Wastewater database reveals fate of pharmaceutical and care products

A database of Pharmaceuticals and Personal Care Products (PPCPs) found in wastewater treatment plants has been developed. It provides information on the occurrence and removal efficiency of these products in different types of treatment processes.

French researchers, partly funded by the EC projects NORMAN and KNAPPE¹, compiled the database based on information from 117 studies into wastewater from Europe, Brazil and North America. 184 different PPCP molecules were identified in all. These covered a range of pharmaceuticals, including hormones, antiseptics, beta blockers (drugs used for heart conditions) and antidepressants. Personal care products included musk fragrances (perfume), sunscreen chemicals and insect repellents.

The study examined the concentrations of PPCPs found in influents (wastewater entering the plant for treatment) and effluents (cleaned waste water). The removal rate of PPCPs from different types of wastewater plants was also determined.

Treated wastewater can be discharged back into the environment when it still contains traces of medicines and personal care products not removed by the treatment process. There is concern that aquatic creatures can be affected by constant exposure to these contaminants.

The researchers classified the PPCP molecules into different classes. Hormones, then analgesics (painkillers) and anti-inflammatories, followed by antibiotics were the most commonly researched classes among the 117 studies. Specific hormone molecules (estrone and 17B-estradiol) received the most research attention. The database revealed that 80 per cent of the research focus was on 33 molecules. This might be due to the high levels of prescription of these products and/or concern over the potential toxic effects of these molecules in the environment.

PPCP concentrations were determined for wastewater influents and effluent. The lowest concentration of PPCPs in both influents and effluents were hormones: the highest concentrations found in influents were analgesic-anti-inflammatories (naproxen and paracetamol) and salicylic acid (derived from aspirin or the break-down of other products). In effluents the highest concentrations of PPCPs were analgesic-anti-inflammatories (ibuprofen and naproxen).

In addition, the database was used to identify the PPCPs that were not entirely removed by the treatment process. The highest rates of removal (over 80 per cent) were found for the disinfectant triclosan, the antibiotic norfloxacin and the hormones, 17b-estradiol and estriol. The lowest rates of removal (less than 30 per cent) were found for a number of molecules, including the beta blockers, atenolol and metroprolol, and the anti-epiletic, carbamazepine. The removal rates varied widely across the studies and researchers suggest this is due to the variety of activated sludge treatment plants found in different countries.

The database was also used to compare the removal efficiency of different types of wastewater treatment processes. The activated sludge process with nitrogen removal (the most common process in Europe, in line with meeting the European Urban Waste Water Directive, 91/271/EEC (1991)²) and the membrane bioreactor methods were the most efficient in removing PPCPs from wastewater.

1. NORMAN (Network of reference laboratories for monitoring of emerging of environmental pollutants) and KNAPPE (Knowledge and Need Assessment on Pharmaceutical Products in Environmental Waters) were supported by the European Commission under the Sixth Framework Programme. See: www.norman-network.com and www.knappe-eu.org.
2. See: http://ec.europa.eu/environment/water/water-urbanwaste/index_en.html

Source: Miège, C., Choubert, J.M., Ribeiro, L. et al. (2009). Fate of pharmaceuticals and personal care products in wastewater treatment plants - Conception of a database and first results. Environmental Pollution. 157:1721-1726.

Contact: cecile.miege@cemagref.fr