Prolonged lifetime of biological activated carbon filters through enhanced biodegradation of melamine.

Micropollutants can be removed in Biological Activated Carbon (BAC) filters through biodegradation, besides adsorption, when the conditions are favorable. In the present study, we build upon previous work on melamine biodegradation and activated carbon regeneration in batch experiments and assess the efficiency of this process in continuous flow lab-scale BAC filters. Melamine is frequently detected at low concentrations in surface water and is used here as a model micropollutant.

Melamine degradation to bioregenerate granular activated carbon.

The industrial chemical melamine is often detected in surface water used for drinking water production, due to its wide application and insufficient removal in conventional wastewater treatment plants. Melamine can be removed from water by adsorption onto granular activated carbon (GAC), nevertheless, GAC needs periodic reactivation in costly and energy intense processes. As an alternative method, GAC can also be regenerated using biomass capable of degrading melamine in a process called bioregeneration.

Biodegradation and adsorption of micropollutants by biological activated carbon from a drinking water production plant.

The presence of micropollutants in surface water is a potential threat for the production of high quality and safe drinking water. Adsorption of micropollutants onto granular activated carbon (GAC) in fixed-bed filters is often applied as a polishing step in the production of drinking water. Activated carbon can act as a carrier material for biofilm, hence biodegradation can be an additional removal mechanism for micropollutants in GAC filters.

Diffusion of hydrophilic organic micropollutants in granular activated carbon with different pore sizes.

Hydrophilic organic micropollutants are commonly detected in source water used for drinking water production. Effective technologies to remove these micropollutants from water include adsorption onto granular activated carbon in fixed-bed filters. The rate-determining step in adsorption using activated carbon is usually the adsorbate diffusion inside the porous adsorbent.

Effect of low concentrations of dissolved oxygen on the activity of denitrifying methanotrophic bacteria.

Chemical energy can be recovered from municipal wastewater as biogas through anaerobic treatment. Effluent from direct anaerobic wastewater treatment at low temperatures, however, still contains ammonium and considerable amounts of dissolved methane. After nitritation, methane can be used as electron donor for denitrification by the anaerobic bacterium 'Candidatus Methylomirabilis oxyfera'.

Effect of temperature on denitrifying methanotrophic activity of 'Candidatus Methylomirabilis oxyfera'.

The activity of denitrifying methanotrophic bacteria at 11-30 °C was assessed in short-term experiments. The aim was to determine the feasibility of applying denitrifying methanotrophic bacteria in low-temperature anaerobic wastewater treatment. This study showed that biomass enriched at 21 °C had an optimum temperature of 20-25 °C and that activity dropped as temperature was increased to 30 °C.