Integrated approach towards quantifying carbon dioxide and methane release from waste stabilization ponds.

Accurate estimations of gaseous emissions and carbon sequestration in wastewater processing are essential for the design, operation and planning of treatment infrastructure, particularly considering greenhouse gas reduction targets. In this study, we look at the interplay between biological productivity, hydrodynamics and evasion of carbon-based greenhouse gases (GHG) through diffusion and ebullition in order to provide direction for more accurate assessments of their emissions from waste stabilization ponds (WSPs). The ponds stratified in the day and mixed at night.

Giving waterbodies the treatment they need: A critical review of the application of constructed floating wetlands.

Water quality is declining worldwide and an increasing number of waterbodies lose their ecological function due to human population growth and climate change. Constructed floating wetlands (CFWs) are a promising ecological engineering tool for restoring waterbodies. The functionality of CFWs has been studied in-situ, in mesocosms and in the laboratory, but a systematic review of the success of in situ applications to improve ecosystem health is missing to date.

A novel single-parameter approach for forecasting algal blooms.

Harmful algal blooms frequently occur globally, and forecasting could constitute an essential proactive strategy for bloom control. To decrease the cost of aquatic environmental monitoring and increase the accuracy of bloom forecasting, a novel single-parameter approach combining wavelet analysis with artificial neural networks (WNN) was developed and verified based on daily online monitoring datasets of algal density in the Siling Reservoir, China and Lake Winnebago, U.S.

Sterols indicate water quality and wastewater treatment efficiency.

As the world's population continues to grow, water pollution is presenting one of the biggest challenges worldwide. More wastewater is being generated and the demand for clean water is increasing. To ensure the safety and health of humans and the environment, highly efficient wastewater treatment systems, and a reliable assessment of water quality and pollutants are required.

Development of Toxicological Risk Assessment Models for Acute and Chronic Exposure to Pollutants.

Alert level frameworks advise agencies on a sequence of monitoring and management actions, and are implemented so as to reduce the risk of the public coming into contact with hazardous substances. Their effectiveness relies on the detection of the hazard, but with many systems not receiving any regular monitoring, pollution events often go undetected. We developed toxicological risk assessment models for acute and chronic exposure to pollutants that incorporate the probabilities that the public will come into contact with undetected pollution events, to identify the level of risk a system poses in regards to the pollutant.

Halogen Radicals Promote the Photodegradation of Microcystins in Estuarine Systems.

The transport of microcystin, a hepatotoxin produced by cyanobacteria (e.g., Microcystis aeruginosa), to estuaries can adversely affect estuarine and coastal ecosystems.

Greenhouse gas emissions from waste stabilisation ponds in Western Australia and Quebec (Canada).

Waste stabilisation ponds (WSPs) are highly enriched environments that may emit large quantities of greenhouse gases (GHG), including CO2, CH4 and N2O. However, few studies provide detailed reports on these emissions. In the present study, we investigated GHG emissions from WSPs in Western Australia and Quebec, Canada, and compared emissions to WSPs from other climatic regions and to other types of aquatic ecosystems.

Could the presence of larger fractions of non-cyanobacterial species be used as a predictor of microcystin production under variable nutrient regimes?

The occurrence of cyanobacteria and microcystin is highly dynamic in natural environments and poses one of the biggest challenges to water resource management. While a number of drivers are known to be responsible for the occurrence of cyanobacterial blooms, the drivers of microcystin production are not adequately known. This study aims to quantify the effects of the changes in the structures of phytoplankton and cyanobacterial communities on the dynamics of microcystin production under highly variable nutrient concentration.

The importance of lake sediments as a pathway for microcystin dynamics in shallow eutrophic lakes.

Microcystins are toxins produced by cyanobacteria. They occur in aquatic systems across the world and their occurrence is expected to increase in frequency and magnitude. As microcystins are hazardous to humans and animals, it is essential to understand their fate in aquatic systems in order to control health risks.

Contribution of sediments in the removal of microcystin-LR from water.

Microcystins are produced by several species of cyanobacteria and can harm aquatic organisms and human beings. Sediments have the potential to contribute to the removal of dissolved microcystins from the water body through either adsorption to sediment particles or biodegradation by the sediment's bacterial community. However, the relative contribution of these two removal processes remains unclear and little is known about the significance of sediment's overall contribution.

Effects of the Distribution of a Toxic Microcystis Bloom on the Small Scale Patchiness of Zooplankton.

Toxic cyanobacterial blooms can strongly affect freshwater food web structures. However, little is known about how the patchy occurrence of blooms within systems affects the spatial distribution of zooplankton communities. We studied this by analysing zooplankton community structures in comparison with the spatially distinct distribution of a toxic Microcystis bloom in a small, shallow, eutrophic lake.

Spatial and temporal variability in the relationship between cyanobacterial biomass and microcystins.

The increasing incidence of toxic cyanobacterial blooms, together with the difficulties to reliably predict cyanobacterial toxin (e.g. microcystins) concentration, has created the need to assess the predictive ability and variability of the cyanobacterial biomass-microcystin relationship, which is currently used to assess the risk to human and ecosystems health.

Effects of rainfall patterns on toxic cyanobacterial blooms in a changing climate: between simplistic scenarios and complex dynamics.

Toxic cyanobacterial blooms represent a serious hazard to environmental and human health, and the management and restoration of affected waterbodies can be challenging. While cyanobacterial blooms are already a frequent occurrence, in the future their incidence and severity are predicted to increase due to climate change. Climate change is predicted to lead to increased temperature and changes in rainfall patterns, which will both have a significant impact on inland water resources.

The impact of diel vertical migration of Daphnia on phytoplankton dynamics.

Diel vertical migration (DVM) of large zooplankton is a very common phenomenon in the pelagic zone of lakes and oceans. Although the underlying mechanisms of DVM are well understood, we lack experimental studies on the consequences of this behaviour for the zooplankton's food resource-the phytoplankton. As large zooplankton species or individuals migrate downwards into lower and darker water strata by day and upwards into surface layers by night, a huge amount of herbivorous biomass moves through the water column twice a day.

The effect of different zooplankton grazing patterns resulting from diel vertical migration on phytoplankton growth and composition: a laboratory experiment.

Diel vertical migration (DVM) of herbivorous zooplankton is a widespread behavioural phenomenon in freshwater ecosystems. So far only little attention has been paid to the impact of DVM on the phytoplankton community in the epilimnion. Some theoretical models predict that algal population growth in the epilimnion should depend on the herbivores' migration and grazing patterns: even if migrating zooplankton consume the same total amount of algae per day in the epilimnion as non-migrating zooplankton, nocturnal grazing should result in enhanced algal growth and favour algal species with high intrinsic growth rates over species with lower intrinsic growth rates.