burden to the atmosphere. A review of the literature o...

Carbon cycling in peatlands A review of processes and controls

Changes of water table position influence carbon cycling in peatlands, but effects on the sources and sinks of carbon are difficult to isolate and quantify in field investigations due to seasonal dynamics and covariance of variables. We thus investigated carbon fluxes and dissolved carbon produc- tion in peatland mesocosms from two acidic and oligotrophic peatlands under steady state conditions at two different water table positions. Exchange rates and CO2 ,C H4 and DOC production rates were si- multaneously determined in the peat from diffusive-advective mass-balances of dissolved CO2 ,C H4 and DOC in the pore water. Incubation experiments were used to quantify potential CO2, CH4, and DOC production rates. The carbon turnover in the saturated peat was dominated by the production of DOC (10-15 mmol m 2 d 1 ) with lower rates of DIC (6.1-8.5 mmol m 2 d 1 ) and CH4 (2.2-4.2 mmol m 2 d 1 ) production. All production rates strongly decreased with depth indicating the impor- tance of fresh plant tissue for dissolved C release. A lower water table decreased area based rates of photosynthesis (24-42%), CH4 production (factor 2.5-3.5) and emission, increased rates of soil respi- ration and microbial biomass C, and did not change DOC release. Due to the changes in process rates the C net balance of the mesocosms shifted by 36 mmol m 2 d 1 . According to our estimates the change in C mineralization contributed most to this change. Anaerobic rates of CO2 production rates deeper in the peat increased significantly by a factor of 2-3.5 (DOC), 2.9-3.9 (CO2), and 3-14 (CH4) when the water table was lowered by 30 cm. This phenomenon might have been caused by easing an inhibiting effect by the accumulation of CO2 and CH4 when the water table was at the moss surface.

/pdf/carbon-turnover-in-peatland-mesocosms-exposed-to-different-40a8elqmms.pdf

Carbon turnover in peatland mesocosms exposed to different water table levels

https://www.uni-muenster.de/imperia/md/content/landschaftsoekologie/hydrologiebodenkunde/profblodauliteratur/_23__blodau_2006.pdf

Christian Blodau

Papers

Peatlands and the carbon cycle: from local processes to global implications - a synthesis

Mobilization of arsenic by dissolved organic matter from iron oxides, soils and sediments.

Carbon cycling in peatlands A review of processes and controls

Carbon turnover in peatland mesocosms exposed to different water table levels

A review of acidity generation and consumption in acidic coal mine lakes and their watersheds.