How do WWTPs operational parameters affect the removal rates of EU Watch list compounds? (original) (raw)
Related papers
Due to recent developments in environmental legislation in Europe (e.g. European Union (EU) and Switzerland), many WWTPs will be equipped with ozonation. These new regulations will aim at controlling the discharge of Trace Organic Compounds (TOrCs) into the natural environment. Switzerland is the first country that enforced TrOC control at the point source on a national scale using five indicator compounds. The EU will soon establish a watch list with compounds (including 3 pharmaceuticals) for which monitoring data will have to be gathered on which further regulatory developments will be based. In the United States, some WWTPs were proactively equipped with ozonation (mainly to protect surface waters/water sources) but as in the EU, control at the point source is not enforced by law. Furthermore, the US focus is mainly on disinfection. Further data on the occurrence and fate of TOrCs is essential for the development of effective and accepted regulation. In parallel, on-line monitor...
2012
The paper summarizes the results of researches realized at full and pilot scale by Istituto Mario Negri (IT) and Politecnico di Milano on the presence, fate and removal of pharmaceutical active compounds (PhACs) in the sewage of Milan Nosedo WWTP. Removal rates in Nosedo WWTP were higher than those measured in other treatment plants in Italy but many PhACs were still present in treated water, at concentration ranges spanning from few to several hundred ng∙L -1 . Four sampling campaign were realized on the full plant conventional activated sludge plant (CAS) and a pilot membrane bioreactor (MBR), to compare the removal efficiency and sludge adsorption capacity and to study the effect of sludge retention time (SRT) on removal rates in MBR. Higher removal rates were observed for some PhACs in MBR, but not for the recalcitrant ones. Moreover, the operation of the MBR at four SRTs in the range 15-50 days did not demonstrate an effect of this parameter on PhACs removal. Adsorption on slud...
Stability and removal of anti-inflammatory dexamethasone sodium phosphate (DSP), anti-anxiety drug diazepam (valium) and spironolactone (SP) from wastewater produced at Al-Quds University Campus were investigated. Kinetic studies in both pure water (abiotic degradation) and in sludge (biodegradability) at room temperature were investigated. They demonstrated that DSP underwent degradation to its hydrolytic derivative, simply named dexamethasone, in both media. The first order hydrolysis rate of DSP in activated sludge at 25°C (3.80×10-6 s-1) was about 12-fold greater than in pure water (3.25×10-7 s-1). Diazepam showed high chemical stability toward degradation in pure water, and underwent faster biodegradation in sludge providing two main degradation products. The degradation reactions in sludge and pure water showed first order kinetics with rate constant values of 2.6 × 10-7 s-1 and 9.08 × 10-8 s-1 , respectively. The potassium-sparing diuretic (water pill) SP underwent degradation to its hydrolytic derivative, canrenone, in both media. The first order hydrolysis rate of SP in activated sludge at 25°C (3.80×10-5 s-1) was about 49-fold greater than in pure water (7.4×10-7 s-1). The overall performance of WWTP was also assessed showing that 90% of spiked DSP and SP were removed together with its newly identified metabolites. WWTP also showed that UF and RO were relatively sufficient in removing spiked diazepam to a safe level. In order to check for different tools to be used instead of ultra-filtration membranes, the effectiveness of adsorption and filtration by micelle-clay preparation for removing DSP was ascertained in comparison with activated charcoal. Batch adsorption in aqueous suspensions of the micelle-clay composite and activated carbon was well described by Langmuir isotherms showing the best results for micelle-clay material. Besides, filtration of DSP, DZ and SP aqueous solutions by columns filled in with a mixture of sand and micelle-clay complex showed complete removal of each drug at concentration higher than sand/activated-charcoal filled filters at flow rates of 2 mL min-1 .