Municipal Treatment Plant Effluents Research Articles

Maintaining NPDES Permit Compliance at Power Plants While Using Municipal Treatment Plant Effluent with Variable Ammonia and Nitrate Levels.

Maintaining NPDES Permit Compliance at Power Plants While Using Municipal Treatment Plant Effluent with Variable Ammonia and Nitrate Levels.

Bioavailability and Distribution and of Ceria Nanoparticles in Simulated Aquatic Ecosystems, Quantification with a Radiotracer Technique

Although the presence of manufactured nanoparticles in the aquatic environment is still largely undocumented, their release could certainly occur in the future, particularly via municipal treatment plant effluents of cities supporting nano-industries. To get an initial estimate of the environmental behavior of nanomaterials, we investigated the distribution and accumulation of ceria nanoparticles in simulated aquatic ecosystems which included aquatic plant, shellfish, fish, water, and sediment using a radiotracer technique. Radioactive ceria (141CeO2) nanoparticles with a diameter of ca. 7 nm were synthesized by a precipitation method and added to the simulated aquatic ecosystems. The results indicate that the concentration of ceria nanoparticles in water decreased to a steady-state value after 3 days; meanwhile, the concentrations of ceria nanoparticles in the aquatic plant and sediment increased to their highest values. The distribution and accumulation characteristics of ceria nanoparticles in various aquatic organisms were different. Ceratophyllum demersum showed a high ability of accumulation of ceria nanoparticles from water.

Hydraulics of sub-superficial flow constructed wetlands in semi arid climate conditions

This paper reports the evaluation of the hydraulics of two constructed wetland (cw(s)) plants located in Apulia (the South Eastern Italy region characterized by semi arid climate conditions). These fields were planted with Phragmites australis hydrophytes and are supplied with local secondary wastewater municipal treatment plant effluent. Each plant--Kickuth Root-Zone method based--covers an area of approx. 2,000 m2. The evapotranspiration phenomenon has been evaluated within perforated tubes fixed to the field bottom and very high values--up to 40 mm/d--were found. Hydraulic conductivity has been evaluated by in situ measurements at different field points. Hydraulic gradients and the piezometric curve within the field are also reported.

Occurrence of triiodinated X-ray contrast agents in the aquatic environment

High concentrations of adsorbable organic iodine (AOI) are found in municipal treatment plant effluents and surface waters by specific organic halogen determination. The high AOI is caused by widely used triiodinated X-ray contrast agents, which are very stable and hydrophilic. We have analysed specifically surface water influenced by a municipal treatment plant effluent, the surface water after bank filtration and raw drinking water. The X-ray contrast agents were determined by liquid chromatography-mass spectrometry with positive electrospray ionization after enrichment by solid phase extraction. Diatrizoate and iopromide, two triiodinated contrast agents are detectable in all samples, whereby the less polar component iopromide seems to be reduced during bank filtration. Just a trace of iopromide is identified in surface water after bank filtration and in the raw drinking water. Approximately 60% of the initial AOI is extractable and approximately 25% of the extractable AOI can be identified as specific triiodinated contrast agents.