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Pharmaceuticals in wastewater conference

In the Meander Medical Center Amersfoort STOWA organized a conference about the presence of pharmaceuticals in wastewater. The main part of pharmaceuticals used by patients enters the wastewater via urine and feces. Wastewater treatment plants (WWTPs) have not been designed to deal with such compounds, and as a result significant concentrations of pharmaceuticals and metabolites enter the surface water.  More and more attention is being paid to this phenomenon. In Switzerland and Germany additional treatment for WWTP effluent is being studied and implemented, and also in the Netherlands there is an increasing interest in additional treatment. Many participants, from hospitals, drinking water utilities, water boards, universities and research institutes, attended the conference.

The majority of pharmaceuticals enters the water cycle by municipal WWTPs, but also for hospitals the presence of pharmaceuticals in wastewater is a matter of concern. People have to realize that it is important to prevent pharmaceuticals from entering the wastewater, as was mentioned by Stef Bots from the Amersfoort hospital.

Recently STOWA carried out a hotspot analysis, and Bert Palsma (of STOWA) showed that the results of this analysis should be considered in relation to the receiving surface water. Also Aad Oomens (Waterboard de Dommel) mentioned that e.g. priority should be given to surface water with a high importance for nature. Furthermore, also other routes by which pharmaceuticals may enter the watercycle should be considered (Bert Palsma). Michael Bentvelsen (Union of Waterboards) pointed out that the EU is developing a strategy that is based both on source protection measures and end of pipe treatment. This is in line with the chain measures that were presented by Marc de Rooy (Ministery of Infrastructure and Watermanagement). The Dutch government will provide additional funding for this.

Several pilot investigations were presented during the conference. In Switzerland 100 large WWTPs out of 700 will be extended, in order to protect sources for drinking water. The main focus is on ozone, but also activated carbon will be applied. In Germany main focus in additional WWTP treatment is on activated carbon (micropoll.ch, koms-bw.de, and masterplan-wasser.nrw.de).

In the Netherlands also focus is on ozone and activated carbon. Oscar (Hoogheemraadschap van Delfland) presented results obtained with the “Zoeterwaterfabriek De Groote Lucht”, where ozonization is combined with biofiltration. Many compounds could be effectively removed. In the pilot Ge(o)zond, combining ozonization with ceramic filtration of the effluent, also good results were obtained for the removal of carbamazepine, diclofenac and caffeine, according to Sabine Gabriel of PWN. The main problem of ozonization processes is the formation of bromate as a byproduct. However, in oxidation processes always byproducts and transformation products may be formed.

Hermand Evenblij presented the first results of the PACAS project in Papendrecht, where powdered activated carbon is added to WWTP sludge. This resulted in a good removal of pharmaceuticals, and a decreased toxicity of the water produced. However, the activated carbon content of the effluent couldn’t be measured, although it was shown to be below 0,1 mg/L. As this involves small, loaded particles, this may be a point of concern.

In the pilot at WWTP Hostermeer the 1-STEP filter (activated carbon for the removal of nutrients and micropollutants) is combined with ozone. Manon Bechger (Waternet) showed that increasing the ozone concentration resulted in a longer running time of the activated carbon.

Advanced oxidation based on UV/H2O2 processes can also be very effective, especially if ion exchange for the removal of the humic acid fraction is applied as a pre-treatment method, as shown by Roberta Hofman-Caris (KWR) for the pilot at WWTP Panheel.

Arjan Verhoeff (Drents Overijsselse Delta) presented the results of ecologic effect measurements, and the importance of sampling techniques and bioassays. Many participants pointed out that effect measurements (like bioassays) of surface water are the most important means to judge the effectiveness of treatment technologies. Finally, Ruud Steen (The Water laboratory) indicated that it is very important to know about analytical methods in order to be able to correctly interpret the results obtained.